BOWER SIZE AND MALE REPRODUCTIVE SUCCESS IN A CICHLID FISH LEK

For Cyrtocara eucinostomus in Lake Malawi, bower height appears to be a crucial characteristic used by females in determining with which males to court and eventually spawn. Males more vigorously defended, and were less likely to abandon, taller bowers, a pattern consistent at all depths, although the species showed a peak density of bowers at 6.0-7.5 m depth. The lower-depth distribution of bowers is probably due to nocturnal predation by deep-dwelling catfish, and the upper-depth distribution depends on wave action eroding the bowers. When bowers were experimentally removed, new bowers were built immediately, but not at exactly the same spot. The top diameter of the bower was reestablished in one day. These bower characteristics were specific for this species. The new bowers grew at a rate of c1 cm per day and reached the heights of control bowers in c2 wk. C. eucinostomus bred year-round but with a distinct breeding peak in both the wet and the dry seasons. During these periods, the density of bowers at 6.0-7.5 m appeared saturated, with a distance of c2.5 m between the centers of the nearest neighbors' territories. -from Authors