Feeding ecology of the piked spurdog Squalus megalops (Chondrichthyes: Squalidae) in the Gulf of Gabès (central Mediterranean Sea)
Sondes Marouani A B , Hasna Kadri A , Sami Karaa A and Mohamed Nejmeddine Bradai A
+ Author Affiliations
- Author Affiliations
A National Institute of Sciences and Technologies of the Sea (Center of Sfax), PO Box 1035, Sfax 3018, Tunisia.
B Corresponding author. Email: sondesmarouani@yahoo.fr
Marine and Freshwater Research 69(1) 48-55 https://doi.org/10.1071/MF17018
Submitted: 25 January 2017 Accepted: 21 July 2017 Published: 26 September 2017
Abstract
The present study investigated the feeding ecology of the piked spurdog (Squalus megalops) in the Gulf of Gabès (Tunisia) with regard to sex, size class and season. A study of stomach contents from the 630 individuals examined showed that the species consumed teleosts (percentage index of relative importance (%IRI) = 80.32), cephalopods (%IRI = 11.96) and crustaceans (%IRI = 7.68). A three-factor multivariate analysis of variance (MANOVA) demonstrated significant differences in diet related to size, season and sex. Trophic position analysis revealed that S. megalops is a secondary consumer throughout its life. Quantitative analysis indicated that the species is a generalist feeder with an ontogenetic change in preferred prey from crustaceans to teleosts. The niche breadths of S. megalops in both sexes were broad.
Additional keywords: dietary shift, trophic niche.
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