Identifying predators of the SW Atlantic Patagonian scallop Zygochlamys patagonica using stable isotopes

Spatial distribution, biomass and size structure of Ctenodiscus australis (Echinodermata: Asteroidea) in shelf-break areas, Argentine

“…As this species is a deposit feeder, the relationship between feeding mode and productive environment helps to explain the registered biomass in more septentrional areas of distribution in the Argentine Sea. Although other studies, developed with stable isotopes, showed that scallops and ophiuriods are important items in the diet of C. australis (Botto et al 2006), we suggest that C. australis is feeding on sediments enriched with discards of the scallop fishery, mainly scallop soft tissues and ophiuroids, dominant taxa in the study community (Bremec & Lasta 2002;Bremec et al 2006).…”

“…Depth was selected because of its importance in echinoderm distribution (Ventura & da Costa Fernandes 1995;Howell et al 2002;Kim & Thurber Ctenodiscus australis in shelf-break areas, Argentine 609 2007). Patagonian scallop biomass was selected as it is related to fishing effort and considering discards could be a feeding source to C. australis (see Botto et al 2006). Pearson correlations between variables were computed before the analysis.…”

“…King & Broderip, 1832) fishing grounds has been broadly studied (Bremec et al 2000Bremec & Lasta 2002;Botto et al 2006;Schejter & Bremec 2007). These fishing grounds have been exploited by factory vessels since 1996; catches in the order of 50,000 tons year (1 rank this species among the most important scallop fishery in the world (Ciocco et al 2006).…”

“…It is a characteristic species of the Magellanic Biogeographic Province (Bernasconi 1964;Bastida et al 1992), distributed from Southern Brazil (238S) to eastern Tierra del Fuego and Malvinas Islands, at a depth range of 70Á700 m (Clark & Downey 1992). C. australis is considered a mesopredator, mainly on scallops and ophiuroids, after a stable isotopes study about trophic relationships in the benthic community dominated by Zygochlamys patagonica (Botto et al 2006). Furthermore, C. australis is a brood-protecting asteroid that hides its young under the paxillaes (Lieberkind 1926;Bernasconi 1941).…”

Identifying environmental constraints at the edge of a species’ range: scallop Psychrochlamys patagonica in the SW Atlantic Ocean

“…Considering these water masses with contrasting thermohaline characteristics, the species' northern border of distribution could be primarily explained by the strong gradient occurring at this oceanographic discontinuity. Several macroinvertebrates, such as the gastropods Odontocymbiola magellanica and Adelomelon ancilla (common predators of Psychrochlamys patagonica: Botto et al 2006), also have the same northern border of distribution in the SAO (Olivier & Scarabino 1972). Thermohaline gradients have been associated with biogeographic boundaries worldwide, constraining species' geographical ranges (Wilson et al 1996, Gaylord & Gaines 2000.…”