Naslov
Fat reserves and moisture content in relation to sexual cycle of sardine, Sardina pilchardus (Walb., 1792), in the Eastern Middle Adriatic fishery grounds (Croatia)

Autori
Mustać, Bosiljka ; Sinovčić, Gorenka

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

Izvornik
Abstracts of the XXth International Congress of Zoology ; u: Integrative Zoology 3 (2008) (S) / - Pariz, 2008, 38-38

Skup
International Congress of Zoology (20 ; 2008)

Mjesto i datum
Pariz, Francuska, 26.08.2008. - 29.08.2008

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
sardine; Adriatic Sea; fat content; sexual cycle; condition

Sažetak
The fat reserves, moisture and sexual cycle of sardine, Sardina pilchardus (Walb., 1792), were studied from monthly random samples of purse seine catches from March 2004 to February 2005. Catches were realised in offshore (Dugi Otok) and inshore waters (Virsko more) of the Mid Adriatic Sea. A total of 1, 219 sardine specimens were collected, out of which 668 were males and 541 females. Fish were measured, weighed and sexed. The sexual cycle analysis was based on the temporal evolution of gonadosomatic index and gonad mass. Gonadosomatic index (GSI) was calculated by expressing the monthly gonad weight as a proportion of the total body weight. The fat content was examined on the basis of monthly analyses of mesenteric fat in the visceral cavity and by determining the amount of lipid content in sardine tissues using Soxhlet’ s s method. The total length of sardine ranged from 13.0 to 19.0 cm and the mass from 16.7 to 51.5 g. The reproductive period was from October to April. The mean percentage of mesenteric fat grades in visceral cavity points to the greatest fat quantities in August, when grade 4 (fattest fish) presence amounted 72%. The value is the result of an increase of mesenteric fat started in June and proceeding in the successive months until October. During autumn, a decrease trend is evident and it becomes pronounced in winter and spring (lowest mesenteric fat quantity). Thereafter an increase in mesenteric fat was recorded, indicated by the records of grades 3 and 4. Due to such variations in mesenteric fat and tissue lipid during year, i.e. its greatest levels in summer (out of spawning) and lowest levels in the colder part of the year (during sardine spawning), it was assumed that quantity of sardine fat was affected by its sexual cycle. Lipid content in terms of sardine tissue dry weight showed the same trends as mesenteric fat - highest amounts during resting phase of reproduction (41.1%) and lowest during the peak of spawning (1.0-2.2%). Amounts of total lipids and moisture in sardine tissues showed that females had more fat content and less moisture than males. An inverse correlation between fat content and sexual cycle on one side and lipid content and moisture on the other has been noted. Sardine condition index had low, but similar, values between March and May, which tend to grow and peak during June, August and September. Namely, the fish from the period in which stages V and VI were not presented was generally in better condition ( = 0.8234) than the fish caught during the spawning season ( = 0.7409). After that it decreased during the November-February period.

Izvorni jezik
Engleski

Znanstvena područja
Biologija, Biotehnologija

POVEZANOST RADA