Gondwanalimnadia Rogers, Rabet and Weeks,, 2016

Rogers, D. Christopher, 2020, Spinicaudata Catalogus (Crustacea: Branchiopoda)., Zoological Studies 59 (45), pp. 1-44 : 11-12

Gondwanalimnadia Rogers, Rabet and Weeks,

2016b

= Afrolimnadia Rogers, Rabet and Weeks, 2012

Diagnosis: (modified from Rogers et al. 2012) Populations composed of males and hermaphrodites; amplexus is venter to venter. Rostrum variable, typically rounded in females, acute to aciculate in males. Angle between rostrum and frons from 80° to 100°. Occipital notch occipital condyle absents. Pedunculate frontal organ length 0.7 to 2.5x distance of organ from ocular tubercle. Carapace dorsal margin smooth, lacking carinae, hinge line arcuate, rarely sinuate. Carapace surface between growth lines slightly to strongly malleate. Umbone absent. Carapace unpigmented. Muscle scar angle 35° to 40° from normal, i.e., body horizontal axis. Clasper endopods bearing an apical suctorial organ. Endite IV with an apical dense field of long spines. Female thoracopods IX and X with prolonged exopods for egg attachment. Thoracic segments smooth. Telson with posteriorly directed spiniform projection present at ventroposterior angle, anteriad of cercopod base. Telson posteriolateral spine rows confluent dorsally, confluence not projecting. Each row with 10–15 spines. Caudal filament originating between spine rows at third spine pair from confluence. Caudal filament never borne on mound. Cercopods dorsal margin sinuate, longer than ventral telson margin. Cercopod medial surface with single basal spine and longitudinal row of plumose setae along proximal 80%. Cercopod with subapical, dorsal cirri, extending 5% of the cercopod length. Males amplex females venter to venter, at right angles to female’s body. Egg diameter 100–150 μm, spherical to subspherical. Eggs with narrow, slit shaped depressions, separated by narrow ridges.

Comments: Rogers et al. (2012) described this genus based on material ascribed to Eulimnadia alluaudi . The name Afrolimnadia , however, was preoccupied for a fossil genus of spinicaudatan clam shrimp ( Lioestheriidae ) (Tasch 1987), and the same authors amended the name to Gondwanalimnadia ( Rogers et al. 2016b) . The authors were not fully confident in the specific determination for the material ascribed to this genus (see below). Therefore, whereas the genus is valid (based upon morphological ( Rogers et al. 2012) and molecular ( Weeks et al. 2009) studies) the identity of the sole species placed in this genus remains unclear. The egg is depicted by Rabet (2010).

Attributed Species

Gondwanalimnadia alluaudi ( Daday, 1926)

= Eulimnadia alluaudi Daday, 1926

= Limnadia alluaudi ( Daday, 1926)

= Afrolimnadia alluaudi ( Daday, 1926)

Comments: The material examined by Rogers et al. (2012) was collected from the Republic of South Africa, identified based on the original description and other references to the South African fauna ( Brendonck 1999). However, this species was originally described from Madagascar. There are obvious inconsistencies in the egg morphology ( Rabet 2010) between the populations.

Imnadia Hertzog, 1935

Diagnosis: (modified from Rogers et al. 2012). Populations composed of males and females; amplexus is venter to venter. Angle between rostrum and frons 100° to 80°. Occipital notch broad and shallow, twice as broad as deep. Occipital condyle conical. Frontal organ sessile. Carapace with dorsal margin smooth, lacking carinae, hinge line arcuate. Carapace surface between growth lines smooth. Umbone absent. Carapace without pigmentation. Muscle scar angle 30° from normal. Thoracic segments smooth. Clasper endopods each bearing an apical suctorial organ. Endite IV with apical dense field of long spines. Eggs attaching to prolonged exopods of thoracopods IX and X. Telson with posteriorly directed spiniform projection present on ventroposterior angle. Telson posterior margin spine rows confluent dorsally, not projecting. Each row with 11–19 spines. Caudal filament born on a low mound or not, originating between spine rows between third through six spines from confluence. Cercopods slightly sinuate, each medially with longitudinal row of long plumose setae on proximal 60%. Setal row terminates with a single spine. Cercopod with subapical dorsal cirrus, extending 35% of cercopod length.

Eggs 100-150 μm in diameter, subspherical with slit shaped polygonal depressions separated by lamellar ridges ( Thiéry and Gasc 1991).

Comments: Monotypic.

Attributed Species

Imnadia yeyetta Hertzog, 1935

= Imnadia voitestii Botnariuc and Orghidan, 1941

= Imnadia cristata Marinček, 1972

= Imnadia banatica Marinček & Valvajter, 1982

= Imnadia panonica Marinček et Petrov, 1984

Comments: Austria, the Balkans, Czech Republic, France, (Loeffler 1961; Šrámek-Hušek et al. 1962; Straškraba 1966; Thiéry and Pont 1987; Miličić and Petrov 2007; Eder 2002). Marinček and Petrov (1984) review the variation in this species. Brtek (1957) provides a redescription.