About
Project Overview
Peracarids are an extremely large and diverse group of crustaceans that are found everywhere on Earth, from deserts to the deepest ocean trenches. The most familiar peracarids are the terrestrial isopods, commonly known as roly polies, that are frequently found under rocks or plant pots. There are deep sea and freshwater versions of roly polies. They come in the most amazing body forms/shapes and sizes — peracarids do just about everything except fly. Despite being found everywhere, very little is known about the relationships within Peracarida, limiting understanding of how the group came to be so species-rich and variable.
The central goal of this project is to resolve the relationships within Peracarida. At least 30 undergraduate students, three graduate students, and a postdoctoral researcher will be trained in molecular laboratory techniques, bioinformatics, peracarid taxonomy, identification and description of new species, data management, and career development. Three workshops will be held to train 31 graduate students and early career professionals in peracarid systematics, collection, identification, preservation, bioinformatics, and data management. Project outreach will include social media, outreach to schools in diverse districts (Anchorage, Los Angeles, and western Alabama), museum exhibits, and bilingual (Spanish/English) outreach in traditional broadcast media and a short documentary film.
Why Peracarida?
Most people are familiar with the terrestrial isopods, known as roly polies, ball bugs, or slaters, found in gardens and under rocks, favorites of small children. However, peracarids are found in all environments, from terrestrial deserts to the depths of ocean trenches. They reach staggering diversity on land, in shallow-water tropical reefs, and in the Southern Ocean. The majority are marine, although some exist only in groundwater or cave waters, and still others persist in hot springs at temperatures up to 40° C. Most are small (less than 1 cm long) although the largest reach 40 cm. Peracarids do just about everything but fly.
The superorder Peracarida contains about 26,000 described species distributed in one fossil and 12 extant orders, representing 1/3 of all non-hexapod crustacean diversity. Peracarida is one of the few large areas of the eukaryotic tree of life that still remains dark at this level. A robust phylogeny for the Peracarida will go far to enhance our understanding of the Crustacea as a whole.
Project Goals
The central goal of our project is to resolve the phylogeny of the Peracarida, one of Earth’s most astonishingly diverse animal groups, by uniting the work and collections of peracarid biologists worldwide in a comprehensive molecular analysis. This comprehensive coverage is possible due to the broad and enthusiastic collaboration offered by the worldwide community of peracarid systematists. Taxon sampling will be very broad, incorporating all orders and all families with 2 or more species. We will use a target capture phylogenomic approach with probe design informed by publicly available genomic data supplemented with three new peracarid genomes and 50 new transcriptomes from representatives of under-studied lineages. We expect that this sequence-based phylogeny will resolve persistent uncertainties that still remain after more than a century of morphological work. DNA barcoding (16S, COI, 18S) of some of the more speciose clades will add “flesh to the skeleton” exposing some of the enormous peracarid biodiversity. A well supported phylogenetic backbone will permit significant progress toward answering important questions raised by the extreme diversity displayed by peracarid morphology, ecology, systematics, and life history.
We will bring this diverse group of crustaceans to light by:
- Applying modern genomic approaches
2. Expanding sampling of species
