The crescent gunnel (''Pholis laeta''), also known as the bracketed blenny, 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 ...

belonging to 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 ...

Pholidae ''Pholidae'' is a family of marine ray-finned fishes, known as gunnels, in the scorpaeniform suborder Zoarcoidei. These are fishes of the littoral zone and are mainly found in North Pacific Ocean, with two species found in the North Atlantic Ocea ...

, the gunnels. This fish occurs in the shallow coastal waters of the eastern North Pacific Ocean.

Taxonomy

The crescent gunnel was first formally described in 1873 by the American paleontologist and biologist Edward Drinker Cope with the type locality given as

Sitka russian: Ситка , native_name_lang = tli , settlement_type = Consolidated city-borough , image_skyline = File:Sitka 84 Elev 135.jpg , image_caption = Downtown Sitka in 1984 , image_size ...

Unalaska Unalaska ( ale, Iluulux̂; russian: Уналашка) is the chief center of population in the Aleutian Islands. The city is in the Aleutians West Census Area, a regional component of the Unorganized Borough in the U.S. state of Alaska. Unalaska ...

Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S., ...

. The specific name ''laeta'' means "joyful", "glad" or "pleasant", Cope did not explain his choice of this name but did refer to the types as “rather brilliantly colored” specimens.

Description

''Pholis laeta'', like other gunnels, is somewhat eel-like. It grows to a maximum

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 . 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 conv ...

contains between 74 and 80 spines and the

anal 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 ...

contains 35 to 37. soft rays. 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 rounded and the

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 are tiny. There are two rows of blackish crescent-shaped markings each with a yellow spot in the their centers along the back, and these identify this species from other gunnels. The overall color of the body may vary from orange-brown to olive-green, the color being camouflage and color phases vary with habitat.

Distribution and habitat

The crescent gunnel is found in the eastern Pacific along the western coast of North America from the

Bering Sea The Bering Sea (, ; rus, Бе́рингово мо́ре, r=Béringovo móre) is a marginal sea of the Northern Pacific Ocean. It forms, along with the Bering Strait, the divide between the two largest landmasses on Earth: Eurasia and The Ameri ...

coast of Alaska through the

Aleutian Islands The Aleutian Islands (; ; ale, Unangam Tanangin,”Land of the Aleuts", possibly from Chukchi language, Chukchi ''aliat'', "island"), also called the Aleut Islands or Aleutic Islands and known before 1867 as the Catherine Archipelago, are a cha ...

south as far as Crescent City in

northern California Northern California (colloquially known as NorCal) is a geographic and cultural region that generally comprises the northern portion of the U.S. state of California. Spanning the state's northernmost 48 counties, its main population centers incl ...

. ''Pholis laeta'' lives in shallow, marine areas. It may also be found out of water under seaweed or rocks. It is known to live in the

demersal zone The demersal zone is the part of the sea or ocean (or deep lake) consisting of the part of the water column near to (and significantly affected by) the seabed and the benthos. The demersal zone is just above the benthic zone and forms a layer of ...

at depths of up to 73 metres. This fish is common in such habitats as tide pools and in intertidal environmentsm and may be found under rocks that are protected by seaweed.

Biology

The crescent gunnel reach sexual maturity at approximately in length. The females lay masses of 600 to 1,600 eggs in late winter, January and February. The demersal eggs stick to each other and to the substrate and are sometimes guarded by one of the parents. They hatch into larvae after 2 months and join the plankton. In Alaska colder water temperatures can delay breeding. They can live for up to 6 years. The crescent gunnels likely eats marine worms as well as small species of

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 ...

. It is an important prey item for larger vertebrate predators and these include

great blue heron The great blue heron (''Ardea herodias'') is a large wading bird in the heron family Ardeidae, common near the shores of open water and in wetlands over most of North America and Central America, as well as the Caribbean and the Galápagos ...

(''Ardea herodias''),

pigeon guillemot The pigeon guillemot (''Cepphus columba'') () is a species of bird in the auk family, Alcidae. One of three species in the genus ''Cepphus'', it is most closely related to the spectacled guillemot. There are five subspecies of the pigeon guille ...

(''Cepphus columba''),

North American river otter The North American river otter (''Lontra canadensis''), also known as the northern river otter and river otter, is a semiaquatic mammal that endemism, only lives on the North American continent, along its waterways and coasts. An adult North Amer ...

(''Lontra canadensis''),

American mink The American mink (''Neogale vison'') is a semiaquatic species of mustelid native to North America, though human intervention has expanded its range to many parts of Europe, Asia and South America. Because of range expansion, the American mink i ...

(''Mustela vison''), and larger fishes. However, have been found to be a lower quality food for pigeon guillemot chicks and pairs that caught a high number of crescent gunnels do not show high reproductive success. These fishes hide in

rockpool A tide pool or rock pool is a shallow pool of seawater that forms on the rocky intertidal shore. Many of these pools exist as separate bodies of water only at low tide. Many tide pool habitats are home to especially adaptable animals that ...

s or tiny crevices under rocks or in vegetation, they may even emerge fully from water at low tide, and are apparently able to breathe air not submerged.

References

{{Taxonbar, from=Q2338665 Crescent gunnel Fish described in 1873 Taxa named by Edward Drinker Cope