Handfish | |
---|---|
Brachionichthys hirsutus | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Actinopterygii |
Order: | Lophiiformes |
Suborder: | Antennarioidei |
Family: | Brachionichthyidae T. N. Gill, 1878 |
Genera | |
see text |
Handfish are marine ray-finned fishes belonging to the family Brachionichthyidae, a group which comprises five genera and 14 extant species and which is classified within the suborder Antennarioidei in the order Lophiiformes, the anglerfishes. [2] These benthic marine fish are unusual in the way they propel themselves by walking on the sea floor rather than swimming.
The handfish were first proposed as a family, Brachionichthyidae, in 1878 by the American ichthyologist Theodore Gill. [3] The Brachionichthyidae is classified within the suborder Antennarioidei within the order Lophiiformes, the anglerfishes. [4] The Brachionichthyidae is regarded as the most basal family within the suborder Antennarioidei. [5]
The handfish family, Brachionichthyidae, contains the following genera: [4] [6]
† = Extinct
Handfish are found today in the coastal waters of southern and eastern Australia and around the island state of Tasmania. This is the most species-rich of the few marine fish families endemic to the Australian region, with all but three species found there. [8] There are 14 species of handfish around Tasmania. [9]
The biology of handfishes is poorly known and their typically small population sizes and restricted distributions make them highly vulnerable to disturbance. Some species are considered to be critically endangered. [10]
Handfish grow up to 15 cm (5.9 in) long, and have skin covered with denticles (tooth-like scales), giving them the alternative name warty anglers. They are slow-moving fish that prefer to 'walk' rather than swim, using their modified pectoral fins to move about on the sea floor. These highly modified fins have the appearance of hands, hence their scientific name, from Latin bracchium meaning "arm" and Greek ichthys meaning "fish".[ citation needed ]
Like other anglerfish, they possess an illicium, a modified dorsal fin ray above the mouth, but it is short and does not appear to be used as a fishing lure.[ dubious – discuss ] The second dorsal spine is joined to the third by a flap of skin, making a crest. [11]
The prehistoric species, Histionotophorus bassani , from the Lutetian of Monte Bolca, is now considered to be a handfish, sometimes even being included in the genus Brachionichthys . Considering the low extant diversity, restricted geographical distribution, and very meagre fossil record of antennarioids in general, the existence of fossil representatives of the family Brachionichthyidae is unusual. [10]
In 1996, the spotted handfish (Brachionichthys hirsutus) was the first marine fish to be listed as critically endangered in the IUCN Red List. [12] [13] With its only habitat in the Derwent River estuary and surrounds, it is threatened by the Northern Pacific seastar's invasion into southern Australian waters. The Northern Pacific seastar (Asterias amurensis), preys on not only the fish eggs, [14] but also on the sea squirts (ascidians) [15] that help to form the substrate that the fish spawn on. [16]
The cause of the decline in spotted handfish is unclear. Suggested causes may include disturbance of benthic communities and predation on egg masses by the introduced northern Pacific seastar, habitat modification through increased siltation, heavy metal contamination or urban effluent. The lack of a pelagic larval stage and low rates of dispersal may be responsible for their restricted distributions and may also have an impact on handfishes ability to recolonise areas where they once occurred. [8]
In March 2020, the smooth handfish (Sympterichthys unipennis) was declared extinct in the IUCN Red List. [17] [12] Once common enough to be one of the first fish to be described by European explorers of Australia, but not seen for well over a century, this is the first modern-day marine fish to be officially declared extinct. [12] However, this was reversed in September 2021, as there is not sufficient data to confirm this status. [18] [19]
In October 2021, the endangered and very rare pink handfish (Brachiopsilus dianthus [20] ) was seen for the first time since 1999, in footage from a camera placed on the sea bed off Tasmania at a depth of 150 m (490 ft). Prior to this sighting, it had been assumed that this species was confined to shallow waters. The discovery that it has a greater range than previously thought may give cause for optimism regarding its survival. [9]
As of December 2021 [update] three species of handfish are listed as threatened under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) and the IUCN: [8]
All three of the above are listed as Endangered under the Tasmanian Threatened Species Protection Act 1995 , [21] [22] [23] and all handfish species are protected under the Tasmanian Living Marine Resources Management Act 1995, which prohibits their collection in State waters without a permit. [8]
The Northern Pacific seastar is an invasive species in Australia.
