Fishes

21 pages, 9196 KiB

Open AccessArticle

The Effects of Transport Stress (Temperature and Vibration) on Blood Biochemical Parameters, Oxidative Stress, and Gill Histomorphology of Pearl Gentian Groupers

by Dan Fang, Jun Mei, Jing Xie and Weiqiang Qiu

Fishes 2023, 8(4), 218; https://doi.org/10.3390/fishes8040218 - 21 Apr 2023

Cited by 4 | Viewed by 2439

Abstract

The transport of living fish is an important part of the fish farming process. The transport usually causes fish stress. This study evaluated the effects of transport temperature and vibration frequency on water quality, blood biochemical parameters, gill histomorphology, oxidative stress, and meat [...] Read more.

The transport of living fish is an important part of the fish farming process. The transport usually causes fish stress. This study evaluated the effects of transport temperature and vibration frequency on water quality, blood biochemical parameters, gill histomorphology, oxidative stress, and meat quality of pearl gentian groupers after transport. First, 1-year-old groupers (450 ± 25 g) were transported in plastic bags for 48 h, including the following treatments: no shaking, transported at 15 °C, shaking at 70 rpm, transported at 15 °C (15 °C/70 rpm); shaking at 120 rpm, transported at 15 °C (15 °C/120 rpm); no shaking, transported at 25 °C; shaking at 70 rpm, transported at 25 °C (25 °C/70 rpm); and shaking at 120 rpm, transported at 25 °C (25 °C/120 rpm). Serum, liver, gill, and muscle samples were collected for testing at 0, 12, 24, 36, and 48 h of exposure. During the 48 h transport, total ammonia nitrogen (TAN), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-PX), and malondialdehyde (MDA) were significantly increased in the transport group compared to the control group. In the early stage of transportation, aspartate aminotransferase (AST), alanine aminotransferase (ALT), cortisol (COR), lactate dehydrogenase (LDH), and glucose (GLU) in the transportation groups were significantly higher than those in the control group, while the water quality pH and dissolved oxygen (DO) levels decreased significantly. Compared with untransported fish, the total free amino acid (TFAA) content increased by 40.27% and 31.74% in the 25 °C/70 rpm and 25 °C/120 rpm groups, respectively. In addition, the results of hematoxylin–eosin staining and scanning electron microscopy showed that the epithelial cells in the high-speed group were swollen, the gill lamella was severely curved, and a large amount of mucus was secreted. This study explores the basic information of transportation, which will help to select the conditions that are more suitable for the successful transportation of pearl gentian groupers. Full article

(This article belongs to the Section Biology and Ecology)

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16 pages, 2879 KiB

Open AccessArticle

Morphometric Variations of Nile Tilapia (Oreochromis niloticus) (Linnaeus, 1758) Local Strains Collected from Different Fish Farms in South Western Highland Agro-Ecological Zone (SWHAEZ), Uganda: Screening Strains for Aquaculture

by Gerald Kwikiriza, Mourine J. Yegon, Nelson Byamugisha, Apulnal Beingana, Faith Atukwatse, Alex Barekye, Juliet K. Nattabi and Harald Meimberg

Fishes 2023, 8(4), 217; https://doi.org/10.3390/fishes8040217 - 20 Apr 2023

Cited by 1 | Viewed by 3525

Abstract

Despite the global contribution of aquaculture as an important pillar for food and nutritional security, its rapid growth has been hampered by inadequate and poor-quality seed due to inbreeding, hybridization of related stocks, and poor-quality broodstock. Phenotypic and genotypic characterization of Nile tilapia [...] Read more.

Despite the global contribution of aquaculture as an important pillar for food and nutritional security, its rapid growth has been hampered by inadequate and poor-quality seed due to inbreeding, hybridization of related stocks, and poor-quality broodstock. Phenotypic and genotypic characterization of Nile tilapia in natural water bodies of Uganda has been studied but research gaps remain on the morphometric characterization of farmed O. niloticus in Uganda, which hinders selective breeding initiatives. This study characterized O. niloticus from various farmers in Uganda’s Southwestern Highland Agro-Ecological Zone using their morphometric traits. In this study, 8 morphometric traits were taken on each of the 258 fish samples collected with at least 30 samples sampled from each pond system in the zone. The morphometric data generated were analyzed using multivariate analysis. In order to delineate the populations from the different ponds, Discriminant Function analysis (DFA) was performed on the dataset and distribution plots generated to test on the purity of the strains. There were significant differences in the morphometric traits among the populations with the Victoria fish population having the highest standard length while the Kyoga population had the highest weight. Morphometric characterization grouped the fish into three clusters, indicative that fish farms in the zone possibly had different sources of fish seed. The condition factor, which is a measure of wellbeing of the fish, showed that all the populations displayed an isometric growth which is indicative of the fish growing in length as it is in weight. The results of this study provide evidence that local O. niloticus from different farms display differences in body shape as a result of using fish seed from different sources. This aspect can be applied in selective breeding programs after establishing the genetic structure of the farmed Nile tilapia stock. Full article

(This article belongs to the Special Issue Development of Sustainable Aquaculture Production)

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16 pages, 968 KiB

Open AccessFeature PaperArticle

Survey Evaluation of Florida’s Freshwater Fisheries Long-Term Monitoring Program

by Kimberly I. Bonvechio, Ramesh Paudyal, Chelsey Crandall and Andrew K. Carlson

Fishes 2023, 8(4), 216; https://doi.org/10.3390/fishes8040216 - 19 Apr 2023

Viewed by 1076

Abstract

Natural resource monitoring programs benefit from routine evaluation. Here, Florida’s statewide Freshwater Fisheries Long-Term Monitoring (LTM) program is used to show how stakeholder surveys can be integral to this process. In 2022, an online questionnaire was sent to internal stakeholders, i.e., state agency [...] Read more.

Natural resource monitoring programs benefit from routine evaluation. Here, Florida’s statewide Freshwater Fisheries Long-Term Monitoring (LTM) program is used to show how stakeholder surveys can be integral to this process. In 2022, an online questionnaire was sent to internal stakeholders, i.e., state agency personnel who collect, enter, or use freshwater fisheries data for fisheries and habitat management purposes. The survey’s primary objective was to evaluate the program at its 15-year mark; secondary objectives were to compare results with a similar survey conducted at the 4-year mark, compare results among respondents based on experience and functional role, and develop recommendations for strategic initiatives to further improve the program. The survey consisted of 43 questions across six sections of program evaluation: demographics; field sampling; data entry, summary, and reporting; management decision support; programmatic views; and additional input. Respondents generally had positive views of the LTM program, but the survey revealed differences among respondents with different functional roles (e.g., fisheries researchers and managers viewed the decisional value, priority, and sample sizes of LTM data more favorably than habitat managers) while highlighting high-priority future initiatives (e.g., database development). Our results demonstrate the utility of stakeholder surveys as an important step in evaluating monitoring programs. Full article

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14 pages, 1453 KiB

Open AccessArticle

Survival, Energy Status, and Cellular Stress Responses of the Juvenile Swimming Crab Portunus trituberculatus under Acute Nitrite Stress

by Xiaochen Liu, Daixia Wang, Yan Shang, Xuee Yu, Baoquan Gao, Jianjian Lv, Jitao Li, Ping Liu, Jian Li and Xianliang Meng

Fishes 2023, 8(4), 215; https://doi.org/10.3390/fishes8040215 - 19 Apr 2023

Cited by 1 | Viewed by 1381

Abstract

Nitrite is a common pollutant encountered in aquaculture systems. During intensive hatchery, accumulation of nitrite can cause massive mortality of juvenile crustaceans. However, the nitrite toxicity and cellular stress responses in juvenile crustaceans is not clearly understood. Here, we investigate the survival, energy [...] Read more.

