Conference Agenda

Acanthocolpids are a family of digenean trematodes mired with taxonomic instability and complexity. The life cycle is generally typified by trophic transmission via fish second-intermediate hosts and fish definitive hosts, with some exceptions. We described a new species of Acanthocolpidae from the Great Barrier Reef, which is the first known parasite for its definitive host, the sailfin snapper, Symphorichthys spilurus (Lutjanidae). Morphologically, this new species is consistent with the genus Pseudolepidapedon. However, phylogenetic analyses with our novel sequence data, the first for an Indo-Pacific species of the genus, also implicates some species of Stephanostomum, an infamously problematic and likely polyphyletic genus with over 90 species. These findings complicate the relationship and blur the boundaries between Pseudolepidapedon and Stephanostomum. Additionally, although the sailfin snapper is a large predatory fish, it feeds mostly on benthic invertebrates, and our new species bears some similarity to one of the exceptional species of acantholpids known to use molluscs, rather than fishes, as second-intermediate hosts. We discuss the potential taxonomic and life cycle revelations suggested by the discovery of this new species.