Плодовитость синего краба в северной части Охотского моря

Abstract

The absolute, relative individual, and relative population fecundity (average number of eggs per ovigerous female) in ovigerous females of the blue king crab ( Paralithodes platypus ) from the northern part of the Sea of Okhotsk were analyzed. The absolute fecundity varied from 15 000 to 181 900 eggs per female and increased with the body size in all areas under study. The maximum upper values of absolute fecundity were registered near the bank and Iony Island, as well as in the Shelikhov Gulf. The minimum upper values were recorded near Cape Khanyangda. Equations describing the dependence “fecundity - carapace width” were provided for every investigated area. For same-sized females, the absolute fecundity was higher in the Shelikhov Gulf and lower near Cape Khanyangda. The relative individual fecundity varied from 56 to 205 eggs per 1 g of specimen body weight. The mean values of relative fecundity within the studied areas differed insignificantly. The relative population fecundity decreased from east to west along the coast of the Sea of Okhotsk, from the bar of the Gulf Shelikhov to Cape Khanyangda. Its maximum and minimum values were 87 300 and 39 500 eggs, respectively. The relative population fecundity of P. platypus from the bank of Iony Island was not subject to clinal variability due to the specific hydrological conditions of the area. The mean reproductive effort varied slightly between the studied areas and equaled 9.0-10.8%. The average width and length of purple and eyed eggs were 1.05 and 1.21 mm and 1.21 and 1.43 mm, respectively.