Growth production of two notothenioid fish species from different geographical regions of the Antarctica

• Main Author: Wetjen, Maj
• Format: Thesis
• Language: unknown
• Published: 2013
• Subjects: Antarctic; South Shetland Islands; The Antarctic; Weddell; Weddell Sea; Antarc*; Antarctica
• Online Access: https://epic.awi.de/id/eprint/43106/; https://epic.awi.de/id/eprint/43106/1/Master_Maj.pdf; https://hdl.handle.net/10013/epic.49596; https://hdl.handle.net/10013/epic.49596.d001

To date, the ecology and in particular mechanisms influencing the growth and the distribution of Antarctic fish are still poorly understood. This study provides data about the age and growth of two dominant notothenioid fish species: the pelagic keystone species Pleuragramma antarcticum and the benthopelagic species Trematomus eulepidotus. Fish were sampled from different geographical regions of the Antarctic waters during expeditions with the research vessel POLARSTERN in 2003/2004, 2011, and 2012. Age was determined by sagittal otolith increment analysis. By applying the von Bertalanffy growth formula, growth curves for both species from the different study sites of the Antarctica were generated in order to assess their growth performance. Analysis revealed a maximum age of 13 years for P. antarcticum and 19 years for T. eulepidotous. Both species had relatively slow growth with growth coefficients (k) of 0.16 – 0.25 for P. antarcticum and 0.11 – 0.23 for T. eulepidotus and neither grew especially large. Nevertheless, T. eulepidotus achieved larger maximum lengths than P. antarcticum overall. Both species had significantly higher growth rates and a better nutritional condition at lower latitudes of the South Shetland Islands compared to the more southern areas of the eastern Weddell Sea. In this study, growth performances of the two species from different geographical areas are presented and compared both intra- and interspecifically. After Ccomparing these data, it is evident that both species grow faster at higher annual mean temperatures. Furthermore, fast growth coefficients were associated with lower maximum ages and therefore, seem to reduce the longevity of fish.