Diet of striped dolphins (Stenella coeruleoalba) in southern Spanish waters

Abstract

Identifiable food remains were analyzed from 46 stomachs of striped dolphins (Stenella coeruleoalba) stranded in southern Spain between 2007 and 2014. Results suggest that the species feeds mainly on mesopelagic and neritic fish, but also on oceanic squids. Fish species of the family Myctophidae were the main prey in terms of numerical importance and reconstructed prey weight (62% N and 29% W), followed by squids of the family Ommastrephidae (20% W) and bogue (Boops boops) (15% W). The most important prey taxa according to the General Importance Index (GII) were C. maderensis, Ommastrephidae gen. spp., Notoscopelus spp., and M. punctatum. Higher number of mesopelagic myctophids were found in dolphins from the Mediterranean (73% vs. 29% N), while more demersal gobiids and European hake (Merluccius merluccius) were found in those from the Atlantic (44% vs. 1% and 8% vs. <1% N), where a more varied diet was also observed. Differences were also seen in the seasonal importance of some prey, as well as between years, sexes, and maturity states. The diet composition suggests that most of feeding occurred in oceanic regions, during twilight and night hours, while the observed dietary variation may reflect differences in topography, and changes in the prey availability.

Social and community structure of striped dolphins in a semienclosed Mediterranean embayment

“…Deep‐water squid tend to come closer to the surface at night than in daytime, in association with the Deep Scattering Layer (DSL; Benoit‐Bird et al, 2017; and see Benoit‐Bird et al, 2009 for spinner dolphins Stenella longirostris in Hawaii and dusky dolphins Lagenorhynchus obscurus in New Zealand). Information from 46 stomach contents of striped dolphins stranded along the Mediterranean coast of Spain between 2007 and 2014 was also suggestive of most feeding occurring during twilight and night hours (Saavedra et al, 2022). Based on existing information, however, it is difficult to assess the influence of diet, prey species, prey availability, and foraging behavior on the group size and association patterns of striped dolphins.…”

Amphiatlantic Dolphins’ Prey: Indicators of Speciation, Trophic Competition and Global Warming? A Review

“…There are numerous studies that analyze the stomach contents of Tt [27][28][29], Dd [30][31][32][33] and Sc [34][35][36][37]. Some studies only analyze fish as prey species [27], others only cephalopods [34,38] and others also account for crustaceans [39,40].…”