{"id":12166,"date":"2025-07-31T13:25:30","date_gmt":"2025-07-31T11:25:30","guid":{"rendered":"https:\/\/www.npkrka.hr\/?p=12166"},"modified":"2025-12-02T13:01:32","modified_gmt":"2025-12-02T12:01:32","slug":"determining-the-state-of-the-population-of-softmouth-trout-salmo-obtusirostris-using-e-dna-and-visual-census-methodes","status":"publish","type":"post","link":"https:\/\/npkrka.hr\/en_us\/2025\/07\/31\/determining-the-state-of-the-population-of-softmouth-trout-salmo-obtusirostris-using-e-dna-and-visual-census-methodes\/","title":{"rendered":"Determining the state of the population of softmouth trout"},"content":{"rendered":"

[hr]Utvr\u0111ivanje stanja populacije mekousne pastrve (Salmo obtusirostris<\/em>) metodom ekolo\u0161ke DNA i vizualnog cenzusa.<\/strong><\/p>\n

Niti u jednom od dosada\u0161njih istra\u017eivanja \u2013 koja su znatno doprinijela utvr\u0111ivanju strukture i raznolikosti autohtone ihtiofaune Nacionalnog parka \u201eKrka\u201c, kao i brojnosti i prisutnosti stranih i prenesenih vrsta riba u slivu rijeke Krke \u2013 nije utvr\u0111ena prisutnost mekousne pastrve (Salmo obtusirostris<\/em>), koja se navodi u starijoj literaturi. Cilj najnovijeg istra\u017eivanja bio je primijeniti novu metodu u istra\u017eivanju prisutnosti mekousne pastrve, uz pomo\u0107 tehnike ekolo\u0161ke DNA (eDNA) .<\/p>\n

Kako bi se u uzorku eDNA, koji sadr\u017ei mje\u0161avinu DNA svih vrsta koje se mogu na\u0107i na odre\u0111enom lokalitetu mogla detektirati mekousna pastrva, potrebno je prona\u0107i specifi\u010dne molekularne markere za tu vrstu. Uzorkovanje je obavljeno na vi\u0161e lokacija, i to primarno na mjestima koja se u literaturi navode kao mjesta obitavanja te vrste. Kako bi se pove\u0107ao stupanj efikasnosti i preciznosti te metode, trebalo je uzeti uzorke mekousne pastrve, ali i drugih salmonidnih vrsta, kako u Krki tako i na drugim lokacijama gdje ta vrsta obitava, a to su rijeke Jadro, \u017drnovnica i Vrljika. Uzorci trbu\u0161ne peraje uzeti su od vi\u0161e vrsta riba: kalifornijske pastrve (Oncorhynchus mykiss<\/em>), poto\u010dne ili dunavske pastrve (Salmo trutta<\/em> ili S. labrax<\/em>), primorske pastrve (Salmo farioides<\/em>), Krkinog pijora (Phoxinus krkae<\/em>) i mekousne pastrve (Salmo obtusirostris<\/em>).<\/p>\n

Sljede\u0107i koraci bili su razvijanje specijalne metode za detekciju mekousne pastrve, pretraga podataka i banke gena, amplifikacija specifi\u010dnih molekularnih markera za tu i srodne vrste s istra\u017eivanog podru\u010dja, bioinformati\u010dka analiza s ciljem utvr\u0111ivanja regije koja je specifi\u010dna za tra\u017eenu vrstu u odnosu na druge vrste i usporedba s mekousnom pastrvom iz rijeka Vrljika i Jadro. DNA je izolirana iz komadi\u0107a peraja vrsta iz porodice Salmonidae prikupljenih u podru\u010djima Krke, Vrljike i Jadra u kojima obitava mekousna pastrva, koja je poslu\u017eila kao pozitivna kontrola. Na kraju je testirano djelovanje restrikcijskog enzima na odabrane molekularne markere u ciljanoj vrsti, kao i u drugim vrstama iz te porodice, kako bi se utvrdilo postoji li uo\u010dljiva razlika me\u0111u njima. Tijekom pretra\u017eivanja prona\u0111eno je nekoliko potencijalnih markera, no najboljim su se \u010dinili citokrom b, somatolaktin i laktat dehidrogenaza. Od tih markera, restrikcijskom digestijom somatolaktina mogu\u0107e je detektirati prisutnost mekousne i razlikovati je od drugih vrsta porodice Salmonidae u podru\u010dju rijeke Krke u uzorcima eDNA.<\/p>\n

