SS4.04 The Relevance of Gelatinous Zooplankton to Interdisciplinary Linkages
Date: Friday, June 14, 2002
Time: 9:15:00 AM
Location: Saanich
BayhaKM, University of Delaware, Newark, USA,
McDonald, J, H, University of Delaware, Newark, USA,
Gaffney, P, M, University of Delaware, Lewes, USA,
The ctenophore genus Mnemiopsis currently contains two species (M. leidyi and M. mccradyi), ranging from Massachusetts to Southern Argentina. Over the past 20 years, these ctenophores have invaded the Black, Azov and Caspian Seas. In order to clarify the taxonomy and population genetics of Mnemiopsis, we have collected nuclear and mitochondrial sequence data from representatives of both putative species. The entire (233 bp) nuclear rDNA internal transcribed spacer region 1 (ITS-1) was sequenced from 50 individuals collected from 19 different geographic regions spanning the ctenophore's native and invaded ranges. We found no length variation in ITS-1. Furthermore, percent sequence divergence was low (0-0.9%) and within the range of intra-specific ITS-1 divergence found in other organisms, which does not support the presence of more than one species of Mnemiopsis. One genotype was found only in South America (Brazil and Argentina), while all other common genotypes were shared between the North American Atlantic/Gulf of Mexico coasts and the invaded regions. Results from ongoing studies of additional nuclear and mitochondrial markers will also be presented.