Mukai Yukinori, Sanudin Noorsyarinah, Firdaus Rian Freddie, Saad Shahbudin
Institute of Oceanography and Maritime Studies (INOCEM), Kulliyyah of Science, International Islamic University Malaysia, Jalan Sultan Ahmad Shah, Bandar Indera Mahkota, 25200 Kuantan, Pahang, Malaysia.
Zoolog Sci. 2013 Jun;30(6):421-4. doi: 10.2108/zsj.30.421.
In general, African catfish shows higher survival rates in the dark conditions than in the light conditions. In this study, larval behavior of African catfish was observed under 0, 0.01, 0.1, 1, 10, and 100 lx using a CCD camera to investigate the reason why African catfish larvae show higher survival rates in dark conditions. The larvae showed significantly higher swimming activity under 0, 0.01, and 0.1 lx than that under 10 and 100 lx. The larvae also showed significantly increased aggressive behavior under 10 and 100 lx; the swimming larvae attacked resting individuals more frequently under 10 and 100 lx than under 0, 0.01, and 0.1 lx. The aggressive behavior and sharp teeth of the attacking larvae appeared to induce skin surface lesions on injured larvae. Chemical substances were then generated from the injured skin surface, and these chemical stimuli triggered cannibalistic behavior in other fish near the injured fish. The results of this study demonstrate that the higher survival rates of African catfish larvae under dark conditions are a result of inactivity and subsequent increase in chemical releasing stimuli concentrations around inactive individuals that triggers feeding behavior in nearby active catfish. Therefore, we recommend larval rearing of African catfish in dark or dim conditions, as it improves catfish survival rates.
一般来说，非洲鲶鱼在黑暗条件下的存活率高于光照条件下。在本研究中，使用CCD相机观察了非洲鲶鱼幼鱼在0、0.01、0.1、1、10和100勒克斯光照强度下的行为，以探究非洲鲶鱼幼鱼在黑暗条件下存活率更高的原因。幼鱼在0、0.01和0.1勒克斯光照强度下的游泳活动明显高于在10和100勒克斯光照强度下。幼鱼在10和100勒克斯光照强度下的攻击行为也显著增加；与在0、0.01和0.1勒克斯光照强度下相比，游泳的幼鱼在10和100勒克斯光照强度下更频繁地攻击静止的个体。攻击幼鱼的攻击行为和锋利牙齿似乎会导致受伤幼鱼的皮肤表面出现损伤。然后，受伤的皮肤表面会产生化学物质，这些化学刺激会引发受伤鱼附近其他鱼类的同类相食行为。本研究结果表明，非洲鲶鱼幼鱼在黑暗条件下较高的存活率是由于不活动以及随后不活动个体周围化学释放刺激浓度增加，从而触发附近活跃鲶鱼的摄食行为。因此，我们建议在黑暗或昏暗条件下饲养非洲鲶鱼幼鱼，因为这样可以提高鲶鱼的存活率。
