Биологическая характеристика пурпурного кальмара Sthenoteuthis oualaniensis (Lesson, 1830) в верхнем звукорассеивающем слое северной части Аравийского моря
Based on the trawl catches (January 1990), the population of purpleback flying squid Sthenoteuthis oualaniensis in the upper SSL (depths ranging from 0 to 120 m) was studied in the northern part of the Arabian Sea during the night time. Altogether, 48 trawl surveys were performed, 628 squid specimens were analyzed, and 1,028 of ind. were measured. Data on length composition and other biological properties made it possible to determine that the squid population is not homogeneous. Average length of squids increases with the depth: small squids prevail at the depths from 41 to 60 m, and the larger ones – at the level of 81-100 m. As depth increases, specific abundance of small and large squids fluctuates in phase opposition; however, the number of both groups decreases at the SSL lower limit. Throughout the entire SSL, mature males prevail over immature ones in abundance; their share increases with the depth increase. Immature females prevail at the depths from 0 to 80 m; their abundance is twice as much as of mature ones. At the range from 81 to 120 m, the structure of developmental stages of females changes, and the number of mature and immature ones gets almost equal. Sex ratio at every level is close to 1:1, excluding the range of 81-100 m, where the number of females is twice as high as of males. Fish is the main food source for squids at every depth range, including lanternfish, which were recorded most often in the upper SSL. Other food sources were crustaceans, including swimming crabs, which were reported in the medium and lower areas of the SSL; and cephalopods, which were found in squid stomachs throughout the entire SSL, more often – in the lower and upper layers. In order to assess stocks of purpleback flying squids in the northern part of the Arabian Sea using a midwater trawl as a fishing gear and applying a direct method, it is practical to operate in the lower part of the SSL at the depths range from 80 to 120 m, where large squids prevail in abundance.
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| Format: | Conference Material biblioteca |
| Language: | Russian |
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Kerch Branch ("YugNIRO") of FSBSI "AzNIIRKH"
2017
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| Subjects: | Sthenoteuthis oualaniensis, Purpleback flying squid, Length composition, Sex ratio, Food organisms, Stomach content, Stock assessment, Trawl surveys, Sexual maturity, Abundance, Vertical distribution, Sound scattering layer, |
| Online Access: | http://hdl.handle.net/1834/11061 |
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