Pinnotheridae de Haan, 1833

Pinnotheridae comprises a diverse group of small crabs that live as symbionts within vertebrates. All Pinnotheridae are marine species with a worldwide distribution, living in close relationship with their hosts. Independently of the type of host or symbiotic relationship (parasitic, commensalistic), all species with known larval development present free-living larval stages (except Tunicotheres moseri, where larval stages develop in the abdominal enclosure of the parental female). The larval development comprises  a zoea phase, with a variable number of stages (2–5),  and a megalopa phase with a single stage. Approximately 290 pinnotherid species have been described, and information on larval developmental stages is available for 54 of them. This leaflet presents the distinctive features of the larval stages for 12 out of 13 species distributed in ICES area: Pinnixulala retinens, Pinnixa cylindrica, P. lunzi, Rathbunixa sayana, Tubicolixa chaetopterana, Afropinnotheres monodi, Dissodactylus mellitae, Nepinnotheres pinnotheres, Pinnotheres  bicristatus, P.  pectunculi, P.  pisum, Tumidotheres  maculatus, and Zaops  ostreus. Complete larval development is only known for 6 of these species. Illustrated keys to identify the known zoea and megalopa stages are included.