# Aeglidae

The Aeglidae are a family of freshwater crustaceans currently restricted to South America. They are the only anomurans to be found in fresh water except for a single hermit crab species, Clibanarius fonticola, on Espiritu Santo, Vanuatu. They live between 20° S and 50° S, at altitudes between 320 and 3,500 m (1,050–11,480 ft).

## Description

Aeglids resemble squat lobsters in that the abdomen is partly tucked under the thorax. The notable sexual dimorphism in the abdomen is related to the behaviour of carrying fertilised eggs on the pleopods. The carapace length of the largest species may approach 6 cm (2.4 in), but most are considerably smaller.
Aeglids are omnivorous, preferring plant matter, but also eating adult insects, molluscs, fish and fly larvae.
The internal anatomy has been described for Aegla cholchol and generally resembles that of other anomurans, particularly galatheoid squat lobsters. The morphology of the antennal gland bladder differs from that in other anomurans in having a twisted tubular structure which was interpreted as an adaption to the freshwater lifestyle.

### Life cycle

Mating is preceded by a period of courtship, and does not coincide with moulting, as it does in many other decapods. The eggs of aeglids hatch as juveniles which closely resemble the adults. They are cared for by their parents and live at the bottom of the body of water.

## Extant taxa

Aegla, the only extant genus in the family, contains around 74 described extant species. Of the 63 species and subspecies described by 2008, two are found in lakes, four in caves, and the remaining 57 are found mainly in rivers. 42 species are found in Brazil, all restricted to the country's southern and southeastern regions (Rio Grande do Sul alone is home to 24). Other countries with species are Argentina, Bolivia, Chile, Paraguay and Uruguay. More than a third of the species are considered threatened, and in Brazil alone 26 species are officially recognized as threatened, including 8 critically endangered.

### Species

This list contains all the described species as of 2013:
* Aegla abtao Schmitt, 1942
* Aegla affinis Schmitt, 1942
* Aegla alacalufi Jara & López, 1981
* Aegla araucaniensis Jara, 1980
* Aegla bahamondei Jara, 1982
* Aegla brevipalma Bond-Buckup & Santos in Santos et al., 2012
* Aegla camargoi Buckup & Rossi, 1977
* Aegla castro Schmitt, 1942
* Aegla cavernicola Türkay, 1972
* Aegla cholchol Jara & Palacios, 1999
* Aegla concepcionensis Schmitt, 1942
* Aegla denticulata Nicolet, 1849
* Aegla expansa Jara, 1992
* Aegla franca Schmitt, 1942
* Aegla franciscana Buckup & Rossi, 1977
* Aegla georginae Santos & Jara in Santos et al., 2013
* Aegla grisella Bond-Buckup & Buckup, 1994
* Aegla hueicollensis Jara & Palacios, 1999
* Aegla humahuaca Schmitt, 1942
* Aegla inconspicua Bond-Buckup & Buckup, 1994
* Aegla inermis Bond-Buckup & Buckup, 1994
* Aegla intercalata Bond-Buckup & Buckup, 1994
* Aegla intermedia Girard, 1855
* Aegla itacolomiensis Bond-Buckup & Buckup, 1994
* Aegla jarai Bond-Buckup & Buckup, 1994
* Aegla jujuyana Schmitt, 1942
* Aegla laevis (Latreille, 1818)
* Aegla lata Bond-Buckup & Buckup, 1994
* Aegla leachi Bond-Buckup & Buckup in Santos et al., 2012
* Aegla leptochela Bond-Buckup & Buckup, 1994
* Aegla leptodactyla Buckup & Rossi, 1977
* Aegla ligulata Bond-Buckup & Buckup, 1994
* Aegla longirostri Bond-Buckup & Buckup, 1994
* Aegla ludwigi Santos & Jara in Santos et al., 2013
* Aegla manni Jara, 1980
* Aegla marginata Bond-Buckup & Buckup, 1994
* Aegla manuniflata Bond-Buckup & Santos in Santos et al., 2009
* Aegla microphthalma Bond-Buckup & Buckup, 1994
* Aegla muelleri Bond-Buckup & Buckup in Bond-Buckup et al., 2010
* Aegla neuquensis Schmitt, 1942
* Aegla oblata Bond-Buckup & Santos in Santos et al., 2012
* Aegla obstipa Bond-Buckup & Buckup, 1994
* Aegla occidentalis Jara, Pérez-Losada & Crandall, 2003
* Aegla odebrechtii Müller, 1876
* Aegla papudo Schmitt, 1942
* Aegla parana Schmitt, 1942
* Aegla parva Bond-Buckup & Buckup, 1994
* Aegla paulensis Schmitt, 1942
* Aegla perobae Hebling & Rodrigues, 1977
* Aegla pewenchae Jara, 1994
* Aegla plana Buckup & Rossi, 1977
* Aegla platensis Schmitt, 1942
* Aegla pomerana Bond-Buckup & Buckup in Bond-Buckup et al., 2010
* Aegla prado Schmitt, 1942
* Aegla renana Bond-Buckup & Santos in Santos et al., 2010
* Aegla ringueleti Bond-Buckup & Buckup, 1994
* Aegla riolimayana Schmitt, 1942
* Aegla rossiana Bond-Buckup & Buckup, 1994
* Aegla rostrata Jara, 1977
* Aegla saltensis Bond-Buckup & Jara in Bond-Buckup et al., 2010
* Aegla sanlorenzo Schmitt, 1942
* Aegla scamosa Ringuelet, 1948
* Aegla schmitti Hobbs III, 1979
* Aegla septentrionalis Bond-Buckup & Buckup, 1994
* Aegla serrana Buckup & Rossi, 1977
* Aegla singularis Ringuelet, 1948
* Aegla spectabilis Jara, 1986
* Aegla spinipalma Bond-Buckup & Buckup, 1994
* Aegla spinosa Bond-Buckup & Buckup, 1994
* Aegla strinatii Türkay, 1972
* Aegla talcahuano Schmitt, 1942
* Aegla uruguayana Schmitt, 1942
* Aegla violacea Bond-Buckup & Buckup, 1994

## Fossil taxa
### Haumuriaegla

Haumuriaegla glaessneri is a species known only from fossils of Haumurian age (Late Cretaceous) found near Cheviot, New Zealand. At the time of its discovery, Haumuriaegla was the only known fossil from the family and the only marine member.

### Protaegla

Protaegla miniscula was discovered in rocks of Albian age from the Tlayúa Formation, near Tepexi de Rodríguez, Mexico.

### Evolution

The family as a whole is thought to have originated around 75 million years ago in a marine environment, and then entered South America from the Pacific side during the Oligocene.