''Alphestes immaculatus'', the Pacific mutton 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 h ...

which is classified within the subfamily

Epinephelinae 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 ...

, 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 ...

s, in the

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

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 ca ...

which also includes the

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 ...

and

sea bass Sea bass is a common name for a variety of different species of marine fish. Many fish species of various families have been called sea bass. In Ireland and the United Kingdom, the fish sold and consumed as sea bass is exclusively the European ...

es. It is a predatory fish of the rocky coastlines of the eastern Pacific Ocean.

Description

''Alphestes immaculatus'' has a strongly compressed, deep body with large eyes and a short snout and a straight forehead. The

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 c ...

has 11 spines and 17-19 soft rays while the anal fin has 3 spines and 9 soft rays. It has a rounded preopercle with an obviously serrated rear edge and a large spine, which is usually covered with skin, projecting downward and forward at its angle. The head and body are marbled reddish brown in colour, with obscure bars and small dark and pale spots all over the head, body and dorsal, anal and

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 ...

s. The

pectoral 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 ...

s have 7 or 8 irregular horizontal series of small dark spots running across them. The 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 ...

is but they are more normally around .

Distribution

''Alphestes immaculatus''is found in the

Eastern Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...

from southern

Baja California Baja California (; 'Lower California'), officially the Free and Sovereign State of Baja California ( es, Estado Libre y Soberano de Baja California), is a state in Mexico. It is the northernmost and westernmost of the 32 federal entities of Mex ...

and the

Gulf of California The Gulf of California ( es, Golfo de California), also known as the Sea of Cortés (''Mar de Cortés'') or Sea of Cortez, or less commonly as the Vermilion Sea (''Mar Bermejo''), is a marginal sea of the Pacific Ocean that separates the Baja C ...

south as far as Peru. It is also found around the

Islas Marías The Islas Marías ("Mary Islands") are an archipelago of four islands that belong to Mexico. They are located in the Pacific Ocean, some off the coast of the state of Nayarit and about southeast of the tip of Baja California. They are part of t ...

and

Revillagigedos The Revillagigedo Islands ( es, Islas Revillagigedo, ) or Revillagigedo Archipelago are a group of four volcanic islands in the Pacific Ocean, known for their unique ecosystem. They lie approximately from Socorro Island south and southwest of C ...

of Mexico, the Galápagos,

Malpelo Island Malpelo is a small oceanic island in the eastern Pacific Ocean, located about west of the Colombian mainland with a military post manned by the Colombian Armed Forces. It consists of a sheer and barren rock with three high peaks, the highest ...

in Colombia and

Cocos Island Cocos Island ( es, Isla del Coco) is an island in the Pacific Ocean administered by Costa Rica, approximately southwest of the Costa Rican mainland. It constitutes the 11th of the 13 districts of Puntarenas Canton of the Province of Puntarena ...

in Costa Rica.

Habitat and biology

''Alphestes immaculatus'' is a secretive, camouflaged species of shallow water found in

sea grass Seagrasses are the only flowering plants which grow in marine (ocean), marine environments. There are about 60 species of fully marine seagrasses which belong to four Family (biology), families (Posidoniaceae, Zosteraceae, Hydrocharitaceae an ...

beds and rocky reefs at depths between . During the day it stays hidden in crevices or lying among seaweed, relying on their cryptic colouration to escape detection by predators. Occasionally, a fish will partially bury itself in sand. They become mobile at night, searching for their main prey of benthic invertebrates and small fishes. It is normally a solitary species but has been seen in small groups of up to 6 individuals. They can live for up to nine years. Muscle hepcidin expression could be significant in the immune response in fish. The expression of HAMP1 gene of A. immaculatus in muscle at basal conditions could describe a mechanism of protection upon the invasion of pathogens before a strong stimulus.

Taxonomy

''Alphestes immaculatus'' was first formally described in 1936 by the American ichthyologist Charles M. Breder Jr. (1897-1983). It has been confused with the closely related and somewhat similar mutton hamlet '' Alphestes afer'' of the western Atlantic.

Utilisation

''Alphestes immaculatus'' is not a target of commercial fisheries although some artisanal fisheries do catch it using lines or gill nets. In Mexico the value of this species at market has increased as larger grouper species stocks dwindle through overfishing.

References

External links

* {{Taxonbar, from=Q2447109 Epinephelini Fish described in 1936