Longhorn cowfish | |
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A longhorn cowfish in Aquarium Finisterrae (Spain) | |
Several boxfish, including the longhorn cowfish. | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Actinopterygii |
Order: | Tetraodontiformes |
Family: | Ostraciidae |
Genus: | Lactoria |
Species: | L. cornuta |
Binomial name | |
Lactoria cornuta | |
Synonyms [2] | |
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The longhorn cowfish (Lactoria cornuta), also called the horned boxfish, is a species of marine ray-finned fish belonging to the family Ostraciidae, the boxfishes. This species is recognizable by its long horns that protrude from the front of its head, rather like those of a cow or bull. [3] They are a resident of the Indo-Pacific region and can grow up to 50 cm (20 in) long.
Adults are reef fish, often solitary and territorial, and live around sand or rubble bottom up to a depth of 50 m (160 ft). They are omnivorous, feeding upon benthic algae, various microorganisms, and foraminiferans that it strains from sediments, sponges, polychaete worms from sand flats, mollusks, small crustaceans, and small fish, able to feed on benthic invertebrates by blowing jets of water into the sandy substrate. Longhorn cowfish protect the coral reefs they live in by being predators of the invertebrates that destroy the reefs. They are also important in the growth and creation of coral reefs for this same reason. [4]
The longhorn cowfish was first formally described as Ostracion cornutus in the 10th edition of Systema Naturae published in 1758 by Carl Linnaeus with its type locality given as India. [5] In 1902 David Starr Jordan and Henry Weed Fowler proposed the subgenus Lactoria within Ostracion and designated O. cornutus as its type species. [6] The 5th edition of Fishes of the World classifies this genus within the family Ostraciidae in the suborder Ostracioidea within the order Tetraodontiformes. [7]
The longhorn cowfish is classified within the genus Lactoria, an name that means a "milkcow", a reference to the large spines above the eyes resembling the horns of a cow. The fishes in this genus are known as cowfishes, as are some related species. The specific name cornutus, means "horned", an allusion to the large spines in front of the eyes. [8]
Its primary habitat is coral reefs in lagoons, on reef flats, estuaries, bays, and on protected seaward reefs. [9] Juveniles associate with Acropora corals. Depth range is 1–45 m (3 ft 3 in – 147 ft 8 in), perhaps up to 100 m (330 ft).
Red Sea and East Africa eastward through Indonesia to Marquesas, northward to southern Japan. Including Tuamotus, southern Korea, north to the Ryukyu Islands of southern Japan, south to Australia and Lord Howe Island. Tropical and subtropical waters. The specimens found in India are a new development in the last couple years, and it is speculated that cyclones or typhoons brought Lactoria cornuta to a new environment. [10] [11]
There is no known sexual dimorphism, so both male and female display a yellow to olive base color, which is decorated with white or bluish spots. Paired courtship just before or after sunset. Eggs and ichthyoplankton are pelagic. Females generally are larger than males. Males grow to be 65–155 mm with an average of 103 mm, while females grow to be 83–250 mm with an average of 121 mm. Female longhorn cowfish also weigh more than males with a weight range of 17–156 g with an average of 33 g while males have a weight range of 12–116 g with an average of 26 g. [9]
One distinction from other fish is the lack of a gill cover, which is replaced by a small slit or hole. The hexagonal plate-like scales of these fish are fused together into a solid, triangular, box-like carapace, from which the fins and tail protrude. They have large eyes immediately behind the horns. [9] Their unique method of swimming, called ostraciiform swimming, causes them to look as if they are hovering. They have no pelvic skeleton, so they lack pelvic fins. The tail fin of the longhorn cowfish can be the same length as its body, as it relies on its fins for movement. [12] They are such slow swimmers cowfish are easily caught by hand, making a grunting noise when captured. The cowfish are also able to produce two kinds of sounds using muscles connected to their swim bladder, hums and clicks. [13] This species of cowfish is the most well-known cowfish species in the aquarium trade.
If severely stressed, this species may be able to exude deadly toxin, pahutoxin, an ichthyotoxic, hemolytic, heat-stable, non-dialyzable, non-protein poison in the mucous secretions of their skin. It is apparently unique among known fish poisons; it is toxic to the boxfish and mimics sea cucumber toxins in general properties.
The horns of the Longhorn cowfish may have evolved to make it more difficult to swallow for predators. The horns of the boxfish can be used to ward off predators through charging at the predator. [14] If damaged, these horns can grow back within a few months. [15] These horns are mostly hollow and composed of mineralized collagen fibers. [16] Both the hard armor exoskeleton and the use of the toxic secretion are solid defenses against predators. There are also egg predators like wrasses and [[damselfishes]]. Larger species in the family are able to ward off the egg predators, but the Longhorn Cowfish spawn close to the substrate in order to hide themselves and their eggs from the predators. [17]
This fish forms harems with 3–4 females in each one. The females spawn shortly after sunset, or during the day when there is a large amount of cloud cover. The spawning season lasts from February to early October. [17] The oval eggs of species in the genus Lactoria hatch into the juvenile larvae. These larvae are distinct because they form the box carapace armor that is present on the longhorn cowfish. [18]
On Pamban Island, the local belief was that when the land got separated, the cows on the island metamorphosed into these fish and fed on seaweed. [19]
The honeycomb cowfish, is a species of marine ray-finned fish belonging to the family Ostraciidae, the boxfishes. This fish is found in the Western Atlantic Ocean.
