Some larval stages of three Australian crabs belonging to the families Homolidae and Raninidae, and observations on the affinities of these families (Crustacea: Decapoda).

Abstract

Descriptions are given of the first zoeal stage of Latreillia australiensis Henderson (Homolidae), a megalopa ascribed to Paromola petterdi (Grant) (Homolidae) and all zoeal stages and the megalopa of Lyreidus tridentatus de Haan (Raninidae). These larvae are compared with other known larvae of their respective families and the larval characters of these families are summarized.

Larval characters indicate the Homolidae to be a rather primitive offshoot from the ancestral stock of the Brachyura and the Raninidae to be a less primitive offshoot from the same stock. They do not favour the grouping of the Homolidae with the Dromiidae in the Dromiacea or the grouping of the Raninidae with the Dorippidae, Calappidae, and Leucosiidae in the Oxystomata.