Leptocephalus larvae are the unique stage of larval development in all groups of fishes from the superorder Elopomorpha (Anguilliformes, Elopiformes and Notacanthiformes). To explain the leptocephalus strategy of larv...Leptocephalus larvae are the unique stage of larval development in all groups of fishes from the superorder Elopomorpha (Anguilliformes, Elopiformes and Notacanthiformes). To explain the leptocephalus strategy of larval development, various attempts have been made on the morphology, physiology and biochemistry of leptocephalus larvae. However, the feeding mechanism of leptocephalus larvae is still unknown. The Japanese eel (Anguilla japonica) larvae were found to have well developed scotopic vision, mechanoreception and chemoreception. Both early and leptocephalus larvae of Japanese eel actively ingested a kind of paste food by first touching the food with their snout and then tearing off a big mouthful of the paste with their sharp teeth. Chemoreception was shown to be critical to elicit the feeding response. Feeding by Sflex posture from a distance might be of some significance for the early larvae to catch movable food. It is proposed that that the natural food of Japanese eel larvae would be relatively large, rather soft, inactive and negatively phototactic. The developmental mode of sensory system and behavior of Japanese eel larvae seems to be similar to some deep sea fishes but contrast with most marine teleost fishes.展开更多
文摘Leptocephalus larvae are the unique stage of larval development in all groups of fishes from the superorder Elopomorpha (Anguilliformes, Elopiformes and Notacanthiformes). To explain the leptocephalus strategy of larval development, various attempts have been made on the morphology, physiology and biochemistry of leptocephalus larvae. However, the feeding mechanism of leptocephalus larvae is still unknown. The Japanese eel (Anguilla japonica) larvae were found to have well developed scotopic vision, mechanoreception and chemoreception. Both early and leptocephalus larvae of Japanese eel actively ingested a kind of paste food by first touching the food with their snout and then tearing off a big mouthful of the paste with their sharp teeth. Chemoreception was shown to be critical to elicit the feeding response. Feeding by Sflex posture from a distance might be of some significance for the early larvae to catch movable food. It is proposed that that the natural food of Japanese eel larvae would be relatively large, rather soft, inactive and negatively phototactic. The developmental mode of sensory system and behavior of Japanese eel larvae seems to be similar to some deep sea fishes but contrast with most marine teleost fishes.
