Eritrean butterflyfish
Encyclopedia
The Eritrean Butterflyfish or Crown Butterflyfish, Chaetodon paucifasciatus, is a species
of butterflyfish
(family
Chaetodontidae). It is essentially just known from the Red Sea
and the Gulf of Aden
, but has been reported from East Africa
.
It grows up to 14 cm (5.5 in) in length. It is white with black chevrons, except for a red zone stretching from the aft dorsal fin
across the caudal peduncle to the end of the anal fin. A red bar runs vertically through the caudal fin. There are black eyestripes and a black "crown" with white border.
Eritrean Butterflyfish are oviparous fish forming monogamous pairings during breeding. They are usually found in pairs or in small groups over coral
and rubble areas from 1m to 30m depth. They feed on coral polyps, gorgonians, algae
, polychaete worms and small crustacean
s.
This fish fares well in the aquarium
and thus is sought after by hobbyists.
(C. madagaskariensis) and Atoll Butterflyfish
es (C. mertensii), and the more distant Pearlscale Butterflyfish
(C. xanthurus).
The "crowned" Chaetodon are a clearly recognizable clade
, but their further relationships are otherwise less clear. They were often placed in the subgenus
Exornator, or considered a distinct subgenus Rhombochaetodon. According to various DNA sequence
studies, some older and more singular lineages. These include species such as the Asian Butterflyfish (C. argentatus), the Blue-striped Butterflyfish (C. fremblii) and Burgess' Butterflyfish (C. burgessi). C. burgessi is in fact so peculiar that it was placed in a monotypic
subgenus Roaops. But recognition of this would probably result in several other small or monotypic subgenera becoming justified, and the older Rhombochaetodon would be the more conveniently apply to the entire radiation.
But the expanded group is of unclear relationships to species like the Speckled Butterflyfish
(C. citrinellus) and the Four-spotted Butterflyfish (C. quadrimaculatus). These might be members of the subgenus Exornator – the lineages around the Spot-banded Butterflyfish (C. punctatofasciatus) – and C. citrinellus certainly looks somewhat similar to these. Yet phylogenetically, their position towards Rhombochaetodon is unresolved, and ultimately it might be better to merge both Rhombochaetodon and Roaops in Exornator. If the genus Chaetodon
is split up, Exornator might become a subgenus of Lepidochaetodon or a separate 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 is essentially just known 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 the Gulf of Aden
Gulf of Aden
The Gulf of Aden is located in the Arabian Sea between Yemen, on the south coast of the Arabian Peninsula, and Somalia in the Horn of Africa. In the northwest, it connects with the Red Sea through the Bab-el-Mandeb strait, which is about 20 miles wide....
, but has been reported from 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:...
.
It grows up to 14 cm (5.5 in) in length. It is white with black chevrons, except for a red zone stretching from the aft 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...
across the caudal peduncle to the end of the anal fin. A red bar runs vertically through the caudal fin. There are black eyestripes and a black "crown" with white border.
Eritrean Butterflyfish are oviparous fish forming monogamous pairings during breeding. They are usually found in pairs or in small groups over 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...
and rubble areas from 1m to 30m depth. They feed on coral polyps, gorgonians, algae
Algae
Algae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms, such as the giant kelps that grow to 65 meters in length. They are photosynthetic like plants, and "simple" because their tissues are not organized into the many...
, polychaete worms and small crustacean
Crustacean
Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...
s.
This fish fares well 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...
and thus is sought after by hobbyists.
Systematics
C. paucifasciatus is one of the "crowned" butterflyfishes. These form a group of largely allopatric species sharing the overall color pattern of dark forward-pointing chevrons on silvery hues, (usually) a black-and-white crown spot and yellow to red hindparts to a stunning degree; they differ in the exact combination of hues and some small pattern details. Other members of this lineage are the closely related SeychellesSeychelles butterflyfish
The Seychelles Butterflyfish, Chaetodon madagaskariensis, is a species of butterflyfish . It is found in the Indian Ocean from eastern Africa east to Cocos-Keeling Islands and Christmas Island, north to Sri Lanka...
(C. madagaskariensis) and Atoll Butterflyfish
Atoll butterflyfish
The Atoll Butterflyfish, Chaetodon mertensii, is a species of butterflyfish . It is found in the Pacific Ocean from the Ryukyu Islands to the Philippines and extending to Lord Howe Island, Rapa Iti and the Tuamotus....
es (C. mertensii), and the more distant Pearlscale Butterflyfish
Pearlscale butterflyfish
The Pearlscale Butterflyfish is a species of butterflyfish also known as Yellow-tailed Butterflyfish or Philippines Chevron Butterflyfish...
(C. xanthurus).
The "crowned" Chaetodon are a clearly recognizable clade
Clade
A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...
, but their further relationships are otherwise less clear. They were often placed 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, or considered a distinct subgenus Rhombochaetodon. According to various DNA sequence
DNA sequence
The sequence or primary structure of a nucleic acid is the composition of atoms that make up the nucleic acid and the chemical bonds that bond those atoms. Because nucleic acids, such as DNA and RNA, are unbranched polymers, this specification is equivalent to specifying the sequence of...
studies, some older and more singular lineages. These include species such as the Asian Butterflyfish (C. argentatus), the Blue-striped Butterflyfish (C. fremblii) and Burgess' Butterflyfish (C. burgessi). C. burgessi is in fact so peculiar that it was placed in a monotypic
Monotypic
In biology, a monotypic taxon is a taxonomic group with only one biological type. The term's usage differs slightly between botany and zoology. The term monotypic has a separate use in conservation biology, monotypic habitat, regarding species habitat conversion eliminating biodiversity and...
subgenus Roaops. But recognition of this would probably result in several other small or monotypic subgenera becoming justified, and the older Rhombochaetodon would be the more conveniently apply to the entire radiation.
But the expanded group is of unclear relationships to species like the Speckled Butterflyfish
Speckled butterflyfish
Chaetodon citrinellus is a species of butterflyfish . It is commonly known as the Speckled Butterflyfish or Citron Butterflyfish...
(C. citrinellus) and the Four-spotted Butterflyfish (C. quadrimaculatus). These might be members of the subgenus Exornator – the lineages around the Spot-banded Butterflyfish (C. punctatofasciatus) – and C. citrinellus certainly looks somewhat similar to these. Yet phylogenetically, their position towards Rhombochaetodon is unresolved, and ultimately it might be better to merge both Rhombochaetodon and Roaops in 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 or a separate genus.