Nitrite is a common pollutant encountered in aquaculture systems. During intensive hatchery, accumulation of nitrite can cause massive mortality of juvenile crustaceans. However, the nitrite toxicity and cellular stress responses in juvenile crustaceans is not clearly understood. Here, we investigate the survival, energy metabolism, and cellular stress responses in juvenile P. trituberculatus, an important aquaculture species in China, under acute nitrite stress. The results revealed nitrite resulted in a significant decrease in survival rate of juvenile swimming crab. After nitrite exposure, the activity of catabolic enzymes, such as HK, PK, CS, and CPT-1, were initially enhanced, and then they showed significant decrease at the late stage of exposure, accompanied by reduction in ATP and adenylate energy charge (AEC). The impaired energy homeostasis was possibly associated with disturbed AMPK signaling and enhanced anaerobic metabolism, which was indicated by the high levels of LDH activity and HIF-1α expression. Furthermore, we found that nitrite stress can depress antioxidant systems and unfold protein responses, causing oxidative damage and endoplasmic reticulum (ER) stress, and this, in turn, can trigger autophagy and apoptosis through both caspase-dependent and caspase-independent pathways. The results of the present study improve our understanding regarding adverse effects of nitrite on P. trituberculatus and provide valuable information for hatchery management. Full article

(This article belongs to the Special Issue Recent Advances in Crab Aquaculture)

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17 pages, 2458 KiB

Open AccessFeature PaperArticle

Environmental Impacts on Skin Microbiomes of Sympatric High Arctic Salmonids

by Erin F. Hamilton, Collin L. Juurakko, Katja Engel, Josh D. Neufeld, John M. Casselman, Charles W. Greer and Virginia K. Walker

Fishes 2023, 8(4), 214; https://doi.org/10.3390/fishes8040214 - 18 Apr 2023

Cited by 3 | Viewed by 1536

Abstract

In the region of King William Island, Nunavut, in the Canadian high Arctic, populations of salmonids including Arctic char (Salvelinus alpinus), cisco (Coregonus autumnalis and C. sardinella) as well as lake whitefish (C. clupeaformis) are diadromous, overwintering [...] Read more.

In the region of King William Island, Nunavut, in the Canadian high Arctic, populations of salmonids including Arctic char (Salvelinus alpinus), cisco (Coregonus autumnalis and C. sardinella) as well as lake whitefish (C. clupeaformis) are diadromous, overwintering in freshwater and transitioning to saline waters following ice melt. Since these fish were sampled at the same time and from the same traditional fishing sites, comparison of their skin structures, as revealed by 16S rRNA gene sequencing, has allowed an assessment of influences on wild fish bacterial communities. Arctic char skin microbiota underwent turnover in different seasonal habitats, but these striking differences in dispersion and diversity metrics, as well as prominent taxa involving primarily Proteobacteria and Firmicutes, were less apparent in the sympatric salmonids. Not only do these results refute the hypothesis that skin communities, for the most part, reflect water microbiota, but they also indicate that differential recruitment of bacteria is influenced by the host genome and physiology. In comparison to the well-adapted Arctic char, lake whitefish at the northern edge of their range may be particularly vulnerable, and we suggest the use of skin microbiomes as a supplemental tool to monitor a sustainable Indigenous salmonid harvest during this period of change in the high Arctic. Full article

(This article belongs to the Special Issue Biomonitoring and Conservation of Freshwater & Marine Fishes)

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20 pages, 2960 KiB

Open AccessFeature PaperArticle

Endurance Swimming Is Related to Summer Lake Survival of Rainbow Trout in a Warm Lake with Avian Piscivores

by Christine E. Verhille and Anthony P. Farrell

Fishes 2023, 8(4), 213; https://doi.org/10.3390/fishes8040213 - 18 Apr 2023

Viewed by 1398

Abstract

Fitness of fish is assumed to be influenced by locomotion performance, but empirical evidence linking swimming capacity to survival in nature remains sparse. Poor triploid (3N) fish aerobic swimming performance in conjunction with production of sibling diploid (2N) and 3N populations of genetically [...] Read more.

Fitness of fish is assumed to be influenced by locomotion performance, but empirical evidence linking swimming capacity to survival in nature remains sparse. Poor triploid (3N) fish aerobic swimming performance in conjunction with production of sibling diploid (2N) and 3N populations of genetically identical origin to minimize variability among compared populations make 3N trout an informative system to test hypotheses about fitness consequences of fish locomotion. Here, we ask if reduced survival of 3N relative to 2N trout in natural ecosystems during periods of high temperature relate to a lower aerobic swimming capacity and aerobic scope of 3N compared with 2N conspecifics. Three-yearly cohorts of conspecific 2N and 3N hatchery-reared, yearling rainbow trout were ranked for swimming endurance, externally marked for their endurance quantile, and then stocked into two lakes as yearlings to quantify their survival in the wild over summer as a function of ploidy, temperature and endurance; all while tracking temperature and depth habitat utilization via telemetry. As expected, 3N swimming endurance was lower than that of 2N, but with considerable individual overlap. Aerobic swimming endurance, especially for 3N, was predictive of summer survival in a warm lake where piscivorous birds potentially exerted high predation pressure, resulting in low fish survival. This empirical evidence of a connection between swimming endurance and fitness provides support for long held assumptions of this relationship and could inform future sport fishing stocking industry practices to match fish strains to ideal habitats. Full article

(This article belongs to the Section Biology and Ecology)

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17 pages, 3544 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Effect of Photoperiod and Transfer Time on Atlantic Salmon Smolt Quality and Growth in Freshwater and Seawater Aquaculture Systems

by Enrique Pino Martinez, Albert Kjartan Dagbjartarson Imsland, Anne-Camilla Diesen Hosfeld and Sigurd Olav Handeland

Fishes 2023, 8(4), 212; https://doi.org/10.3390/fishes8040212 - 18 Apr 2023

Cited by 3 | Viewed by 1960

Abstract

Smoltification is a key process in Atlantic salmon aquaculture, given it prepares the fish for a successful transit from fresh to seawater. However, industry players have not yet reached a consensus on the best protocols to produce high-quality smolts. In this study, we [...] Read more.

Smoltification is a key process in Atlantic salmon aquaculture, given it prepares the fish for a successful transit from fresh to seawater. However, industry players have not yet reached a consensus on the best protocols to produce high-quality smolts. In this study, we assessed how the combination of two photoperiod regimes in freshwater (continuous light or LL, and natural photoperiod or LDN) and four transfer times to seawater (February, March, April, and May) affected smolt development and their subsequent growth in seawater until slaughter during commercial production. The results demonstrated that smoltification and growth in freshwater were only slightly modulated by the photoperiod treatment and were instead much more affected by the limiting effect of the low water temperature during that period. In seawater, the growth rate was the highest in the same groups, which had, however, experienced a delay in growth when in freshwater, and consequently, no differences in the final body weight between the eight treatments were found. Such compensatory growth in the sea was probably enhanced by the increasing smolt quality, which could allow for better performance in seawater. A significant link between the weight at slaughter and weight at transfer was observed only in the groups with a lower smolt quality (LL-Feb, LDN-Feb and LDN-Mar), which suggests that larger individuals could cope better with a saline environment. In contrast, smaller smolts probably suffered greater osmotic stress that hindered their performance at sea. Afterwards, as smolt quality increased in the subsequent transfer groups, the relevance of this size effect decreased. This means that the industry may benefit from transferring larger smolts to seawater, especially if these are suspected of having developed suboptimal seawater tolerance. Those individuals are likely to cope better with saline conditions than smaller smolts. Future research should focus on the possible long-term effects of freshwater-rearing regimes on smolt performance in the seawater phase. Full article

(This article belongs to the Section Sustainable Aquaculture)

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14 pages, 3674 KiB

Open AccessArticle

Feeding Habit-Specific Heavy Metal Bioaccumulation and Health Risk Assessment of Fish in a Tropical Reservoir in Southern China

by Di Wu, Hao Feng, Ying Zou, Juan Xiao, Pengfei Zhang, Yuxiang Ji, Sovan Lek, Zhiqiang Guo and Qiongyao Fu

Fishes 2023, 8(4), 211; https://doi.org/10.3390/fishes8040211 - 18 Apr 2023

Cited by 4 | Viewed by 1684

Abstract

Dietary uptake is well known as the predominant pathway of heavy metal bioaccumulation in organisms. Our study used a typical tropical reservoir and fish as a modeling system to test the hypothesis that feeding habits and living habitats significantly affect heavy metal bioaccumulation [...] Read more.

