Age and reproduction in two Antarctic plunderfishes (Artedidraconidae) from the Weddell Sea.

The Antarctic plunderfishes (Artedidraconidae) are a poorly known component of the bottom fish fauna inhabiting the continental shelf of the High Antarctic Zone. Biological data on these fishes are still rather scarce and generally based on only a few specimens. To increase the knowledge of this group, we investigated the reproductive biology and population age structure of Artedidraco skottsbergi and Dolloidraco longedorsalis, the most abundant plunderfishes collected during the 2013/2014 expedition of the RV Polarstern in the Weddell Sea. Based on macroscopic and histological analyses, we found that both species exhibited prolonged gametogenesis and produced few eggs. Estimates of absolute and relative fecundity were lower in A. skottsbergi than in D. longedorsalis, ranging from 69 ± 7 oocytes per female and 11.4 ± 4.3 oocytes/g, and from 209 ± 73 oocytes per female and 13.5 ± 3.7 oocytes/g, respectively. Female size at first spawning was estimated to be 9.5 and 11 cm in A. skottsbergi and D. longedorsalis, respectively. Age and growth were assessed through otolith readings, and estimates of age ranged between 6-14 years in A. skottsbergi and 3-14 years in D. longerdorsalis. The von Bertalanffy growth parameters were only estimated for D. longedorsalis (L = 12.5 cm, k = 0.27, t0 = - 0.06). The results of this study provide insights into some of the biological aspects of these species and shed new light on their life strategies, which show similarities to those of other notothenioids.