Title Analiza sastava populacije vrste Arca noae (Linnaeus,1758) iz Kaštelanskog zaljeva Title (english) Population structure analysis of species Arca noae (Linnaeus, 1758) from Kaštela Bay Author Nikol Petrić Mentor Sanja Puljas (mentor)Committee member Sanja Puljas (predsjednik povjerenstva)Committee member Mate Šantić (član povjerenstva)Committee member Antonela Paladin (član povjerenstva)Granter University of Split Defense date and country 2022-09-29, Croatia Scientific / art field, NATURAL SCIENCES Abstract Uz vrste Pecten jacobaeus, Venus verrucosa, Mytilus galloprovincialis i Ostrea edulis, vrsta Arca noae jedna je od značajnijih komercijalnih školjkaša koji su izloženi prekomjernom iskorištavanju. Iako se o biologiji vrste dosta zna, zasad ne postoji dovoljno podataka o intenzitetu ribolova i stanju iskorištavanih populacija. Stoga je cilj ovog rada bio utvrditi razinu ribolovnog pritiska na populaciju iz Kaštelanskog zaljeva u svrhu prikupljanja informacija za procjenu stanja populacije na ovom lokalitetu. Određivan je dužinski sastav jedinki u komercijalnom ulovu s osvrtom na udio jedinki manjih od minimalne dopuštene lovne dužine. Uz opisivanje sastava jedinki u odnosu na spol i veličinu jedinki, istražen je i reproduktivni potencijal vrste, te trenutni selektivni pritisak na jedinke određenog spola i određenih dužinskih kategorija. Za analizu komercijalnog ulova obrađeno je 50 jedinki, a za analizu reproduktivnog potencijala jedinki kraćih duljina od dozvoljene lovne dužine obrađeno je 20 jedinki. Svim jedinkama određeni su morfometrijski parametri, te je za svaku jedinku određen spol histološkom metodom. Zabilježen je selektivni pritisak obzirom na spol. Od 50 analiziranih jedinki iz komercijalnog ulova, 12 (24%) su bili mužjaci dok je 38 (76%) bilo ženskog spola. 34% jedinki bilo je nedoraslo (<50 mm). 76,5% nedoraslih jedinki u ulovu bile su ženke, dok je gotovo isti udio ženki zabilježen i kod ulova doraslih jedinki (76%). Zabilježen je i selekcijski pritisak na ženke dužine ljuštura između 50 i 60 mm. Analizirano je i 20 mladih jedinki raspona dužina od 25,79 mm do 35,62 mm u svrhu utvrđivanja reproduktivnog potencijala i dužinske kategorije kod koje jedinke iz Kaštelanskog zaljeva postaju spolno aktivne. Reproduktivni potencijal jedinki iz komercijalnog ulova i svih mladih jedinki iznosio je 100%. Ovim istraživanjem potvrđeno je da jedinke znatno kraćih dužina od minimalne dozvoljene lovne dužine imaju mogućnost sudjelovanja u mrijestu, ali upozorava na mogućnost prekomjernog iskorištavanja sve manjih jedinki u budućnosti budući da je ustanovljeno da populacijom dominiraju mlađe ženke.
Abstract (english) Along with the species Pecten jacobaeus, Venus verrucosa, Mytilus galloprovincialis and Ostrea edulis, the species Arca noae is one of the most important commercial bivalves subject to overfishing. Although much is known about the biology of the species, there is currently insufficient data on the intensity of fishing and the status of exploited populations. Therefore, the aim of this work was to determine the extent of fishing pressure on the population in Kaštela Bay in order to gather information for assessing the status of the population in this area. The length composition of individuals in the commercial catches was determined based on the proportion of individuals smaller than the minimum allowable length for hunting. In addition to describing the composition of individuals in terms of sex and size, the reproductive potential of the species and current selection pressure on individuals of a particular sex and length categories were also examined. Fifty individuals were processed for commercial capture analysis and 20 individuals were processed for reproductive potential analysis of individuals shorter than the allowed hunting length. Morphometric parameters were determined for all individuals, and the sex of each individual was determined by histological method. Selective pressure in relation to sex was recorded. Of the 50 individuals analysed from the commercial catch, 12 (24%) were male, while 38 (76%) were female. 34% of the individuals were immature (< 50 mm). 76.5% of juveniles in the catch were female, while almost the same proportion of females were in the catch of mature individuals (76%). Selection pressure on females with shell length between 50 and 60 mm was also observed. Twenty juvenile individuals ranging in length from 25.79 mm to 35.62 mm were analysed to determine the reproductive potential and length category at which individuals from Kaštela Bay become sexually active. The reproductive potential of individuals from the commercial catch and all juveniles was 100%. This study confirmed that individuals significantly shorter than the minimum allowable length for hunting have the potential to participate in spawning. However, it cautions against the potential overfishing of smaller individuals in the future, as it was found that the population is dominated by younger females.
Keywords
Arca noae
prekomjerno iskorištavanje
komercijalni ulov
reproduktivni potencijal
Keywords (english)
Arca noae
overexploitation
commercial catch
reproductive potential
Language croatian URN:NBN urn:nbn:hr:166:057442 Study programme Title: Biology and Chemistry; specializations in: major in teaching Type of resource Text File origin Born digital Access conditions Access restricted to authenticated users Terms of use Created on 2023-02-17 11:00:30
