| Halfmoon picassofish | |
|---|---|
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Tetraodontiformes |
| Family: | Balistidae |
| Genus: | Rhinecanthus |
| Species: | R. lunula |
| Binomial name | |
| Rhinecanthus lunula Randall & Steene 1983 | |
Rhinecanthus lunula, commonly known as the halfmoon picassofish, is a species of balistid triggerfish first described by John E. Randall and Roger C. Steene in 1983. [2] [3] It belongs to the Indo-Pacific triggerfish genus Rhinecanthus .
While the standard length of Rhinecanthus lunula holotype is 180 mm (7.1 in), the standard length of other type specimens ranges from 45.6 to 218 mm (1.80 to 8.58 in). R. lunula can be differentiated from other Rhinecanthus species by its soft ray count and distinct coloration. It usually has 26 soft dorsal rays (though sometimes only 25 are observed), between 22 and 24 anal soft rays, and 14 pectoral rays. The longest dorsal soft ray is 11.7 percent of the standard length. A broad, black bar exists on the caudal peduncle. Anterior to the caudal peduncle is a curved black line which gives the species its name “lunula,” the Latin word for crescent. An orange-yellow band starts from the base of the upper lip and extends across the head to the pectoral base. In addition, the fish has a long snout, a concave dorsal profile, and an elongate body. The greatest body depth is between 2.2 and 2.6 percent of its standard length. [4]
Randall and Steene noted many differences between juvenile R. lunula and adults. For example, the caudal fin of a juvenile is rounded in a juvenile before becoming slightly double emarginate as it develops into an adult. Juveniles are also missing some of coloration that stands out in adults: there is no blackish area on the ventral side, black bars below the eyes are not well-developed, and the black crescent near the caudal peduncle (which gives the species its name) is also missing. However, there are also two yellow stripes present on juveniles that are not seen on adults. Additionally, the interorbital space is slightly concave in juveniles but becomes slightly convex in adults. [4]
A rare species, R. lunula has a small geographic distribution. When first described as a species, R. lunula was only known to exist from the Pitcairn Islands to Queensland, Australia. The holotype of the species was collected by John E. Randall in a barrier reef near the Society Islands of Tahiti, and juvenile specimens were collected near Queensland, Australia. [4] While most reported sightings of the species have occurred within the same geographic range noted by Randall and Steene, a single sighting of R. lunula has been recorded by scuba divers in Egypt. [5] However, the fish seen in Egypt may have been misidentified, as other members of the Rhinecanthus, R. aculeatus and R. rectangulus , are known to exist in Africa. [6]
Rhinecanthus lunula are generally found in the outer areas of coral reefs 10 meters or deeper. [4] Though the maximum depth of their habitat is unknown, triggerfishes of the Balistidae are known to exist up to 50 meters deep. [6] Habitat may differ by age for R. lunula, as it is known that Rhinecanthus aculeatus juveniles tend to live near beaches while adults tend to live on barrier reefs. [7] Distribution of a given Balistid species among an ecosystem may also be influenced by their diet and the distribution of food sources. [8]
A main characteristic of the triggerfish family Balistidae, to which Rhinecanthuslunula belongs, is a haremic mating system in which a male has multiple female mates. [9]
Triggerfish are about 40 species of often brightly colored fish of the family Balistidae. Often marked by lines and spots, they inhabit tropical and subtropical oceans throughout the world, with the greatest species richness in the Indo-Pacific. Most are found in relatively shallow, coastal habitats, especially at coral reefs, but a few, such as the oceanic triggerfish, are pelagic. While several species from this family are popular in the marine aquarium trade, they are often notoriously ill-tempered.
The clown triggerfish, also known as the bigspotted triggerfish, is a demersal marine fish belonging to the family Balistidae, or commonly called triggerfish.
The lagoon triggerfish, also known as the blackbar triggerfish, the Picasso triggerfish, or the Picassofish, is a triggerfish, up to 30 cm in length, found on reefs in the Indo-Pacific region.
The reef triggerfish, also known as the rectangular triggerfish, wedgetail triggerfish or by its Hawaiian name humuhumunukunukuāpuaʻa, is one of several species of triggerfish. It is found at reefs in the Indo-Pacific and is the state fish of Hawaii.
