Publication Date:
2019-07-16
Description:
Determination of basic population parameters in long-lived crustacea is hindered by the lack of appropriate methods for age determination. This study uses the pigment lipofuscin as an age marker in the common Antarctic decapod Notocrangon antarcticus from the Eastern Weddell Sea. Resin brain sections of the lateral somacluster of the olfactory lobe of 189 specimens were digitally recorded by confocal microscopy and images were subsequently analysed. A modal progression analysis of the lipofuscin concentration frequency distribution revealed a total of eight regularly-spaced modes presumed to reflect consecutive annual age classes. All eight modes contained females and the first four contained males. No regular modes were obvious in the comparable length-frequency distribution. The average yearly pigment accumulation was nearly linear and estimated as 0.02 % area fraction per year, which is considerably lower than rates published for species from lower latitudes. This is probably explained by the effect of low water temperature on metabolism and lipofuscin accumulation rate. The growth parameters CL* and k from the von Bertalanffy growth function were 22.3 mm CL and 0.79 for females, respectively, and 16.9 mm CL and 0.64 for males, respectively. Mortality and P/B ratio, estimated from catch curves, amounted to 0.44 per year in females and 0.92 per year in males, whereas P/B, calculated from the mass specific growth rate method, was slightly lower. The results indicate that the lipofuscin-inferred population parameters are an improvement compared to what can be learned about N. antarcticus with traditional methods.
Repository Name:
EPIC Alfred Wegener Institut
Type:
Article
,
isiRev
Format:
application/pdf
