Biologija kozice Parapenaeus longirostris (Lucas, 1846) (Crustacea, Decapoda) na šelfu crnogorskog primorja

Abstract

Jedna od najvažnijih komercijalnih vrsta dekapodnih rakova u kočarskom ribolovu na šelfu Crnogorskog primorja je kozica, Parapenaeus longirostris (Lucas, 1846). Istraživanje je obavljeno tokom dvije godine, od novembra 2006. do oktobra 2007. i od juna 2009. do maja 2010. godine pri čemu su uzorci uzimani sa kočarskih brodova mjesečnom dinamikom. Tokom prve godine je ukupno obrađeno 1979 jedinki, od kojih su 1421 (71.80%) bile ženke a 558 (28.20%) mužjaci. Odnos polova je i u drugoj godini bio u korist ženki tokom koje je analizirano 1967 jedinki, od kojih su 1304 (66.30%) bile ženke a 663 (33.70%) mužjaci. Raspon dužina karapaksa svih ulovljenih jedinki zajedno je bio manji u prvoj godini i kretao se od 15 do 37 mm (25.23 ± 4.48) dok je u drugoj taj raspon bio 11-37 mm (24.85 ± 4.48). Uočen je polni dimorfizam: ženke su u prosjeku i duže i teže od mužjaka, i u dužinskim grupama >28- 30 mm CL su 100% prisutne u ulovu. Mužjaci su u boljoj kondiciji od ženki. Vrijednosti alometrijskog koeficijenata b dužinsko-težinskog odnosa u prvoj godini iznose b = 2.58 za ukupan uzorak, b = 2.51 za ženke i b = 2.34 za mužjake; dok te vrijednosti za drugu godinu iznose b = 2.59 za ukupan uzorak, b = 2.57 za ženke i b = 2.33 za mužjake. Prva polna zrelost ženki je nastupila pri dužini karapaksa od 20.48 mm u prvoj godini, odnosno od 19.89 mm CL u drugoj godini...

Parapenaeus longirostris (Lucas, 1846) is one of the most economically important decapod species in the trawl fishery on the Montenegrin shelf (southern Adriatic Sea). Despite its importance, there were no biological studies on the species for that area. Data were obtained from monthly samples taken from commercial catches realized in the southern Adriatic during the period from November 2006 to October 2007 and from June 2009 to May 2010. During the first year among the 1979 specimens, 71.80% were females and 28.20% males, while during the second year of investigation, among the 1967 specimens, 66.30% were females and 33.70% males. The overall sex ratio was in favour of females. The carapace length of all specimens ranged from 15 to 37 mm, with a mean of 25.23 ± 4.48, while during the second year the range of carapace length of all specimens was wider and ranged from 11 to 37 mm, with a mean of 24.85 ± 4.48. A marked sexual dimorphism was observed between males and females: females have a wider size range, greater size and weight. Percentage of females reached 100% in the 28-30 mm size class and beyond. Males were in better condition than females. The calculated allometric coefficient of length-weight relationships was b= 2.58 for the total sample of 2006-2007 year, b= 2.51 for females and b= 2.34 for males; while during the 2009-2010 values were b=2.59 for the total sample, b=2.57 for females and b=2.33 for males. The size at which 50% of the female population reached maturity was at a carapace length of 20.48 mm in the first year and 19.89 mm during the second year...