A new genus and species of thamnocephalid fairy shrimp (Branchiopoda: Anostraca) from Argentina (Chubut Province)

ROGERS, D.C.; ARCHANGELSKY, M.; PESSACQ, P.

NAUPLIUS

Journal of the Brazilian Crustacean Society

Año: 2018 vol. 26 p. 1 - 8

0104-6497

Aeginecta longicauda n. gen., n. sp. is described from materialcollected from a seasonally astatic aquatic habitat in Argentina. It is onlyknown from the type locality and two male specimens; at this point the femaleremains unknown. Specific unique gonopod and genital segment featuresdemonstrate that this taxon represents a unique genus within theThamnocephalidae. Aeginecta n. gen most closely resembles Phallocryptus Biraben, 1951 and Thamnocephalus Packard, 1877. This new genus is easily diagnosed by the compound eye pedunclebeing extremely short, the frons and anterior surface of antennae II broadenedlaterally, with an intervening slit through which the compound eye may view thearea forward on the animal, and the cercopods are as long as the abdomen. Thegonopod proximal portion is bulbous with a transverse cleft, and projectsventrally from the segment. The gonopod distal eversible portion is minute,lamellar, and lies within proximal portion cleft. This is the fifththamnocephalid genus reported from South America. The Neotropical region hasthe greatest thamnocephalid generic diversity in the world.