Engaewa similis
Encyclopedia
Engaewa similis is a species of Australia
n crayfish
in the family Parastacidae
.
region in Western Australia
, and can be found from the Margaret River
to the vicinity of Windy Harbour. Although previously considered an endangered species
, E. similis is now listed as a species of Least Concern
on the IUCN Red List
, since it is abundant at the sites where it persists.
(a single physical example of the species) was found in Augusta, Western Australia
by L. P. Smith in 1961. In 1967, E. F. Riek gave detailed description of the holotype, held at the Western Australian Museum
; it was 36 millimetres (1.4 in) long (cephalothorax
16.5 mm or 0.649606299212598 in), with a blue colour on the chela
, and was similar to Engaewa reducta apart from the shape of the rostrum
, the structure of the chela
and the shape of the telson
and uropods.
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
n crayfish
Crayfish
Crayfish, crawfish, or crawdads – members of the superfamilies Astacoidea and Parastacoidea – are freshwater crustaceans resembling small lobsters, to which they are related...
in the family Parastacidae
Parastacidae
Parastacidae is the family of freshwater crayfish found in the southern hemisphere. The family is a classic Gondwana-distributed taxon, with extant members in South America, Madagascar, Australia, New Zealand and New Guinea, and extinct taxa also in Antarctica.Three genera are to be found in Chile,...
.
Distribution and conservation
E. similis is endemic to the AugustaAugusta, Western Australia
Augusta is a town on the south-west coast of Western Australia, where the Blackwood River emerges into Flinders Bay. It is the nearest town to Cape Leeuwin, on the farthest south-west corner of the Australian continent. In the 2001 census it had a population of 1,694; by 2006 the population of...
region in Western Australia
Western Australia
Western Australia is a state of Australia, occupying the entire western third of the Australian continent. It is bounded by the Indian Ocean to the north and west, the Great Australian Bight and Indian Ocean to the south, the Northern Territory to the north-east and South Australia to the south-east...
, and can be found from the Margaret River
Margaret River
Margaret River is a river in southwest Western Australia. Although small and unremarkable, it is the eponym of the iconic town and tourist region of Margaret River, famous for its surfing, caves and wine....
to the vicinity of Windy Harbour. Although previously considered an endangered species
Endangered species
An endangered species is a population of organisms which is at risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters...
, E. similis is now listed as a species of Least Concern
Least Concern
Least Concern is an IUCN category assigned to extant taxon or lower taxa which have been evaluated but do not qualify for any other category. As such they do not qualify as threatened, Near Threatened, or Conservation Dependent...
on the IUCN Red List
IUCN Red List
The IUCN Red List of Threatened Species , founded in 1963, is the world's most comprehensive inventory of the global conservation status of biological species. The International Union for Conservation of Nature is the world's main authority on the conservation status of species...
, since it is abundant at the sites where it persists.
Description
An adult female holotypeHolotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
(a single physical example of the species) was found in Augusta, Western Australia
Augusta, Western Australia
Augusta is a town on the south-west coast of Western Australia, where the Blackwood River emerges into Flinders Bay. It is the nearest town to Cape Leeuwin, on the farthest south-west corner of the Australian continent. In the 2001 census it had a population of 1,694; by 2006 the population of...
by L. P. Smith in 1961. In 1967, E. F. Riek gave detailed description of the holotype, held at the Western Australian Museum
Western Australian Museum
The Western Australian Museum is the state museum for Western Australia.The Western Australian Museum has seven main sites: two in Perth within the Perth Cultural Centre, two in Fremantle , and one each in Albany, Geraldton, and Kalgoorlie-Boulder...
; it was 36 millimetres (1.4 in) long (cephalothorax
Cephalothorax
The cephalothorax is a tagma of various arthropods, comprising the head and the thorax fused together, as distinct from the abdomen behind. The word cephalothorax is derived from the Greek words for head and thorax...
16.5 mm or 0.649606299212598 in), with a blue colour on the chela
Claw
A claw is a curved, pointed appendage, found at the end of a toe or finger in most mammals, birds, and some reptiles. However, the word "claw" is also often used in reference to an invertebrate. Somewhat similar fine hooked structures are found in arthropods such as beetles and spiders, at the end...
, and was similar to Engaewa reducta apart from the shape of the rostrum
Rostrum (anatomy)
The term rostrum is used for a number of unrelated structures in different groups of animals:*In crustaceans, the rostrum is the forward extension of the carapace in front of the eyes....
, the structure of the chela
Chela
Chela has two main meanings. One derivation comes from Hindi from Sanskrit , meaning "slave" or "servant". In English, the word means a religious student or disciple...
and the shape of the telson
Telson
The telson is the last division of the body of a crustacean. It is not considered a true segment because it does not arise in the embryo from teloblast areas as do real segments. It never carries any appendages, but a forked "tail" called the caudal furca is often present. Together with the...
and uropods.