Family HOLOGNATHIDAE Thomson, 1904

Cleantioides striata

Museums

Museum list

Regional Maps

Family HOLOGNATHIDAE Thomson, 1904

Introduction

Holognathids are an unusual group of idoteid-like valviferans, many of which are tubicolous in the hollow stems of seagrasses (Issel 1912; Hale 1929). Until recently only a single species, from New Zealand, was recognised, but a revision by Poore & Lew Ton (1990) and more recent discoveries have expanded the family diagnosis to include 20 species in four genera from most seas. The diagnosis is from Poore (2001).

Diagnosis

Body straight, more or less flattened or semicylindrical; parallel-sided over most of length. Head and pereonite 1 free. Head more or less semi-cylindrical. Pereonite 4 of similar length to pereonite 3. Pleonites 1–3 articulating with each other and fused pleotelson, or pleonites 1–2 articulating with each other and fused pleotelson, or pleonite 1 articulating with fused pleotelson (other pleonites sometimes indicated laterally or dorsally). Body smooth or slightly sculptured. Dorsal coxal plates 2–7 more or less ventrally expanded over bases of pereopods. Eyes well developed, or reduced or lost (Zenobianopsis only).

Antenna 2 flagellum multiarticulate, or clavate (usually with minute terminal article(s)). Maxillipedal epipod as long as or longer than wide. Pereopod 1 slightly differentiated from pereopod 2, its propodus broader than in pereopod 2. Pereopods 2–4 with irregular fine setae and marginal robust setae; with prominent dactylus, unguis short; pereopod 4 shorter and more spinose than pereopods 3 and 5. Pereopods of males with dense fur of fine setae. Uropodal exopod (smaller ramus) ovate, fringed with setae (if present), more than half as long as endopod.

Oostegites 1–5 functional. Penes fused basally as a penial plate but divided over most of length. Pleopod 1 peduncle short (similar to other pleopods); with marginal setae on rami longer than or equal to length of rami. Pleopod 1 exopod of male laminar. Pleopod 2 of male with appendix masculina about as long as endopod, basally less than half width of endopod.