Ribi
Fakultäten » Mathematisch-naturwissenschaftliche Fakultät » Evolutionsbiologie und Umweltwissenschaften, Institut für » Evolutionary Biology » Prof. Dr. Georg Ribi (verstorben) » Ribi
Completed research project
| Title / Titel | Testing predictions from sexual selection theory using two species of freshwater smails, Viviparus ater and V. contectus. | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Abstract (PDF, 14 KB) | |||||||||
| Summary / Zusammenfassung | Viviparus ater and V. contectus are two species of freshwater prosobranch snails which hybridize in nature. Both species have separate sexes, mate promiscuously, and interspecific matings are frequent where the two species coexist (Trüb and Ribi 1997). We tested the predictions that females should mate with many males, including males of the other species, in order to obtain as much energy-rich ejaculate as possible, whereas males should avoid copulating with females on the other species. We found that males of either species preferred to mate with conspecific females, whereas females accepted copulations by males of any of the two species apparently indiscriminately (Ribi and Katoh 1998). Males provide two types of sperm: eupyrene sperm, which can fertilize eggs, and oligopyrene sperm, which are sterile but rich in protein and starch. The role of oligopyrene sperm in Viviparus is not known. The observed mating preferences of males and females are compatible with an earlier hypothesis that oligopyrene sperm could be a "nuptial gift" of the male to the female. However, recent experiments suggest that oligopyrene sperm may also play a role in sperm competition (Oppliger et al. 1998). |
||||||||
| Publications / Publikationen | Oppliger, A.; Hosken, D. & Ribi, G. (1998): Snail sperm production characteristics vary with sperm competition risk. Philosophical Transactions of the Royal Society, London, Series B, 265: 1527-1534.Ribi, G. & Katoh, M. (1998): Weak preference for conspecific mates in the hybridizing snails Viviparus ater and V. contectus (Mollusca, Prosobranchia). Ethology Ecology & Evolution, 4: 383-392.Trüb, H. & Ribi, G. (1997): High fecundity of hybrids between the sympatric snail species Viviparus ater and V. contectus (Mollusca: Prosobranchia). Heredity, 79: 418-423. | ||||||||
| Keywords / Suchbegriffe | Interspecific hybrids, mate choice, oligopyrene sperm, prosobranch snails, sexual selection, sperm competition, sperm precedence, Viviparus | ||||||||
| Project leadership and contacts / Projektleitung und Kontakte |
|
||||||||
| Funding source(s) / Unterstützt durch |
Others |
||||||||
| In collaboration with / In Zusammenarbeit mit |
|
||||||||
| Duration of Project / Projektdauer | Oct 1996 to Feb 2007 |