''Eudaniela'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

crab Crabs are decapod crustaceans of the infraorder Brachyura (meaning "short tailed" in Greek language, Greek), which typically have a very short projecting tail-like abdomen#Arthropoda, abdomen, usually hidden entirely under the Thorax (arthropo ...

s in the family

Pseudothelphusidae Pseudothelphusidae is a family of freshwater crabs found chiefly in mountain streams in the Neotropics. They are believed to have originated in the Greater Antilles and then crossed to Central America via a Pliocene land bridge. Some species of t ...

Location

Eudaniela are found along the

Andean The Andes ( ), Andes Mountains or Andean Mountain Range (; ) are the longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range is long and wide (widest between 18°S ...

and Coastal

cordillera A cordillera is a chain or network of mountain ranges, such as those in the west coast of the Americas. The term is borrowed from Spanish, where the word comes from , a diminutive of ('rope'). The term is most commonly used in physical geogra ...

Venezuela Venezuela, officially the Bolivarian Republic of Venezuela, is a country on the northern coast of South America, consisting of a continental landmass and many Federal Dependencies of Venezuela, islands and islets in the Caribbean Sea. It com ...

and in the highlands of

Isla Margarita Margarita Island (, ) is the largest island in the Venezuelan state of Nueva Esparta, situated off the north west coast of the country, in the Caribbean Sea. The capital city of Nueva Esparta, La Asunción, is located on the island. History ...

Trinidad and Tobago Trinidad and Tobago, officially the Republic of Trinidad and Tobago, is the southernmost island country in the Caribbean, comprising the main islands of Trinidad and Tobago, along with several List of islands of Trinidad and Tobago, smaller i ...

. Species of ''Eudaniela'' live in

freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. The term excludes seawater and brackish water, but it does include non-salty mi ...

streams and rivers at a high altitude above sea level. On

Tobago Tobago, officially the Ward of Tobago, is an List of islands of Trinidad and Tobago, island and Regions and municipalities of Trinidad and Tobago, ward within the Republic of Trinidad and Tobago. It is located northeast of the larger islan ...

, the ''E. garmani'' construct burrows or hide in naturally occurring crevices near fast-flowing streams. Owing to the nature of the terrain surrounding these streams, ''E.'' garmani are less likely to be observed creating their own burrows.

Biology

''Eudaniela'' have been recorded to reach

sexual maturity Sexual maturity is the capability of an organism to reproduce. In humans, it is related to both puberty and adulthood. ''Puberty'' is the biological process of sexual maturation, while ''adulthood'', the condition of being socially recognized ...

at a large size and also at a relatively old age. Females reach sexual maturity at about three years of age. There is not enough data or information known to determine if any species of ''Eudaniela'' are threatened to become

endangered species An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching, inv ...

. ''Eudaniela'' shell colour has been observed to change with increasing size, with smaller ''Eudaniela'' (<25 mm carapace width, CW) being dark brown and larger ''Eudaniela'' (>50mm CW) being chestnut brown.

Diet

''Eudaniela'' have a distinctive stance when catching

prey Predation is a biological interaction in which one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not ki ...

, adopting a sit and wait strategy. Using the tips of two of their legs supporting them in the water, they used the other two legs to gently sweep back and forth. When prey is detected, a pouncing action was observed. ''Eudaniela'' have been reported as being one of the very few examples of

invertebrates Invertebrates are animals that neither develop nor retain a vertebral column (commonly known as a ''spine'' or ''backbone''), which evolved from the notochord. It is a paraphyletic grouping including all animals excluding the chordate subphylum ...

preying on

vertebrates Vertebrates () are animals with a vertebral column (backbone or spine), and a cranium, or skull. The vertebral column surrounds and protects the spinal cord, while the cranium protects the brain. The vertebrates make up the subphylum Vertebra ...

. Several sightings (albeit not active predation) of ''Eudaniela'' feeding on

snakes Snakes are elongated Limbless vertebrate, limbless reptiles of the suborder Serpentes (). Cladistically Squamata, squamates, snakes are ectothermic, amniote vertebrates covered in overlapping Scale (zoology), scales much like other members of ...

have been recorded. Additionally, it was observed that ''Eudaniela'' prefer to dexterously skin the snakes using their pincers prior to consumption. It has been postulated that within the Tobago ecosystem, ''Eudaniela'' is the

apex predator An apex predator, also known as a top predator or superpredator, is a predator at the top of a food chain, without natural predators of its own. Apex predators are usually defined in terms of trophic dynamics, meaning that they occupy the hig ...

, with no evident predation by other organisms noted.

Species

''Eudaniela'' contains the following species:

References

{{Portal bar, Crustaceans Pseudothelphusidae Crustaceans described in 1971 Apex predators Invertebrates of Venezuela Arthropods of Trinidad and Tobago