The tubemouth (''Siphonognathus argyrophanes'') is a species of

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fishes, is a class of bony fish. They comprise over 50% of living vertebrate species. The ray-finned fishes are so called because their fins are webs of skin supported by bony or hor ...

, a

weed whiting The Odacidae are a small family of ray-finned fishes formerly classified within the order Perciformes, commonly known as cales, and weed whitings. They are related to the much larger families of the wrasses and parrotfish. More recent workers ha ...

from the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Odacidae. It is

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 the southern coatsts of Australia where it is camouflaged to live among beds of seagrass.

Description

The tubemouth has a highly elongated head and body and has a fleshy barbel which protrudes from the end of the upper lip. It has many teeth fused into a beak-like structure. The long-based

dorsal fin A dorsal fin is a fin located on the back of most marine and freshwater vertebrates within various taxa of the animal kingdom. Many species of animals possessing dorsal fins are not particularly closely related to each other, though through conv ...

is low and the shorter

anal fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as se ...

sits below the posterior third of the dorsal fin. It has a long and pointed

caudal fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as se ...

but lacks

pelvic fin Pelvic fins or ventral fins are paired fins located on the ventral surface of fish. The paired pelvic fins are homologous to the hindlimbs of tetrapods. Structure and function Structure In actinopterygians, the pelvic fin consists of two en ...

s. It is green on the back, whitish to red-brown ventrally and has a dark stripe along the flanks. It can attain a

standard length Fish measurement is the measuring of individual fish and various parts of their anatomies. These data are used in many areas of ichthyology, including taxonomy and fisheries biology. Overall length * Standard length (SL) is the length of a fish m ...

of .

Distribution

The tubemouth is endemic to southern Australia where it can be found from Geraldton in

Western Australia Western Australia (commonly abbreviated as WA) is a state of Australia occupying the western percent of the land area of Australia excluding external territories. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to th ...

southwards and then along the southern coast of Australia to the

Gippsland Lakes The Gippsland Lakes are a network of coastal lakes, marshes and lagoons in East Gippsland, Victoria, Australia covering an overall area of about between the rural towns of Lakes Entrance, Bairnsdale and Sale. The largest of the lakes are La ...

in Victoria and

Tasmania ) , nickname = , image_map = Tasmania in Australia.svg , map_caption = Location of Tasmania in AustraliaCoordinates: , subdivision_type = Country , subdi ...

Habitat and biology

The tubemouth occurs in sheltered areas where there is a dense growth of '' Posidonia'' sea grass, no deeper than . There is no known difference between the sexes and the biology of this species is almost unknown.

Taxonomy

The tubemouth closely resembles the

cornetfish The cornetfishes or flutemouths are a small family, the Fistulariidae, of extremely elongated fishes in the order Syngnathiformes. The family consists of a single genus, ''Fistularia'', with four species, found worldwide in tropical and subtropic ...

es and

trumpetfish The trumpetfishes are three species of highly specialized, tubularly-elongated marine fishes in the genus ''Aulostomus'', of the monogeneric family Aulostomidae. The trumpetfishes are members of the order Syngnathiformes, together with the seaho ...

es of the

order Order, ORDER or Orders may refer to: * Categorization, the process in which ideas and objects are recognized, differentiated, and understood * Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of d ...

Syngnathiformes in body shape and form, this is an example of

convergent evolution Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time. Convergent evolution creates analogous structures that have similar form or function but were not present in the last com ...

. It species is apparently so unique in its form that, at first, it was described within the

Fistulariidae The cornetfishes or flutemouths are a small family, the Fistulariidae, of extremely elongated fishes in the order Syngnathiformes. The family consists of a single genus, ''Fistularia'', with four species, found worldwide in tropical and subtropic ...

prior to being classified in its own

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispec ...

family. The extremely slender body and highly elongated snout, are apparent in other members of the genus ''

Siphonognathus ''Siphonognathus'' is a genus of ray-finned fishes, weed whitings in the family Odacidae which are endemic to Southern Australian coastal waters. These fish are characterized by their extremely elongate bodies and live primarily in seagrass bed ...

'', these features, in combination with the lack of pelvic fins, possession of a barbel on the upper lip and extraordinarily high counts of

vertebrae The spinal column, a defining synapomorphy shared by nearly all vertebrates,Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristic i ...

, fin rays and

lateral-line The lateral line, also called the lateral line organ (LLO), is a system of sensory organs found in fish, used to detect movement, vibration, and pressure gradients in the surrounding water. The sensory ability is achieved via modified epithelial ...

scales make it very different from its congeners. Although

Fishbase FishBase is a global species database of fish species (specifically finfish). It is the largest and most extensively accessed online database on adult finfish on the web.

places six species within the genus ''Siphonognathus'', the Catalog of Fishes places four of those species in the separate genus ''Sheardichthys'' and places the fifth on the monospecific genus ''Parodax'', leaving ''Siphonognathus'' as a monospecific genus containing only ''S. argyrophanes''.

References

{{Taxonbar, from=Q5236480 Odacidae Fish described in 1858 Taxa named by John Richardson (naturalist)