Dietary uptake is well known as the predominant pathway of heavy metal bioaccumulation in organisms. Our study used a typical tropical reservoir and fish as a modeling system to test the hypothesis that feeding habits and living habitats significantly affect heavy metal bioaccumulation in fish. Specifically, Cr, Mn, Fe, Ni, Cu, Zn, Cd, and Pb concentrations in water, sediment, and fish, and δ¹³C and δ¹⁵N in 13 fish species were detected in the Songtao Reservoir of Hainan Province, southern China. Our results indicated that Zn concentration in carnivorous fish was higher than in omnivorous fish. Principal components analysis visually differentiated pelagic, benthopelagic, and demersal fish groups. Moreover, we found that the fish feeding in the demersal habitat showed higher heavy metal levels than those in the pelagic habitat. Additionally, the heavy metal contents in demersal fish were significantly positively correlated with sediments, while no positive correlation was observed in pelagic-feeding fish. The δ¹⁵N and the concentration of Ni, Zn in fish had a significantly positive correlation, suggesting the potential biomagnification. In contrast, Ni, Fe, Cu, and Cd negatively correlated with fish body weight/length, indicating the growth dilution effects. Finally, the estimated daily intake (EDI) of the metals was far below the provisional tolerable daily intake (PTDI), and target hazard quotients (THQ) were <1.0, indicating that the fish had no risk for consumption risks. Overall, our finding partially validated the hypothesis that the feeding habits and living habitats significantly influence heavy metal bioaccumulation in fish, which might be a broad generality for metal exposure scenarios in aquatic environments. Full article

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14 pages, 3287 KiB

Open AccessFeature PaperArticle

Experimental Mixed Gillnets Improve Catches of Narrow-Barred Spanish Mackerel (Scomberomorus commerson)

by Luong Trong Nguyen, Khanh Quoc Nguyen and Toan Phi Nguyen

Fishes 2023, 8(4), 210; https://doi.org/10.3390/fishes8040210 - 18 Apr 2023

Cited by 2 | Viewed by 1584

Abstract

A new gillnet made from multiple mesh sizes ranging from 125 to 180 mm of stretched mesh (experimental gillnet) was tested under commercial fishing conditions to compare the fishing performance with that of conventional gillnets with a 125 mm mesh opening (control gillnet). [...] Read more.

A new gillnet made from multiple mesh sizes ranging from 125 to 180 mm of stretched mesh (experimental gillnet) was tested under commercial fishing conditions to compare the fishing performance with that of conventional gillnets with a 125 mm mesh opening (control gillnet). Catch efficiency and size selectivity between the two gillnet types were evaluated throughout one year of fishing in three different locations in the waters of Vietnam. Experimental gillnets caught narrow-barred Spanish mackerel (Scomberomorus commerson), spotted mackerel (Scomberomorus guttatus), and wahoo (Acanthocybium solandri) in comparable amounts to the control gillnets, with the moon phase, month, and depth explaining some of the variation in the catch per unit effort (CPUE). An analysis of the size-dependent catch comparison rates and selectivity parameters showed that the experimental gillnets captured a wider range of narrow-barred Spanish mackerel sizes, but with a substantial proportion of individuals larger than those caught by the control gillnets. This is of higher weight per unit effort, and fishing enterprises therefore could improve their economic benefits by using modified gillnets with multiple mesh sizes. Our findings also support the biological and environmental benefits of the modified gillnet size selection, which might also extend to other species. Full article

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16 pages, 1808 KiB

Open AccessArticle

Use of Ensemble Model for Modeling the Larval Fish Habitats of Different Ecological Guilds in the Yangtze Estuary

by Rong Wan, Pengbo Song, Zengguang Li, Xiangyu Long, Dong Wang and Lu Zhai

Fishes 2023, 8(4), 209; https://doi.org/10.3390/fishes8040209 - 17 Apr 2023

Cited by 1 | Viewed by 1203

Abstract

Estuaries provide nursery habitats for a variety of fish species of different ecological guilds and have complicated environmental conditions. In this study, we applied ensemble species distribution models (SDMs) to four abundant and different ecological guild larval fish species (Hemiculter bleekeri (freshwater [...] Read more.

Estuaries provide nursery habitats for a variety of fish species of different ecological guilds and have complicated environmental conditions. In this study, we applied ensemble species distribution models (SDMs) to four abundant and different ecological guild larval fish species (Hemiculter bleekeri (freshwater guild), Pseudolaubuca sinensis (freshwater guild), Coilia mystus (brackish water guild), and Engraulis japonicus (marine guild)) to explore their suitable habitats and the fish–habitat relationships in the Yangtze Estuary. The results showed that random forest (RF) demonstrated the best performance in all single algorithms and the surface range envelop (SRE) model was scarcely accurate. The ensemble SDMs demonstrated a superior predictive ability compared with any single algorithm, with the true skill statistic (TSS) and the area under the receiver operating characteristic curve (AUC) scores being above 0.899 and 0.641, respectively. Binary presence–absence maps showed the different spatial distribution patterns of the four species. We primarily found the freshwater species (P. sinensis and H. bleekeri) present in the South Branch (west of 122° E), whereas we found the marine species (E. japonicus) anywhere except inside the South Branch (west of 121.8° E). The area for P. sinensis (1615.93 km²) was relatively larger than that for H. bleekeri (1136.87 km²). We predicted that the brackish water species (C. mystus) would most likely be present inside the North Branch (west of 122° E), Eastern Chongming, and outside the South Branch (east of 121.8° E). Salinity, as a key environmental variable, contributed to the spatial variability. A low salinity (sea surface salinity (SSS) < 3) was beneficial for P. sinensis and H. bleekeri but was not suitable for E. japonicus. The SSS suitable range for C. mystus was 5–10 and 12–20. Multiple ecological guild species dwelled in the confluence of salt and fresh water. Our results will play an important role in the design of specific conservation strategies for fishery resources in this area. Full article

(This article belongs to the Special Issue Fisheries and Aquaculture Engineering)

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16 pages, 2943 KiB

Open AccessArticle

Dietary Effects of Nano Curcumin on Growth Performances, Body Composition, Blood Parameters and Histopathological Alternation in Red Tilapia (Oreochromis sp.) Challenged with Aspergillus flavus

by El-Sayed Hemdan Eissa, Bothaina A. Alaidaroos, Samyah D. Jastaniah, Mohammad Bodrul Munir, Manal E. Shafi, Yasmin M. Abd El-Aziz, Walaa K. Bazina, Saadiah binti Ibrahim, Moaheda E. H. Eissa, Marina Paolucci, Fatima S. Alaryani, Nadia N. B. Abd El-Hamed, Mohamed E. Abd El-Hack and Saadea Saadony

Fishes 2023, 8(4), 208; https://doi.org/10.3390/fishes8040208 - 17 Apr 2023

Cited by 11 | Viewed by 1882

Abstract

This research examined the role of nano curcumin (NC) on growth performances, body composition, and blood parameters of red tilapia (Oreochromis sp.) challenged with Aspergillus flavus. Fish (5.0 g ± 0.30) were randomly distributed in four equal groups (20 fish per [...] Read more.

