Journal of Marine Science and Engineering

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2 pages, 190 KiB

Open AccessEditorial

New Research Advances on Marine Invertebrates

by Alexandre Lobo-da-Cunha

J. Mar. Sci. Eng. 2023, 11(1), 6; https://doi.org/10.3390/jmse11010006 - 20 Dec 2022

Viewed by 1016

Abstract

Marine ecosystems encompass a wide variety of invertebrates, pelagic and benthonic, from intertidal to deep-sea habitats in polar to tropical regions [...] Full article

(This article belongs to the Special Issue New Research Advances on Marine Invertebrates)

Research

Jump to: Editorial

36 pages, 14524 KiB

Open AccessArticle

How Do Prostomial Sensory Organs Affect Brain Anatomy? Phylogenetic Implications in Eunicida (Annelida)

by Sabrina Kuhl, Thomas Bartolomaeus and Patrick Beckers

J. Mar. Sci. Eng. 2022, 10(11), 1707; https://doi.org/10.3390/jmse10111707 - 9 Nov 2022

Cited by 3 | Viewed by 2840

Abstract

Eunicida is a taxon of marine annelids currently comprising the taxa Eunicidae, Onuphidae, Dorvilleidae, Oenonidae, Lumbrineridae, Histriobdellidae and Hartmaniella. Most representatives are highly mobile hunters sharing the presence of a sophisticated nervous system but differ in the number and shape of prostomial sensory [...] Read more.

Eunicida is a taxon of marine annelids currently comprising the taxa Eunicidae, Onuphidae, Dorvilleidae, Oenonidae, Lumbrineridae, Histriobdellidae and Hartmaniella. Most representatives are highly mobile hunters sharing the presence of a sophisticated nervous system but differ in the number and shape of prostomial sensory organs (0–3 antennae; 0 or 2 palps; 0, 2 or 4 (+2) buccal lips; 0, 2 or 4 eyes; single-grooved or paired nuchal organs). This makes Eunicida an ideal model to study the following questions: Is the brain morphology affected by different specificities of prostomial sensory organs? Do similar numbers and shapes of prostomial sensory organs hint at close phylogenetic relationships among different eunicidan taxa? How can antennae, palps and buccal lips be differentiated? For the investigation of sensory organs and the nervous system, we performed immunohistochemistry, µCT, TEM, SEM, paraffin histology and semi-thin sectioning. Our results show that brain anatomy is mostly affected on a microanatomical level by sensory organs and that similar specificities of sensory organs support the latest phylogenetic relationships of Eunicida. Further, a reduction of antennae in Eunicida can be suggested and hypotheses about the presence of sensory organs in the stem species of Eunicida are made. Full article

(This article belongs to the Special Issue New Research Advances on Marine Invertebrates)

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23 pages, 21712 KiB

Open AccessArticle

Biological and Proteomic Characterization of the Anti-Cancer Potency of Aqueous Extracts from Cell-Free Coelomic Fluid of Arbacia lixula Sea Urchin in an In Vitro Model of Human Hepatocellular Carcinoma

by Claudio Luparello, Rossella Branni, Giulia Abruscato, Valentina Lazzara, Simon Sugár, Vincenzo Arizza, Manuela Mauro, Vita Di Stefano and Mirella Vazzana

J. Mar. Sci. Eng. 2022, 10(9), 1292; https://doi.org/10.3390/jmse10091292 - 13 Sep 2022

Cited by 6 | Viewed by 2231

Abstract

Echinoderms are an acknowledged source of bioactive compounds exerting various beneficial effects on human health. Here, we examined the potential in vitro anti-hepatocarcinoma effects of aqueous extracts of the cell-free coelomic fluid obtained from the sea urchin Arbacia lixula using the HepG2 cell [...] Read more.

Echinoderms are an acknowledged source of bioactive compounds exerting various beneficial effects on human health. Here, we examined the potential in vitro anti-hepatocarcinoma effects of aqueous extracts of the cell-free coelomic fluid obtained from the sea urchin Arbacia lixula using the HepG2 cell line as a model system. This was accomplished by employing a combination of colorimetric, microscopic and flow cytometric assays to determine cell viability, cell cycle distribution, the possible onset of apoptosis, the accumulation rate of acidic vesicular organelles, mitochondrial polarization, cell redox state and cell locomotory ability. The obtained data show that exposed HepG2 cells underwent inhibition of cell viability with impairment of cell cycle progress coupled to the onset of apoptotic death, the induction of mitochondrial depolarization, the inhibition of reactive oxygen species production and acidic vesicular organelle accumulation, and the block of cell motile attitude. We also performed a proteomic analysis of the coelomic fluid extract identifying a number of proteins that are plausibly responsible for anti-cancer effects. Therefore, the anti-hepatocarcinoma potentiality of A. lixula’s preparation can be taken into consideration for further studies aimed at the characterization of the molecular mechanism of cytotoxicity and the development of novel prevention and/or treatment agents. Full article

(This article belongs to the Special Issue New Research Advances on Marine Invertebrates)

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25 pages, 10446 KiB

Open AccessArticle

Intestine Explants in Organ Culture: A Tool to Broaden the Regenerative Studies in Echinoderms

by Samir A. Bello and José E. García-Arrarás

J. Mar. Sci. Eng. 2022, 10(2), 244; https://doi.org/10.3390/jmse10020244 - 11 Feb 2022

Cited by 3 | Viewed by 2179

Abstract

The cellular events underlying intestine regrowth in the sea cucumber Holothuria glaberrima have been described by our group. Currently, the molecular and signaling mechanisms involved in this process are being explored. One of the limitations to our investigations has been the absence of [...] Read more.

