''Symphodus caeruleus'' 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

wrasse The wrasses are a family, Labridae, of marine fish, many of which are brightly colored. The family is large and diverse, with over 600 species in 81 genera, which are divided into 9 subgroups or tribes. They are typically small, most of them le ...

from 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 ...

Labridae. It is endemic to the Azores in the eastern Atlantic Ocean.

Description

''Symphodus caeruleus'' is a larger species of wrasse than any of its

sympatric In biology, two related species or populations are considered sympatric when they exist in the same geographic area and thus frequently encounter one another. An initially interbreeding population that splits into two or more distinct species sh ...

congeners in the Azores and it has differing

meristic Meristics is an area of ichthyology and herpetology which relates to counting quantitative features of fish and Reptile, reptiles, such as the number of fins or scales. A meristic (countable trait) can be used to describe a particular species of fi ...

counts. This species has 17-18 spines and 8-9 rays in its

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 ...

, 5-6 spines and 7-9 rays in its

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 ...

. It has 33-34 scales in its

lateral line The lateral line, also called the lateral line organ (LLO), is a system of sensory organs found in fish, used to detect movement, vibration, and pressure gradients in the surrounding water. The sensory ability is achieved via modified epithelial ...

. The females are an overall brownish colour, fading ventrally, with a chequered pattern of dark brown spotting on the body. There are four elongated spots on the body, with a fifth on the caudal peduncle which extends onto the proximate portion of 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 ...

, these spots are mirrored in the dorsal and anal fins. The terminal phase males are dark greenish=blue, becoming bluer in the breeding season, with paler fins and a pattern of darker spots similar to that of the females. The males can reach a

standard 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 m ...

of while females attain .

Distribution

''Symphodus caeruleus'' is found in the eastern Atlantic where it is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to the

Azores ) , motto =( en, "Rather die free than subjected in peace") , anthem= ( en, "Anthem of the Azores") , image_map=Locator_map_of_Azores_in_EU.svg , map_alt=Location of the Azores within the European Union , map_caption=Location of the Azores wi ...

Habitat and biology

''Symphodus caeruleus'' is found over shallow, inshore rocky reefs with a good cover of algae which it uses for cover, feeding and nesting. Like many wrasse species this fish is a

protogynous hermaphrodite Sequential hermaphroditism (called dichogamy in botany) is a type of hermaphroditism that occurs in many fish, gastropods, and plants. Sequential hermaphroditism occurs when the individual changes its sex at some point in its life. In particular, ...

, with sexual maturity being attained by males at a

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 and for females. This means that the males can still resemble the initial phase or be in their terminal phase after changing sex from a female. They

spawn Spawn or spawning may refer to: * Spawn (biology), the eggs and sperm of aquatic animals Arts, entertainment, and media * Spawn (character), a fictional character in the comic series of the same name and in the associated franchise ** '' Spawn: ...

from March to June when the larger terminal males form

harems Harem (Persian: حرمسرا ''haramsarā'', ar, حَرِيمٌ ''ḥarīm'', "a sacred inviolable place; harem; female members of the family") refers to domestic spaces that are reserved for the women of the house in a Muslim family. A hare ...

and become

territorial 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 a ...

, this attracts females to spawn their

demersal 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 ...

eggs in the male's nest and the males then provide exclusive care for the eggs. The males still resembling the initial phase, i.e. they look like females, possess larger testes than the terminal phase males and they may attempt to sneakily fertilise the eggs during spawning.

Taxonomy

''Symphodus caeruleus'' was first formally described as ''Centrolabrus caeruleus'' in 1999, previously all wrasses from the genus '' Centrolabrus'' in the Azores had been identified as the emerald wrasse ('' Centrolabrus trutta''). Later studies showed that this species was not as closely related to the rock cook as thought and it was placed in the genus ''

Symphodus ''Symphodus'' is a genus of wrasses native to the eastern Atlantic Ocean and the Mediterranean Sea. Species The currently recognized species in this genus are: * '' Symphodus bailloni'' (Valenciennes, 1839) (Baillon's wrasse) * '' Symphodus caer ...

''. The specific name ''caeruleus'' refers to the blue colouration of the terminal phase males.

References

{{taxonbar, from=Q28150975 caeruleus Endemic fauna of the Azores Fish described in 1999