Heterocarpus is a genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of deep-sea shrimp

Shrimp

Shrimp are swimming, decapod crustaceans classified in the infraorder Caridea, found widely around the world in both fresh and salt water. Adult shrimp are filter feeding benthic animals living close to the bottom. They can live in schools and can swim rapidly backwards. Shrimp are an important...

, mainly of tropical areas all over the world.

Description

Heterocarpus is characterised by the highly unequal second pair of pereiopods: one side is long and thin and the other is short but stronger, besides the carapace

Carapace

A carapace is a dorsal section of the exoskeleton or shell in a number of animal groups, including arthropods such as crustaceans and arachnids, as well as vertebrates such as turtles and tortoises. In turtles and tortoises, the underside is called the plastron.-Crustaceans:In crustaceans, the...

 with one or more longitudinal carinae.

Species

So far, 30 species have been described for this genus, Heterocarpus ensifer

Heterocarpus ensifer

Heterocarpus ensifer is a species of deep-water shrimp. The nominate subspecies is found in the Atlantic Ocean from Spain and Madeira to Angola and from North Carolina to the Gulf of Mexico and Caribbean Sea; other subspecies occur in the Pacific Ocean and around the Philippines and Indonesia...

being the type species

Type species

In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...

. The described species of this genus are:

• Heterocarpus abulbus Yang, Chan & Chu, 2010
• Heterocarpus affins Faxon, 1893
• Heterocarpus alexandri A. Milne-Edwards, 1883
• Heterocarpus amacula Crosnier, 1988
• Heterocarpus calmani Crosnier, 1988
• Heterocarpus chani Li, 2006
• Heterocarpus corona Yang, Chan & Chu, 2010
• Heterocarpus cutressi Monterossa, 1988
• Heterocarpus dorsalis Bate, 1888
• Heterocarpus ensifer
  Heterocarpus ensifer
  Heterocarpus ensifer is a species of deep-water shrimp. The nominate subspecies is found in the Atlantic Ocean from Spain and Madeira to Angola and from North Carolina to the Gulf of Mexico and Caribbean Sea; other subspecies occur in the Pacific Ocean and around the Philippines and Indonesia...
  
  A. Milne-Edwards, 1881
• Heterocarpus inopinatus Tavares, 1999
• Heterocarpus intermedius Crosnier, 1999
• Heterocarpus gibbosus Bate, 1888
• Heterocarpus grimaldii A. Milne-Edwards & Bouvier, 1900
• Heterocarpus hayashii Crosnier, 1988
• Heterocarpus hostilis Faxon, 1893
• Heterocarpus laevigatus Bate, 1888
• Heterocarpus lepidus De Man, 1917
• Heterocarpus longirostris McGilchrist, 1905
• Heterocarpus neisi Burukovsky, 1986
• Heterocarpus oryx A. Milne-Edwards, 1881
• Heterocarpus parvispina Crosnier, 1988
• Heterocarpus reedi Bahamondi, 1955
• Heterocarpus sibogae De Man, 1917
• Heterocarpus signatus Rathbun, 1906
• Heterocarpus tenuidentatus Crosnier, 2006
• Heterocarpus tricarinatus Alcock & Anderson, 1894
• Heterocarpus unicarinatus Borradeile, 1915
• Heterocarpus woodmasoni Alcock, 1901
• Heterocarpus vicarius Faxon, 1893

Ecology

Many Heterocarpus shrimp are known for using bioluminescence

Bioluminescence

Bioluminescence is the production and emission of light by a living organism. Its name is a hybrid word, originating from the Greek bios for "living" and the Latin lumen "light". Bioluminescence is a naturally occurring form of chemiluminescence where energy is released by a chemical reaction in...

 as a defense, spitting it on predators. Studies about their feeding habits, and the fact that they may be found in the stomach contents of some pelagic shark

Shark

Sharks are a type of fish with a full cartilaginous skeleton and a highly streamlined body. The earliest known sharks date from more than 420 million years ago....

s and other fishes is interpreted as they have benthic habits, but they do migrations to the water column at night. Some species of this genus have high fishery

Shrimp fishery

A shrimp fishery is a fishery directed toward harvesting either shrimp or prawns. .-Commercial shrimping:...

potential, such as H. reedi and H. laevigatus.