Diet and daily ration of two nototheniid fish on the shelf of the sub-Antarctic Prince Edward Islands

• Main Authors: Bushula, T, Pakhomov, Evgeny A, Kaehler, Sven, Davis, S, Kalin, R M
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2005
• Subjects: Antarc*; Antarctic; Prince Edward Islands; Copepods
• Online Access: http://vital.seals.ac.za:8080/vital/access/manager/Repository/vital:6948; http://hdl.handle.net/10962/d1011977

The seasonal dietary composition and estimates of daily consumption rate of Lepidonotothen larseni and Gobionotothen marionensis juveniles were obtained for the first time using fish collected near sub-Antarctic Prince Edward Islands during April 1999–2003. The diet of L. larseni consisted mainly of pelagic prey, with copepods and arrow worms making up the most significant prey groups and accounting for 46% and 40% of prey mass, respectively. The diet of G. marionensis was more diverse than that of L. larseni and was composed mainly of benthic prey, including bottom-dwelling decapods (Nauticaris marionis) and sedentary polychaetes, which accounted for 54% and 30% of prey mass, respectively. During the present study, dietary overlap between juveniles of L. larseni and G. marionensis was very low (<5%) indicating that competition for food resources between them was negligible. They not only relied on different prey species, both also exhibited different diel feeding regimes. Daily consumption rate of L. larseni and G. marionensis juveniles was estimated to be 4.5% and 5.2% of body dry mass, respectively. Stomach contents and stable isotope analyses suggested, that both L. larseni and G. marionensis occupy the forth-trophic level of the sub-Antarctic food web but depend mainly on allochthonous and autochthonous (kelp derived) organic matter, respectively.