GENETIC DIVERSITY AND POPULATION STRUCTURE ANALYSES OF THREATENED Amblyceps mangois FROM SUB-HIMALAYAN WEST BENGAL, INDIA THROUGH RAPD AND ISSR FINGERPRINTING

Amblyceps mangois ili “indijski bujični som” je tropska, slatkovodna, vrsta brdskih potoka koja u Indiji ima ukrasno-komercijalnu vrijednost a uključena je u kategoriju “ugrožene” na popisu ugroženih slatkovodnih riba Indije. Kako bi se, uz pomoć markera RAPD i ISSR, istražila genetička arhitektura ove vrste, analizirano je ukupno četrnaest populacija iz regije Terai i Dooars na sjeveru Zapadnog Bengala u Indiji. Opaženi broj alela (S), Neiova genska raznolikost (H) i Shannonov indeks podataka (H´ ili I) ukazali su na najviše vrijednosti u riječnom slivu Teesta i najniže vrijednosti u slivu rijeke Mahananda. Dendrogram na bazi UPGMA i PCoA, temeljeni na RAPD i ISSR otiscima, ukazale su na formiranje skupine populacije rijeka Mahananda i Teesta koja se razlikuje od preostale populacije rijeke Jaldhaka. Četrnaest riječnih populacija su dalje razmatrane u devet skupina premakontinuitetu protoka vode za SHE analizu. Utvrđeno je da su tri komponente tj. uzorak raznolikosti (H‘), bogatstva (S) i jednolikosti (E), varirale i fluktuirale u svih četrnaestpopulacija s više na nižu nadmorsku visinu, kako rijeka teče nizvodno. AMOVA, PhiPT i genetske hijerarhijske analize ukazale su na izrazitu hijerarhijsku strukturu prisutnu u populaciji Ambliceps na istraživanom području. U istraživanju su nađene niske razine genetske raznolikosti/varijacija i genetska hijerarhijska struktura s visokom genetskom divergencijom, kao pokazatelj nedavne slike ugroženog statusa ove vrste. Ova studija je početni pokušaj karakterizacije i procjene genetske arhitekture ribljih vrsta iz ove regije i postoji prostor za upravljanje značajnim jedinicama evolucije (ESU) u svrhu njihovog očuvanja.Amblyceps mangois or the “Indian torrent catfish” is a tropical, freshwater, hill-stream species that has ornamental-commercial value and has been included within the “Endangered” category in the list of threatened freshwater fishes of India. A total fourteen populations from the Terai and Dooars region of northern West Bengal, India were analyzed to studythe genetic architecture of this species with the help of RAPD and ISSR markers. The observed number of alleles (S), Nei’s gene diversity (H) and Shannon’s information index (H´ or I) showed the highest values in the Teesta river system and the lowest values in the Mahananda river system. The UPGMA-based dendrogram and PCoA, based on RAPD and ISSR fingerprints, showed that the Mahananda and the Teesta river populations formed a group distinct from the remaining Jaldhaka river population. We further considered the fourteen riverine populations into nine groups according to the continuity of the water flow for SHE analysis. It was foundthat the three components, i.e. the pattern of diversity (H´), richness (S) and evenness (E), have varied and fluctuated across all fourteen populations from higher to lower altitude as the river flows downstream. AMOVA, PhiPT and genetic hierarchical analyses showed that a distinct hierarchical structure is present in Amblyceps populations in the study region. Low levels of genetic diversity/variation and genetic hierarchical structure with high genetic divergence were found in the present study as an indicator of the recent picture of threatened status of this species. This study is the initial attempt to characterize and evaluate the genetic architecture of the species from this region and there is a scope to manage the evolutionary significant units (ESU) for conservation purpose