''Hypoplectrus indigo'', the indigo hamlet, is a species of marine

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fishes, is a class of bony fish. They comprise over 50% of living vertebrate species. The ray-finned fishes are so called because their fins are webs of skin supported by bony or hor ...

, a sea bass from the

subfamily In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end subfamily botanical names with "-oideae", and zoologi ...

Serraninae which is part of the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Serranidae The Serranidae are a large family of fishes belonging to the order Perciformes. The family contains about 450 species in 65 genera, including the sea basses and the groupers (subfamily Epinephelinae). Although many species are small, in some case ...

, which also includes the

grouper Groupers are fish of any of a number of genera in the subfamily Epinephelinae of the family Serranidae, in the order Perciformes. Not all serranids are called "groupers"; the family also includes the sea basses. The common name "grouper" is u ...

s and

anthias Anthias are members of the family Serranidae and make up the subfamily Anthiinae. Anthias make up a sizeable portion of the population of pink, orange, and yellow reef fishes seen swarming in most coral reef photography and film. The name Anthi ...

. It is found in the central western Atlantic Ocean. It occasionally makes its way into the aquarium trade.

Description

''Hypoplectrus indigo'' has a deep body and head which is highly laterally compressed with a straight forehead and a rather short snout and a protrusible upper jaw. It has an angular preoperculum which has serrations on its edge and a number of small forward pointing spines on its lower margin close to the angle. The continuous

dorsal fin A dorsal fin is a fin located on the back of most marine and freshwater vertebrates within various taxa of the animal kingdom. Many species of animals possessing dorsal fins are not particularly closely related to each other, though through conv ...

has ten spines and 14-17 soft rays. It has long

pelvic fin Pelvic fins or ventral fins are paired fins located on the ventral surface of fish. The paired pelvic fins are homologous to the hindlimbs of tetrapods. Structure and function Structure In actinopterygians, the pelvic fin consists of two en ...

s which extend as far as or beyond the anus. The

caudal fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as se ...

is slightly forked. The body and fins are dark blue and there is a pattern of seven dark blue-black vertical bars on the head and body. The details of the patterning and intensity of the blue background colour on the body and fins shows individual variation with some fish having barrow black stripes running along the upper and lower margins of the caudal fin. This species attains a maximum recorded

total length Fish measurement is the measuring of individual fish and various parts of their anatomies. These data are used in many areas of ichthyology, including taxonomy and fisheries biology. Overall length * Standard length (SL) is the length of a fish ...

of .

Distribution

''Hypoplectrus indigo'' is found in the western Atlantic. Its ranges extends from the Bahamas in the north through the

Gulf of Mexico The Gulf of Mexico ( es, Golfo de México) is an oceanic basin, ocean basin and a marginal sea of the Atlantic Ocean, largely surrounded by the North American continent. It is bounded on the northeast, north and northwest by the Gulf Coast of ...

along the Florida Keys and from

Tuxpan Tuxpan (or Túxpam, fully Túxpam de Rodríguez Cano) is both a municipality and city located in the Mexican state of Veracruz. The population of the city was 78,523 and of the municipality was 134,394 inhabitants, according to the INEGI census o ...

in Mexico and the northern Yucatan Peninsula to northwestern Cuba. In the

Caribbean Sea The Caribbean Sea ( es, Mar Caribe; french: Mer des Caraïbes; ht, Lanmè Karayib; jam, Kiaribiyan Sii; nl, Caraïbische Zee; pap, Laman Karibe) is a sea of the Atlantic Ocean in the tropics of the Western Hemisphere. It is bounded by Mexico ...

it has been recorded throughout the

Antilles The Antilles (; gcf, label=Antillean Creole, Antiy; es, Antillas; french: Antilles; nl, Antillen; ht, Antiy; pap, Antias; Jamaican Patois: ''Antiliiz'') is an archipelago bordered by the Caribbean Sea to the south and west, the Gulf of Mex ...

as far south as

Tobago Tobago () is an List of islands of Trinidad and Tobago, island and Regions and municipalities of Trinidad and Tobago, ward within the Trinidad and Tobago, Republic of Trinidad and Tobago. It is located northeast of the larger island of Trini ...

