Naslov
ISOPOD PARASITE Ceratothoa oestroides (Risso, 1826) IN CULTURED SEABASS (Dicentrarchus labrax L. 1758) FROM THE ADRIATIC AND IMPLICATIONS FOR MANAGEMENT STRATEGIES IN AQUACULTURE

Autori
Čolak, Slavica ; Lovrinov, Mario ; Župan, Ivan ; Tkalčić, Suzana ; Šarić, Tomislav

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

Izvornik
IAAAM 43rd Annual Conference Proceedings, May 2012, Atlanta, Georgia / - , 2012, 30-31

Skup
43rd Annual IAAAM Conference

Mjesto i datum
Atlanta (GA), Sjedinjene Američke Države; Gruzija, 12.05.2012. - 16.05.2012

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Nije recenziran

Ključne riječi
Sea bass; Ceratothoa oestroides; Adriatic; aquaculture

Sažetak
Ceratothoa oestroides is an isopod parasite of the family Cymothoidae, which invades several fish species in shallow waters of the Adriatic Sea. Although never reported in free-ranging populations, it is considered a common isopod parasite in farm-raised sea bass (Dicentrarchus labrax L. 1781). Ceratothoa oestroides is a protandrous, hermaphroditic parasite. Adult male and female parasites live in the buccal cavity of the fish, and their holoxenic life cycle includes a single host. The parasite eggs are laid into the marsupium of the female, where they hatch into “pullus larvae” that actively search for a host upon exit. The negative impact of the parasite on the fish growth and survival has been reported for several sea bass farming operations along the Croatian coast. Infested fish populations have significantly reduced growth and increased mortality compared with non-infested fish. In general, parasitic infection of fish depends on many host-related (age, size), feeding, and environmental factors. The disease prevalence is associated with the presence and numbers of pulli II larvae, fish density, and biogeographical characteristics of the farms. This study of Ceratothoa oestroides infestation in the cultured sea bass was carried out on one fish farm in Zadar County, Croatia. The aim was to provide new insights into parasite life cycle in this geographic area in order to improve existing fish farm management strategies. Samples were considered as one population since they were collected from one offshore cage, and the fish were of the same age and origin. A total of 609 parasitized fish with the body weight ranging 76.2–456.4g were collected during the winter and summer harvest season (a total of 12 sampling periods). Cymothoids were removed from all infested fish, and the number of parasites and their life stages were recorded. Ceratothoa oestroides was identified according to established criteria, and the morphological parameters of each parasite and the host fish were recorded. The number of pulli larvae held in female’s marsupium was counted. The results show no seasonal variation, and no effect of the sea temperature or moon phases on the reproductive activity of Ceratothoa oestroides. Significant positive correlation was found between the fecundity of female parasites and the daylight time. Our study suggests several farm management strategies for the control of cymothoid infections. These include seeding of sea bass fry on farm in autumn period during the shorter daylight time, and introduction of larger fingerlings as possible ways in disease prevention.

Izvorni jezik
Engleski

Znanstvena područja
Biologija, Veterinarska medicina, Biotehnologija

POVEZANOST RADA