ammocete

or am·mo·coete

[ am-uh-seet ]
/ ˈæm əˌsit /

noun

the larval stage of a lamprey.

Origin of ammocete

1855–60; < New Latin ammocoetes literally, something bedded in sand < Greek ámmo(s) sand + koítē bed
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019