Research Article |
Corresponding author: Yuliya V. Bespalaya ( jbespalaja@yandex.ru ) Academic editor: Aleksandr P. Novoselov
© 2018 Yuliya V. Bespalaya, Olga Aksenova, Natalia Zubriy.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Bespalaya YuV, Aksenova OV, Zubriy NA (2018) Molluscan fauna of the lower reaches of the Syoyakha River (Yamal Peninsula). Arctic Environmental Research 18(2): 76-81. https://doi.org/10.3897/issn2541-8416.2018.18.2.76
|
The molluscan fauna of the Syoyakha (Zelenaya) River remain poorly explored even though the Syoyakha is one of the biggest rivers on the Yamal Peninsula. The Syoyakha River is remarkable for its high fish stocking capacity and it plays an important role in the seasonal distribution and migration of commercial fish species. Freshwater mollusks are known to be a major component of freshwater ecosystems and they make up a part of the diet of many commercially important fish species. The species composition of the mollusks inhabiting the lower reaches of the Syoyakha River has been studied. Five bivalve species of the family Sphaeriidae were found, namely Sphaerium corneum (Linnaeus, 1758), Pisidium casertanum (Poli, 1791), P. globulare (Clessin in Westerlund, 1873), P. lilljeborgi (Clessin in Esmark et Hoyer, 1886) and P. dilatatum (Westerlund, 1897). In general, the molluscan fauna of the lower reaches of the Syoyakha River are taxonomically poor, which can be considered typical of freshwater invertebrate communities living at high latitudes. Another reason for the decline in species diversity may lie in the absence of any large transit watercourse in the basin in question allowing northward dispersion of the mollusks. The average density of mollusks in the watercourse stretch under study varied from 98.9 ind./m2 to 620.5 ind./m2. P. globulare settlements had the highest recorded density of 1,442.9 ind./m2. The mollusks are confined to clayey, silty and sandy substrates with remnants of vegetation. The fauna is basically formed by widespread Palearctic and Holarctic mollusk species that have adapted to the extreme conditions of the Arctic. The findings may be used for hydrobiological and fishery characterization of the watercourse given that the recorded species of S. corneum, P. globulare, P. lilljeborgi, and P. dilatatum are a major food item for important fish species, such as cisco, vendace, char, muksun, etc.
Yamal Peninsula, freshwater mollusks, Sphaeriidae , species diversity, Syoyakha River, Arctic.
The ecosystems of the Yamal Peninsula are subject to an intensive anthropogenic influence connected with construction and operation of gas fields (
The first data concerning the composition of the molluscan fauna of water reservoirs on the Yamal Peninsula come from materials collected by the expedition that was organized by the Kuznetsov brothers in 1909 (
Many years of research studies of the freshwater mollusks of the Yamal Peninsula inhabiting the Yuribei River and Lake Yarroto that were undertaken by V.N.
However, the molluscan fauna of the Syoyakha (Zelenaya) River remain poorly explored even though the Syoyakha is one of the largest rivers of the Yamal Peninsula. The watercourse is 165 km long and the watershed covers an area of 4,400 km2 (Bolshakov et al. 1995). The Syoyakha River is remarkable for its high fish capacity and plays an important role in the seasonal distribution and migration of commercial fish species (
The goal of this research was to study the fauna and to analyze the zoogeographical structure of the molluscan fauna in particular in the lower reaches of the Syoyakha (Zelenaya) River.
The Yamal Peninsula is located the Northern part of Western Siberia in the central part of Russia. The Yamal Territory refers to the West Siberian plain (
The mollusk samples of the Yamal Peninsula were collected in the lower reaches of the Syoyakha (Zelenaya) River in July–August 2014 (Fig.
The schematic sampling site map of the study area: А – the schematic study area map, B – sampling sites (the white markers correspond to blank samples (no mollusks found), the grey marker corresponds to samples in which mollusks were found), C – view of the Syoyakha River
The benthic samples were collected using standard methods (
The mollusks were identified according to a number of keys (
The specimens are kept in the collection of the Russian Museum of Biodiversity Hotspots (RMBH) of the N. Laverov Federal Center for Integrated Arctic Research, Russian Academy of Sciences (FCIARtic).
The hydrochemical characteristics of the waters in the Syoyakha River are presented in Table
Species composition and relative abundance of mollusk species in the Syoyakha River samples (Yamal Peninsula). Geographic distribution: PA – Palaearctic, H – Holarctic, C – Cosmopolite, EWS – Europe, Western Siberia.
Species | Geographic distribution | Syoyakha River | |||
Average density (ind./m2)±SD | Density, (ind./m2) min-max | N, ind. | N, % | ||
Sphaerium corneum (Linnaeus, 1758) | PA | 164.8±125.3 | 14.3–435.7 | 300 | 15.9 |
Pisidium casertanum (Poli, 1791) | C | 257.1±175.4 | 107.1–450.0 | 108 | 5.7 |
P. globulare (Clessin in Westerlund, 1873) | EWS | 620.5±504.1 | 71.4–1442.9 | 695 | 36.9 |
P. lilljeborgi (Clessin in Esmark et Hoyer, 1886) | H | 391.6±419.4 | 7.1–978.6 | 603 | 31.9 |
P. dilatatum (Westerlund, 1897) | PA | 98.9±119.4 | 14.3–450.0 | 180 | 9.5 |
Total | 1.886 |
Fives mollusk species of the Sphaeriidae family were found in the lower reaches of the Syoyakha River during the present study (Fig.
Hydrochemical characteristics of the Syoyakha River (Yamal Peninsula, July–August 2014)
Parameters | Syoyakha River |
K+ (mg/l) | 0.53±0.08 |
Na+ (mg/l) | 2.8±0.2 |
Mg2+ (mg/l) | 1.2±0.09 |
CI– (mg/l) | 3.54±0.3 |
SO42– (mg/l) | 1.12±0.08 |
Ca2+ (mg/l) | 2.2±0.2 |
In general, the molluscan fauna of the lower reaches of the Syoyakha River are taxonomically poor compared to the watercourses in both the southern part of Western Siberia (
The reasons for the absence of the gastropod species in the investigated part of the river will require additional studies. It can be assumed that in the lower reaches of the Syoyakha River provide an unsuitable habitat for gastropods.
In general, the bivalves from Syoyakha River are widespread in the Holarctic and Palearctic regions (Table
According to our records, the molluscan fauna of the Syoyakha River are represented by five species of freshwater bivalves of the Sphaeriidae family. The bivalves of the Syoyakha River are widespread Palearctic and Holarctic mollusk species that have adapted to the conditions at high latitudes. The results of research may be used for hydrobiological and fishery characterization of the watercourse given that the recorded species of Sphaerium corneum, Pisidium globulare, P. lilljeborgi, and P. dilatatum are a major food item for commercially important fish species, such as cisco, vendace, char, muksun, etc. (
This research was supported by the Program of the Presidium of the Urals Branch of the Russian Academy of Sciences No. 0409-2018-0148) and grant No. 17-44-290016 р_а of the Russian Foundation for Basic Research.