Details

Autor(en) / Beteiligte

• Sievers, Gerold
• Lobos, Carlos
• Inostroza, Ricardo
• Ernst, Santiago

Titel

The effect of the isopod parasite Ceratothoa gaudichaudii on the body weight of farmed Salmo salar in southern Chile

Ist Teil von

• Aquaculture, 1996-07, Vol.143 (1), p.1-6

Ort / Verlag

Amsterdam: Elsevier B.V

Erscheinungsjahr

1996

Quelle

Elsevier Journal Backfiles on ScienceDirect (DFG Nationallizenzen)

Beschreibungen/Notizen

• A study of the isopod Ceratothoa gaudichaudii, a parasite on farmed Atlantic salmon was carried out on Guar island, Chile, between May 1993 and August 1994. A total of 671 salmon, with an initial body weight of 0.9 kg to 1.1 kg, was selected; one third were naturally infected with one or two growing parasites. The fish were kept in a separate cage and were examined individually, under anaesthesia, five times during the study. On each occasion, the weight and number of the parasites on each fish was recorded. There was an increase in the prevalence of the parasitosis from 33.4% to 98.2%; concurrently, the total number of parasites on salmon rose from 309 to 3987 with an increase of infestation intensity from 1.4 to 6.1 parasites per fish. No adult females with eggs or larvae were found. At the end of the study, salmon with less than three parasites weighed 4428 ± 949 g; those with three to eight parasites weighed 4151 ± 983 g, and those with more than eight parasites weighed 3763 ± 1056 g. A significant difference in weight ( P < 0.05) among the three groups was detected.