''Kyphosus ocyurus'', the blue-striped chub or rainbow chub, 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 chub The sea chubs, also known as rudderfish and pilot fish and in Hawaiian as ''enenue'' or ''nenue'', are a family, Kyphosidae, of fishes in the order Perciformes native to the Atlantic, Indian and Pacific Oceans usually close to shore in marine w ...

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 ...

Kyphosidae The sea chubs, also known as rudderfish and pilot fish and in Hawaiian as ''enenue'' or ''nenue'', are a family, Kyphosidae, of fishes in the order Perciformes native to the Atlantic, Indian and Pacific Oceans usually close to shore in marine w ...

. The species is found in the Pacific Ocean where it prefers rocky substrates.

Description

''Kyphosus ocyurus'' has an elongated, compressed, oval shaped body. The ventral and dorsal profiles of the head are convex with a short snout and a very short, horizontal mouth which opens at the front. The upper jaw is partially concealed beneath the orbital bones when the mouth is closed and the teeth are small, fixed and are incisor-like with flattened tips. There are also teeth in the middle of the roof of the mouth. It has a 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 ...

which has 11 spines in the anterior part which fold down into a scaled groove and 13 soft rays in the posterior part. 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 ...

has three spines and 14 soft rays and is low. 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 ...

deeply forked. All of the body is covered in small, thick and rough scales except for the snout. The body of this species is distinctively coloured with two wavy horizontal stripes, one yellow and one bluish, starting at the mouth and extending to the caudal peduncle. The head is yellow to silvery marked with a blue streak behind eye on he dill cover. It is metallic blue on the back and white on the underparts. It attains 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 although a more common size is a total length of and the maximum published weight is .

Distribution

''Kyphosus ocyurus'' is found in the tropical eastern Pacific Ocean from the Galapagos Islands to

Hawaii Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only stat ...

west to the

Izu Islands The are a group of volcanic islands stretching south and east from the Izu Peninsula of Honshū, Japan. Administratively, they form two towns and six villages; all part of Tokyo Prefecture. The largest is Izu Ōshima, usually called simply Ō ...

of Japan and including

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Palau Palau,, officially the Republic of Palau and historically ''Belau'', ''Palaos'' or ''Pelew'', is an island country and microstate in the western Pacific. The nation has approximately 340 islands and connects the western chain of the Caro ...

and the

Marquesas Islands The Marquesas Islands (; french: Îles Marquises or ' or '; Marquesan: ' ( North Marquesan) and ' ( South Marquesan), both meaning "the land of men") are a group of volcanic islands in French Polynesia, an overseas collectivity of France in th ...

. It also occurs off the American coast from southern

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

to Peru.f>

Habitat and biology

''Kyphosus ocyrus'' is an uncommon species which can be found as both solitary individuals and in schools, frequently mixed with '' K. elegans'' and '' K. vaigiensis''. They live near the surface, no deeper than along rocky shores, in the open ocean and in reefs off isolated islands. They have also been observed to swim rapidly in small schools in open water over deep reefs, along sea walls and at drop-offs. They are also frequently reported near floating logs far out to sea. It is more omnivorous than other species in the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

Kyphosus ''Kyphosus'' is a genus of sea chubs native to the Atlantic, Indian and Pacific oceans. It is the only genus in the subfamily Kyphosinae of the family Kyphosidae. Species There are currently 16 recognized species in this genus: * ''Kyphosus anal ...

'' and its diet includes

zooplankton Zooplankton are the animal component of the planktonic community ("zoo" comes from the Greek word for ''animal''). Plankton are aquatic organisms that are unable to swim effectively against currents, and consequently drift or are carried along by ...

. ''K. ocyurus'' tends not to live in submerged vegetation, preferring a mix of an open water and coral reef environment. In fact, its preferred habitat is that of a hard ocean bottom and ample visibility. Submerged vegetation is preferred for laying fish larvae, and therefore most juveniles and young briefly live in submerged vegetation before reaching adulthood and subsequently moving into a more open ocean environment. In terms of movement and overall ''K. ocyurus'' migration, it tends to widely disperse from the Indo-Pacific Ocean region into the East-Pacific Ocean region and eventually into the North Atlantic Ocean region, and these fish can cross the Pacific Ocean barrier relatively smoothly, preventing otherwise major external and environmental disturbances from negatively affecting the population connectivity of the species. The coelomic organs of ''K. ocyurus'' are similar to those of most of the other members of the family Kyphosidae. The intestine arrangement of ''K. ocyurus'' is complex, with a z-shaped winding pathway with an average length of 28 millimeter., rather than the common single loop, common in many kyphosines but still a more advanced character state when compared to other perciforms. ''K. ocyurus'' has three loops tilted to the right in the z-shaped intestinal pathway instead of one loop, which is common in many of its Kyphosidae relatives.

Taxonomy

''Kyphosus ocyurus'' was first formally described as ''Pimelepterus ocyurus'' in 1882 by David Starr Jordan and Charles Henry Gilbert with the type locality given as

Panama Bay The Panama Bay ( es, Bahia de Panamá) is a large body of water off the coast of southern Panama, at . It is a part of the greater Gulf of Panama. Pollution Problems The Panama Bay is considered to be in an eutrophic state by the World Resources ...

. ''K. ocyurus'' was placed in its own genus, ''Sectator'' but molecular data has revealed that it is the sister species of ''K. vaigiensis'' and is so placed within the genus ''Kyphosus''.

References

External links

* {{Taxonbar, from=Q28599344 ocyurus Fish described in 1882