This research examined the role of nano curcumin (NC) on growth performances, body composition, and blood parameters of red tilapia (Oreochromis sp.) challenged with Aspergillus flavus. Fish (5.0 g ± 0.30) were randomly distributed in four equal groups (20 fish per pond in triplicates) and fed various concentrations of NC fortified with 0 (Control), 40 mg/kg (NC1), 50 mg/kg (NC2), and 60 mg/kg diet (NC3) of nano curcumin. After eight weeks of the feeding trial, the fish were challenged with A. flavus for 15 days, and the cumulative mortality was recorded. Fish fed with different concentrations of NC improved significantly (p < 0.05) the growth performances, feed utilization, and survival rate. There was no significant (p > 0.05) difference between NC2 and NC3 treatments. However, NC3 exhibited higher performances. Fish feed supplemented with NC decreased the mortality rate when challenged with A. flavus. Hence, dietary supplementation of NC enhanced the growth and health status of Oreochromis sp. and protected it from A. flavus infection. This study suggests the optimum inclusion level of NC is a 50–60 mg/kg diet. Full article

(This article belongs to the Special Issue Feed Additives in Aquaculture)

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15 pages, 5287 KiB

Open AccessArticle

Cytotoxic Effects of the Atrazine Herbicide on Erythrocytes and Liver Damage in Lithobates spectabilis

by Maribel Méndez-Tepepa, Karla Hernández-Pérez, Libertad Juárez-Santacruz, Senobia Rosalia Cruz-Lumbreras, Edelmira García-Nieto, Arely Anaya-Hernández and Cuauhtémoc Morales-Cruz

Fishes 2023, 8(4), 207; https://doi.org/10.3390/fishes8040207 - 16 Apr 2023

Cited by 2 | Viewed by 2238

Abstract

In Mexico, atrazine is one of the herbicides most widely authorized and used in different irrigation districts. Atrazine is a herbicide that contaminates aquatic systems. Previous studies have shown that atrazine causes damage to red blood cells and liver tissue in different aquatic [...] Read more.

In Mexico, atrazine is one of the herbicides most widely authorized and used in different irrigation districts. Atrazine is a herbicide that contaminates aquatic systems. Previous studies have shown that atrazine causes damage to red blood cells and liver tissue in different aquatic species, including abnormalities in melanomacrophages. However, more information on amphibians is needed, since most of these studies have been done on fish. Furthermore, no study has determined the effect of atrazine on species native to Mexico. Therefore, in this study, we asked what the effects of atrazine are on the erythrocytes and melanomacrophages of the liver in the male frog (Lithobates spectabilis). In the present study, we analyzed (1) the cytotoxicity of atrazine using the micronucleus test, (2) the area of melanomacrophage centers and the presence of melanin, and (3) the characterization of liver damage using histological techniques. Our results show that atrazine is cytotoxic to erythrocytes, increases the area of and melanin presence in melanomacrophage centers, and causes liver damage in male L. spectabilis. Therefore, hepatotoxicity and cytotoxicity are indicators of environmental stress. We suggest monitoring Mexico’s aquatic systems and further analyzing atrazine effects and other pollutants on native species. Full article

(This article belongs to the Section Biology and Ecology)

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39 pages, 10964 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Molecular Phylogeny, Taxonomy and Distribution Patterns of Trichomycterine Catfishes in the Middle Rio Grande Drainage, South-Eastern Brazil (Siluriformes: Trichomycteridae)

by Wilson J. E. M. Costa, Valter M. Azevedo-Santos, José Leonardo O. Mattos and Axel M. Katz

Fishes 2023, 8(4), 206; https://doi.org/10.3390/fishes8040206 - 15 Apr 2023

Cited by 4 | Viewed by 1860

Abstract

The Rio Grande drainage plays a key role in supplying water and electricity to large urban centres, but some components of its rich ichthyofauna are still poorly known. Based on our field inventories in the middle section of the drainage, we recognised 10 [...] Read more.

The Rio Grande drainage plays a key role in supplying water and electricity to large urban centres, but some components of its rich ichthyofauna are still poorly known. Based on our field inventories in the middle section of the drainage, we recognised 10 trichomycterine endemic species, of which 6 species are new and described herein. A molecular analysis (2600 bp for 43 taxa) indicated that the species of both subgenera do not form monophyletic groups. One species of the subgenus Cryptocambeva is closely related to species from the inner Brazilian Plateau, whereas other species of this subgenus are closely related to species endemic to smaller coastal basins. The species of the subgenus Paracambeva belong to different lineages of a clade endemic to the Rio Grande drainage. These species are diagnosed by the characters of their external morphology and osteology. A key to species identification is provided. The species distribution patterns support delimitation of three areas of endemism, which may have a relevant role for proposals of conservation strategies: the Uberaba, the São João-Sapucaí, and the Tamborete areas. The last one, a small area confined between the Serra da Canastra and the Rio Grande at the Furnas dam, is particularly important for sheltering three endemic trichomycterines and two loricariid catfishes. Full article

(This article belongs to the Special Issue Featured Papers in Taxonomy, Evolution, and Biogeography Section)

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17 pages, 4240 KiB

Open AccessArticle

Temporal Variation in Von Bertalanffy Growth Curves and Generation Time of Southern Gulf of St. Lawrence Spring and Fall Spawning Atlantic Herring (Clupea harengus)

by Jacob Burbank, Jenni L. McDermid, François Turcotte and Nicolas Rolland

Fishes 2023, 8(4), 205; https://doi.org/10.3390/fishes8040205 - 15 Apr 2023

Viewed by 1243

Abstract

Examining temporal changes in the growth and generation time of fish species can be valuable for understanding population responses to different management measures and environmental conditions. Atlantic herring (Clupea harengus-Linnaeus, 1758) is an ecologically and commercially important pelagic forage fish species [...] Read more.

Examining temporal changes in the growth and generation time of fish species can be valuable for understanding population responses to different management measures and environmental conditions. Atlantic herring (Clupea harengus-Linnaeus, 1758) is an ecologically and commercially important pelagic forage fish species that occupies the southern Gulf of St. Lawrence. Here, we developed von Bertalanffy growth curves and estimated yearly values of generation time for NAFO Division 4TVn Atlantic herring for the years from 1988 to 2021. The results indicate a temporal reduction in the growth and generation time of both spring and fall spawning herring. Over the time series, the generation time of spring and fall spawners reduced by approximately 1 and 2 years, respectively. Furthermore, the average generation time of spring spawners across the time series (6.23 years (95% CI: 5.78–6.85 years)) was approximately 1 year lower than that of fall spawners (7.52 years (6.82–8.34 years)). Overall, the findings of this study can be used to better inform stock assessments and rebuilding plans for 4TVn spring and fall spawning Atlantic herring and highlight the importance of examining temporal trends in growth and generation time for more effective management of fish stocks. Full article

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14 pages, 2542 KiB

Open AccessArticle

Experimental Investigation of the Hydrodynamic Characteristics of Longline Aquaculture Facilities under Current and Wave Conditions

by Xinxin Wang, Junyi Xie, Yan Luo, Xiao Wang, Gaobo Guo and Xinxing You

Fishes 2023, 8(4), 204; https://doi.org/10.3390/fishes8040204 - 15 Apr 2023

Cited by 1 | Viewed by 1279

Abstract

In this study, a longline aquaculture facility with lantern nets off the coast of northern China was modelled to conduct hydrodynamic tests starting from the culture unit to the entire facility under various current and wave conditions. The experimental results indicated that the [...] Read more.

