Glass eels
Encyclopedia
Glass eels are the intermediary stage of eels between the leptocephalus
stage and the juvenile stage. The term typically refers to a tranparent glass eel of the family Anguillidae
. These are the freshwater eels that spawn in the ocean, and then enter estuaries as glass eels and swim upstream to live in freshwater during their juvenile growth phase. As the glass eels enter freshwater they start to become pigmented and are typically referred to as elvers. The elvers grow larger and are referred to as yellow eels, which are the juvenile stage of eels before their reproductive maturation begins.
Marine eels of the order Anguilliformes also have a leptocephalus stage, and likely pass through a stage similar to the anguillid glass eels, but they are rarely seen in the ocean.
Leptocephalus
A leptocephalus is the flat and transparent larva of the eel, marine eels, and other members of the Superorder Elopomorpha. Fishes with a leptocephalus larva stage include the most familiar eels such as the conger, moray eel, and garden eel, and the freshwater eels of the family Anguillidae, plus...
stage and the juvenile stage. The term typically refers to a tranparent glass eel of the family Anguillidae
Anguillidae
Anguillidae is a family of fishes that contains the freshwater eels. There are 19 species/subspecies in this family, all in genus Anguilla. They are catadromous, meaning they spend their lives in freshwater rivers, lakes, or estuaries and return to the ocean to spawn...
. These are the freshwater eels that spawn in the ocean, and then enter estuaries as glass eels and swim upstream to live in freshwater during their juvenile growth phase. As the glass eels enter freshwater they start to become pigmented and are typically referred to as elvers. The elvers grow larger and are referred to as yellow eels, which are the juvenile stage of eels before their reproductive maturation begins.
Marine eels of the order Anguilliformes also have a leptocephalus stage, and likely pass through a stage similar to the anguillid glass eels, but they are rarely seen in the ocean.