''Rhycherus filamentosus'', commonly known as the tasselled anglerfish, is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

frogfish Frogfishes are any member of the anglerfish family Antennariidae, of the order Lophiiformes. Antennariids are known as anglerfish in Australia, where the term "frogfish" refers to members of the unrelated family Batrachoididae. Frogfishes are f ...

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to southern

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

in the southwestern

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...

and southeastern

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or ~19.8% of the water on Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia to the east. To the south it is bounded by th ...

. It is a well-camouflaged predator and lies in wait on the seabed for unwary

prey Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill the ...

to approach too close.

Taxonomy

This fish was one of a number of species of fish trawled up from

Gulf St Vincent Gulf St Vincent, sometimes referred to as St Vincent Gulf, St Vincent's Gulf or Gulf of St Vincent, is the eastern of two large inlets of water on the southern coast of Australia, in the state of South Australia, the other being the larger Sp ...

in Southern Australia by

Frederick George Waterhouse Frederick George Waterhouse (25 August 1815 – 7 September 1898) was an English naturalist, zoologist and entomologist who made significant contributions to the study of the natural history of Australia. Waterhouse was born near London, a son ...

, the curator of the

South Australian Museum The South Australian Museum is a natural history museum and research institution in Adelaide, South Australia, founded in 1856 and owned by the Government of South Australia. It occupies a complex of buildings on North Terrace in the cultu ...

. He sent these specimens to the French naturalist

Francis de Laporte de Castelnau Francis may refer to: People *Pope Francis, the head of the Catholic Church and sovereign of the Vatican City State and Bishop of Rome *Francis (given name), including a list of people and fictional characters *Francis (surname) Places * Rural M ...

who was the French consul in

Melbourne Melbourne ( ; Boonwurrung/Woiwurrung: ''Narrm'' or ''Naarm'') is the capital and most populous city of the Australian state of Victoria, and the second-most populous city in both Australia and Oceania. Its name generally refers to a met ...

. de Castelnau formally described this fish in 1872, giving it the name ''Chironectes filamentosus'', but it was later transferred to the genus '' Rhycherus'', making it ''Rhycherus filamentosus''.

Description

Frogfish in this family have laterally compressed, globose bodies, laterally-placed eyes and large, obliquely-slanting mouths. The first dorsal spine is modified into an elongated, slender

illicium ''Illicium'' is a genus of flowering plants treated as part of the family Schisandraceae,

which is tipped by an

esca The anglerfish are fish of the teleost order Lophiiformes (). They are bony fish named for their characteristic mode of predation, in which a modified luminescent fin ray (the esca or illicium) acts as a lure for other fish. The luminescence co ...

, a whitish, worm-like lure. ''Rhycherus filamentosus'' can grow to a total length of about . The skin is copiously decorated with threads and filaments that resemble fronds of red algae. The basic colour of this well-camouflaged fish is reddish-brown, with vertical bars and patches of dark and pale brown, and whitish underparts.

Distribution and habitat

''Rhycherus filamentosus'' is

to Australia and occurs in the southeastern Indian Ocean as well as the southwestern Pacific Ocean. Its range extends from

Spencer Gulf The Spencer Gulf is the westernmost and larger of two large inlets (the other being Gulf St Vincent) on the southern coast of Australia, in the state of South Australia, facing the Great Australian Bight. It spans from the Cape Catastrophe and ...

South Australia South Australia (commonly abbreviated as SA) is a state in the southern central part of Australia. It covers some of the most arid parts of the country. With a total land area of , it is the fourth-largest of Australia's states and territories ...

at 130°E to the eastern end of the

Bass Strait Bass Strait () is a strait separating the island state of Tasmania from the Australian mainland (more specifically the coast of Victoria, with the exception of the land border across Boundary Islet). The strait provides the most direct waterwa ...

at 149°E. It is associated with reefs and can be found down to about .

Ecology

benthic The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from ancient Greek, βένθος (bénthos), meaning "t ...

fish, ''R. filamentosus'' lives on the seabed and seldom swims, instead moving around with its

pectoral Pectoral may refer to: * The chest region and anything relating to it. * Pectoral cross, a cross worn on the chest * a decorative, usually jeweled version of a gorget * Pectoral (Ancient Egypt), a type of jewelry worn in ancient Egypt * Pectoralis ...

and

pelvic The pelvis (plural pelves or pelvises) is the lower part of the trunk, between the abdomen and the thighs (sometimes also called pelvic region), together with its embedded skeleton (sometimes also called bony pelvis, or pelvic skeleton). The ...

fins in a kind of "walk". It is a well-camouflaged

ambush predator Ambush predators or sit-and-wait predators are carnivorous animals that capture or trap prey via stealth, luring or by (typically instinctive) strategies utilizing an element of surprise. Unlike pursuit predators, who chase to capture prey us ...

; it rests on the seabed and when a potential prey approaches, it starts to waggle its esca. If the prey comes closer, the fish positions itself for action, and then strikes with great rapidity by opening its mouth and drawing in the prey by suction.

References

{{Taxonbar, from=Q3919070 Antennariidae Fish of Australia Fish of the Indian Ocean Fish of the Pacific Ocean Fish described in 1872 Taxa named by François-Louis Laporte, comte de Castelnau