The distribution, morphometric characteristics and genetic diversity of largemouth bass (Micropterus salmoides (Lacepede, 1802)) in Croatia

Pastrvski grgeč (Micropterus salmoides (Lacepède, 1802)) dobro je poznata vrsta ribe, ponajviše zbog brojnih istraživanja u Sjevernoj Americi od kuda vrsta i potječe. Pastrvski grgeč, danas rasprostranjen diljem svijeta, na glasu je kao jedna od najpopularnijih i najvrjednijih vrsta riba u sportskom ribolovu i ribolovnom turizmu, u Republici Hrvatskoj se smatra stranom invazivnom vrstom visokog rizika. Cilj ovog istraživanja je proučavanje značajki populacija pastrvskog grgeča u RH. Istraživanje rasprostranjenosti provedeno je pregledom literature, terenskim istraživanjima i pregledom podataka dobivenih od sportskih ribolovaca, te je istraživanjem rasprostranjenosti utvrđen poseban uzorak povećanja broja lokaliteta od početka 20. stoljeća do danas. Morfološke razlike jedinki iz slivova rijeka Drave i Save, te jadranskog sliva (ukupno 15 lokacija) prikazane su dvodimenzionalnom mrežom i analizirane statističkim metodama, te su utvrđene manje morfometrijske razlike između istraživanih grupa. Filogenetska rekonstrukcija se temeljila na sekvencama gena za kontrolnu regiju (CR) te je provedena pomoću metoda najveće parsimonije (MP), najveće vjerojatnosti (ML) i susjednog povezivanja (MJ). Analiza populacijske genetike pastrvskog grgeča u Hrvatskoj sugerira na malu raznolikost i malen broj inicijalno unesenih jedinki, te potvrđuju tezu o ilegalnim translokacijama. Također otkriven je poseban haplotip čije postojanje u jezeru Jarun i zanimljiv filogenetski položaj nisu posve razjašnjen. The largemouth bass (Micropterus salmoides (Lacepède, 1802)) is one of the best known species of fish in the world, mainly because of numerous studies in North America from where it originates. Today largemouth bass is widely spread throughout the world as one of the most popular and valuable fish species in sport fishing and fishing tourism, while in the Republic of Croatia is considered to be a high risk foreign invasive species. The aim of this study is to examine the characteristics of largemouth bass populations in Croatia. Outspread research is conducted through literature reviews, field surveys, and data obtained from sport fishermen. This part of research shows a specific pattern of increasing localities number from the early 20th century to the present. The morphological differences of the individuals from the Drava and Sava river basins and the Adriatic basin (15 sites in total) were shown by a 2D network and analyzed by statistical methods. Minor morphometric differences were found between the studied groups. Phylogenetic reconstruction was based on the control region (CR) gene sequences and was conducted using following methods: maximum parsimony (MP), maximum likelihood (ML), and media joining (MJ). A genetic study of largemouth bass population characteristics in Croatia suggests a small diversity and a small number of individuals initially introduced, and also confirms thesis of illegal translocations. Also, special haplotype is discovered whose existence in Lake Jarun and an interesting phylogenetic position have not been fully clarified.