Status of the veined rapa whelk Rapana venosa (Valeciennes, 1846) population in the north-eastern Black Sea
Based on the results of long-term expeditions carried out to assess the state of Rapana venosa population in the north-eastern Black Sea, some negative changes in the rapa whelk population caused by poor trophic conditions were revealed: their density, biomass and the number of age groups decreased and length and weight parameters declined. The distribution density of the rapa whelk in the biotope and the dynamics of its biomass are found to have changed during the studied period, while the distribution was of a mosaic nature and determined by the trophic supply of the bottom biocenosis. Dynamics analysis of the density and biomass of R. venosa put together with the physiological indices (fatness factor, relative shell thickness) showed their interannual fluctuation in 2011–2015. The results obtained indicate that the current state of R. venosa should be considered as permamently depressed. The population suffers an acute shortage of food organisms, moreover, high food competition is observed within the species. Under these conditions, the population of R. venosa is represented by a large number of small-sized individuals which are of no interest to commercial fishing.
| Main Authors: | , |
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| Other Authors: | |
| Format: | Journal Contribution biblioteca |
| Language: | Russian |
| Published: |
2018
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| Subjects: | Rapana venosa, Long-term records, Population dynamics, Biomass, Age groups, Population density, Food organisms, Food competition, Fatness factor, Mollusc physiology, |
| Online Access: | http://hdl.handle.net/1834/14690 |
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