Diversity and Distribution of Helminths in Wild Ruminants of the Russian Arctic: Reindeer (Rangifer tarandus), Muskoxen (Ovibos moschatus), and Snow Sheep (Ovis nivicola)

Round 1

Reviewer 1 Report

Dear authors

I reviewed the paper entitled Diversity and Distribution of Helminths in Wild Ruminants 

of the Russian Arctic: Reindeer (Rangifer tarandus), Muskoxen (Ovibos moschatus), and Snow Sheep (Ovis nivicola) by Loginova and colleagues. 

This is a very interesting manuscript with excellent pictures. The paper deserves to be published after some revisions. My main concern is related to the introduction. This section needs a major reorganization, since there is no a literature of review about the parasites studied. There are parts of the introduction that fits more on the material and methods section. 

 

Minor revisions

Line 39: delete “etc”

Line 41: delete “obtained”

Lines 50-52: this first phrase of introduction is more adequate to material and method section. Please, moved it or rephased it.

Line 211: delete “That is”

Acceptable. Just few corrections.

Author Response

This is a very interesting manuscript with excellent pictures.

Thank you!

The paper deserves to be published after some revisions. My main concern is related to the introduction. This section needs a major reorganization, since there is no a literature of review about the parasites studied. There are parts of the introduction that fits more on the material and methods section.

We are very grateful to Reviewer for the careful review of our manuscript.

Minor revisions

Line 39: delete “etc”

We deleted “etc” and re-wrote the sentence: <…> across Palearctic North territories: Arkhangelsk Oblast (including Novaya Zemlya archipelago), Karelia and Sakha Republics, Kola, Yamal, Taimyr, and Chukotka Peninsulas, Bering, Svalbard, and Wrangel Island; <…>

Line 41: delete “obtained”

Deleted

Lines 50-52: this first phrase of introduction is more adequate to material and method section. Please, moved it or rephased it.

We re-wrote the introduction as follows:

The relatively low biodiversity of terrestrial animal taxa is a hallmark of Polar regions [1, 2], but this pattern is not obvious for the parasites of Arctic ruminants [3]. Possibly, there are geological and biological factors that influence the diversity of ruminant parasites in the Northern Palearctic. For example, the continuity of the tundra throughout the area allows animals to move freely: mountain ranges are rare and low, and large rivers are covered with ice for most of the year. In the Pleistocene, the ice sheet was located only in the west of the Palearctic [4, 5], and the rest of the territory was continuously inhabited by ruminants. Human activities (including the work of herdsmen, hunters, biologists, and veterinarians) can also have an impact on parasite diversity and distribution. The presence of only three main ruminant species: reindeer (Rangifer tarandus) [6–10], muskox (Ovibos moschatus) [11, 12], and snow sheep (Ovis nivicola) [13, 14,] facilitates the analysis of possible helminth exchange in Palearctic North. Reindeer occupy this territory fairly evenly in contrast to the more limited distribution of snow sheep. Muskoxen became extinct in the Palearctic in the Late Pleistocene (12,000 years ago) and have only recently been reintroduced from the Nearctic (1970ss) [15–17], and their range is still expanding. The aim of this study is to obtain reference data for further monitoring, as this Arctic area is now undergoing active transformation due to climate warming, use of mineral resources, development of transport logistics, etc. Previous helminthological studies were carried out more than 60 years ago [18] for reindeer (mostly domestic) [19] and snow sheep [13, 14], and, to authors’ knowledge, never for muskoxen in Russia. Also, these studies never included DNA analysis (because it was not available at the time), and their results were mostly published in Russian journals and conference proceedings, including so called grey literature [20]. We aim to fill this gap and provide the English-speaking reader the current state of the helminth fauna of selected wild ruminants in the Russian Arctic.

Line 211: delete “That is”

Deleted

Author Response File: Author Response.docx

Reviewer 2 Report

The paper "Diversity and Distribution of Helminths in Wild Ruminants of the Russian Arctic: Reindeer (Rangifer tarandus), Muskoxen (Ovibos moschatus), and Snow Sheep (Ovis nivicola)" is interesting and brings important new data to scientific field.

It is generally well written and I find it to be suitable for publication, but several small changes have to be done before:

Please add a general conclusion in the manuscript.

The use of (?) is very confusing. Please try and remove these all over the text.

Author Response

We are very grateful to Reviewer for the careful review of our manuscript.

It is generally well written and I find it to be suitable for publication, but several small changes have to be done before:

Please add a general conclusion in the manuscript.

We added the following:

5. Conclusion

The diversity of helminths in wild and semi-wild reindeer, muskoxen, and snow sheep was studied using a non-invasive method (coproscopy). In R. tarandus, two genera of trematodes (Paramphistomum and Dicrocoelium) were found, as well as one genus of cestodes (Moniezia), and various nematodes: small gastrointestinal nematodes, Marshallagia sp., Nematodirus spp. (3 different morphological types), Nematodirella sp. (including N. longissimespiculata), Skrjabinema tarandi, Trichuris sp., Capillaria spp., (possibly) Ascaris mosgovoyi, Dictyocaulus sp., Elaphostrongylus rangiferi, Orthostrongylus sp. (possibly, O. macrotis), and Varestrongylus eleguneniensis. A micrograph of what we believe to be A. mosgovoyi is presented for the first time. This is the first report of V. eleguneniensis in the Palearctic. This is also the first report of Orthostrongylus sp. both in relation to R. tarandus and to the Palearctic.

In O. moschatus, no trematodes, one genus of cestodes (Moniezia), and various nematodes (small GIN, Nematodirus sp., Nematodirella sp., Trichuris sp., and DSL of Protostrongylidae) were found.

In O. nivicola, no trematodes, one genus of cestodes (Moniezia), and various nematodes (small GIN, Marshallagia sp., Nematodirus sp., Trichuris sp., Capillarid-type, and Protostrongylus spp.) were found. This is the first report of a Capillarid-type nematode (and its egg micrograph) in show sheep.

 

The use of (?) is very confusing. Please try and remove these all over the text.

We removed all the question marks from the text. When it was related to: 1) Orthostrongylus macrotis and Ascaris mosgovoyi, we added “Possibly”; 2) Protostrongylus sp. and Bdelloid rotifers, we just deleted “?”; 3) “size” (in the beginning of Discussion), we added “host-”.

Author Response File: Author Response.docx