Aeglidae
Encyclopedia
Aeglidae is a family
of freshwater
crustacean
s currently restricted to South America
. They are the only anomura
ns to be found in fresh water except for a single hermit crab
species, Clibanarius fonticola
, on Espiritu Santo
island, Vanuatu
. They live between 20° S
and 50° S
, at altitudes between 320 metres (1,049.9 ft) and 3500 metres (11,482.9 ft).
s, in that the abdomen
is partly tucked under the thorax
. There is a notable sexual dimorphism
in the abdomen
, related to the behaviour of carrying fertilised eggs on the pleopods. Aeglids are omnivorous
, preferring plant matter, but also eating adult insect
s, molluscs
, fish
and fly larva
e.
, 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.
, all restricted to the country's southern and southeastern regions.
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.
age from the Tlayúa Formation
, near Tepexi de Rodríguez
, Mexico
.
side during the Oligocene
.
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
of freshwater
Freshwater
Fresh water is naturally occurring water on the Earth's surface in ice sheets, ice caps, glaciers, bogs, ponds, lakes, rivers and streams, and underground as groundwater in aquifers and underground streams. Fresh water is generally characterized by having low concentrations of dissolved salts and...
crustacean
Crustacean
Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...
s currently restricted to South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
. They are the only anomura
Anomura
Anomura is a group of decapod crustaceans, including hermit crabs and others. Although the names of many anomurans includes the word crab, all true crabs are in the sister group to the Anomura, the Brachyura .-Description:The name Anomala reflects the unusual variety of forms in this group;...
ns to be found in fresh water except for a single hermit crab
Hermit crab
Hermit crabs are decapod crustaceans of the superfamily Paguroidea. Most of the 1100 species possess an asymmetrical abdomen which is concealed in an empty gastropod shell that is carried around by the hermit crab.-Description:...
species, Clibanarius fonticola
Clibanarius fonticola
Clibanarius fonticola is the only species of hermit crab in the world that lives in fresh water. It is found on the island of Espiritu Santo, Vanuatu. While a number of other hermit crabs are terrestrial or live in estuarine habitats, C. fonticola is the only species that spends its life in fresh...
, on Espiritu Santo
Espiritu Santo
Espiritu Santo is the largest island in the nation of Vanuatu, with an area of . It belongs to the archipelago of the New Hebrides in the Pacific region of Melanesia. It is in the Sanma Province of Vanuatu....
island, Vanuatu
Vanuatu
Vanuatu , officially the Republic of Vanuatu , is an island nation located in the South Pacific Ocean. The archipelago, which is of volcanic origin, is some east of northern Australia, northeast of New Caledonia, west of Fiji, and southeast of the Solomon Islands, near New Guinea.Vanuatu was...
. They live between 20° S
20th parallel south
The 20th parallel south is a circle of latitude that is 20 degrees south of the Earth's equatorial plane. It crosses the Atlantic Ocean, Africa, the Indian Ocean, Australasia, the Pacific Ocean and South America....
and 50° S
50th parallel south
The 50th parallel south is a circle of latitude that is 50 degrees south of the Earth's equatorial plane. It crosses the Atlantic Ocean, the Indian Ocean, the Pacific Ocean and South America....
, at altitudes between 320 metres (1,049.9 ft) and 3500 metres (11,482.9 ft).
Description
Aeglids resemble squat lobsterSquat lobster
Squat lobsters are decapod crustaceans of the families Galatheidae, Chirostylidae and Kiwaidae, including the common genera Galathea and Munida. They are not lobsters at all, but are more closely related to porcelain crabs, hermit crabs and then, more distantly, true crabs...
s, in that the abdomen
Abdomen
In vertebrates such as mammals the abdomen constitutes the part of the body between the thorax and pelvis. The region enclosed by the abdomen is termed the abdominal cavity...
is partly tucked under the thorax
Thorax
The thorax is a division of an animal's body that lies between the head and the abdomen.-In tetrapods:...
. There is a notable sexual dimorphism
Sexual dimorphism
Sexual dimorphism is a phenotypic difference between males and females of the same species. Examples of such differences include differences in morphology, ornamentation, and behavior.-Examples:-Ornamentation / coloration:...
in the abdomen
Abdomen
In vertebrates such as mammals the abdomen constitutes the part of the body between the thorax and pelvis. The region enclosed by the abdomen is termed the abdominal cavity...
