Journal of Aquatic Science. 2013, 1(1), 7-10DOI:
Abstract: The effects of Clove Seed extracts as anaesthetic agents in two species of grey mullets Liza Falcipinnis and Liza grandisquamis were assessed. A total of 120 of these species comprising 60 L. Falcipinnis with 30 each of fingerlings (mean length 9.86cm ± 1.11 SD: mean weight 21.20g ± 2.10 SD) and juveniles (mean length 17.24cm ±1.88 SD; mean weight 66.24g ± 4.24SD) and 60 L. grandisquamis also consists of 30 each of fingerlings (mean length 10.24cm ± 1.92 SD; mean weight 23.41 ± 2.21 SD) and juveniles (mean length 18.21cm ±SD; mean weight 71.21g ± 4.12 SD) were sampled from the recruitment ponds at African Regional Aquaculture Center, (ARAC), Buguma, Rivers State and were exposed to clove seed extracts at different concentrations of 0.0mg/L (control), 5.0, 10.0, 15.0, 20.0 and 25.0mg/L. The results obtained indicated a size related response, to Clove seed extracts. The induction time in both species were found to decreased significantly (P < 0.05) as the concentrations of the clove extracts increased with the shortest induction time 55.61(s) observed in fingerlings of L. grandisquamis, while the longest 210.61 (s) was recorded in juveniles of L. falcipinnis. However, the recovery time increased significantly with increasing concentration of the clove seed, with the highest recovery time of 350.11 (s) observed in L. falcipinnis, at 25.0mglL concentration and the lowest 246.91(s) in L. grandisquamis at 5.0mg/L concentration of the clove extracts, with the optimum dosage of 10.0mg/l and 15.0mg/l for fingerlings and juvenile sizes respectively. Interestingly, the survival of the exposed fish during the trial was 100% in both sizes of the two species,as no mortality was recorded in all concentrations of the plant extracts. The findings of this trial, indicated that clove seed extracts was effective, producing minimum stress and zero mortalities and therefore can be recommended as an effective anaesthetic for use in aquaculture.