Batrachoididae

Batrachoididae is the only family in the ray-finned fish order Batrachoidiformes. Members of this family are usually called toadfish, or "frogfish": both the English common name and scientific name refer to their toad-like appearance (batrakhos is Greek for frog).

Toadfish are benthic ambush predators that favor sandy or muddy substrates where their cryptic coloration helps them avoid detection by their prey. Toadfish are well known for their ability to "sing", males in particular using the swim bladder as a sound-production device used to attract mates.

Batrachoididae
Temporal range: Rupelian–Recent
[1]
Opsanus beta 1
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Batrachoidiformes
Family: Batrachoididae
Jordan, 1896
Subfamilies

Batrachoidinae
Halophryninae
Porichthyinae
Thalassophryninae

Description

Toadfish are usually scaleless, with eyes set high on large heads. Their mouths are also large, with both a maxilla and premaxilla, and often decorated with barbels and skin flaps. They are generally drab in colour, although those living on coral reefs may have brighter patterns. They range in size from 7.5 cm (3.0 in) length in Thlassophryne megalops, to 57 cm (22 in) in the Pacuma toadfish.[2]

The gills are small and occur only on the sides of the fish. The pelvic fins are forward of the pectoral fins, usually under the gills, and have one spine with several soft rays.[2] For the two separate dorsal fins, the first is smaller with spines, while the second has from 15 to 25 soft rays. The number of vertebrae range from 25 to 47.

Toadfishes of the genus Porichthys, the midshipman fishes, have photophores and four lateral lines. All toadfishes possess sharp spines on the first dorsal fin and on the opercle (gill cover). In fish of the subfamily Thalassophryninae, these are hollow and connect to venom glands capable of delivering a painful wound to predators.[2]

Distribution and habitat

Toadfishes are found worldwide. Most toadfish are marine, though some are found in brackish water and one subfamily, the Thalassophryninae, is found exclusively in freshwater habitats in South America. In particular, Daector quadrizonatus and Thalassophryne amazonica are known from the Atrato River in Colombia and the Amazon River, respectively.

Habits and reproduction

Toadfishes are bottom-dwellers, ranging from near-shore areas to deep waters. They tend to be omnivorous, eating sea worms, crustaceans, mollusks, and other fish. They often hide in rock crevices, among the bottom vegetation, or even dig dens in the bottom sediments, from which they ambush their prey. Toadfish can survive out of water for as long as 24 hours, and some can move across exposed mudflats at low tide using their fins.[2]

Males make nests, and then attract females by "singing", that is, by releasing air by contracting muscles on their swim bladders. The sound has been called a 'hum' or 'whistle', and can be loud enough to be clearly audible from the surface. The eggs are sticky on one side, so the female can attach them to the side of the nest. Each male attracts numerous females to his nest, so the eggs within have multiple mothers.

The male then guards the nest against predators. During this period, the male must survive on a limited supply of food, as he is not able to leave the immediate vicinity to hunt. The eggs rapidly develop into embryos, but these remain attached to the side of the nest until the age of about three to four weeks. After this time, they continue to cluster around and hide behind the male, until they are large enough to fend for themselves. This degree of parental care is very unusual among fishes.[2]

Genera

About 80 species of toadfishes are grouped into 21 genera, as:[3]

Order Batrachoidiformes

Economics

Toadfish are not normally commercially exploited, but they are taken by local fishermen as a food fish, and by trawlers where they usually end up as a source of fishmeal and oil. Some smaller toadfish from brackish-water habitats have been exported as freshwater aquarium fishes.

The western Atlantic species Opsanus tau, known as the oyster toadfish, is quite widely used as a research animal, while a few species, most notably Thalassophryne amazonica, are occasionally kept as aquarium fish.

