Mother-offspring recognition and kin-preferential behaviour in the crayfish Orconectes limosus

Kin recognition and helping behaviour directed towards kin may be adaptive in many ecological contexts. In freshwater crayfish, maternal females engage in extended care of juveniles, and protect dependent juveniles from predation and cannibalism. However, the relationships between mothers and recently independent offspring have been understudied. Here, I report evidence that juveniles that have been independent of their mothers for >= 10 days are able to discriminate between their own mothers and unfamiliar maternal females, and prefer to associate with their own mothers when offered a choice. In addition, I report that mothers are significantly less likely to cannibalise their own young than the young of other females, even >= 10 days after being separated from their independent offspring. In addition, males were significantly more likely to cannibalise juveniles than recently maternal females, even when those juveniles were not the females' own offspring. This may be attributable either to a reduced propensity for cannibalism by females, or higher energetic requirements by males. In summary, the extended preferential behaviour by females towards their own juveniles suggests that kin relationships may be maintained for longer than the period of active maternal care in Orconectes limosus, and the implications of this behaviour on population structure warrant further investigation.