In this study, a longline aquaculture facility with lantern nets off the coast of northern China was modelled to conduct hydrodynamic tests starting from the culture unit to the entire facility under various current and wave conditions. The experimental results indicated that the drag coefficients of the lantern net model with weights of 0.5, 0.75, and 1.0 kg were 0.75, 0.83, and 0.91, respectively, in the Reynolds number range of 1 × 10⁴–1 × 10⁶. The current-driven upstream mooring line was more dominant than the wave-driven tension, and a simplified model of the longline facility accurately predicted the mooring line tension under the current conditions. The scope of the mooring line (defined as the length of the mooring line related to the water depth) played an important role in eliminating an order of magnitude difference in mooring tension under the wave conditions. The amplitudes of the vertical movement of the longline facility were smaller than the wave height when L/L_m was less than 1.5. Therefore, detailed information is needed to better understand the hydrodynamic characteristics and motion response of longline aquaculture facilities for the safe operation of longline structures in offshore environments, in order to process high-quality oyster products. Full article

(This article belongs to the Special Issue Fisheries and Aquaculture Engineering)

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24 pages, 2022 KiB

Open AccessArticle

Transcriptional Profiling of Populations in the Clam Ruditapes decussatus Suggests Genetically Determined Differentiation in Gene Expression along Parallel Temperature Gradients and between Races of the Atlantic Ocean and West Mediterranean Sea

by Carlos Saavedra, Massimo Milan, Ricardo B. Leite, David Cordero, Tomaso Patarnello, M. Leonor Cancela and Luca Bargelloni

Fishes 2023, 8(4), 203; https://doi.org/10.3390/fishes8040203 - 14 Apr 2023

Viewed by 1522

Abstract

Ongoing ocean warming due to climate change poses new challenges for marine life and its exploitation. We have used transcriptomics to find genetically based responses to increased temperature in natural populations of the marine clam Ruditapes decussatus, which lives along parallel thermal [...] Read more.

Ongoing ocean warming due to climate change poses new challenges for marine life and its exploitation. We have used transcriptomics to find genetically based responses to increased temperature in natural populations of the marine clam Ruditapes decussatus, which lives along parallel thermal gradients in southern Europe. Clams of the Atlantic and West Mediterranean races were collected in northern (cool) and a southern (warm) localities. The animals were kept in running seawater in the warm, southern Atlantic locality for a 15-week period. During this period, water temperature was raised to typical southern European summer values. After this period, an expression profile was obtained for a total of 34 clams and 11,025 probes by means of an oligonucleotide microarray. We found distinct transcriptional patterns for each population based on a total of 552 differentially expressed genes (DEGs), indicating innate differences which probably have a genetic basis. Race and latitude contributed significantly to gene expression differences, with very different sets of DEGs. A gene ontology analysis showed that races differed mainly in the genes involved in ribosomal function and protein biosynthesis, while genes related to glutathione metabolism and ATP synthesis in the mitochondria were the most outstanding with respect to north/south transcriptional differences. Full article

(This article belongs to the Special Issue Omics Analysis in Marine Invertebrate Biology)

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13 pages, 2688 KiB

Open AccessArticle

Age and Growth of European Sardine (Sardina pilchardus) in the Central Mediterranean Sea: Implication for Stock Assessment

by Gualtiero Basilone, Rosalia Ferreri, Angelo Bonanno, Simona Genovese, Marco Barra and Salvatore Aronica

Fishes 2023, 8(4), 202; https://doi.org/10.3390/fishes8040202 - 13 Apr 2023

Cited by 1 | Viewed by 1592

Abstract

Understanding the drivers of fish growth is essential for predicting productivity, stability, and resilience of exploited populations. For the European sardine (Sardina pilchardus) in the Strait of Sicily (Central Mediterranean Sea, GSA16), growth parameters or length at age estimates have never [...] Read more.

Understanding the drivers of fish growth is essential for predicting productivity, stability, and resilience of exploited populations. For the European sardine (Sardina pilchardus) in the Strait of Sicily (Central Mediterranean Sea, GSA16), growth parameters or length at age estimates have never been published before. To fill this data gap, the length and age as well as the von Bertalanffy parameters (the most widely used growth model) were estimated. Data from landing samples during the period 2009–2019 were collected by two methods (purse seine and mid-water pelagic trawl). Temporal trends in average length at age, as well as an overall age-length key were obtained and compared with other areas across the geographical distribution range of sardine in the Mediterranean Sea. The observed age range was 0–3 years with most of the individuals belonging to Age 1 (52%) and Age 2 (43%). The mean length at age, for the entire study period, was 11.7 (±0.08) cm for Age 0; 13.4 (±0.09) cm for Age 1; 15 (±0.1) cm for Age 2; and 16.6 (±0.11) cm for Age 3. Furthermore, during the considered period, a reduction in the length at age was observed in the older classes (Age 2 and Age 3). The estimated parameters of the von Bertalanffy growth model were L_inf = 18 (±1.15) cm, K= 0.459 (±0.018), and t₀ = −1.99 (±0.008) and, accordingly, the mortality vector was obtained according to Gislason’s model, for each age class, these values were 0.99 (0.98–1.02) C at Age 0; 0.71 (0.7–0.73) y⁻¹ at Age 1; 0.6 (0.59–0.62) y⁻¹ at Age 2; 0.54 (0.53–0.56) y⁻¹ at Age 3; and 0.51 (0.49–0.53) y⁻¹ at Age 4. Results appeared in agreement with literature from other areas of the Mediterranean Sea and suggested a poor condition status of the sardine stock in the GSA16. Full article

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13 pages, 1122 KiB

Open AccessArticle

Phylogenetic Relationships of the Pseudogobionini Group (Teleostei: Cyprinidae) with Selection Pressure Analyses to Genes of Mitochondrial Genome

by Lin Chen, Xiaoyu Zhang and Huanzhang Liu

Fishes 2023, 8(4), 201; https://doi.org/10.3390/fishes8040201 - 13 Apr 2023

Viewed by 1274

Abstract

We newly sequenced complete mitochondrial genomes (mitogenome) of two gudgeon species Saurogobio dabryi and S. punctatus, and we downloaded 49 gudgeon mitogenomes from GenBank to investigate the phylogeny of the Pseudogobionini group and analyze selection pressure of the genes. With genera Gobio [...] Read more.

We newly sequenced complete mitochondrial genomes (mitogenome) of two gudgeon species Saurogobio dabryi and S. punctatus, and we downloaded 49 gudgeon mitogenomes from GenBank to investigate the phylogeny of the Pseudogobionini group and analyze selection pressure of the genes. With genera Gobio, Acanthogobio, and Romanogobio as outgroups, the phylogeny of the Pseudogobionini group was revealed as ((Xenophysogobio + Gobiobotia) + (Saurogobio + (Abbottina + (Pseudogobio + Biwia complex)))) based on the concatenated nucleotide sequences of 13 protein-coding genes (PCGs). Based on the molecular phylogeny and morphological or osteological characters, we proposed a classification system of the Pseudogobionini group. Moreover, five pairs of sister taxa were selected for gene selection pressure analyses to explore the link of mitochondrial gene evolution to group differentiation and adaptations. We detected significantly different dN/dS values in 11 out of 13 (excluding ND3 and ND4L) PCGs in five pairs of clades, significantly different mean dN/dS, dN, and/or dS values in 8 out of 13 PCGs (excluding ND2, ATP8, ND3, ND4L, and ND6) in three pairs of sub-clades and seven positively selected sites in another three pairs of sub-clades. These results indicated that mitochondrial gene evolution might have contributed to group differentiation and adaptations especially for river or lake environments. Full article

(This article belongs to the Section Taxonomy, Evolution, and Biogeography)

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16 pages, 12278 KiB

Open AccessArticle

Relationship between Jaw Malformations and Long-Chain PUFA’s in Seriola lalandi Larvae during the Spawning Season at a Commercial Hatchery

by Cesar Toledo, Eduardo Rubilar, Lorena Marchant, Jessica Dörner, Lorenzo Márquez, Víctor Martínez and Patricio Dantagnan

Fishes 2023, 8(4), 200; https://doi.org/10.3390/fishes8040200 - 13 Apr 2023

Cited by 1 | Viewed by 1722

Abstract

Jaw malformations imply an important problem during the commercial production of Seriola lalandi larvae and juvenile fish in Chile and New Zealand. Since the rate of malformations in other fish species has been associated with the content of long-chain PUFA (LC-PUFA) in neutral [...] Read more.

