Morbillivirus in Risso’s dolphins (Grampus griseus): a phylogenetic and pathological study in the Canary Islands

Abstract

The earliest evidence of morbillivirus infection (MI) dates to 1982. Since then, cetacean morbilliviruses have been detected in at least 26 different cetacean species, both mysticetes and odontocetes, causing a wide range of lesions and different mortality rates. In the Canary Islands, these viruses (DMV and PWMV strains) have been detected in different cetacean species, including short-finned pilot whales and bottlenose dolphins. Risso’s dolphins have been reported year-round in the Canary waters and are considered a resident species. No information is currently available on MI prevalence in this species in this ocean region. Our results show a 16.6% MI prevalence in Risso’s dolphins in the Canary Islands (n=12) over a 12-year period. Phylogenetic analysis shows that the strains from the two positive specimens are phylogenetically quite distant, suggesting that more than one strain infects the Risso’s dolphin population in this region, and the strain detected in specimen 2 has been circulating mainly in the northeastern Atlantic Ocean from 2007 to 2013.