Two types of maternal care for juveniles observed in Caprella monoceros Mayer, 1890 and Caprella decipiens Mayer, 1890 (Amphipoda: Caprellidae)

Abstract

The juveniles of Caprella monoceros after emerging from the brood pouch cling to their mother's body for 16.0 days. The juveniles molt and grow at least four times while on their mother. The mother often grooms her juveniles with 1st gnathopods, and defends the juveniles from other caprellids. Even after moving from the mother's body to a seaweed substratum the juveniles stay near their mother for more than 10 days, and are often picked up and carried by their mother when she moves away. On the other hand, the juveniles of Caprella decipiens after emerging from the brood pouch do not cling to their mother, but immediately move to the seaweed substratum around the mother and stay there to molt and grow for 32.5 days. The juveniles are defended by their mother. Only at the time when their mother moves away, juveniles cling to the mother and are carried to other places. During the maternal care period, moltings of mothers seem to be suppressed in C. monoceros, while mothers of C. decipiens continue to molt. The females of C. monoceros mature at a smaller size and produce fewer eggs than C. decipiens.