Jaw malformations imply an important problem during the commercial production of Seriola lalandi larvae and juvenile fish in Chile and New Zealand. Since the rate of malformations in other fish species has been associated with the content of long-chain PUFA (LC-PUFA) in neutral lipids of the diet, the relationship between body LC-PUFA and the rate of malformations, together with a transcriptomic analysis of genes related to the metabolism and transport of lipids in commercially produced S. lalandi larvae have been investigated in the present work. A total of 10 batches of S. lalandi larvae were obtained and cultured at about 22 °C following the protocols of a Chilean commercial hatchery during the spawning season. There were three larval batches that were collected in August (austral winter), three batches that were obtained in October (spring), and finally four spawning events that were obtained in December-January (spring-summer). The rate and type of jaw malformations, the profile of long-chain PUFA (LC-PUFA) of total lipids during larval culture, and the distribution of LC-PUFA were analyzed. Additionally, a transcriptome analysis related to lipid metabolism in 40-day-old larvae was performed. As a result, a decrease in the rate of malformations was recorded from August to December. DHA showed a steep decrease between days 1 and 10 of culture, probably due to the consumption of yolk sac lipids, but a higher proportional change was noted in larvae that hatched during August. The DHA content in polar lipids (PL) and neutral lipids (NL) of 40-day-old larvae increased from August to December, so that the abundance of DHA was higher in PL in larvae that hatched in December, but it was higher in NL in those larvae that hatched in October. In conclusion, the rate of jaw malformations was associated with the rapid decline in DHA during early larval life and the highest abundance of DHA in neutral lipids at the end of the larval life. Full article

(This article belongs to the Special Issue Feed and Nutrition Research in Aquaculture)

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16 pages, 1670 KiB

Open AccessArticle

Impact of Streptococcus agalactiae Challenge on Immune Response, Antioxidant Status and Hepatorenal Indices of Nile Tilapia: The Palliative Role of Chitosan White Poplar Nanocapsule

by Afaf N. Abdel Rahman, Sameh H. Ismail, Moustafa M. S. Fouda, Abdelwahab A. Abdelwarith, Elsayed M. Younis, Samah S. Khalil, Mahmoud M. El-Saber, Ahmed E. Abdelhamid, Simon J. Davies and Rowida E. Ibrahim

Fishes 2023, 8(4), 199; https://doi.org/10.3390/fishes8040199 - 12 Apr 2023

Cited by 7 | Viewed by 1741

Abstract

A new insight into the synthesis of the herbal plant (White poplar, Poplus alba) leave extract using chitosan nanocapsule was studied. The in vitro antibacterial activity of chitosan white poplar nanocapsule (CWPNC) against Streptococcus agalactiae (S. agalactiae) was [...] Read more.

A new insight into the synthesis of the herbal plant (White poplar, Poplus alba) leave extract using chitosan nanocapsule was studied. The in vitro antibacterial activity of chitosan white poplar nanocapsule (CWPNC) against Streptococcus agalactiae (S. agalactiae) was determined. About 120 fish were categorized for 7 days into four groups. The first and second (CWPNC) groups were treated with 0 mg/L and 3 mg/L CWPNC in the water, respectively, without being challenged; the first group was a control. The third (S. agalactiae) and fourth (CWPNC + S. agalactiae) groups were treated with 0 and 3 mg/L CWPNC, respectively, and challenged with S. agalactiae (0.5 × 10⁷ CFU/mL). The obtained results revealed that CWPNC had an in vitro antibacterial activity against S. agalactiae. Moreover, S. agalactiae infection caused a significant elevation (p < 0.05) in the lipid peroxidation (malondialdehyde) and hepatorenal biomarkers, as well as the lowest significant (p < 0.05) survival rate (33.33%). Moreover, a significant depletion (p < 0.05) in the level of antioxidants (catalase and superoxide dismutase) and the immune indicators (immunoglobulin, lysozyme activity, and complement 3) were the consequences of S. agalactiae infection. Treatment of the infected fish with 3 mg/L CWPNC alleviated these bad circumstances. Full article

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16 pages, 1445 KiB

Open AccessArticle

Implementing Ecosystem Approach to Fisheries Management in the Western and Central Pacific Fisheries Commission: Challenges and Prospects

by Huihui Shen and Liming Song

Fishes 2023, 8(4), 198; https://doi.org/10.3390/fishes8040198 - 12 Apr 2023

Cited by 1 | Viewed by 2609

Abstract

The ecosystem approach to fisheries management (EAFM) is considered one of the key management approaches for addressing global resource decline and promoting the health and resilience of ecosystems. This paper explores how the Western and Central Pacific Fisheries Commission (WCPFC), which manages tuna [...] Read more.

The ecosystem approach to fisheries management (EAFM) is considered one of the key management approaches for addressing global resource decline and promoting the health and resilience of ecosystems. This paper explores how the Western and Central Pacific Fisheries Commission (WCPFC), which manages tuna fisheries, has incorporated the ecosystem approach into its management and decision-making system. This study finds that (1) the WCPFC lacks incentives to adopt EAFM as a whole due to its management priorities on target species and some key bycatch species; (2) inadequate scientific information on associated species and the environment hinders ecosystem risk assessments, leading to delays in EAFM-related decisions; and (3) the organization has given little consideration to human factors. The authors suggest developing an EAFM vision with a clear roadmap to guide the implementation of EAFM and applying area-based management tools in cases where there is limited data and scientific information. The proposed coordination mechanism aims to address growing concerns about labor issues by involving multiple stakeholders in the development of a management measure on labor standards. Full article

(This article belongs to the Special Issue The Great Reset in Fisheries Management: Fisheries under Contrasting Environmental and Human-Induced Effects)

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12 pages, 3247 KiB

Open AccessArticle

Age and Growth Characteristics of Okamejei kenojei in the West Sea of South Korea According to Coronal Vertebral Microstructure

by Byoung-Il Youn, Dong-Hyuk Choi, Tae-Hyoung Roh, Seung-Hwan Lee, Kyeong-Ho Han, Dae-Hyeon Kwon and Maeng-Jin Kim

Fishes 2023, 8(4), 197; https://doi.org/10.3390/fishes8040197 - 10 Apr 2023

Cited by 1 | Viewed by 1581

Abstract

In this study, the growth and age characteristics of Okamejei kenojei in the West Sea of South Korea were examined, and specimens were collected by bottom trawls from January to December 2019. The relationship between disc width (L) and body weight [...] Read more.

In this study, the growth and age characteristics of Okamejei kenojei in the West Sea of South Korea were examined, and specimens were collected by bottom trawls from January to December 2019. The relationship between disc width (L) and body weight (W) was W = 6.1 × 10⁻³ L^3.40. Age was determined by measuring annuli on the vertebral centrum surface, which forms around June every year. The spawning period was extrapolated from monthly changes of the gonadosomatic index in June–July. The relationship between the vertebral centrum radius and disc width, which was analyzed separately for females and males, was determined as L = 16.159R^0.6145 and L = 15.543R^0.6851, respectively. Finally, O. kenojei growth, that is, the disc width (L) at a certain age (t), was expressed using the von Bertalanffy growth equation as L_t = 58.70(1 − e^{−0.21(t+0.12)}) for females and L_t = 53.94(1 − e^{−0.26(t+0.05)}) for males. This study provides basic data on the age characteristics of O. kenojei for future research and more efficient fish stock management. Full article

(This article belongs to the Section Biology and Ecology)

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15 pages, 2947 KiB

Open AccessArticle

Metabonomic Analysis of Macrobrachium rosenbergii with Iron Prawn Syndrome (IPS)

by Xi-Lian Li, Pei-Jing Shen, Wen-Ping Jiang, Ji-Lun Meng, Hai-Hua Cheng and Qiang Gao

Fishes 2023, 8(4), 196; https://doi.org/10.3390/fishes8040196 - 09 Apr 2023

Viewed by 1409

Abstract

We previously reported on the comparison of proteomic data between seven tissue types of a novel “iron prawn” species. However, no transcripts or metabolic information are available for this species. We therefore performed shotgun LC–MS/MS metabonomic and RNA-seq analyses of the total protein [...] Read more.

