Courriel : Loic.Kever@ulg.ac.be
The Ophidiiformes contain approximately 135 genera and 400 species. Despite the number of species, data about their general biology are very scarce. My work concerns mainly the Ophidiidae that are active during the night in shallow water, being buried in the sand during the day. Most Ophidiidae have a complex sound producing apparatus (three pairs of sonic muscles, rocker bone, modified vertebrae and swimbladder, etc.). Moreover, these structures are characterised by an important sexual dimorphism. However, their calls remain mostly unknown. My first aim is to describe the sonic apparatus with its morphological variations and to explain the sonic mechanism with the help of sound characteristics. Hearing capacities and inner ear morphology are almost unknown in Ophidiidae. My second goal can be subdivided in three parts: drawing audiograms for some species, seeking for variations in hearing capacities, enhancing the comprehension about the function of the different morphological structures of the inner hear.
As a member of the ‘Genbas’ projet (http://genbas.be), I work on the reproductive behavior of Ophthalmotilapia species. This project aims to (1) characterize the genomic differentiation that drives the speciation process and (2) verify whether/and to what extent the same genomic changes are maintaining the ‘integrity’ of the gene pools of the resulting sister species.
Four species (O. ventralis, O. nasuta, O. boops, and O. heterodonta) were described in this genus but the status of O. heterodonta is still debated. All Ophthalmotilapia are maternally mouthbrooding cichlids endemic to the Lake Tanganyika. These fish are characterized by large eyes and a pronounced sexual dimorphism; territorial males mainly differ from females in their color patterns and the size of their pelvic fins which are much longer and possess ‘egg dummies’ at their distal end. During the mating, males present the egg dummies to the female which try to put them into her mouth. At the same time, the male probably release sperm to ensure egg fertilization inside the female mouth.
My goal is to produce detailed ethograms for the three (recognized) Ophthalmotilapia species in order to determine if they show some differences in their reproductive behavior. Although sound production associated with reproduction behavior was reported in many haplochromine clichids, sounds were never recorded in other tribes of East African Great Lakes cichlids. Thus, I also try to determine if Ophthalmotilapia spp. produce communication sounds especially during courtship and mating.