Publication details
THE EYE FLUKE AFFECTS SEXUAL ORNAMENTATION OF THE EUROPEAN BITTERLING MALES
| Authors | |
|---|---|
| Year of publication | 2012 |
| Type | Conference abstract |
| MU Faculty or unit | |
| Citation | |
| Description | Parasites may cause alterations in many aspects of the host biology including the reproduction. We investigated the effects of the eye fluke Diplostomum pseudospathaceum (Trematoda) on sexual ornamentation of its host, the European bitterling (Rhodeus amarus). The bitterlings are small freshwater cyprinid fish with unique way of reproduction. The males attract females to spawn into the gills of live unionid mussels. Females choose the male according its size, colouring and rate of courting. Metacercarial stages of D. pseudospathaceum located in the eye lenses may induce cataract formation and blindness, and also changes in behaviour and colouring of the fish host. In this study, we investigated whether the eye fluke affects the eye redness (an index of male dominance) in bitterling males during the spawning season using the experimentally infected fish. We measured the area of the red spot and red intensity at the beginning, in the middle and at the end of bitterling breeding season. We compared the eye redness between males infected (1) previous year (long-term infection), (2) during the breeding season (short-term infection) and (3) uninfected control. Control fish showed significantly larger red area and higher red intensity compared to long-term infected fish at the beginning of breeding season. Conversely during the middle breeding season control males had smaller and less colored spot than long-term infected fish. At the end of breeding season short-term infected fish showed significantly higher eye redness compared to long-term infected and control fish. Our results indicate that uninfected males focus their reproduction on the beginning of breeding season, when large proportion of females is ready to spawn. On the contrary long-term infected and especially short-term infected males spread out their reproductive effort to the later part of breeding season. |