The orange-lined triggerfish is a demersal triggerfish. Although Balistapus is a monotypic genus, it is closely related to the genus Balistoides.
The raccoon butterflyfish, also known as the crescent-masked butterflyfish, lunule butterflyfish, halfmoon butterflyfish, moon butterflyfish, raccoon butterfly, raccoon, raccoon coralfish, and redstriped butterflyfish, is a species of marine ray-finned fish, a butterflyfish belonging to the family Chaetodontidae. It is found in the Indian and Pacific Oceans.
The blacktip grouper, also known as the redbanded grouper, blacktipped cod, black-tipped rockcod, footballer cod, red-barred cod, red-barred rockcod, scarlet rock-cod or weathered rock-cod, is a species of marine ray-finned fish, a grouper from the subfamily Epinephelinae which is part of the family Serranidae, which also includes the anthias and sea basses. It is found in the tropical Indo-Pacific region. It is the type species of the genus Epinephelus.
Epinephelus andersoni, the catface grouper, brown-spotted grouper, catface rockcod or brown spotted rockcod, is a species of marine ray-finned fish, a grouper from the subfamily Epinephelinae which is part of the family Serranidae, which also includes the anthias and sea basses. It is found in the southwestern Indian Ocean where it is associated with reefs.
The yellow grouper, also known as the banded grouper, is a species of marine ray-finned fish, a grouper from the subfamily Epinephelinae which is part of the family Serranidae, which also includes the anthias and sea basses. It is found in eastern Asian waters of the Western Pacific Ocean. Its natural habitats are shallow seas and rocky reefs.
The tenspine grouper is a species of marine ray-finned fish, a grouper from the subfamily Epinephelinae which is part of the family Serranidae, which also includes the anthias and sea basses. It is found along the western coast of Mexico and Central America, but is a very rare fish of which little information exists.
Plectropomus laevis, known commonly as the black-saddled coral grouper, cluespotted coral trout, blacksaddled coral trout, blue-spot trout, Chinese footballer, footballer cod, footballer coral trout, oceanic coral trout or tiger trout, is a species of marine ray-finned fish, a grouper from the subfamily Epinephelinae which is part of the family Serranidae, which also includes the anthias and sea basses. It is found in the Indo-Pacific region.
Cantherhines dumerilii is a species of fish in the family Monacanthidae, the filefishes. Its common names include whitespotted filefish, barred filefish, orange-fin file, and yelloweye leatherjacket. It is distributed in the Indian and Pacific Oceans where it is found on coral reefs.
Naso lituratus is a species of fish in the family Acanthuridae, the tangs and unicornfishes. Its common names include barcheek unicornfish, naso tang, and orange-spine unicornfish.
The blackbelly triggerfish is a ray-finned fish in the family Balistidae found in the Indo-Pacific. It occasionally makes its way into the aquarium trade. It is sometimes known as the blackpatch triggerfish.
The mailed butterflyfish, also known as the reticulated butterflyfish or black butterflyfish, is a species of marine ray-finned fish, a butterflyfish belonging to the family Chaetodontidae, This species is found on reefs in the central and western Pacific Ocean. It can be found in the aquarium trade.
Chilomycterus reticulatus, the spotfin burrfish, spotted burrfish, Pacific burrfish, spotfin porcupinefish or few-spined porcupinefish, is a species of fish in the genus Chilomycterus, which is part of the porcupinefish family Diodontidae.
Canthidermis maculata, also known as rough triggerfish or spotted oceanic triggerfish, is a species of triggerfish native to the tropical and subtropical oceans worldwide. Unlike most triggerfish, they are mostly pelagic.
Siganus virgatus, the barhead spinefoot, doublebar rabbitfish or doublebar spinefoot is a species of marine ray-finned fish, a rabbitfish belonging to the family Siganidae. It is found in the Indo-Pacific region.
Epinephelus bruneus, the longtooth grouper, is a species of marine ray-finned fish, a grouper from the subfamily Epinephelinae which is part of the family Serranidae, which also includes the anthias and sea basses. It is found in northwest Pacific in eastern Asia.
Plectroglyphidodon dickii, common name blackbar devil, Dick's damsel or narrowbar damselfish, is a species of damselfish in the family Pomacentridae. This species was formerly classified as Dascyllus aruanus, but recently the populations of western Indian Ocean and Pacific Ocean have been split off.
