Ecomorphic variation in gemmoscleres of Ephydatia fluviatilis Linnaeus (Porifera: Spongillidae) with comments upon its systematics and ecology
- Department of Biological Sciences, Louisiana State University in New Orleans, New Orleans, Louisiana, U.S.A.
An ecological and taxonomic investigation of Ephydatia fluviatilis was conducted. E. fluviatilis was found in alkaline fresh waters and slightly brackish waters. Extreme variation was found in the gemmoscleres of E. fluviatilis from different Louisiana habitats. The variation appeared to be ecomorphic and related to the chemical characteristics of the habitats. Laboratory investigations, based on the formation of gemmules by sponges maintained under different conditions were used to determine the nature and extent of this variation. The experimental studies demonstrated that gemmoscleres of different forms can develop in sponges from the same locality if exposed to different environmental conditions and that Ephydatia robusta (Potts, 1887) as revised by Penney & Racek (1968), is synonymous with Ephydatia fluviatilis. Results of these studies demonstrate the difficulty of using such characteristics for the recognition of species, subspecies and other evolutionary units.
- 1 - sciences appliquees, technologies et medecines
- 2 - sciences biologiques et medicales
- 3 - sciences biologiques fondamentales et appliquees. psychologie
- 4 - psychologie. psychophysiologie