Recherche - Observatoire océanologique de Banyuls sur mer
Laboratoire Arago

Gobies (Gobiidae, Perciformes), with more than 30 genera and some 120 species, are one of the most diverse European fish families, inhabiting both marine and freshwater habitats. The Mediterranean Sea (excluding the Black Sea) is inhabited by 60 species, with considerably high number of endemic taxa (24) in this area. Furthermore, five Mediterranean gobies extend their distribution into the Atlantic just to the Gibraltar area. On the other hand, North-Eastern Atlantic is inhabited by 47 species, of which only 7 are endemic to this area. There are considerable differences in the known occurrence of gobies in different parts of the Mediterranean, from 46 species recorded in Adriatic Sea to only 10 species reported for the South-Western part of Mediterranean (Morocco and Algeria). For Banyuls, 16 species have been reported. Within two weeks of our stay, we have found 15 species, of which 5 were not reported for Banyuls before. So, at least 20 species of gobies are present near OOB. Phylogenetic relationships of European gobies have been studied in detail only in genus Neogobius (Black Sea region) and partly in some of the sand-gobies, mainly genus Pomatoschistus. We investigated the phylogenetic relationships of European gobies by the molecular-genetic methods; especially we tested the monophyly of large genera. Cytochrome b was amplified and sequenced for 45 European taxa. The analyses showed several of the studied genera are polyphyletic. This applies to Knipowitschia, Pomatoschistus, Gobius, Neogobius and Padogobius. The attention was further focused on genus Gobius, whose members form two distinct clusters. One includes three species (G. cobitis, G. paganellus and M. maderensis - so called rock gobies), the other cluster includes the remaining studied European species (13 species, including Zosterissesor ophiocephalus). Furthermore, genus Knipowitschia from Adriatic basin was analysed in detail. These mostly strictly freshwater gobies form also two different lineages, one related with the pontocaspian K. caucasica, the second one with Adriatic Pomatoschistus canestrinii. The aim of our ASSEMBLE project is to study the genetic divergence of distant populations of the same taxa. Many species are known only from a few specimens and small number of localities, usually geographically very distant. However, they can be in fact widespread, but due to cryptic way of life escape to attention. Genetic diversification of the majority of the Mediterranean gobies is completely unknown. Molecular genetic comparison of distant populations of the same species will show if gene-flow exists between the populations or if the populations are isolated from each other. It has direct implication on taxonomy, conservation as well as biogeography of gobies in the Mediterranean.

Séminaire présenté par Radek Sanda (National Museum, Prague, Czech Republic)