Spot-tail butterflyfish
Encyclopedia
The Spot-tailed Butterflyfish, Chaetodon ocellicaudus, is a species
of butterflyfish
(family
Chaetodontidae). It is found in the Pacific Ocean
from Malaysia to New Guinea
, north to the Philippines
and Palau
in Micronesia
.
It grows to a maximum of 15 cm (5.9 in) long. Nearly identical to the Black-backed Butterflyfish (C. melannotus), it differs only in the shape of the black mark on the caudal peduncle, in lacking a black mark on the chest, a lighter back, and in having an average of 14 rather than 15 pectoral fin rays.
C. ocellicaudus belongs to the large subgenus
Rabdophorus which might warrant recognition as a distinct genus
. In this group, it appears to be a close relative of the Black-backed Butterflyfish and somewhat less close to the Yellow-dotted Butterflyfish
(C. selene). These are all of oval shape, silvery with yellow fins and snout, ascending diagonal stripes, and black markings around the eyes, on the caudal peduncle, and sometimes on the back. Next closest seem the Saddle Butterflyfish
(C. ephippium) and the Dotted Butterflyfish
(C. semeion), but these are already so distant that their ancestors must have diverged from those soon after the Rabdophorus lineage started to diversify.
The Spot-tailed Butterflyfish is found at depths between 3 and 15 m in coral reefs. They occur in coral-rich areas of reef flats, lagoon
s and seaward reefs. Juveniles tend to keep inshore. Adults are usually seen in pairs. These fish feed on soft coral polyps (e.g. Litophyton viridis and species of the genera Clavularia, Nephthia and Sarcophyton
).
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 found in the Pacific Ocean
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
from Malaysia to New Guinea
New Guinea
New Guinea is the world's second largest island, after Greenland, covering a land area of 786,000 km2. Located in the southwest Pacific Ocean, it lies geographically to the east of the Malay Archipelago, with which it is sometimes included as part of a greater Indo-Australian Archipelago...
, north to the Philippines
Philippines
The Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...
and Palau
Palau
Palau , officially the Republic of Palau , is an island nation in the Pacific Ocean, east of the Philippines and south of Tokyo. In 1978, after three decades as being part of the United Nations trusteeship, Palau chose independence instead of becoming part of the Federated States of Micronesia, a...
in Micronesia
Micronesia
Micronesia is a subregion of Oceania, comprising thousands of small islands in the western Pacific Ocean. It is distinct from Melanesia to the south, and Polynesia to the east. The Philippines lie to the west, and Indonesia to the southwest....
.
It grows to a maximum of 15 cm (5.9 in) long. Nearly identical to the Black-backed Butterflyfish (C. melannotus), it differs only in the shape of the black mark on the caudal peduncle, in lacking a black mark on the chest, a lighter back, and in having an average of 14 rather than 15 pectoral fin rays.
C. ocellicaudus belongs to the large 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...
Rabdophorus which might warrant recognition as a distinct genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
. In this group, it appears to be a close relative of the Black-backed Butterflyfish and somewhat less close to the Yellow-dotted Butterflyfish
Yellow-dotted butterflyfish
The Yellow-dotted Butterflyfish, Chaetodon selene, is a poorly known fish species which has been recorded in the Indo-Pacific region from Malaysia, Indonesia, New Guinea, Taiwan and Japan....
(C. selene). These are all of oval shape, silvery with yellow fins and snout, ascending diagonal stripes, and black markings around the eyes, on the caudal peduncle, and sometimes on the back. Next closest seem the Saddle Butterflyfish
Saddle butterflyfish
The Saddle Butterflyfish, Chaetodon ephippium, is a species of butterflyfish . It is found in the Indian and Pacific Oceans from Sri Lanka and the Cocos-Keeling Islands to the Hawaiian, Marquesan and Tuamoto islands, north to southern Japan, south to Rowley Shoals and New South Wales in...
(C. ephippium) and the Dotted Butterflyfish
Dotted butterflyfish
The Dotted Butterflyfish, Chaetodon semeion, is a species of butterflyfish . It is found in the Indian Ocean and Pacific Ocean from the Maldives to the Tuamotu Islands, north to the Ryukyu Islands and south to the Great Barrier Reef.It grows to a maximum of long. The body is golden yellow...
(C. semeion), but these are already so distant that their ancestors must have diverged from those soon after the Rabdophorus lineage started to diversify.
The Spot-tailed Butterflyfish is found at depths between 3 and 15 m in coral reefs. They occur in coral-rich areas of reef 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 reefs. Juveniles tend to keep inshore. Adults are usually seen in pairs. These fish feed on soft coral polyps (e.g. Litophyton viridis and species of the genera Clavularia, Nephthia and Sarcophyton
Sarcophyton
* In the Plant Kingdom , Sarcophyton is a genus of flowering plants from the orchid family, Orchidaceae: Sarcophyton * In the Animal Kingdom , Sarcophyton is a genus of soft coral in the family Alcyoniidae: ??...
).