We previously reported on the comparison of proteomic data between seven tissue types of a novel “iron prawn” species. However, no transcripts or metabolic information are available for this species. We therefore performed shotgun LC–MS/MS metabonomic and RNA-seq analyses of the total protein from “iron prawns”. KEGG analysis revealed that the largest group consisted of a total of 114 KEGG pathway proteins, comparing the “iron prawns” with the normal prawns. A total of 423 peptides, corresponding to metabolic pathways, ABC transporters, starch and sucrose metabolism, insulin resistance/secretion, fatty digestion and absorption, and lipid metabolism, were identified. The pathways of carbohydrate and amino acid metabolism decreased in female iron prawns, while organic acid and its derivatives increased. However, the pathway of organic acid and its derivatives decreased and lipid metabolism increased in the male iron prawns. The pathways of choline metabolism in cancer and glycerophospholipid/histidine/propanoate metabolism have been significantly affected in iron prawns. Our work provides insight into the understanding of the formation mechanism of the “iron prawn”. Full article

(This article belongs to the Special Issue Transcriptomics in Aquaculture: Current Status and Applications)

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19 pages, 12104 KiB

Open AccessArticle

Gills of Molly Fish: A Potential Role in Neuro-Immune Interaction

by Doaa M. Mokhtar, Marwa M. Hussein, Giacomo Zaccone, Alessio Alesci, Eugenia Rita Lauriano and Ramy K. A. Sayed

Fishes 2023, 8(4), 195; https://doi.org/10.3390/fishes8040195 - 08 Apr 2023

Cited by 3 | Viewed by 1755

Abstract

This study identified the cellular compositions of the gills in molly fish and their role in immunity using light-, electron- microscopy, and immunohistochemistry. The molly fish gills consisted of four holobranchs spaced between five branchial slits. Each hemibranch carried many fine primary and [...] Read more.

This study identified the cellular compositions of the gills in molly fish and their role in immunity using light-, electron- microscopy, and immunohistochemistry. The molly fish gills consisted of four holobranchs spaced between five branchial slits. Each hemibranch carried many fine primary and secondary gill lamellae. The gill arch was a curved cartilaginous structure, from which radiated the bony supports of the primary lamellae. The gill arch contained the afferent and efferent brachial arteries. The gill arch was covered by epidermal tissue rich with mucous cells. The primary lamella had a central cartilaginous support and efferent and afferent arterioles and was covered with pavement cells (PVC), salt-secreting chloride cells, and pale-staining mucous cells. These chloride cells contained abundant mitochondria and tubulovesicular system and are involved in ionic transport with a potential role in detoxification. The surface of the secondary lamellae (site of gaseous exchange) consisted of overlapping or interdigitating PVC supported and separated by pillar cells. Other cells were found within the gill epithelium and interstitial connective tissues, including lymphocytes, macrophages, monocytes, telocytes, stem cells, astrocytes, and neuroepithelial cells. The immunohistochemical analysis revealed that APG-5, iNOS-2, IL-1β, NF-κB, and TGF-B showed positive immunoreactivity in macrophages. The epithelium of the primary gill lamellae contained positive-GFAP astrocytes and S100 protein—chloride cells. The stem cells expressed SOX9, myostatin, and Nrf2. Neuroendocrine cells expressed S100 protein. In conclusion, the current work suggests that the gills of molly fish are multifunctional organs and are involved in immune reactions. Full article

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13 pages, 3719 KiB

Open AccessArticle

Sex Ratio, Spawning Period, and Sexual Group Maturity of the Largehead Hairtail Trichiurus japonicus (Teleostei: Trichiuridae) in Korean Waters

by So Ryung Shin, Hyeon Jin Kim, Jae Won Kim, Dae-Hyeon Kwon, Junghwa Choi, Jung Jun Park and Jung Sick Lee

Fishes 2023, 8(4), 194; https://doi.org/10.3390/fishes8040194 - 07 Apr 2023

Cited by 3 | Viewed by 1779

Abstract

This study was performed to obtain information on the sex ratio, spawning period, and size at sexual maturity for fishery management of the largehead hairtail Trichiurus japonicus in Korean waters. The overall sex ratio (female, F; male, M) was 1:0.46 (n = 1274 [...] Read more.

This study was performed to obtain information on the sex ratio, spawning period, and size at sexual maturity for fishery management of the largehead hairtail Trichiurus japonicus in Korean waters. The overall sex ratio (female, F; male, M) was 1:0.46 (n = 1274 females:589 males, 68.4% female) and as fish increased in length, the proportion of females increased. The oocyte development pattern was group-synchronous development, for which oocyte groups at different stages can be identified within the same ovary. The average gonadosomatic index (GSI) showed two peaks in June (3.03) and August (3.10) in females and in May (1.81) and September (2.24) in males. The median value of GSI showed two peaks in May (2.65F, 1.78M) and September (2.55F, 1.87M) for both females and males. As a result of analyzing the GSI and the monthly gonadal developmental stages, the main spawning season was estimated to be bi-annual (May–June and September–October). The anal length of fish at 50% sexual maturity was analyzed using a logistic regression model and was determined to be 16.38 cm (female) and 18.31 cm (male). Full article

(This article belongs to the Section Biology and Ecology)

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17 pages, 1484 KiB

Open AccessArticle

Reproductive Ecology of the Chilean Round Ray (Urotrygon chilensis, Günther, 1872) in the Southern Gulf of California

by Carlos J. Alvarez-Fuentes, Javier Tovar-Ávila, Jorge Payan-Alejo, Darío A. Chávez-Arrenquín, Isaias H. Salgado-Ugarte and Felipe Amezcua

Fishes 2023, 8(4), 193; https://doi.org/10.3390/fishes8040193 - 04 Apr 2023

Cited by 1 | Viewed by 1288

Abstract

The Chilean round ray (Urotrygon chilensis, Günther, 1872) is commonly caught as bycatch in the Mexican Pacific, but changes in its reproductive ecology as a consequence of fishery effects have never been investigated. In this work, the reproductive ecology of this species [...] Read more.

The Chilean round ray (Urotrygon chilensis, Günther, 1872) is commonly caught as bycatch in the Mexican Pacific, but changes in its reproductive ecology as a consequence of fishery effects have never been investigated. In this work, the reproductive ecology of this species was determined in the Southern Gulf of California (SGC). Total length (TL) ranged from 11.4 to 51.6 cm, and females were larger than males. Size at maturity (TL₅₀) was estimated at 27.5 cm for females and 25.3 cm for males. The seasonal variation of mature individuals, the presence of pregnant females, the mean oocyte size, the size of embryos and the smallest free-living specimens along the year suggest the existence of two reproductive periods during the year in the SGC, and the size of birth was estimated to be 11.2 to 15.6 cm TL. The average fecundity was 2.14 embryos. Spatial variations detected in size at maturity, fecundity, and reproductive cycle along the Mexican Pacific coast suggest the presence of separated populations. Some of these differences could be related to differences in maximum size attained in each region, though fishing pressure and environmental factors could have an important role, too. Full article

(This article belongs to the Section Biology and Ecology)

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10 pages, 1282 KiB

Open AccessArticle

Effect of Stocking Density and Feeding Strategy on Zootechnical Parameters and Profitability of Nile Tilapia (Oreochromis niloticus) Reared in Floating Cages in Toho-Todougba Complex Lagoon in Benin Republic

by Romaric Aïzonou, Arsène Mathieu Houssou, Guillaume Koussovi, Comlan Eugène Dessouassi, Mardochée Ephraïm Achoh, Sessien Lionnel Hounhouedo, Clovis Idossou Hountchémè and Hyppolite Agadjihouèdé

Fishes 2023, 8(4), 192; https://doi.org/10.3390/fishes8040192 - 03 Apr 2023

Viewed by 1578

Abstract

This study aimed to compare the growth performance and economic profitability of rearing Oreochromis niloticus in floating cages using three feeding strategies (5 days a week, 6 days a week, and 7 days a week) coupled with three stocking densities (20, 40, and [...] Read more.

