Trophic ecology of the Patagonian skate, Bathyraja macloviana, on the Argentine continental shelf

Abstract

When this article was originally published the legend for Figure 1 was incorrect. The correct legend and figure are printed below. The publisher regrets this error. 66°64°62°60°58°56°54°W 44°4 2°4 0°3 8°N Mar del Plata San Matías Gulf 200 m 100 m 50 m S o u t h w e s t e r n A t l a n t i c O c e a n South America Figure 1. Map of the study area on the northern Argentine continental shelf, showing bottom trawl locations where Patagonian skate, Bathyraja macloviana, were not (open squares) or were (filled squares) caught. The rectangle in the inset represents the study area.

Food habits of the rough rayRaja radula(Chondrichthyes: Rajidae) from the Gulf of Gabès (central Mediterranean Sea)

“…This indicates that males and females occupy similar areas or encounter similar prey. Similar findings have been reported for other skates (Braccini & Perez 2005;Scenna et al 2006;San Martín et al 2007).…”

“…The percentage of empty stomachs of R. radula captured in the Gulf of Gabès as well as in the Gulf of Tunis (VI = 24.64%; Capapé & Azouz 1975), was relatively high compared to the percentage on dietary studies of small skates (Smale & Cowley 1992;Ellis et al 1996;Scenna et al 2006;Rinewalt et al 2007). The high percentage of empty stomachs may reflect a short period of feeding followed by periods of rapid digestion.…”

“…A generalist predator has a broad dietary niche, whereas the food niche of a specialist is narrow. Many skates are classified as specialist feeders (Ebert et al 1991;Braccini & Perez 2005;Scenna et al 2006;San Martín et al 2007), whereas, several others species are considered to be generalist feeders (Smale & Cowley 1992;Koen et al 2001). On the other hand, the index of importance and Shannon-Weiner diversity index indicated that a wider variety of prey items were consumed as rays change in size suggesting that large specimens of R. radula are a specialized predator.…”

Hábitos alimentarios de la raya de cola corta, <i>Bathyraja brachyurops</i> (Chondrichthyes, Rajidae), en el Atlántico Sudoccidental

“…The diet of five species of Bathyraja have been briefly described on the Argentinean continental shelf (Sánchez and Mabragaña, 2002), and only the feeding habits of the Patagonian skate B. macloviana have been thoroughly studied (Mabragaña et al, 2005;Scenna et al, 2006). Brickle et al (2003) provided some data on diet composition of B. albomaculata, B. brachyurops and B. griseocauda around the Malvinas Islands.…”

From coexistence to competitive exclusion: can overfishing change the outcome of competition in skates (Chondrichthyes, Rajidae)?

“…On the other hand, B. macloviana is the smallest species of the genus in the southwestern Atlantic, reaching 67 cm in total length and matures at 5-6 years (Bücker, 2006). Both species are specialized feeders, being polychaetes their dominant prey (Mabragaña et al, 2005;Scenna et al, 2006;Ruocco et al, 2009), which results in a high dietary overlap suggestive of a potential competitive interaction between them (Brickle et al, 2003). Thus, B. albomaculata and B. macloviana are a good model system to study the competitive release hypothesis in skates because both species suffer a similar fishing pressure, potentially overlap in the use of some resource (i.e.…”