The cellular events underlying intestine regrowth in the sea cucumber Holothuria glaberrima have been described by our group. Currently, the molecular and signaling mechanisms involved in this process are being explored. One of the limitations to our investigations has been the absence of suitable cell culture methodologies, required to advance the regeneration studies. An in vitro system, where regenerating intestine explants can be studied in organ culture, was established previously by our group. However, a detailed description of the histological properties of the cultured gut explants was lacking. Here, we used immunocytochemical techniques to study the potential effects of the culture conditions on the histological characteristics of explants, comparing them to the features observed during gut regeneration in our model in vivo. Additionally, the explant outgrowths were morphologically described by phase-contrast microscopy and SEM. Remarkably, intestine explants retain most of their original histoarchitecture for up to 10 days, with few changes as culture time increases. The most evident effects of the culture conditions on explants over culture time were the reduction in the proliferative rate, the loss of the polarity in the localization of proliferating cells, and the appearance of a subpopulation of putative spherulocytes. Finally, cells that migrated from the gut explants could form net-like monolayers, firmly attached to the culture substrate. Overall, regenerating explants in organ culture represent a powerful tool to perform short-term studies of processes associated with gut regeneration in H. glaberrima under controlled conditions. Full article

(This article belongs to the Special Issue New Research Advances on Marine Invertebrates)

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25 pages, 13305 KiB

Open AccessArticle

Functional Histology and Ultrastructure of the Digestive Tract in Two Species of Chitons (Mollusca, Polyplacophora)

by Alexandre Lobo-da-Cunha, Ângela Alves, Elsa Oliveira and Gonçalo Calado

J. Mar. Sci. Eng. 2022, 10(2), 160; https://doi.org/10.3390/jmse10020160 - 26 Jan 2022

Cited by 4 | Viewed by 4087

Abstract

To continue the investigation on the digestive system of polyplacophoran molluscs, a histological and ultrastructural study of the oesophagus, stomach and intestine of Chaetopleura angulata and Acanthochitona fascicularis was carried out. Stomach content examination revealed an omnivorous diet. In both species the epithelium [...] Read more.

To continue the investigation on the digestive system of polyplacophoran molluscs, a histological and ultrastructural study of the oesophagus, stomach and intestine of Chaetopleura angulata and Acanthochitona fascicularis was carried out. Stomach content examination revealed an omnivorous diet. In both species the epithelium of the whole digestive tract consisted mostly of elongated absorptive cells with an apical border of microvilli. Cilia were also frequently present. Mitochondria and electron-dense lysosomes were the prominent organelles in the region above the nucleus. The basal region was characterised by an association of mitochondria, peroxisomes and lipid droplets. In general, glycogen deposits were also abundant in absorptive cells. The ultrastructural features indicate that the absorptive cells of the digestive tract epithelium are involved in endocytosis, intracellular digestion and storage of reserves. Histochemical techniques showed that the secretory cells of the digestive tract contained proteins and polysaccharides in their secretory vesicles. The secretory cells with vesicles of low electron density were classified as mucous cells, and the ones with electron-dense vesicles were designated basophilic cells due to their staining by basic dyes in light microscopy. Additionally, basal cells that seem to correspond to enteroendocrine cells containing oval electron-dense vesicles were found along the digestive tract epithelium of both species. The thin outer layer of the digestive tract wall consisted of muscle cells and nerves embedded in connective tissue. Full article

(This article belongs to the Special Issue New Research Advances on Marine Invertebrates)

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9 pages, 1112 KiB

Open AccessArticle

Differentiation of Crystal Cells, Gravity-Sensing Cells in the Placozoan Trichoplax adhaerens

by Tatiana D. Mayorova

J. Mar. Sci. Eng. 2021, 9(11), 1229; https://doi.org/10.3390/jmse9111229 - 6 Nov 2021

Cited by 1 | Viewed by 2417

Abstract

Trichoplax adhaerens are simple animals with no nervous system, muscles or body axis. Nevertheless, Trichoplax demonstrate complex behaviors, including responses to the direction of the gravity vector. They have only six somatic cell types, and one of them, crystal cells, has been implicated [...] Read more.

