The Australian angelshark (''Squatina australis'') is a species of
angelshark
The angelsharks are a group of sharks in the genus ''Squatina'' of the family Squatinidae. They commonly inhabit sandy seabeds close to in depth. Many species are now classified as critically endangered by the International Union for Conservat ...
,
family
Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...
Squatinidae, found in the
subtropical waters of southern
Australia from
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 ...
to
New South Wales
)
, nickname =
, image_map = New South Wales in Australia.svg
, map_caption = Location of New South Wales in AustraliaCoordinates:
, subdivision_type = Country
, subdivision_name = Australia
, established_title = Before federation
, es ...
between
latitude
In geography, latitude is a coordinate that specifies the north– south position of a point on the surface of the Earth or another celestial body. Latitude is given as an angle that ranges from –90° at the south pole to 90° at the north po ...
s
18°S and
41°S, at depths down to 255 m (840 ft). Its length is up to 1.52 m (5 ft). Reproduction is
ovoviviparous
Ovoviviparity, ovovivipary, ovivipary, or aplacental viviparity is a term used as a "bridging" form of reproduction between egg-laying oviparous and live-bearing viviparous reproduction. Ovoviviparous animals possess embryos that develop insi ...
, with up to 20 pups in a litter.
Description
The Australian angelshark has a broad, vertically compressed body and large triangular pectoral fins with free trailing flaps. The snout has fringed barbels beside the nostrils and a pair of spiracles. Each of these is set at a distance from the eye of about one and a half times the diameter of the eye. There are two small dorsal fins set far back and the tail fin is small. The maximum length is about and this shark has no large eyespots on the body. Male individuals are fully mature at around total length.
Distribution and habitat
The Australian angelshark is native to the
continental shelf of southern Australia being found along the coasts of
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 ...
,
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 ...
,
Victoria
Victoria most commonly refers to:
* Victoria (Australia), a state of the Commonwealth of Australia
* Victoria, British Columbia, provincial capital of British Columbia, Canada
* Victoria (mythology), Roman goddess of Victory
* Victoria, Seychelle ...
,
Tasmania
)
, nickname =
, image_map = Tasmania in Australia.svg
, map_caption = Location of Tasmania in AustraliaCoordinates:
, subdivision_type = Country
, subdi ...
and
New South Wales
)
, nickname =
, image_map = New South Wales in Australia.svg
, map_caption = Location of New South Wales in AustraliaCoordinates:
, subdivision_type = Country
, subdivision_name = Australia
, established_title = Before federation
, es ...
at depths down to about . It is usually found on sandy or muddy seabeds and in
seagrass meadow
A seagrass meadow or seagrass bed is an underwater ecosystem formed by seagrasses. Seagrasses are marine (saltwater) plants found in shallow coastal waters and in the brackish waters of estuaries. Seagrasses are flowering plants with stems and ...
s, often close to rocky reefs.
Behaviour
The Australian angelshark lies semi-submerged in the sediment on the seabed during the day, eating anything that comes too close. It emerges at night to actively seek out
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 ...
.
Its diet consists of small fish, crustaceans and other invertebrates.
This shark is ovoviviparous, retaining its developing embryos in its
oviduct
The oviduct in mammals, is the passageway from an ovary. In human females this is more usually known as the Fallopian tube or uterine tube. The eggs travel along the oviduct. These eggs will either be fertilized by spermatozoa to become a zygote, ...
, with a litter of up to twenty young being born. Little is known of its breeding habits, but the closely related
Pacific angelshark (''Squatina californica'') has a
gestation
Gestation is the period of development during the carrying of an embryo, and later fetus, inside viviparous animals (the embryo develops within the parent). It is typical for mammals, but also occurs for some non-mammals. Mammals during preg ...
period of about ten months.
[
]
Status
The Australian angelshark is listed by the IUCN in its Red List of Threatened Species
The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biolog ...
as being of "Least Concern
A least-concern species is a species that has been categorized by the International Union for Conservation of Nature (IUCN) as evaluated as not being a focus of species conservation because the specific species is still plentiful in the wild. Th ...
". This is because the population size is large and appears to be stable. The fish is used for food, being marketed under the name of "monkfish", but is not easily caught by line-fishing or netting because of its habit of lying immersed in the sediment but can be caught by dragging a trawl across the seabed.[
]
References
* Compagno, Dando, & Fowler, ''Sharks of the World'', Princeton University Press, New Jersey 2005
{{DEFAULTSORT:angelshark, Australian
Australian angelshark
Fish of Australia
Marine fish of Southern Australia
Australian angelshark