Metalimnadia Mattox, 1952

Rogers, D. Christopher, 2020, Spinicaudata Catalogus (Crustacea: Branchiopoda)., Zoological Studies 59 (45), pp. 1-44 : 14-15

Metalimnadia Mattox, 1952

= Paraimnadia Roessler, 1991a

Diagnosis: (modified from Rogers et al. 2012) Populations composed of males and females; amplexus is venter to venter. Rostrum acute, truncated or elongate and truncated in both sexes. Angle between rostrum and frons 80° to 110°. Occipital notch present. Frontal organ sessile, slightly protruding. Carapace dorsal margin smooth, without dorsal carinae. Umbone present, with lateral carinae or tubercles. Hinge line straight or arcuate, anterior end may project. Carapace surface between growth lines smooth, punctate, or malleate. Carapace often with pigmentation. Muscle scar circular or elongate, with angle at 20 degrees from normal. Thoracic segments sometimes with dorsoposterior ridge margined with spines or setae. Male first two thoracopods with endopod bearing an apical suctorial organ. Endite IV typical for family. Eggs attaching to prolonged exopods of thoracopods IX and X. Telson with spiniform projection on ventroposterior angle, anteriad of cercopod base. Telson posterior spine rows confluent dorsally, with confluence not projecting. Each row with nine to 16 spines. Caudal filament originating between spine rows at second, third, or fourth spines from confluence. Cercopods straight in proximal two thirds and slightly arcuate apically. Cercopods each medially with longitudinal row of short or long plumose setae along proximal 60%. Setal row terminates with short spine. Cercopod with subapical dorsal cirrus. Eggs 130 to 160 μm in diameter, subcylindrical and tumid. Eggs with thin ridges, with regularly spaced spinules.

Comments: Roessler (1995b) and Rogers et al. (2020) note that there are undescribed species in Brazil. This genus appears to be rock pool specialists.

Attributed Species