Trichoplax adhaerens are simple animals with no nervous system, muscles or body axis. Nevertheless, Trichoplax demonstrate complex behaviors, including responses to the direction of the gravity vector. They have only six somatic cell types, and one of them, crystal cells, has been implicated in gravity reception. Multiple crystal cells are scattered near the rim of the pancake-shaped animal; each contains a cup-shaped nucleus and an intracellular crystal, which aligns its position according to the gravity force. Little is known about the development of any cell type in Trichoplax, which, in the laboratory, propagate exclusively by binary fission. Electron and light microscopy were used to investigate the stages by which crystal cells develop their mature phenotypes and distributions. Nascent crystal cells, identified by their possession of a small crystal, were located farther from the rim than mature crystal cells, indicating that crystal cells undergo displacement during maturation. They were elongated in shape and their nucleus was rounded. The crystal develops inside a vacuole flanked by multiple mitochondria, which, perhaps, supply molecules needed for the biomineralization process underlying crystal formation. This research sheds light on the development of unique cells with internal biomineralization and poses questions for further research. Full article

(This article belongs to the Special Issue New Research Advances on Marine Invertebrates)

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12 pages, 5683 KiB

Open AccessEditor’s ChoiceArticle

Microscopic Anatomy of the Lining of Hemal Spaces in the Penaeid Shrimp, Sicyonia ingentis

by Rachel Brittany Sidebottom, Sabi Bang and Gary Martin

J. Mar. Sci. Eng. 2021, 9(8), 862; https://doi.org/10.3390/jmse9080862 - 11 Aug 2021

Cited by 1 | Viewed by 3900

Abstract

The purpose of this paper is to present a morphological description of three different types of acellular material lining hemal spaces in a shrimp, providing a background for addressing future questions. The vasculature of the penaeid shrimp, Sicyonia ingentis, includes vessels leading [...] Read more.

The purpose of this paper is to present a morphological description of three different types of acellular material lining hemal spaces in a shrimp, providing a background for addressing future questions. The vasculature of the penaeid shrimp, Sicyonia ingentis, includes vessels leading from the heart into arteries which branch and expand into sinuses before returning hemolymph back to the heart. Early work showed that an endothelium was absent, and a basement membrane (BM) separated tissues from the hemolymph. Therefore, it was suggested that hemocytes could identify anything other than the BM as a “foreign” entity. This study demonstrates three major types of acellular material lining the hemal spaces of S. ingentis. Cardiomyocytes, digestive gland tubules, and abdominal muscle fibers are covered by BMs. Major arteries are lined by a fibrillin-like fibrous material. Finally, sheaths of collagenous connective tissues cover the heart and digestive gland as well as the outer surface of arteries, the gut, and gonad. Our understanding of hemocyte receptors and extracellular matrices in general have greatly expanded but the biochemical composition of the matrices lining crustacean hemal spaces, their role in regulating nutrient uptake, and the cells responsible for their deposition deserve further attention. Full article

(This article belongs to the Special Issue New Research Advances on Marine Invertebrates)

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9 pages, 6529 KiB

Open AccessArticle

Histologic Examination of a Sea Pig (Scotoplanes sp.) Using Bright Field Light Microscopy

by Elise E. B. LaDouceur, Linda A. Kuhnz, Christina Biggs, Alicia Bitondo, Megan Olhasso, Katherine L. Scott and Michael Murray

J. Mar. Sci. Eng. 2021, 9(8), 848; https://doi.org/10.3390/jmse9080848 - 6 Aug 2021

Cited by 2 | Viewed by 4696

Abstract

Sea pigs (Scotoplanes spp.) are deep-sea dwelling sea cucumbers of the phylum Echinodermata, class Holothuroidea, and order Elasipodida. Few reports are available on the microscopic anatomy of these deep-sea animals. This study describes the histologic findings of two, wild, male and female [...] Read more.

Sea pigs (Scotoplanes spp.) are deep-sea dwelling sea cucumbers of the phylum Echinodermata, class Holothuroidea, and order Elasipodida. Few reports are available on the microscopic anatomy of these deep-sea animals. This study describes the histologic findings of two, wild, male and female Scotoplanes sp. collected from Monterey Bay, California. Microscopic findings were similar to other holothuroids, with a few notable exceptions. Sea pigs were bilaterally symmetrical with six pairs of greatly enlarged tube feet arising from the lateral body wall and oriented ventrally for walking. Neither a rete mirabile nor respiratory tree was identified, and the large tube feet may function in respiration. Dorsal papillae protrude from the bivium and are histologically similar to tube feet with a large, muscular water vascular canal in the center. There were 10 buccal tentacles, the epidermis of which was highly folded. Only a single gonad was present in each animal; both male and female had histologic evidence of active gametogenesis. In the male, a presumed protozoal cyst was identified in the aboral intestinal mucosa, and was histologically similar to previous reports of coccidians. This work provides control histology for future investigations of sea pigs and related animals using bright field microscopy. Full article

(This article belongs to the Special Issue New Research Advances on Marine Invertebrates)

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