Diet composition and feeding habits of the crocodile shark
03 June 2022
Diet composition and feeding habits of the crocodile shark, Pseudocarcharias kamoharai
Marcos D. Calle-Morán, Ana R. Hernández-Téllez, Evelyn R. Tibán-Vivar, Yari E. Intriago-Vera, Israel G. Del Valle-Coello, Beatriz C. Loor-Jama, Ángel R. Ganchozo-López
ABSTRACT:
The objective of the present study was to determine the diet composition and feeding habits of the crocodile shark, Pseudocarcharias kamoharai, in Ecuadorian waters, Southeast Pacific Ocean, at a general level, as well as by sex, year, and sexual maturity stage. A total of 401 individuals with their respective stomachs were sampled in the Santa Rosa fishery port, Ecuador; 200 were females and 201 males, with a total length (TL) between 50 to 117 cm and 72.5 to 100 cm, respectively. The number of stomach contents analyzed in this study was sufficient to describe the diet of P. kamoharai, as the asymptote was reached at 100 digestive tracts. A total of 24 prey species were identified, out of which 16 were cephalopods and eight bony fishes. The main identified prey species were the cockeyed squid, Histioteuthis heteropsis, the sharpear enope squid, Ancistrocheirus lesueurii, the purpleback flying squid, Sthenoteuthis oualaniensis, the Jumbo flying squid, Dosidicus gigas, and the neon flying squid, Ommastrephes bartramii. Pseudocarcharias kamoharai was considered a specialist predator that preferred five prey species (Bi = 0.09), and differences were observed by sex, years, and maturity stages. The trophic overlap was high in both females and males (Cλ = 0.98) between the years 2012–2013 and 2017–2018 (Cλ = 0.91), as well as between immature and mature individuals (Cλ = 0.95). The trophic level was Tlk = 4.37, which indicates that this species is a quaternary consumer or a tertiary carnivore.
Environ Biol Fish (2022). DOI: 10.1007/s10641-022-01277-x