, related to the behaviour of carrying fertilised eggs on the pleopods. Aeglids are omnivorous
Omnivore
Omnivores are species that eat both plants and animals as their primary food source...
, preferring plant matter, but also eating adult insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s, molluscs
Mollusca
The Mollusca , common name molluscs or mollusksSpelled mollusks in the USA, see reasons given in Rosenberg's ; for the spelling mollusc see the reasons given by , is a large phylum of invertebrate animals. There are around 85,000 recognized extant species of molluscs. Mollusca is the largest...
, fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
and fly larva
Larva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...
e.
Life cycle
Mating is preceded by a period of courtshipCourtship
Courtship is the period in a couple's relationship which precedes their engagement and marriage, or establishment of an agreed relationship of a more enduring kind. In courtship, a couple get to know each other and decide if there will be an engagement or other such agreement...
, and does not coincide with moulting
Ecdysis
Ecdysis is the moulting of the cuticula in many invertebrates. This process of moulting is the defining feature of the clade Ecdysozoa, comprising the arthropods, nematodes, velvet worms, horsehair worms, rotifers, tardigrades and Cephalorhyncha...
, as it does in many other decapods
Decapoda
The decapods or Decapoda are an order of crustaceans within the class Malacostraca, including many familiar groups, such as crayfish, crabs, lobsters, prawns and shrimp. Most decapods are scavengers. It is estimated that the order contains nearly 15,000 species in around 2,700 genera, with...
. The eggs
Egg (biology)
An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...
of aeglids hatch as juveniles
Juvenile (organism)
A juvenile is an individual organism that has not yet reached its adult form, sexual maturity or size. Juveniles sometimes look very different from the adult form, particularly in terms of their colour...
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 is the only extant genus in the family, and contains around 68 described extant species, with a further four as yet undescribed. 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. Ten species are found in BrazilBrazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
, all restricted to the country's southern and southeastern regions.
Species
- Aegla abtao Schmitt, 1942
- Aegla affinis Schmitt, 1942
- Aegla alacalufi Jara & López, 1981
- Aegla araucaniensis Jara, 1980
- Aegla bahamondei Jara, 1982
- 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 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 leptochela Bond-Buckup & Buckup, 1994
- Aegla leptodactyla Buckup & Rossi, 1977
- Aegla ligulata Bond-Buckup & Buckup, 1994
- Aegla longirostri Bond-Buckup & Buckup, 1994
- 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 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
Haumuriaegla
Haumuriaegla glaessneri is a speciesSpecies
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
known only from fossils of Haumurian age (Late Cretaceous
Late Cretaceous
The Late Cretaceous is the younger of two epochs into which the Cretaceous period is divided in the geologic timescale. Rock strata from this epoch form the Upper Cretaceous series...
) found near Cheviot, New Zealand
Cheviot, New Zealand
Cheviot is a town in the Hurunui District of north Canterbury, on the east coast of the South Island of New Zealand. It is on the Main North Line railway and State Highway 1 approximately north of Christchurch. It was originally called Mackenzie after politician John McKenzie, who was closely...
. 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 AlbianAlbian
The Albian is both an age of the geologic timescale and a stage in the stratigraphic column. It is the youngest or uppermost subdivision of the Early/Lower Cretaceous epoch/series. Its approximate time range is 112.0 ± 1.0 Ma to 99.6 ± 0.9 Ma...
age from the Tlayúa Formation
Tlayúa Formation
The Tlayúa Formation is an Early Cretaceous geological formation near Tepexi de Rodríguez, Puebla, Central Mexico.-Lepidosaurs:Cyanobacteria, foraminifera, algae, gymnosperms, sponges,...
, near Tepexi de Rodríguez
Tepexi de Rodríguez (municipality)
Tepexi de Rodríguez is a town and municipality in Puebla in south-eastern Mexico.-References:...
, Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
.
Evolution
The family as a whole is thought to have originated around in a marine environment, and then entered South America from the PacificPacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
side during the Oligocene
Oligocene
The Oligocene is a geologic epoch of the Paleogene Period and extends from about 34 million to 23 million years before the present . As with other older geologic periods, the rock beds that define the period are well identified but the exact dates of the start and end of the period are slightly...
.