engleski

LESSEPSIAN FISH MIGRANTS IN THE ADRIATIC

The catch of Terapon theraps in 2007. brought the number of lessepsian fish migrants that were recorded in the Adriatic Sea to 11. Occurence of T. theraps is of particular interest since its record was first for the Mediterranean, what's more, it was found a great distance from the usual distribution area. Similar are the cases of Pampus argenteus and Epinephelus coioides. The latter was considered rare and recent invader and its presence in the Mediterranean was acknowledged only from the coast of Israel, hence it's presence in the northernmost part of the Adriatic is rather surprising (northernmost record in the Mediterranean). Considering record of P. argenteus, one specimen was caught in 1896 in front of Rijeka. This is the only record of this species in the Mediterranean, hence its presence is even more surprising. Nevertheless, this record undoubtly represents first confirmed lessepsian fish migrant in the Mediterranean Sea. Furthermore, one specimen of Hemiramphus far was recorded at the entrance of the Adriatic Sea, along the Albanian coast in 1986 as like as Parexocoetus mento. In the same year, one specimen of Parexocoetus mento was also recorded in Albanian coastal waters. Albanian coastal waters yielded another record of lessepsian fish, in 1995 a single specimen of Saurida undosquamis was caught. In the summer of 2000, a specimen of Sphyraena chrysotaenia was caught in the Bay of Gornji Molunat. In the summer of the same year, a specimen of Leiognathus klunzingeri was captured near the island of Mljet in the Southern Adriatic. This record represents its northernmost occurence in the Mediterranean Sea. Another migrant, Stephanolepis diaspros, has been recorded in the southern Adriatic in the summer of 2002. It is the northernmost record for this species in the Mediterranean and is also the first occurence of a member of this family (Monacanthidae) for the Adriatic Sea. Two specimens of Siganus rivulatus were captured by the beach seine near the islet Bobara (southern Adriatic, Croatian coast) in autumn of 2000. This is also northernmost occurence of this species in Mediterranean Sea. In 2006 Fistularia commersonii, of which two specimens were recorded, occured in Adriatic. There are many indicies pointing out that climate change on a global scale has influenced and changed assemblage of Adriatic ichthyofauna in a more or less signifacant amount in regard to new species present in the area. The Adriatic Sea is obviously becoming a westward distribution path of lessepsian migrants and it would be very interesting to observe this invasion on a larger time scale especially in the context of the response of such species to the new enviroment. We conclude that biological invasions still didn't affect Adriatic ichthyofauna in an amount which could have negative consequences on indigenous fish species. However, increasing abundance of some thermophillic species could potentialy shift ecological balance in a unpredictable directions. In any case, we empasize the need for further research and evaluation of migrant species status on continuous basis.

fish; migration; lessepsian migrants; Adriatic

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