Planktonic cnidarians in a cold-core ring in the Gulf of Mexico
The species composition and abundance of medusae and siphonophorescollected in March 1993 across a Gulf of Mexico cold-core ring (CCR)were analysed. Samples were collected in day and night time by oblique tows(100 m to surface) with a plankton net. Medusae were represented by 12 species,which by com...
| Autores: | , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2002 |
| País: | México |
| Institución: | Universidad Nacional Autónoma de México |
| Repositorio: | Redalyc-UNAM |
| OAI Identifier: | oai:redalyc.org:45873103 |
| Acceso en línea: | https://www.redalyc.org/articulo.oa?id=45873103 |
| Access Level: | acceso abierto |
| Palabra clave: | Biología medusae ecology siphonophores mesoscale eddy |
| Sumario: | The species composition and abundance of medusae and siphonophorescollected in March 1993 across a Gulf of Mexico cold-core ring (CCR)were analysed. Samples were collected in day and night time by oblique tows(100 m to surface) with a plankton net. Medusae were represented by 12 species,which by combined numbers were almost equally abundant within and outsidethe CCR. However, the two species that together comprised >66% of all medusaeinside the CCR (Nausithoë punctata and Liriope tetraphylla) were rare outsidethe CCR and species most common outside (combined >66% of all medusaeoutside) were either absent or rare inside the CCR. Siphonophores were representedby 25 species; the seven most abundant within the CCR were also thosemost abundant outside. Because of day/night migrational patterns, consistentlygreater total numbers of siphonophores were found at night in the upper 100mlayer. Cluster analysis confirmed these differences in siphonophore compositionand abundance between daylight and night samples but also showed differencesbetween night samples inside and outside the CCR. Although they wereuncommon within the CCR, two rare species of Lensia and two of Ceratocymbawere found only in collections inside this feature. Two other species of Lensia, athird species of Ceratocymba, and four other overall uncommon siphonophoreswere found only outside the CCR. Thus, differences at the species level indicatethat pelagic cnidarians are not uniformly distributed in this zone of the gulf, butrather they vary in response to mesoscale changes in their physical environment. |
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