Meeting Abstract

P3.42  Wednesday, Jan. 6  Phylogeny of shallow water jellyfish (Scyphozoa: Discomedusae) from the Gulf of California, Mexico. GOMEZ DAGLIO, Liza E.*; DAWSON, Michael N; University of California, Merced; University of California, Merced lgomezdaglio@ucmerced.edu

Scyphozoans are important pelagic predators throughout the world’s oceans, but their diversity, distribution, ecology, and systematics are poorly known. The Gulf of California (the Gulf) presents a microcosm of this problem; the area is renowned for high endemic diversity in other taxa, but only three scyphomedusae have been documented previously. Here, we propose to address the biodiversity of shallow water scyphomedusae and establish their phylogenetic relationships with and times of separation from congeneric scyphozoans, especially sister taxa in other regions. We recorded 10 species in the Gulf, including 5 new species. One species, new to science, belongs in Family Lobonematidae previously known only from the Western Pacific. Resultant phylogenies of the genera Aurelia, Stomolophus and Chrysaora obtained by Maximum likelihood analyses (COI) indicate the Gulf’s scyphomedusae are sister taxa of the Atlantic clade. These data suggest a tropical origin for the Gulf scyphofauna. The major vicariant event that promoted the speciation of these jellyfish was likely the closure of the Panamanian Isthmus. However, the analyses of Cassiopea showed that is an introduced species in the Gulf. The phylogenies of the remaining taxa collected – Pelagia, Lobonematidae, Phacellophora, and Phyllorhiza – affirm the importance of studying Gulf of California and Central America medusae for understanding global patterns of diversity in Scyphozoa.