The first rapid biodiversity survey and beta-diversity assessment for endoparasitic marine trematode flatworms based in objective genetic barcode data. (APSF 21048)

APSF 21048 | Amount: $30,331 | Project Leader: S Martin | Project Period:

A project undertaken at Murdoch University, and supervised by Storm Martin.

There are at least as many parasitic as free-living animals, and parasites comprise a substantial component of undescribed biodiversity. Among the largest parasite groups exploiting marine fishes is the Trematoda. Trematodes are obligate endoparasitic flatworms. They exploit virtually all lineages of vertebrates as adults as well as many invertebrate and vertebrate groups as intermediate hosts, usually reaching their final host by moving up the food-chain. As adults, most trematodes reside in the host gut, causing negligible pathology, but some reside within the circulatory system, other organs or even under the scales in fishes.

The marine trematode fauna of Queensland waters is among the best understood worldwide, in particular the fauna there is well represented with genetic barcode data. In modern taxonomy, these genetic data are particularly useful for morphologically difficult groups like trematodes. Elsewhere around Australia the marine trematode fauna is poorly known and seldom investigated.

We will leverage the expertise, understanding and resources accumulated from decades of world-leading trematode research in Queensland to rapidly document and identify comparable biodiversity from the largely unexplored waters of Western Australia, with particular emphasis on the tropical waters of Ningaloo Reef. We will use a molecular-first approach, surveying the fish fauna broadly, generating molecular barcode data for every trematode species encountered and comparing these data against those from Queensland to quickly identify common taxa, flag those expected but apparently absent and discover new taxa. We aim to provide novel sequence data for at least 200 species, record 150 species not previously known from Western Australia, and discover and describe 50 species new to science.

Marine trematode biogeography is poorly understood and a glaring global knowledge gap impeding deeper investigations of diversity, evolution and population biology. Because the tropical fish faunas of Western Australia and Queensland are similar, the trematode faunas should likewise be similar. However, genetic connectivity for trematodes might be restricted relative to that of their fish hosts, because trematodes have only brief free-living stages and do not exploit the dispersive larval stage of reef fishes. Thus, fishes common to Western Australia and Queensland might host closely related but distinct species.

This study will constitute the largest single effort to catalogue marine parasite fauna in Western Australia to date and will dramatically increase the biodiversity of marine parasites known in the state. Worldwide, this study will be the first broad-scale, rapid survey for marine trematodes using molecular barcoding, and the first molecular-based comparison of marine trematode diversity between two regions across substantive breadth of the fauna.