Speckled butterflyfish
Encyclopedia
Chaetodon citrinellus is a species
of butterflyfish
(family
Chaetodontidae). It is commonly known as the Speckled Butterflyfish or Citron Butterflyfish. It is found in the Indo-Pacific
: the Red Sea
, East Africa
to the Hawaii
an, Marquesan and Tuamotu islands, north to southern Japan
and south to Australia
.
It is a distinct species, most closely related to the Four-spotted Butterflyfish (C. quadrimaculatus). Together they are basal in the subgenus
Exornator, and might be intermediate between the core group of this subgenus and the species of the Rhombochaetodon (or Roaops) lineage. If that is correct, the latter would require to be merged into Exornator. If the genus Chaetodon
is split up, Exornator might become a subgenus of Lepidochaetodon.
As its names suggest, it is pale yellow with numerous small dark spots. There is also a black bar extending above and below the eye and a black margin to the anal fin. The largest recorded specimen was 13 centimetres (5.1 in) long.
C. citrinellus is common in shallow exposed reef
flats, lagoon
s, and seaward reef
s, generally in relatively open areas with scattered coral
s. They may occasionally be found at greater depth, as deep as 36 metres (118.1 ft). They feed on small worm
s, small benthic invertebrate
s, coral polyps and filamentous algae.
Adults usually swim in pairs (pairs form during breeding), while juveniles are more often seen in small aggregations and commonly mix with other similar sized juveniles, especially of the Sunburst Butterflyfish
(C. kleinii). They are oviparous.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of butterflyfish
Butterflyfish
The butterflyfish are a group of conspicuous tropical marine fish of the family Chaetodontidae; the bannerfish and coralfish are also included in this group. Found mostly on the reefs of the Atlantic, Indian and Pacific Oceans, there are approximately 120 species in 10 genera...
(family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Chaetodontidae). It is commonly known as the Speckled Butterflyfish or Citron Butterflyfish. It is found in the Indo-Pacific
Indo-Pacific
The Indo-Pacific is a biogeographic region of the Earth's seas, comprising the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the seas connecting the two in the general area of Indonesia...
: the Red Sea
Red Sea
The Red Sea is a seawater inlet of the Indian Ocean, lying between Africa and Asia. The connection to the ocean is in the south through the Bab el Mandeb strait and the Gulf of Aden. In the north, there is the Sinai Peninsula, the Gulf of Aqaba, and the Gulf of Suez...
, East Africa
East Africa
East Africa or Eastern Africa is the easterly region of the African continent, variably defined by geography or geopolitics. In the UN scheme of geographic regions, 19 territories constitute Eastern Africa:...
to the Hawaii
Hawaii
Hawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...
an, Marquesan and Tuamotu islands, north to southern Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
and south to Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
.
It is a distinct species, most closely related to the Four-spotted Butterflyfish (C. quadrimaculatus). Together they are basal in the subgenus
Subgenus
In biology, a subgenus is a taxonomic rank directly below genus.In zoology, a subgeneric name can be used independently or included in a species name, in parentheses, placed between the generic name and the specific epithet: e.g. the Tiger Cowry of the Indo-Pacific, Cypraea tigris Linnaeus, which...
Exornator, and might be intermediate between the core group of this subgenus and the species of the Rhombochaetodon (or Roaops) lineage. If that is correct, the latter would require to be merged into Exornator. If the genus Chaetodon
Chaetodon
Chaetodon is a tropical fish genus in the family Chaetodontidae. Like their relatives, they are known as "butterflyfish". This genus is by far the largest among the Chaetodontidae, with about 90 living species included here, though most might warrant recognition as distinct genera.Several subgenera...
is split up, Exornator might become a subgenus of Lepidochaetodon.
Description and ecology
C. citrinellus is common in shallow exposed reef
Reef
In nautical terminology, a reef is a rock, sandbar, or other feature lying beneath the surface of the water ....
flats, lagoon
Lagoon
A lagoon is a body of shallow sea water or brackish water separated from the sea by some form of barrier. The EU's habitat directive defines lagoons as "expanses of shallow coastal salt water, of varying salinity or water volume, wholly or partially separated from the sea by sand banks or shingle,...
s, and seaward reef
Reef
In nautical terminology, a reef is a rock, sandbar, or other feature lying beneath the surface of the water ....
s, generally in relatively open areas with scattered coral
Coral
Corals are marine animals in class Anthozoa of phylum Cnidaria typically living in compact colonies of many identical individual "polyps". The group includes the important reef builders that inhabit tropical oceans and secrete calcium carbonate to form a hard skeleton.A coral "head" is a colony of...
s. They may occasionally be found at greater depth, as deep as 36 metres (118.1 ft). They feed on small worm
Worm
The term worm refers to an obsolete taxon used by Carolus Linnaeus and Jean-Baptiste Lamarck for all non-arthropod invertebrate animals, and stems from the Old English word wyrm. Currently it is used to describe many different distantly-related animals that typically have a long cylindrical...
s, small benthic invertebrate
Invertebrate
An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...
s, coral polyps and filamentous algae.
Adults usually swim in pairs (pairs form during breeding), while juveniles are more often seen in small aggregations and commonly mix with other similar sized juveniles, especially of the Sunburst Butterflyfish
Sunburst butterflyfish
The Sunburst Butterflyfish is also known as the Black-lipped Butterflyfish or Klein's Butterflyfish. In the creoles of Mauritius and Réunion it is called papillon...
(C. kleinii). They are oviparous.