Blackback butterflyfish
Encyclopedia
The Black-backed Butterflyfish or blackback butterflyfish Chaetodon melannotus, is a species
of butterflyfish
(family
Chaetodontidae). It ranges from the Red Sea
and East Africa to Samoa
, to southern Japan and throughout Micronesia
.
This fish grows up to 18 cm (c.7 in) long, and may live for up to 20 years. When observed at night or when frightened, this species changes color; the dorsal
portion of the body turns black except for two white patches.
It belongs to the large subgenus
Rabdophorus which might warrant recognition as a distinct genus
. In this group, it appears a close relative of the Spot-tailed Butterflyfish (C. ocellicaudus) 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.
These oviparous fish are common on staghorn coral
thickets, they are less seen on exposed parts of reef
s. Black-backed butterflyfish are generally found between 4 and 20 m deep, usually solitary, in pairs during the breeding season. Juveniles are more commonly found inshore, in pairs or traveling in small groups.It feeds primarily on the polyp
s of soft and hard coral
s. The Black-backed Butterflyfish is easy to maintain in the aquarium
by the standards of its genus
.
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 ranges from 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...
and East Africa to Samoa
Samoa
Samoa , officially the Independent State of Samoa, formerly known as Western Samoa is a country encompassing the western part of the Samoan Islands in the South Pacific Ocean. It became independent from New Zealand in 1962. The two main islands of Samoa are Upolu and one of the biggest islands in...
, to southern Japan and throughout 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....
.
This fish grows up to 18 cm (c.7 in) long, and may live for up to 20 years. When observed at night or when frightened, this species changes color; the dorsal
Dorsum (biology)
In anatomy, the dorsum is the upper side of animals that typically run, fly, or swim in a horizontal position, and the back side of animals that walk upright. In vertebrates the dorsum contains the backbone. The term dorsal refers to anatomical structures that are either situated toward or grow...
portion of the body turns black except for two white patches.
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 a close relative of the Spot-tailed Butterflyfish (C. ocellicaudus) 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.
These oviparous fish are common on staghorn coral
Staghorn coral
The Staghorn coral is a branching coral with cylindrical branches ranging from a few centimetres to over two metres in length and height. It occurs in back reef and fore reef environments from 0 to 30 m depth. The upper limit is defined by wave forces, and the lower limit is controlled by...
thickets, they are less seen on exposed parts of reef
Reef
In nautical terminology, a reef is a rock, sandbar, or other feature lying beneath the surface of the water ....
s. Black-backed butterflyfish are generally found between 4 and 20 m deep, usually solitary, in pairs during the breeding season. Juveniles are more commonly found inshore, in pairs or traveling in small groups.It feeds primarily on the polyp
Polyp
A polyp in zoology is one of two forms found in the phylum Cnidaria, the other being the medusa. Polyps are approximately cylindrical in shape and elongated at the axis of the body...
s of soft and hard 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. The Black-backed Butterflyfish is easy to maintain in the aquarium
Aquarium
An aquarium is a vivarium consisting of at least one transparent side in which water-dwelling plants or animals are kept. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, marine mammals, turtles, and aquatic plants...
by the standards of 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...
.