actinula
/akˈtɪnjʊlə/Zoology
noun
In some hydrozoans: a mobile tentaculate larva, which develops from a planula and transforms into an adult polyp or medusa after dispersal.
Origin
Late 19th century; earliest use found in George Allman (1812–1898), naturalist. From ancient Greek ἀκτῖν-, ἀκτίς ray + -ula, after planula.