REVSYS

The goals of the Rennaissance Taxonomy of Semaeostome Scyphomedusae project is to increase understanding of the evolution of the semaeostome group of true jellyfishes. This group has a high profile with the general public because semaeostome species often are exhibited in aquaria and may be implicated in "jellyfish blooms".

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REVSYS: Rennaissance Taxonomy of Semaeostome Scyphomedusae A Systematic Framework for Understanding Jellyfish Blooms and Invasive Species NSF DEB-0717078

Overview

Approximately 63 morphospecies of semaeostome jellyfishes, divided among 19 genera and three families, are currently described world-wide. The low taxonomic diversity purportedly reflects low levels of endemism and a high proportion of cosmopolitan species. However, recent molecular analyses suggest 2-to-10-fold greater species diversity in many genera and changes to long-standing phylogenetic hypotheses, suggesting that there have been major difficulties in inferring the taxonomic significance of historically used morphological features due to a dearth of characters, homoplasy, incorrect assignment of homology, and various other problems.

Recent quantitative statistical analyses of morphology in several semaeostome genera have, however, revealed that macromorphological features may be more numerous than previously thought. Moreover, most morphological features are variable and many molecularly-inferred species may also be morphologically distinguishable using univariate, multivariate and phylogenetic statistics. Such statistical morphological analyses may therefore contribute to integrative phylogenetics and a renaissance in scyphozoan systematics.

We propose to extend the developing quantitative and statistical approach to morphological analyses of scyphomedusae in unison with more rigorous multi-locus molecular phylogenetic analyses. Our goals are [i] to generate a robust approach to species identification and description for semaeostomes employing, at least in part, morphological information and [ii] to make the approach accessible to biologists who need accurate identifications in the field.

Our objectives are: [1] Inventory existing natural history collections of all known species of semaeostomes from diverse geographic locations, including the type localities whenever possible. [2] Use collections to establish methods for collecting data suited to rigorous statistical comparative morphological analyses of medusae. [3] Use existing collections that are suitably preserved to generate a robust phylogeny based on DNA sequencing of 2 mitochondrial and 4 nuclear markers. [4] Integrate morphological and molecular data to [a] identify morphological characters, or suites thereof, that can be used to reliably identify semaeostome species and [b] revise the systematics of species in the three semaeostome families including publishing new species descriptions. [5] Develop tools that use the new systematic framework to improve the accuracy of future systematic research. [6] Make these tools widely available to enable non-specialists to use morphological characters to accurately identify semaeostomes in the field.

Broader impacts: Accurate species descriptions are important to many scientific disciplines. Our project will establish methods that will resolve the currently confused systematics of semaeostomes thus providing a robust evolutionary framework for integrative and comparative studies of ecological variation and tools for reliable identification of species causing jellyfish blooms and of invasive species. We will establish widely accessible, easy to use, web-based protocols for identifying semaeostomes including an interactive polychotomous key. The Scyphozoan website will be further developed as the source for gathering and depositing methods, data, and analyses (e.g. spreadsheets, database, digital images, sequence alignments, phylogeny reconstructions, image analysis) pertinent to semaeostome medusae.

Benefits to society include the provision of information on jellyfish species that is applicable to the management of coastal ecosystems and fisheries, and to the public understanding of the marine environment both domestically and internationally.

Personnel

PI: Michael N Dawson co-PI: Allen G. Collins Postdoc: Keith M. Bayha Graduate: Liza E. Gomez Daglio