. It also occurs along the mainland coasts of Central and South America from Mexico to Mamitupo in Panama and among the offshore islands of Venezuela.

Habitat and biology

''Hypoplectrus indigo'' is a solitary species of coral reefs at depths of . The species in the genus ''

Hypoplectrus ''Hypoplectrus'' is a genus of fishes commonly known as hamlets, found mainly in coral reefs in the Caribbean Sea and the Gulf of Mexico, particularly around Florida and the Bahamas. They are a popular choice for hobbyist saltwater aquariums, and ...

'' are synchronous

hermaphrodite In reproductive biology, a hermaphrodite () is an organism that has both kinds of reproductive organs and can produce both gametes associated with male and female sexes. Many Taxonomy (biology), taxonomic groups of animals (mostly invertebrate ...

s and they have the ability to move between "male" and "female" roles when

spawning Spawn is the eggs and sperm released or deposited into water by aquatic animals. As a verb, ''to spawn'' refers to the process of releasing the eggs and sperm, and the act of both sexes is called spawning. Most aquatic animals, except for aquati ...

. The colour pattern of this species bears a slight resemblance to that of the blue species in the genus '' Chromis'' and it has been suggested that the indigo hamlet is an

aggressive mimic Aggressive mimicry is a form of mimicry in which predators, parasites, or parasitoids share similar signals, using a harmless model, allowing them to avoid being correctly identified by their prey or host. Zoologists have repeatedly compare ...

of either the

blue chromis ''Chromis cyanea'' (blue chromis) is a damselfish in the subfamily ''Pomacentrinae'', found in Bermuda, southern Florida and the Caribbean Sea. It is collected for the aquarium trade. Habitat and ecology Being a shallow water fish, the blue ...

(''C. cyaneus'') or '' C. insolata''. However, neither of the ''Chromis'' species really resembles ''H. indigo'' with its darker blue-black bars and other workers are not convinced by this hypothesis. These fish remain close to bottom and defend small

territories A territory is an area of land, sea, or space, particularly belonging or connected to a country, person, or animal. In international politics, a territory is usually either the total area from which a state may extract power resources or an ...

on or near reefs. They are wary fish but can be curious, when approach they often retreat a short distance vut then often return and approach stationary divers. This is a

carnivorous A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant whose food and energy requirements derive from animal tissues (mainly muscle, fat and other sof ...

species which feeds on other fishes and non-sessile

benthic The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from ancient Greek, βένθος (bénthos), meaning "t ...

crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group ...

Taxonomy

''Hypoplectrus indigo'' was first formally described as ''Plectropoma indigo'' in 1851 by the

Cuba Cuba ( , ), officially the Republic of Cuba ( es, República de Cuba, links=no ), is an island country comprising the island of Cuba, as well as Isla de la Juventud and several minor archipelagos. Cuba is located where the northern Caribbea ...

zoologist Zoology ()The pronunciation of zoology as is usually regarded as nonstandard, though it is not uncommon. is the branch of biology that studies the Animal, animal kingdom, including the anatomy, structure, embryology, evolution, Biological clas ...

Felipe Poey (1799-1891) with

Havana Havana (; Spanish: ''La Habana'' ) is the capital and largest city of Cuba. The heart of the La Habana Province, Havana is the country's main port and commercial center.

, Cuba given as the type locality.

Utilisation

''Hypoplectrus indigo'' is infrequently found in the

aquarium An aquarium (plural: ''aquariums'' or ''aquaria'') is a vivarium of any size having at least one transparent side in which aquatic plants or animals are kept and displayed. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, aq ...

trade. It is said to thrive when house appropriately.

References

External links

* * {{Taxonbar, from=Q2081608

indigo Indigo is a deep color close to the color wheel blue (a primary color in the RGB color space), as well as to some variants of ultramarine, based on the ancient dye of the same name. The word "indigo" comes from the Latin word ''indicum'', m ...

Fish described in 1851 Fish of the Dominican Republic