See also

References

  1. ^ Tomáš Přikryl; Giorgio Carnevale (2017). "An Oligocene toadfish (Teleostei, Percomorpha) from Moravia, Czech Republic: The earliest skeletal record for the order Batrachoidiformes". Bulletin of Geosciences. 92 (1): 123–131. doi:10.3140/bull.geosci.1662.
  2. ^ a b c d e Hutchins, J. Barry (1998). Paxton, J.R.; Eschmeyer, W.N., eds. Encyclopedia of Fishes. San Diego: Academic Press. pp. 135–136. ISBN 0-12-547665-5.
  3. ^ Froese, Rainer, and Daniel Pauly, eds. (2008). "Batrachoididae" in FishBase. December 2008 version.

Further reading

  • Nelson, Joseph S. (2006) "Order Batrachoidiformes" Fishes of the World (4th ed.) John Wiley & Sons, Hoboken, NJ, ISBN 978-0-471-25031-9 pp. 248–249.
  • Collette, B. B. "Order Batrachoidiformes, Batrachoididae, Toadfishes." In Carpenter, Kent E. (ed.) (2002) The living marine resources of the Western Central Atlantic Vol. 2, Bony fishes. Pt. 1 Acipenseridae to Grammatidae Food and Agriculture Organization of the United Nations, Rome (Special publication of the American Society of Ichthyologists and Herpetologists no. 5) ISBN 92-5-104826-6
  • Collette, B.B. and J. L. Russo (1981) "A Revision of the Scaly Toadfishes, Genus Batrachoides, with Descriptions of Two New Species from the Eastern Pacific" Bulletin of Marine Science 31(2): pp. 197–233.
  • Hutchins, J.B. (1976) "A revision of the Australian frogfishes (Batrachoididae)" Records of the Western Australian Museum 4(1): pp. 3–43.
  • Sepkoski, Jack (2002). "A compendium of fossil marine animal genera". Bulletins of American Paleontology. 364: 560. Archived from the original on 2011-07-23. Retrieved 2011-05-17.
  • CBC Radio Quirks and Quarks show podcast segment on unique toad fish habits with links to primary sources.

External links

Austrobatrachus

Austrobatrachus is a genus of toadfishes found in the Atlantic and Indian Oceans off the coast of South Africa.

Banded toadfish

The banded toadfish (Aphos porosus) is a species of toadfish found along the Pacific coast of South America where it is found in Chile, Ecuador and Peru. This species grows to a length of 28 centimetres (11 in) TL. It is the only member of the monotypic genus Aphos. Unlike the other genus, Porichthys in this subfamily the banded toadfish lacks photophores.

Batrachoides

Batrachoides is a genus of toadfishes.

Batrachoidinae

Batrachoidinae is a subfamily of toadfish in the family Batrachoididae. It contains 25 species in the following 6 genera:

Amphichthys (2 species)

Batrachoides (9 species)

Opsanus (6 species)

Potamobatrachus (1 species)

Sanopus (6 species)

Vladichthys (1 species)

Batrachomoeus

Batrachomoeus is a genus of toadfishes.

Batrachomoeus dubius

The eastern frogfish (Batrachomoeus dubius) is a bottom-dwelling fish endemic to coastal eastern Australia, from Fraser Island, Queensland to Kiama, New South Wales. It is an ambush predator with a large expandable stomach, capable of swallowing crustaceans, molluscs and other fishes whole.

Chatrabus

Chatrabus is a genus of toadfishes native to the Atlantic coast of southern Africa.

Halophryne

Halophryne is a genus of toadfishes found in the Pacific and Indian Oceans.

Halophryninae

The Halophryninae is a largely Old World subfamily of toadfish, part of the family Batrachoididae.

Midshipman fish

Midshipman fish belong to the genus Porichthys of toadfishes. They are distinguished by having photophores (which they use to attract prey and after which they are named, reminding some of a naval uniform's buttons) and four lateral lines. Typical midshipman fishes, such as the plainfin midshipman (Porichthys notatus), are nocturnal and bury themselves in sand or mud in the intertidal zone during the day. At night they float just above the seabed. Some species have venomous dorsal spines and are capable of inflicting serious injuries if handled.

