DAIRELLIDAE Bovallius, 1887

Zeidler, Wolfgang, 2004, A review of the families and genera of the hyperiidean amphipod superfamily Phronimoidea Bowman & Gruner, 1973 (Crustacea: Amphipoda: Hyperiidea), Zootaxa 567, pp. 1-66 : 48

Family DAIRELLIDAE Bovallius, 1887

Diagnosis

Body length up to 10 mm; highly transparent. Head large, broad laterally. Eyes large, occupying most of head surface, divided into dorsal and ventral groups of ocelli. Pereon very broad with much narrower pleon tucked underneath. Pereonites 1 & 2 fused. Coxae fused with pereonites (suture sometimes visible). Antennae 1, four­articulate in females; multi­articulate in males, with enlarged callynophore, with two­field brush of aesthestascs medially. Antennae 2 absent in females, or reduced to small knob on cuticle; multi­articulate in males. Mandibles without palp in both sexes; molar relatively well­developed. Maxillae 1 with palp and reduced outer lobe; inner lobe absent. Maxillae 2 consist of a relatively large, single, pear­shaped plate. Maxilliped reduced to simple plate barely covering one­third of Mx2; inner and outer lobes fused or lost. Gnathopods and pereopods simple. Pereopods 3–7 subequal in length. Uropods with articulated endopods and exopods. Telson trapezoid, very small. Gills on pereonites 2–6. Oostegites on pereonites 2– 5.

One genus: Dairella .

Remarks

A most unusual feature of this family is the maxilliped, which is reduced to a single plate, a character shared only with the Paraphronimidae . However, the maxilliped only covers about one­third of the second maxillae, suggesting that the inner and outer lobes have been lost, and only the peduncle remains. In the Paraphronimidae there is a definite suture between the peduncle and the fused inner and outer lobes. Such a suture is absent in the Dairellidae .