Naslov
Towards a reliable assessment of the European conger eel, Conger conger (L.) in the Mediterranean Sea: Population parameters for life history

Autori
Matić-Skoko, Sanja ; Ferri, Josipa ; Tutman, Pero ; Skaramuca, Daria ; Đikić, Domagoj ; Lisičić, Duje ; Franić, Zdenko ; Skaramuca, Boško

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Sustainable Fisheries in a Changing World / Huntingford, Felicity - Edinburgh : FSBI Conference Ltd, 2012, 222-222

Skup
6th World Fisheries Congress

Mjesto i datum
Edinburgh, Ujedinjeno Kraljevstvo, 07.05.2012. - 11.05.2012

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
age determination; growth; feeding; Conger conger; Mediterranean

Sažetak
Basic biological data, as important input parameters for stock assessment techniques, for the population of the European conger eel, Conger conger (L.) are presented based on a one-year study conducted in the north-central Mediterranean (Adriatic coastal waters). The total length (TL) and weight (W) of the sampled congers eels (N = 317) ranged from 23.4 to 144.0 cm and 43.8 to 6180.0 g, respectively. Majority of all sampled conger eels were females. The greatest increase of gonadosomatic index occurred in winter but the absence of males and mature females in the coastal waters suggests sexual separation, different spawning migration patterns and spawning grounds somewhere in deeper waters. Ground otoliths displayed a clearly visible pattern of alternating opaque and translucent zones which were used to estimate C. conger ages. Both edge-type and marginal increment analysis confirmed the formation of a single growth annulus per year. The relationship between the total length and age was described by the von Bertalanffy growth model: TL = 187.231 – exp (-0.11(t + 0.23)). Observed maximum age of coastal conger eel population was 8 years although most of the sampled fish were 5 years old. C. conger is opportunistic predator and its diet was composed mainly of fishes, followed by crustaceans and cephalopods. Due expressed site fidelity, wide prey spectrum (33 taxa) reflected local marine community structure and biodiversity level. There was no difference (P > 0.05) among the food items of fish specimens in different size classes or those sampled in different seasons. Regarding the fact that several important biological indices are still unclear, intensified and integrated research throughout Mediterranean is necessary in order to determine a common strategy for reliable assessment of this species.

Izvorni jezik
Engleski

Znanstvena područja
Biologija

POVEZANOST RADA