Saddle butterflyfish
Encyclopedia
The Saddle Butterflyfish, Chaetodon ephippium, is a species
of butterflyfish
(family
Chaetodontidae). It is found in the Indian
and Pacific Ocean
s 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 Australia
.
It is a large butterflyfish, at up to 30 cm (nearly 12 in) long together with the Lined Butterflyfish
(C. lineolatus) the giant among its genus
. In shape it resembles certain angelfishes more than most of its relatives. The overall color is yellowish grey, with a large black spot bordered below by a broad white band on the back and wavy blue lines on the lower sides. The throat and the outline of the hind parts is bright yellow. Adults have a filament extending posteriorly from the upper part of the soft portion of the dorsal fin
.
The Saddle Butterflyfish is found at depths between 0 and 30 m in coral reef
s. It feeds on filamentous algae, small invertebrate
s, coral polyps, and fish eggs.
It belongs to the large subgenus
Rabdophorus which might warrant recognition as a distinct genus
. In this group, it appears to represent a distinct lineage, with the Dotted Butterflyfish
(C. semeion) perhaps the only somewhat closely related species. Next closest seems to be a group including the Black-backed Butterflyfish (C. melannotus), Spot-tailed Butterflyfish (C. ocellicaudus) and Yellow-dotted Butterflyfish
(C. selene), but these are already so distant that their ancestors must have diverged from the Saddle Butterflyfish's soon after the Rabdophorus lineage started to diversify.
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 Indian
Indian Ocean
The Indian Ocean is the third largest of the world's oceanic divisions, covering approximately 20% of the water on the Earth's surface. It is bounded on the north by the Indian Subcontinent and Arabian Peninsula ; on the west by eastern Africa; on the east by Indochina, the Sunda Islands, and...
and 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...
s from Sri Lanka
Sri Lanka
Sri Lanka, officially the Democratic Socialist Republic of Sri Lanka is a country off the southern coast of the Indian subcontinent. Known until 1972 as Ceylon , Sri Lanka is an island surrounded by the Indian Ocean, the Gulf of Mannar and the Palk Strait, and lies in the vicinity of India and the...
and the Cocos-Keeling Islands to the Hawaiian
Hawaiian Islands
The Hawaiian Islands are an archipelago of eight major islands, several atolls, numerous smaller islets, and undersea seamounts in the North Pacific Ocean, extending some 1,500 miles from the island of Hawaii in the south to northernmost Kure Atoll...
, Marquesan and Tuamoto 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...
, south to Rowley Shoals
Rowley Shoals
The Rowley Shoals is a group of three atoll-like coral reefs south of the Timor Sea, about 260 km west of Broome on the northwestern Australian coast, centered around , on the edge of one of the widest continental shelves in the world. Each atoll covers an area of around 80 to 90 km² within the rim...
and New South Wales
New South Wales
New South Wales is a state of :Australia, located in the east of the country. It is bordered by Queensland, Victoria and South Australia to the north, south and west respectively. To the east, the state is bordered by the Tasman Sea, which forms part of the Pacific Ocean. New South Wales...
in 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 large butterflyfish, at up to 30 cm (nearly 12 in) long together with the Lined Butterflyfish
Lined butterflyfish
The Lined Butterflyfish is a butterflyfish , one of the largest species in the genus Chaetodon...
(C. lineolatus) the giant among its 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 shape it resembles certain angelfishes more than most of its relatives. The overall color is yellowish grey, with a large black spot bordered below by a broad white band on the back and wavy blue lines on the lower sides. The throat and the outline of the hind parts is bright yellow. Adults have a filament extending posteriorly from the upper part of the soft portion of the dorsal fin
Dorsal fin
A dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fishes, marine mammals , and the ichthyosaurs...
.
The Saddle Butterflyfish is found at depths between 0 and 30 m in coral reef
Coral reef
Coral reefs are underwater structures made from calcium carbonate secreted by corals. Coral reefs are colonies of tiny living animals found in marine waters that contain few nutrients. Most coral reefs are built from stony corals, which in turn consist of polyps that cluster in groups. The polyps...
s. It feeds on filamentous algae, small 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 fish eggs.
It 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 represent a distinct lineage, with 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) perhaps the only somewhat closely related species. Next closest seems to be a group including the Black-backed Butterflyfish (C. melannotus), Spot-tailed Butterflyfish (C. ocellicaudus) and 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), but these are already so distant that their ancestors must have diverged from the Saddle Butterflyfish's soon after the Rabdophorus lineage started to diversify.