Effects of intrinsic and extrinsic factors on the diet of Bathyraja macloviana, a benthophagous skate

Abstract

The effects of intrinsic (sex, maturity stage and body size) and extrinsic (depth and region) factors on the diet of Bathyraja macloviana, in the south-west Atlantic Ocean, were evaluated using a multiple-hypothesis modelling approach. Bathyraja macloviana fed mainly on polychaetes followed by amphipods, isopods and decapods. Effects of intrinsic and extrinsic factors on diet composition of this species were found. The consumption of polychaetes had a humped relationship with total length (L(T), and isopods and decapods increased with increasing L(T). Immature individuals preyed on amphipods more heavily than mature individuals. Furthermore, region and depth had an important effect on the consumption of isopods, decapods and amphipods. Such ontogenetic changes and spatial patterns may provide insights into understanding the regulatory mechanisms of marine communities.

Trophic niche partitioning of five skate species of genus Bathyraja in northern and central Patagonia, Argentina

“…Changes in the diet of skates may depend on intrinsic (i.e., ontogenetic) or extrinsic (i.e., anthropogenic activities) factors (Barbini et al, 2013). Significant intraspecific differences have been found between the feeding habits of mature and immature individuals, suggesting that consumption is conditioned by the size of the individual and the habitat that it occupies depending on the stage of maturity (Belleggia et al, 2008;Bizzarro et al, 2007;Koen Alonso et al, 2001;Sommerville et al, 2011).…”

Ecological singularity of temperate mesopredatory myliobatoid rays (Chondrichthyes: Myliobatiformes)

“…Many skates are known to consume fewer amphipods or polychaetes as they grow (e.g. Orlov 1998;Belleggia et al 2008;Ruocco et al 2009;Barbini and Lucifora 2011, 2012bMain and Collins 2011;Barbini et al 2013;Š antić et al 2013). Among myliobatoid rays, microcrustaceans (such as amphipods) or polychaetes are dominant prey of species in the families Urolophidae and Urotrygonidae (Platell et al 1998;Marshall et al 2008;Flores-Ortega et al 2011;Navia et al 2011;Yick et al 2011;Navarro-González et al 2012;Jacobsen and Bennett 2013), which are generally small (McEachran and de Carvalho 2002b;Last and Stevens 2009), and several dasyatid species consume fewer amphipods or polychaetes with increasing body size (e.g.…”