Abstract | Tijekom jednogodišnjeg istraživanja populacije kneza u istočnom dijelu Jadrana analizirane su ukupno 1393 jedinke, od čega 214 primarnih mužjaka (15,3%), 433 sekundarna mužjaka (31,1%), 570 ženki (40,9%), 104 jedinke u prijelaznom obliku (7,5%), te 72 jedinke neodređenog spola (5,2%). Omjer mužjaka i ženki nije se značajno razlikovao od 1:1. Raspon ukupne dužine tijela svih analiziranih primjeraka iznosio je od 4,8 do 22,2 cm (12,3 ± 2,55 cm), a mase od 0,9 do 104,4 g (18,8 ± 13,14 g). U dužinskim razredima od 6,0 do 12,0 cm zabilježen je veći broj ženki, dok u razredima od 13,0 do 22,0 cm dominiraju mužjaci. Dužinsko – maseni rast kneza je pozitivno alometrijski (b = 3,233), a vrijednost indeksa kondicije relativno je niska (IK = 0,862). Srednje vrijednosti morfometrijskih odnosa ne razlikuju se značajno između primarnih mužjaka i ženki, dok se sekundarni mužjaci razlikuju u osam odnosa. U ishrani kneza najzastupljenija su koljena Mollusca (razredi Gastropoda i Bivalvia) i Arthropoda (red Decapoda). Rast kneza opisan je von Bertalanffyevim modelom rasta (L∞ = 25,4 cm; k = 0,16; t0 = -1,19), a zabilježena je i značajna razlika u parametrima rasta među spolovima. Najveća zabilježena starost iznosila je 7 godina za mužjake i 5 godina za ženke. Starost kneza moguće je uspješno procijeniti na temelju dužine i mase otolita. Knez se u istočnom Jadranu razmnožava od travnja do rujna, s vrhuncem u lipnju i srpnju. Dužina prve spolne zrelosti primarnih mužjaka iznosi 8,5 cm, ženki 9,5 cm, a sekundarnih mužjaka 13,6 cm. Fekunditet kneza nalazio se u rasponu od 907 do 29582 zrelih oocita (8796,9 ± 5946,43), a uočeno je da se povećava s porastom veličine tijela, masom gonada i starosti jedinki. Ukupna smrtnost kneza u istočnom Jadranu je Z = 1,28, prirodna smrtnost iznosi M = 0,41, a ribolovna smrtnost F = 0,87. Udio kneza u lovinama obalne mreže potegače migavice iznosi 1,75% gledajući broj primjeraka, odnosno 1,60% gledajući masu ulova. Udio kneza u lovinama sportskih ribolovaca značajno je veći pri ribolovu s obale (48,0% broja ulovljenih primjeraka i 34,0% mase), nego pri ribolovu iz brodice (14,0% broja ulovljenih primjeraka i 9,7% mase). Srednja lovna dužina i masa kneza statistički su značajno manje pri ribolovu s obale (13,9 cm i 28,1 g), nego pri ribolovu iz brodice (16,7 cm i 48,3 g). |
Abstract (english) | A total of 1393 Coris julis specimens from the eastern Adriatic were analyzed: 214 primary males (15.3%), 433 secondary males (31.1%), 570 females (40.9%), 104 intermediate specimens (7.5%) and 72 specimens of undetermined sex (5.2%). Total length of specimens ranged from 4.8 to 22.2 cm (12.3 ± 2.55 cm) and weight from 0.9 to 104.4 g (18.8 ± 13.14 g). Females dominated in length classes from 6.0 to 12.0 cm and males in length classes from 13.0 to 22.0 cm. The length-weight relationship showed positive allometric growth (b = 3.233) and estimated condition factor was relatively low (CF = 0.862). No difference was found between primary males and females regarding measured morphometric characteristics, while secondary males differed from these two groups in eight characters. Diet of the Mediterranean rainbow wrasse was dominated by species in phylum Mollusca (classes Gastropoda and Bivalvia) and phylum Arthropoda (order Decapoda). The growth was described by von Bertalanffy growth model (L∞ = 25.4 cm; k = 0.16; t0 = -1.19) and significant difference in growth parameters between males and females was found. Maximum determined age for males and females was 7 and 5 years, respectively. Age of the Mediterranean rainbow wrasse was successfully estimated based on the otolith length and weight. Spawning of C. julis in the eastern Adriatic takes place from April until September, with a peak in June and July. Length of the first sexual maturity is 8.5 cm for primary males, 9.5 cm for females and 13.6 cm for secondary males. The female fecundity ranged from 907 to 29582 oocytes (8796.9 ± 5946.43) and it increased with body size, gonad size and age of the fish. Total mortality of C. julis in the eastern Adriatic was Z = 1.28, with natural mortality M = 0.41 and fishing mortality F = 0.87. In the landings of the coastal beach seine 'migavica', C. julis accounted for the 1.8% of the numbers caught and 1.6% of the total catch weight. In the 'hook and line' sport fishing, proportion of C. julis in overall catches was significantly higher for shore angling (48.0% of the numbers caught and 34.0% of the total weight), compared to the boat angling (14.0% of the numbers caught and 9.7% of the total weight). |