Differences in the timing of egg extrusion and reproductive investment between primiparous and multiparous females of the southern king crab Lithodes santolla

Abstract

This study analysed differences in the timing of egg extrusion, reproductive investment and spatial distribution between primiparous and multiparous females of the southern king crab (SKC) Lithodes santolla. Early publications had reported that, in the San Jorge Gulf (SJG; 45–47°S), Argentina, SKCs mated annually, mainly in December. In this work, in coastal areas of SJG, we found small females in postmoult with recently extruded eggs in September–October. At the same time, one SKC female fraction was in intermoult with eggs close to hatching. Evidence suggests that females with recently extruded eggs were primiparous, while females with eggs close to hatching were multiparous. Primiparous females were less fecund than multiparous females of the same size, but no differences were found in the egg dry mass between these female fractions. The size-frequency distribution observed suggests a spatial segregation between primiparous and multiparous females, with the former being concentrated in the coastal areas of SJG. Differences in reproductive traits between primiparous and multiparous females have been widely reported in crab species with determinate growth, but rarely in crabs with indeterminate growth as lithodids.