This study aimed to compare the growth performance and economic profitability of rearing Oreochromis niloticus in floating cages using three feeding strategies (5 days a week, 6 days a week, and 7 days a week) coupled with three stocking densities (20, 40, and 60 fish·m⁻³). Male monosex fish measuring 6.44 ± 0.18 cm and weighing 3.42 ± 0.7 g were used. The controls were weighed every 15 days from the 35th day of rearing until 185 days to assess zootechnical parameters. BioMar feed (Efico Cromis 832F) was used during the study, and the feed ration was adjusted for each treatment every 2 weeks. At the end of the study, the average weights varied from 293.09 g to 468.41 g for the conditions of 40 fish·m⁻³ with a 5/7-day diet and 20 fish·m⁻³ with a 7/7-day diet, respectively. The yield per m² values were between 7.11 kg and 23.17 kg, respectively. On the other hand, the economic profitability was better with the condition of 40 fish.m⁻³ with daily feeding. These results suggest that in the Toho-Todougba lagoon complex, a stocking density between 40 and 60 fish·m⁻³ coupled with daily feeding (three times a day) promotes the optimization of fish production and profitability of fish farming. Full article

(This article belongs to the Special Issue Development of Sustainable Aquaculture Production)

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14 pages, 3308 KiB

Open AccessArticle

Loss-of-Function of xpc Sensitizes Zebrafish to Ultraviolet Irradiation

by Kai Liu, Zhaoxiang Sun, Chun Yang, Li Jan Lo and Jun Chen

Fishes 2023, 8(4), 191; https://doi.org/10.3390/fishes8040191 - 03 Apr 2023

Cited by 1 | Viewed by 1222

Abstract

Xeroderma pigmentosum complementation group C (XPC) protein recognizes bulky DNA adducts to initiate global genomic nucleotide excision repair (GG-NER). Humans carrying germline mutations in the XPC gene display strong susceptibility to skin and certain internal cancers. In addition to its role in NER, [...] Read more.

Xeroderma pigmentosum complementation group C (XPC) protein recognizes bulky DNA adducts to initiate global genomic nucleotide excision repair (GG-NER). Humans carrying germline mutations in the XPC gene display strong susceptibility to skin and certain internal cancers. In addition to its role in NER, recent studies have indicated that XPC is also involved in other DNA damage repair pathways and transcription regulation. In this report, we generated a zebrafish xpc knockout mutant. Zebrafish xpc^−/− mutant fish develop relative normally and are fertile. However, the mutant embryos were more sensitive to ultraviolet (UV) irradiation. Upon UV irradiation, compared with the wild type embryos, mutant embryos accumulated significantly higher levels of unrepaired DNA damages and apoptotic cells, which led to more severe abnormal development. Transcriptome analysis showed that the p53 signal pathway and apoptosis were enriched in the over upregulated genes in UV-irradiated mutant embryos, suggesting that high levels of unrepaired DNA lesions activated p53 to trigger apoptotic activity in mutant embryos. More interestingly, up to 972 genes in the untreated mutant embryos were differentially expressed, compared with those in the untreated WT. Among these differentially expressed genes (DEGs), 379 genes did not respond to UV irradiation, indicating that Xpc plays a role in addition of DNA damage repair. Our results demonstrate that Xpc is an evolutionally conserved factor in NER repair. Zebrafish xpc^−/− mutant also provides a platform to study other functions of Xpc beyond the DNA damage repair. Full article

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11 pages, 1175 KiB

Open AccessBrief Report

Zootechnical Brown Trout (Salmo trutta L. 1758) Ovarian Fluid Fails to Upregulate the Swimming Performances of Native Mediterranean Brown Trout (Salmo cettii Rafinesque, 1810) Sperm in the Biferno River

by Giusy Rusco, Michele Di Iorio, Stefano Esposito, Pierpaolo Gibertoni, Emanuele Antenucci, Valentino Palombo, Alessandra Roncarati and Nicolaia Iaffaldano

Fishes 2023, 8(4), 190; https://doi.org/10.3390/fishes8040190 - 31 Mar 2023

Viewed by 1470

Abstract

In external fertilizer fish, ovarian fluid (OF) seems to play a key role in fertilization success, improving spermatozoa swimming performance. These OF/sperm interaction mechanisms are frequently species-specific and/or population-specific and could decrease the risk of genetic introgression of wild populations from introduced or [...] Read more.

In external fertilizer fish, ovarian fluid (OF) seems to play a key role in fertilization success, improving spermatozoa swimming performance. These OF/sperm interaction mechanisms are frequently species-specific and/or population-specific and could decrease the risk of genetic introgression of wild populations from introduced or escaped zootechnical individuals. The Mediterranean brown trout (Salmo cettii) is threatened by genetic introgression with strains of domestic brown trout (Salmo trutta) that were introduced for recreational purposes. The aim of our study was to test if native S. cettii females, rather than zootechnical S. trutta, produce OF with a greater ability to upregulate the sperm motility of conspecific males. Thus, we compared the sperm swimming performances of males inhabiting the Biferno River (Molise region—Southern Italy) activated in native S. cettii vs. zootechnical S. trutta female’s OFs. In our study, native females’ OFs (20% diluted), compared to spring water, has the ability to significantly boost the sperm performance of the autochthonous males, while zootechnical S. trutta fails. These preliminary results suggest that OF-sperm interactions could potentially influence or direct the hybridization mechanisms involving the native Mediterranean trout inhabiting the Biferno River and the domestic lineage of brown trout introduced in the past. Full article

(This article belongs to the Special Issue Fish Biodiversity in the Mediterranean)

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19 pages, 24955 KiB

Open AccessArticle

Juvenile and Trash Fish Excluder Device (JTED) for Taiwanese Bottom Trawl

by Chao-Ching Chen, Hsin-Zong Lin and Kuo-Wei Lan

Fishes 2023, 8(4), 189; https://doi.org/10.3390/fishes8040189 - 30 Mar 2023

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Abstract

Juvenile and trash fish excluder devices (JTEDs) are used to mitigate the ecological impact of trawling. Trawling has a large ecological footprint in Taiwan. Thus, this study designed three JTEDs, which differed only in grid interval, for single boat bottom otter trawls that [...] Read more.

Juvenile and trash fish excluder devices (JTEDs) are used to mitigate the ecological impact of trawling. Trawling has a large ecological footprint in Taiwan. Thus, this study designed three JTEDs, which differed only in grid interval, for single boat bottom otter trawls that are commonly used in Taiwan. The designed JTEDs were tested in the waters off of Kaohsiung on a Kaohsiung-based bottom trawler, and the results were as follows. (1) At least 300 species were caught, and 189 of these species had little commercial value; their weight accounted for 52.5% of the total catch. (2) The three JTEDs had good exclusion performance. (3) The ratios of the weight of bycatch excluded to the weight of total catch were 7.9%, 29.1%, and 36.2%, for grid intervals of 10, 15, and 20 mm, respectively. (4) JTEDs with grid intervals of 10, 15, and 20 mm were associated with a 0.4%, 11.5%, and 19.0% loss in revenue, respectively. (5) Mature (and thus commercially valuable) Loliginidae tended to be excluded when the grid interval was 20 or (especially) 15 mm. In general, the designed JTEDs should be used at a grid size of 15 mm because this strikes the best balance between profitability and sustainability. Full article

(This article belongs to the Section Fishery Facilities, Equipment, and Information Technology)

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Fishes, Volume 8, Issue 4 (April 2023) – 48 articles

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