Biology and Ecology of Squalus Blainville (Risso, 1827) from the Eastern Mediterranean

Biology and Ecology of Squalus Blainville (Risso, 1827) from the Eastern Mediterranean

Elizabeth Grace Tunka Bengil

ABSTRACT:

The objective of this study is to contribute to the knowledge gap on the biology of the longnose spurdog, Squalus blainville (Risso, 1827), that has very scarce information in the Levantine Sea, eastern Mediterranean Sea. This study utilized opportunistic sampling methods to fill information gaps without causing more damage or stress to a threatened species. Moreover, it provides information on longnose spurdog’s biological and ecological features from by-catch individuals. In this regard, a total of 184 individuals, 99 females and 85 males, at different maturity stages were examined. Among these individuals 66 (44 females, 32 males) had prey items in their stomach and the main food source was identified as teleosts (IRI % 63.55), and cephalopods (IRI % 22.38) and crustaceans (IRI % 12.78) were identified as a secondary food group. Trophic levels were estimated as 4.28, 4.13 and 4.05, for the datasets of all, female, and male, respectively. The information produced in this study is an important base line for regional assessment or for conservation measures for the species. Besides providing information on a data deficient species, this study also shows that the opportunistic method, utilizing landed by-catch individuals, produces information for scientific purposes and can be practical and effective to assess regional status as well as develop species-specific measures in regional scale.

Thalassas (2022), DOI: 10.1007/s41208-022-00482-w

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