Global Phylogeography
Phylogeny and Biogeography of Scyphozoa and Discomedusae
Michael N Dawson, et al.


Project Outline

Until early in this century, Aurelia aurita was considered to be an ecological generalist distributed circumglobally between about 70° N and 50° S. Molecular analyses demonstrated that this was not the case; there are at least 14 species of Aurelia found in different regions of the world, each presumably adapted to local conditions. A similar story can be told about Cyanea capillata, and probably many other widely distributed taxa. The probable preponderance of cryptic species is a problem because we know little about a species unless we know it's boundaries; we cannot know where it's distribution ends, how short or far it disperses, its upper or lower temperature tolerances, how much it eats, what it can eat, it's metabolic rate, grow rate, fecundity, it's ecological impact, whether it blooms, or is invasice, etc. This project - at the nexus of CnidToL and REVSYS - aims to increase our knowledge of species boundaries by sampling many scyphozoan taxa from many locations around the world. The preliminary map of species distributions that results will provide a template for reinterpreting the ecological data that has been collected over many decades on many species in its appropriate taxonomic context. Thus, each person has the potential to know the species they are working with, its true characteristics, and how it differs from other closely (or distantly) related species ... the essence of any comparative biology or study of biodiversity.



Target species are listed in the Systematics pages of The Scyphozoan (see especially Coronatae, Rhizostomeae, Semaeostomeae), as are the samples collected to date and their locations. If you can contribute any additional specimens, please contact Mike Dawson (mdawson AT ucmerced DOT edu). The protocol for preservation of samples is a slight modification of the standard protocol for CnidToL, as follows.

Collecting up to 10 specimens using your standard procedure, rinse the bell margin or oral arms that you will sample with clean water. Biopsy a piece of tissue rich in dermis that is about half the size of your small finger-nail. Preserve the tissue in excess 95% ethanol (i.e. about 10 times as much ethanol as tissue) in a screw-cap, o-ring, 2 ml vial. Preserve the remainder of the medusa in 4-7% formalin-in-seawater such that the final concentration of formalin is 2-4%. Store the ethanol+tissue in a freezer until you are ready to send it to CnidToL; allow the specimen in formalin to 'fix' for at least 3-4 weeks before sending to CnidToL. When ready, pack the samples robustly (see shipping) and send them to one of the two following address (Contact Mike to ask which is most appropriate for the specimens in hand).
Dr. Paulyn Cartwright,
Department of Ecology and Evolutionary Biology,
Haworth Hall, RM 7016, 1200 Sunnyside Ave.,
University of Kansas, Lawrence,
KS 66045, USA
Dr. Michael N Dawson
School of Natural Sciences
University of California, Merced
P.O. Box 2039
Merced, CA 95344


Why get involved?

In addition to being able to identify which species you are working with, this project offers multiple opportunities for collaboration and co-authorship. A single species might be collected from multiple locations for a regional phylogeographic study (samples from different environments, or on different sides of a supposed biogeographic boundary are particularly interesting), or multiple species might be collected from a single region (for a biodiversity survey), or multiple species might be collected from multiple regions for a biogeographic study. All of these studies might additionally lead to descriptions of new species or other taxonomic revisions.