MORBILLIVIRUS INFECTION IN BOTTLENOSE DOLPHINS: EVIDENCE FOR RECURRENT EPIZOOTICS IN THE WESTERN ATLANTIC AND GULF OF MEXICO

Morbillivirus infection is widespread among odontocetes of the western Atlantic and Gulf of Mexico. Serologic evidence of infection in bottlenose dolphins, Tursiops truncatus , was first detected during an epizootic along the mid-Atlantic coast in 1987. Here, we report recurrent epizootics in the coastal dolphin population since at least the early 1980s based on serological surveys and regional stranding frequencies. The first observed epizootic of this series occurred in the Indian and Banana Rivers in 1982 and was followed by others on the mid-Atlantic coast in 1987–1988 and in the Gulf of Mexico between 1992 and 1994. This temporal pattern of infection is likely facilitated by the population size and its fragmentation into relatively discrete coastal communities. Introduction of morbillivirus into a community with a sufficient number of naive hosts may precipitate an epizootic, depending on the potential for transmission within the group. Propagation of an epizootic along the coast is probably determined by frequency of contact between adjacent communities and seasonal migrations.
Morbillivirus antibodies were also detected in serum from offshore bottlenose dolphins. The sero-prevalence in the latter may be higher than in coastal dolphins because of their close association with enzootically infected pilot whales ( Globicephala spp.). Occasional contact between offshore and coastal dolphins may provide an epizootiologic link between pilot whales and coastal dolphin communities.     

STOMACH CONTENTS OF LONG-FINNED PILOT WHALES (GLOBICEPHALA MELAS) STRANDED ON THE U.S. MID-ATLANTIC COAST

Ten prey taxa were recorded from the stomach contents of eight long-finned pilot whales ( Globicepbala melas ) independently stranded along the U.S. mid-Atlantic coast. Relative importance of prey species was determined by methods that incorporate prey frequencies of occurrence, proportions of numerical abundance, and proportions of reconstructed mass. Separate analyses of trace (free, durable body parts representing well-digested prey items) and non-trace (relatively intact prey specimens) food material were conducted in order to address biases caused by differential rates of digestion and passage through the gastrointestinal tract. Different measures of prey importance yielded varying results, but the long-finned squid ( Loligo pealei ) was the most important prey species regardless of how prey importance was defined. Fishes were relatively unimportant in the diet. Our results indicate that the diets of western North Atlantic long-finned pilot whales differ substantially from what has been previously reported in the literature and that results from food-habits studies that utilize different techniques may not be comparable.     

SYSTEMATICS OF ANADYOMENE SPECIES (ANADYOMENACEAE,CHLOROPHYTA) IN THE TROPICAL WESTERN ATLANTIC1

Three new species of Anadyomene are described. Anadyomene lacerata has pinnately branched veins and a unique lacerated margin formed by elongated vein cells. Anadyomene linkiana consists of a perforate blade arising by polychotomous branching from a distinct stripe, and A. howei has an eperforate, delicate blade of polychotomously branched cells and a smooth margin of elongated vein cells. Distinguishing features of the five previously described species are clarified, and all eight taxa are illustrated. Observations in the field and from more than 400 herbarium specimens form the basis for a discussion of Indo-Pacific affinities, ecological adaptations, cell division, reproduction, and ordinal status. A phylogenetic analysis based on 17 equally weighted characters produced a cladistic gradation, indicating that Anadyomene is a monophyletic genus. The most basal species (A. saldanhae, A. linkiana, A. howei, A. menziesii) show only polychotomous branching. In contrast, the distal group (A. pavonina, A. stellata, A. rhizoidifera, A. lacerata) have pinnate interstitial cells along the veins in addition to polychotomous branching at the vein apices.