TY - JOUR
T1 - Diet composition and feeding habits of the pelagic thresher shark Alopias pelagicus in Eastern Central Pacific Ocean, Ecuadorian waters
AU - Calle-Morán, Marcos D.
AU - Galván-Magaña, Felipe
N1 - Funding Information:
MDCM thanks Mexico's Consejo Nacional de Ciencia y Tecnología (CONACYT) for the graduate scholarship granted to study and gaining my Master degree. This paper is derived from my Master's thesis.
Publisher Copyright:
© Marine Biological Association of the United Kingdom 2020
Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2020/8/1
Y1 - 2020/8/1
N2 - The diet and feeding habits of the pelagic thresher shark Alopias pelagicus were analysed based on 104 stomachs (N = 84 females, 20 males) collected off Santa Rosa de Salinas, in the Ecuadorian Pacific. The sharks were caught between February 2008 and January 2009 in artisanal fisheries. The trophic spectrum of A. pelagicus included 19 prey items (10 cephalopods and 9 teleost fishes), the main four prey were the red flying squid Ommastrephes bartramii, jumbo squid Dosidicus gigas, the purpleback flying squid Sthenoteuthis oualaniensis and the South Pacific hake Merluccius gayi. The trophic niche was narrow (Bi = 0.2), thus the pelagic thresher could be considered a specialist predator. The analysis of dietary overlap showed high similarity between the diets of females and males (Cλ = 0.99), immature and mature females (Cλ = 0.81), immature and mature males (Cλ = 0.72), sizes of 141-230 cm TL and 231-321 cm TL (Cλ = 0.97), as well as sharks in rainy season and dry season (Cλ = 0.77). Using canonical of correspondence analysis (CCA), we found similarities in the diet for all categories recorded (sex: canonical r = 0.38, P = 0.97; sexual maturity stage: canonical r = 0.54, P = 0.31; sizes: canonical r = 0.55, P = 0.26; seasons of the year: canonical r = 0.61, P = 0.75). The trophic level estimated for A. pelagicus was 5.0, which is typical of top predators (quaternary consumers or tertiary carnivores).
AB - The diet and feeding habits of the pelagic thresher shark Alopias pelagicus were analysed based on 104 stomachs (N = 84 females, 20 males) collected off Santa Rosa de Salinas, in the Ecuadorian Pacific. The sharks were caught between February 2008 and January 2009 in artisanal fisheries. The trophic spectrum of A. pelagicus included 19 prey items (10 cephalopods and 9 teleost fishes), the main four prey were the red flying squid Ommastrephes bartramii, jumbo squid Dosidicus gigas, the purpleback flying squid Sthenoteuthis oualaniensis and the South Pacific hake Merluccius gayi. The trophic niche was narrow (Bi = 0.2), thus the pelagic thresher could be considered a specialist predator. The analysis of dietary overlap showed high similarity between the diets of females and males (Cλ = 0.99), immature and mature females (Cλ = 0.81), immature and mature males (Cλ = 0.72), sizes of 141-230 cm TL and 231-321 cm TL (Cλ = 0.97), as well as sharks in rainy season and dry season (Cλ = 0.77). Using canonical of correspondence analysis (CCA), we found similarities in the diet for all categories recorded (sex: canonical r = 0.38, P = 0.97; sexual maturity stage: canonical r = 0.54, P = 0.31; sizes: canonical r = 0.55, P = 0.26; seasons of the year: canonical r = 0.61, P = 0.75). The trophic level estimated for A. pelagicus was 5.0, which is typical of top predators (quaternary consumers or tertiary carnivores).
KW - Alopias pelagicus
KW - Dietary overlap
KW - Ecuador
KW - Pelagic thresher shark
KW - Trophic level
KW - Trophic niche width
UR - http://www.scopus.com/inward/record.url?scp=85093863752&partnerID=8YFLogxK
U2 - 10.1017/S0025315420000569
DO - 10.1017/S0025315420000569
M3 - Artículo
AN - SCOPUS:85093863752
SN - 0025-3154
VL - 100
SP - 837
EP - 845
JO - Journal of the Marine Biological Association of the United Kingdom
JF - Journal of the Marine Biological Association of the United Kingdom
IS - 5
ER -