LIFE HISTORY ASPECTS OF LEPTOCLINUS MACULATUS (STICHAEIDAE: LUMPENINAE) IN NORWEGIAN ARCTIC WATERS
Camilla Ottesen1, Svetlana A. Murzina2, Haakon Hop3, Stig Falk-Petersen3,
Jorgen Schou Christiansen1
1University of Tromso, N-9037 Tromso, Norway, e-mail: camilla.ottesen@uit.no 2Institute of Biology, Karelian Research Centre RAS, Petrozavodsk, 185640, Russia 3Norwegian Polar Institute, N-9296 Tromso, Norway
The species daubed shanny (Leptoclinus maculatus) is among the most abundant fish species in the epibenthic ichthyofauna of the Arctic waters of Norway, particularly in Svalbard fjords.
Both larvae and adults have been found in relative high abundances along the ice edges inside fjords as well as the ice edgeof North-East Svalbard, and thrive at temperatures below 0°C. This species is likely an important
component of Arctic food chain leading up to seabirds, but the life history of this species is still largely
unknown. This study has resolved several life history aspects, including sex, size and age distribution, growth, age at maturity and reproduction. Samples of L. maculates were obtained from: Kongsfjorden, Isfjorden and its side-branches, Smeerenburgfjorden, Hinlopenstredet and Storfjorden. We also sampled specimens from the north-east ice edge of Svalbard, the southern Spitsbergen and the Barents Sea south to Bjornoya. The sampling extended from April to October, and the material was pooled since there were no significant differences among areas or month of sampling except for reproduction. Leptoclinus maculatus is sexually dimorphic in size, growth and age of maturity. The populations are generally dominated by males. Length-weight relationship revealed that the males grow to a larger size than females (124 mm versus 113 mm), and both sexes have a positive allometric growth. There was no differences in age distribution between the sexes, but size-at-age analysis (von Bertalanffy growth function) showed that males are larger than the females at the same age and achieve a longer asymptotic length than the females. Age at maturity is about 4 years for males and 6 years for females. The gonadosomatic index of females increased from