RESUMO
The toxicity of water-ethanol extracts of garlic (Allium sativum), ginger (Zingiber officinale), basil (Ocimum basilicum), bitter chaparro (Castela tortuousa), onion (Allium cepa) and papaya (Carica papaya) against adults, eggs and oncomiracidia of Neobenedenia spp. parasites was examined. Parasites were exposed to continuous immersion and treated as follows: extracts were tested at three dilutions: 1:10, 1:50 and 1:100 made with filtered seawater (35 g l-1); ethanol (70%) was evaluated at the same dilutions of 1:10 (7% ethanol), 1:50 (1.4% ethanol) and 1:100 (0.07% ethanol) and a seawater (35 g l-1) control. The antiparasitic effect was measured on: (1) adult survival, egg production and time to detachment from the culture vessel; (2) egg development and cumulative egg hatching; and (3) oncomiracidia survival. All three dilutions of ginger and dilutions 1:100 and 1:50 of basil extract reduced adult survival in vitro, time to detachment from the surface of the culture vessel, egg production and oncomiracidia survival. Bitter chaparro extract reduced adult egg production and oncomiracidia survival. Hatching success was significantly reduced (P < 0.05) in basil extract (1:100) to 86.6% compared to the seawater control (100%). Dilutions 1:10 of ginger and basil exhibited the highest impact on the biological parameters of Neobenedenia sp. Our study demonstrates that water-ethanol extracts of ginger, basil and bitter chaparro are toxic against Neobenedenia sp. life stages.
Assuntos
Ectoparasitoses/veterinária , Doenças dos Peixes/tratamento farmacológico , Helmintíase Animal/tratamento farmacológico , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Trematódeos/efeitos dos fármacos , Animais , Antiplatelmínticos/farmacologia , Antiplatelmínticos/uso terapêutico , Ectoparasitoses/tratamento farmacológico , Ectoparasitoses/parasitologia , Doenças dos Peixes/parasitologia , Helmintíase Animal/parasitologia , Magnoliopsida/química , Óvulo/efeitos dos fármacos , Óvulo/fisiologia , Trematódeos/fisiologiaAssuntos
Ácidos Docosa-Hexaenoicos/farmacologia , Expressão Gênica , Linoleoil-CoA Desaturase/genética , Perciformes/genética , Animais , Ácidos Docosa-Hexaenoicos/administração & dosagem , Relação Dose-Resposta a Droga , Larva/genética , Larva/crescimento & desenvolvimento , Larva/metabolismo , Linoleoil-CoA Desaturase/metabolismo , Perciformes/crescimento & desenvolvimento , Perciformes/metabolismoRESUMO
Reproduction in yellowtail snapper Lutjanus argentiventris took place after compressing the seasonally changing day length into a 3 month period applied during two consecutive winters, with the longest and shortest days in December and February, respectively. During the first winter, there was no clear peak of days of spawning and the production of viable eggs was similar from the longest and throughout the decreasing day lengths until reproduction ceased. The level of plasma vitellogenin rose abruptly to a maximum concentration during the increasing day length and then decreased dramatically before the longest day length. During the second winter, a clear peak in the number of days of spawning and the highest production of viable eggs occurred around the longest day length. These results showed that it is feasible to synchronize day length between winter-induced and natural summer and autumn reproduction to produce eggs and larvae during the year.