FEEDING, DISTRIBUTION, AND REPRODUCTIVE-BEHAVIOR OF CYAMIDS (CRUSTACEA, AMPHIPODA) LIVING ON HUMPBACK AND RIGHT WHALES

Cyamids are little-known amphipod crustaceans that live only on cetace ans. Specimens were collected from strandings of three right whales (E ubalaena glacialis) and one humpback whale (Megaptera novaeangliae). T he intestinal contents of cyamids from the humpback whale indicated th at they feed on a layer of whale skin containing pigment. The single s pecies of cyamid from the humpback whale had a male-biased sex ratio ( 70% male) and its distribution indicated that males were competing for access to females. Two species of cyamids from the callosities of rig ht whales occurred in different microhabitats. No reproductive synchro ny was found between cyamids and their hosts. A species of cyamid that occurs in large patches on the head of young right whale calves disap pears from the head when calf growth slows at approximately 2 months o f age; this habitat shift may indicate a change in the quality or quan tity of new skin.