The spotted handfish is a rare Australian fish in the handfish family, Brachionichthyidae, classified as critically endangered on the IUCN Red List 2020. It has a highly restricted range, being found only in the estuary of Derwent River, Tasmania, and nearby areas, with the main threat to its existence being an invasive species, the Northern Pacific seastar.
Brachionichythys is a genus of marine ray-finned fish belonging to the family Brachionichthyidae, the handfishes. These fishes are confined to the southeastern Indian Ocean and southwestern Pacific Ocean off Australia.
The sargassum fish, anglerfish, or frog fish is a species of marine ray-finned fish belonging to the family Antennariidae, the frogfishes, the only species in the genus Histrio. It lives among Sargassum seaweed which floats in subtropical oceans. The scientific name comes from the Latin histrio meaning a stage player or actor and refers to the fish's feeding behaviour.
The ocellated frogfish is a species of marine ray-finned fish belonging to the family Antennariidae, the frogfishes. This fish is found in the Western Atlantic Ocean.
The starry handfish, starry seabat or minipizza batfish, is species of marine ray-finned fish belonging to the family Ogcocephalidae, the deep-sea batfishes or seabats. This fish is found on the continental shelves of the Indo-Pacific oceans at depths of between 50 and 400 m. They are up to 30 cm long.
Brachiopsilus is a genus of marine ray-finned fishes belonging to family Brachionichthyidae, the handfishes. The fishes in this genus are endemic to Australia.
Pezichthys is a genus of marine ray-finned fishes belonging to family Brachionichthyidae, the handfishes. The fishes in this genus are endemic to southern Australia. These fishes are all extremely localised in distribution and are rare.
Thymichthys is a genus of marine ray-finned fishes belonging to the family Brachionichthyidae, the handfishes. Like all members of the handfish family these fishes are endemic to Australia.
Sympterichthys is a genus of marine ray-finned fish belonging to the family Brachionichthyidae, the handfishes. These fishes are endemic to Australia.
Kuiterichthys is a genus of marine ray-finned fishes belonging to the subfamily Histiophryninae in the family Antennariidae, the frogfishes. These fishes are endemic to Australia.
Phyllophryne is a monospecific genus of marine ray-finned fish belonging to the subfamily Histiophryninae in the family Antennariidae, the frogfishes. The only species in the genus is Phyllophryne scortea, the white-spotted anglerfish, smooth anglerfish or smooth frogfish, which is endemic to southern Australia.
The red handfish is a species of marine ray-finned fishes belonging to the family Brachionichthyidae, the handfishes. Like all members of the handfish family this fish is endemic to Australia. The IUCN classify the red handfish as Critically Endangered.
Ziebell's handfish is a species of marine ray-finned fish belonging to the family Brachionichthyidae, the handfishes. This species is endemic to eastern and southern Tasmania. It is a very rare species and the International Union for Conservation of Nature classifies it as Critically Endangered.
The smooth handfish is a possibly extinct species of handfish in the genus Sympterichthys. It was likely endemic to waters off the coast of Tasmania, mainly the D’Entrecasteaux Channel. It was declared extinct by the IUCN Red List in 2020, marking the first entirely marine fish classified as such. However, in 2021 its status was changed to Data Deficient due to uncertainties over the exhaustiveness of the unsuccessful surveys to find this species. It is known only from its holotype collected by French explorers in 1802.
Moulton's handfish is species of marine ray-finned fish belonging to th efamily Brachionichthyidae, the handfishes. This species is endangered and is endemic to the waters off southeastern Australia.
Abantennarius dorehensis, the New Guinean frogfish, bandtail frogfish, Dorei frogfish or white-spotted frogfish, is a species of marine ray-finned fish belonging to the family Antennariidae, the frogfishes. The New Guinean frogfish is found in the Indo-Pacific region.
Antennatus tuberosus, the tuberculate anglerfish, pygmy angler, pygmy frogfish or tuberculated frogfish, is a species of marine ray-finned fish belonging to the family Antennariidae, the frogfishes. This fish is found in the Indian and Pacific Oceans.
Antennarioidei is a suborder of marine ray-finned fishes belonging to the order Lophiiformes, the anglerfishes.
The Australian spotted handfish, also known as the Australian handfish or common handfish, is a species of marine ray-finned fish belonging to the family Brachionichthyidae, the handfishes. This species is endemic to eastern and southern Australia.