Ostracion is a genus of marine ray-finned fishes belonging to the family Ostraciidae, the boxfishes. These fishes are found in the Indo-Pacific region as far east as the eastern Pacific coasts of the Americas.
The yellow boxfish is a species of marine ray-finned fish belonging to the family Ostraciidae, the boxfishes. This species is found in reefs throughout the Pacific Ocean and Indian Ocean as well as the southeastern Atlantic Ocean. Recorded occasionally since 2011 in the Levantine waters of the Mediterranean Sea which it likely entered via the Suez Canal, it is a species appreciated in the aquarium trade. They are known for their cuboid body shape, bright yellow and black spotted coloration, and the secretion of a toxic mucus when threatened.
The scrawled cowfish is a species of marine ray-finned fish belonging to the family Ostraciidae, the boxfishes. This species is found in the Western Atlantic Ocean.
Ostracion solorense, the reticulate boxfish, scribbled boxfish, Solor boxfish or striped boxfish, is a species of marine ray-finned fish belonging to the family Ostraciidae, the boxfishes. This species is found in the far eastern Indian Ocean and Western Pacific Ocean.
Lactophrys triqueter the smooth trunkfish, is a species of marine ray-finned fish belonging to the family Ostraciidae, the boxfishes. The smooth trunkfish is found in the Western Atlantic Ocean.
The spotted boxfish, also known as the black boxfish, ornate boxfish or white-spotted boxfish, is a species of marine ray-finned fish belonging to the family Ostraciidae, the boxfishes. This species is found in the Indian and Pacific Oceans. It occurs on reefs at depths of from 1 to 30 metres. This species grows to a length of 25 centimetres. Males and females differ in colour: males are blackish on the back with white spots, and have bluish sides with bright yellowish bands and spots. Females and juveniles are dark brown to blackish with white spots. As with other species of boxfish, the spotted boxfish's bony carapace gives it a distinctly angular appearance; it has been described as resembling an ottoman.
Acanthostracion is a genus of marine ray-finned fishes belonging to the family Ostraciidae, the boxfishes. These fishes are found in the Atlantic Ocean.
Lactophrys is a genus of marine ray-finned fishes belonging to the family Ostraciidae, the boxfishes. The boxfishes in this genus are found in the western Atlantic Ocean and are known as trunkfishes.
Lactoria is a genus of marine ray-finned fishes belonging to the family Ostraciidae, the boxfishes. The fishes in this genus are found in the Indo-Pacific, with one species extending into the southeastern Atlantic.
Ostracion rhinorhynchos, the horn-nosed boxfish or torpedo boxfish, is a species of ray-finned fish belonging to the family Ostraciidae, the boxfishes. This fish occurs in the Indo-West Pacific region.
Aracana aurita, the Shaw's cowfish, painted boxfish, southern cowfish or striped cowfish, is a species of marine ray-finned fish belonging to the family Aracanidae, the deepwater boxfishes or temperate boxfishes. This species is endemic to the seas off southern Australia.
The thornback cowfish, is a species of marine ray-finned fish belonging to the family Ostraciidae, the boxfishes. This species is found throughout the tropical Indo-Pacific from East Africa to the Bass Islands. It can grow to a maximum length of 23 cm (9 in). It is an uncommon fish that feeds on small invertebrates that it picks up off the sea bed.
The Shortnose boxfish is a species of marine ray-finned fish belonging to the family Ostraciidae, the boxfishes. This species is found in the Indian and Pacific Oceans.
Lactophrys trigonus, the buffalo trunkfish or trunkfish, is a species of marine ray-finned fish belonging to the family Ostraciidae, the boxfishes. The buffalo trunkfish is found in the Western Atlantic Ocean.
The island cowfish, also known as the hogfish, bottlefish boxfish or island boxfish, is a species of marine ray-finned fish belonging to the family Ostraciidae, the cowfishes. This fish is found around the islands of the mid-Atlantic Ocean and has been recorded from Western Africa.
Lactoria diaphana, the roundbelly cowfish, diaphonous cowfish, many-spined cowfish, spiny cowfish or transparent cowfish, is a species of marine ray-finned fish belonging to the family Ostraciidae, the boxfishes. This fish is found in the southeastern Atlantic Ocean and the Indo-Pacific.
Ostracion immaculatum, the bluespotted boxfish or immaculate boxfish, is a species of marine ray-finned fish belonging to the family Ostraciidae, the boxfishes. This species is found in the Western Pacific Ocean off Eastern Asia.
Ostracion trachys, the rough boxfish or roughskin trunkfish, is a species of marine ray-finned fish belonging to the family Ostraciidae, the boxfishes. It is found in the Western Indian Ocean around the Mascarenes.
Whitley's boxfish is a species of marine ray-finned fish belonging to the family Ostraciidae, the boxfishes. This fish is found in the Eastern Central Pacific Ocean.