Metodu eDNA markera preporu\u010dljivo je koristiti u kombinaciji s nekim drugim standardnim ihtiolo\u0161kim metodama kao komplementaran na\u010din istra\u017eivanja ili monitoringa nekog podru\u010dja i ribljih zajednica, bez invazivnog u\u010dinka ili prenagla\u0161ene selektivnosti. Kao nadopuna te metode, kori\u0161tena je i metoda vizualnog cenzusa uz pomo\u0107 ronjenja i upotrebe podvodnog drona (ROV). Metoda vizualnog cenzusa pokazala se pogodnom za detekciju malih benti\u010dkih vrsta uskog areala kretanja, kao \u0161to su glavo\u010di ili babice, i pelagi\u010dkih riba koje formiraju plove i kre\u0107u se u vodenom stupcu. Za razliku od toga, pokazala se manje uspje\u0161nom u detekciji manje brojnih vrsta koje ne formiraju velike plove pa se \u010desto kod drugih ihtiolo\u0161kih metoda u uzorku pojavljuju pojedina\u010dno.<\/p>\n

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[en]
\nDetermining the state of the population of softmouth trout<\/strong>
\nDetermining the state of the population of softmouth trout (Salmo obtusirostris<\/em>) using eDNA and visual census method.<\/strong><\/p>\n

Research to date that has significantly contributed to determining the structure and diversity of the indigenous ichthyofauna of Krka National Park, and the abundance and presence of alien and translocated species in the Krka River basin, has not detected the presence of the softmouth trout (Salmo obtusirostris<\/em>), recorded in the literature to inhabit these waters. The aim of this research was to apply new methods to detect the presence of softmouth trout using the eDNA method.<\/p>\n

eDNA samples contain a mixture of the DNA of all species found in a given locality. In order to detect the presence of the softmouth trout, it is necessary to find specific molecular markers for this species. Sampling was performed at multiple locations, primarily those listed in the literature as the habitat for this species. In order to increase the degree of efficacy and precision of this method, it was necessary to take samples of softmouth trout, and other salmonid species, both in the Krka River and at other localities where this species lives, i.e., the Jadro, \u017drnovnica and Vrljika Rivers. Pectoral fin samples were taken from several fish species: rainbow trout (Oncorhynchus mykiss<\/em>), Danube trout (Salmo trutta<\/em> or S. labrax<\/em>), Adriatic brown trout (Salmo farioides<\/em>), Krka minnow (Phoxinus krkae<\/em>), and softmouth trout (Salmo obtusirostris<\/em>).<\/p>\n

The next step was to develop a special method to detect softmouth trout, and to conduct a data and GeneBank search, and amplification of specific molecular markets for this species and related species from the study area, and to perform a bioinformational analysis to determine appropriate regions specific to the species in question, in relation to other species, and in comparison with the softmouth trout from the Vrljika and Jadro Rivers. The DNA was isolated from a fin clip from species of the family Salmonidae collected in the Krka, Vrljika and Jadro Rivers where the softmouth trout resides, and served as a positive control Finally, sections of the restrictive enzyme were tested for the selected molecular markets in the target species and other related species in the family, in order to determine whether there are clear differences. During the research, a number of potential markers were identified, and the clearest were cytochrome b, somatolactin, and lactate dehydrogenase. Of these markers, restriction digestion of somatolactin was able to detect the presence of softmouth trout and differentiate it from other salmonid species in the Krka River area in the eDNA samples.<\/p>\n

The eDNA marker method is most effective when combined with other standard ichthyological methods as a complementary research method, or with monitoring of an area or fish community, with any invasive impacts or over-selection. In this study, the visual census method was selected, and scuba diving and the use of an underwater drone (ROV) were applied. The visual census method proved to be good for the detection of small benthic species with a small range of movement, such as gobies, and for pelagic fish that form schools and that move in the water column. However, this method proved to be less successful for the detection of less abundant species that do not school, and often appear only individually in samples using other ichthyology methods.<\/p>\n

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Determining the state of the population of softmouth trout (Salmo obtusirostris) using eDNA and visual census method.<\/p>","protected":false},"author":2,"featured_media":12167,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[44],"tags":[],"class_list":["post-12166","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-research"],"_links":{"self":[{"href":"https:\/\/npkrka.hr\/en_us\/wp-json\/wp\/v2\/posts\/12166","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/npkrka.hr\/en_us\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/npkrka.hr\/en_us\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/npkrka.hr\/en_us\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/npkrka.hr\/en_us\/wp-json\/wp\/v2\/comments?post=12166"}],"version-history":[{"count":4,"href":"https:\/\/npkrka.hr\/en_us\/wp-json\/wp\/v2\/posts\/12166\/revisions"}],"predecessor-version":[{"id":14143,"href":"https:\/\/npkrka.hr\/en_us\/wp-json\/wp\/v2\/posts\/12166\/revisions\/14143"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/npkrka.hr\/en_us\/wp-json\/wp\/v2\/media\/12167"}],"wp:attachment":[{"href":"https:\/\/npkrka.hr\/en_us\/wp-json\/wp\/v2\/media?parent=12166"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/npkrka.hr\/en_us\/wp-json\/wp\/v2\/categories?post=12166"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/npkrka.hr\/en_us\/wp-json\/wp\/v2\/tags?post=12166"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}