Echinoderm diseases and pathologies

Abstract

Echinoderms are basal deuterostomes and the sister phylum to the chordates. All are marine animals with effective and robust innate immunity. Echinoderms are host to diseases in both larvae and adults, which include bald sea urchin disease, sea star wasting disease, among others that are defined by a range of different and often overlapping symptoms The diseases infect either individual animals or entire populations depending on the virulence and rate of spread and can lead to death in individuals or to mass die-offs. Pathogens include marine bacteria, typically Gammaproteobacteria and members of the Vibrio splendidus clade, as well as protists and viruses. Identify the initiating pathogen has been challenging but DNA sequencing approaches provide an avenue for pathogen identification, for differentiating between an initiating pathogen and organisms that cause the secondary infections, and for characterising changes to the normal microbiome of an infected echinoderm. Echinoderm pathologies have direct impacts on marine ecology and on aquaculture for edible species that, in some cases, can be alleviated by optimising the habitat conditions for healthy echinoderm populations.