Opsanus

Opsanus is a genus of toadfishes found in the western Atlantic Ocean. It currently has six recognised species, with the latest one described in 2005.

Porichthyinae

Porichthyinae is a subfamily of toadfish in the family Batrachoididae. They are found in the eastern Pacific Ocean and western Atlantic from Canada to Argentina. The species of this subfamily have no venom glands or subopercular spines, they have canine like teeth and two solid spines in the dorsal fin.

Potamobatrachus trispinosus

Potamobatrachus trispinosus is a species of toadfish endemic to Brazil where it is found in the Araguaia and Tocantins Rivers. This species grows to a length of 5 cm (2.0 in).

Sanopus

Sanopus is a genus of toadfishes restricted to the Atlantic coast of Central America and Mexico.

Splendid toadfish

The splendid toadfish (Sanopus splendidus) also called the coral toadfish and the Cozumel splendid toadfish is a species of toadfish entirely endemic to the island of Cozumel.

Commonly found under coral outcroppings. Dens can be spotted by the sloping sand patch. They are very difficult to coax out in the open.

Unlike any other member of the toadfish family, the splendid toadfish is distinctive for its vibrant colors. It has bright yellow fins which also contain distinctive patterning, while its head contains dark and white stripes.

The species has a total of eight fins; two dorsal fins, two pectoral fins, two pelvic fins, a caudal fin and an anal fin. The midline of the upper body contains the two dorsal fins; a short fin with sharp spines in 3 spots and a long fin which extends over much of the upper body and is flowing. Two rounded pectoral fins are found behind the head, and they are larger than two smaller pointed pelvic fins positioned right in front of the undersurface. Also on the undersurface, towards the rear, along the tip of the tail, the splendid toadfish has a small and rounded caudal fin. With the exception of the pelvic fins, all the fins are bordered by a bright yellow coloring.

The structural features of the species however are similar to other members in the family, such as the flat and broadened head and barbells. Like most species that dwell close to the sand, the splendid toadfish has eyes located on the top of its head which look directly upwards as there is mostly no need for a horizontal vision. Small and sharp teeth also fill wide jaws.

Thalassophryne maculosa

Thalassophryne maculosa, the Cano toadfish, is a species of toadfish which is common along the Caribbean coasts of South America from Colombia to Trinidad and Venezuela. It occurs on the sandy bottoms of reef flats, lagoons, and seaward edges of reefs where it sits partially buried in the substrate. It is a venomous species with the venom being delivered through spines and wounds from the spines have been known to cause severe symptoms of pain and illness that may persist for up to a week. A study of the holotype of Batrachus uranoscopus, said to be a freshwater toadfish from Madagascar, in the Muséum national d’Histoire Naturelle in Paris found that it was most probably a misslabelled specimen of Thalassophryne maculosa and that subsequent records of Batrachus uranoscopus were attributable to Allenbatrachus meridionalis, a species found in Madagascar. T. maculosa is the type species of the genus Thalassophryne, the generic name translates from Greek as "sea toad" while the specific name is Latin for "spotted".

Thalassophryninae

Thalassophryninae is a subfamily of toadfish in the family Batrachoididae. The species in the subfamily are characterised by the possession of two dorsal fin spines, a lack of subopercular spines, with the dorsal and opercular spines being hollow and have venom glands at their base. They do not have canine teeth.

Toadfish

Toadfish is the common name for a variety of species from several different families of fish, usually because of their toad-like appearance. "Dogfish" is a name for certain species along the gulf coast.

Vladichthys gloverensis

Vladichthys gloverensis is a species of toadfish known only from the Atlantic Coast of Belize and Honduras, where it is found on reefs. This species grows to a standard length of 5.6 cm (2.2 in). The generic name honours the toadfish expert Vladimir "Vlad" Walters (1927-1987) while the specific name denotes Glover's Reef in Belize.

This page is based on a Wikipedia article written by authors (here).
Text is available under the CC BY-SA 3.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.