The fauna of Australia consists of a huge variety of animals; some 83% of mammals, 89% of reptiles, 90% of fish and insects and 93% of amphibians that inhabit the continent are endemic to Australia. This high level of endemism can be attributed to the continent's long geographic isolation, tectonic stability, and the effects of an unusual pattern of climate change on the soil and flora over geological time. A unique feature of Australia's fauna is the relative scarcity of native placental mammals. Consequently, the marsupials – a group of mammals that raise their young in a pouch, including the macropods, possums and dasyuromorphs – occupy many of the ecological niches placental animals occupy elsewhere in the world. Australia is home to two of the five known extant species of monotremes and has numerous venomous species, which include the platypus, spiders, scorpions, octopus, jellyfish, molluscs, stonefish, and stingrays. Uniquely, Australia has more venomous than non-venomous species of snakes.
Jellyfish and sea jellies are the informal common names given to the medusa-phase of certain gelatinous members of the subphylum Medusozoa, a major part of the phylum Cnidaria. Jellyfish are mainly free-swimming marine animals with umbrella-shaped bells and trailing tentacles, although a few are anchored to the seabed by stalks rather than being mobile. The bell can pulsate to provide propulsion for highly efficient locomotion. The tentacles are armed with stinging cells and may be used to capture prey and defend against predators. Jellyfish have a complex life cycle; the medusa is normally the sexual phase, which produces planula larva that disperse widely and enter a sedentary polyp phase before reaching sexual maturity.
The Scyphozoa are an exclusively marine class of the phylum Cnidaria, referred to as the true jellyfish. It may include the extinct fossil group the Conulariida, whose affinities are uncertain and widely debated.
Box jellyfish are cnidarian invertebrates distinguished by their cube-shaped medusae. Some species of box jellyfish produce extremely potent venom: Chironex fleckeri, Carukia barnesi and Malo kingi. Stings from these and a few other species in the class are extremely painful and can be fatal to humans.
Aurelia aurita is a widely studied species of the genus Aurelia. All species in the genus are closely related, and it is difficult to identify Aurelia medusae without genetic sampling; most of what follows applies equally to all species of the genus. The most common method used to identify the species consists of selecting a jellyfish from a harbour using a device, usually a drinking glass and then photographing the subject. This means that they can be released in to the harbour shortly afterwards and return to their natural habitat.
The Beryciformes are a poorly-understood order of carnivorous ray-finned fishes consisting of 7 families, 30 genera, and 161 species. They feed on small fish and invertebrates. Beyond this, little is known about the biology of most member species because of their nocturnal habits and deepwater habitats. All beryciform species are marine and most live in tropical to temperate, deepwater environments. Most live on the continental shelf and continental slope, with some species being found as deep as 2,000 m (6,600 ft). Some species move closer to the surface at night, while others live entirely in shallow water and are nocturnal, hiding in rock crevices and caves during the day. Several species are mesopelagic and bathypelagic. Beryciformes' bodies are deep and mildly compressed, typically with large eyes that help them see in darker waters. Colors range from red to yellow and brown to black, and sizes range from 8–61 cm (3.1–24.0 in). Member genera include the alfonsinos, squirrelfishes, flashlight fishes, fangtooth fishes, spinyfins, pineconefishes, redfishes, roughies, and slimeheads. A number of member species are caught commercially, including the alfonsino, the splendid alfonsino, and the orange roughy, the latter being much more economically important. Some species have bioluminescent bacteria contained in pockets of skin or in light organs near the eyes, including the anomalopids and monocentrids.
The prowfish is a species of perciform marine fish found in the northern Pacific Ocean. It is the only extant member of the family, Zaproridae. Another species, Araeosteus rothi, is known from Late Miocene marine strata in Southern California.
The lion's mane jellyfish, also known as the giant jellyfish, arctic red jellyfish, or the hair jelly, is one of the largest known species of jellyfish. Its range is confined to cold, boreal waters of the Arctic, northern Atlantic, and northern Pacific Oceans. It is common in the English Channel, Irish Sea, North Sea, and in western Scandinavian waters south to Kattegat and Øresund. It may also drift into the southwestern part of the Baltic Sea. Similar jellyfish – which may be the same species – are known to inhabit seas near Australia and New Zealand. The largest recorded specimen was measured by Alexander Agassiz off the coast of Massachusetts in 1865 and had a bell with a diameter of 210 centimetres and tentacles around 36.6 m (120 ft) long. Lion's mane jellyfish have been observed below 42°N latitude for some time in the larger bays of the east coast of the United States.
Rhizostomae or Rhizostomeae is an order of jellyfish. Species of this order have neither tentacles nor other structures at the bell's edges. Instead, they have eight highly branched oral arms, along which there are suctorial minimouth orifices. These oral arms become fused as they approach the central part of the jellyfish. The mouth of the animal is also subdivided into minute pores that are linked to coelenteron.
The family Stromateidae or butterfish contains 15 species of fish in three genera. Butterfishes live in coastal waters off the Americas, western Africa and in the Indo-Pacific.
Grunters or tigerperches are ray-finned fishes in the family Terapontidae. This family is part of the superfamily Percoidea of the order Perciformes.
Nomeidae, the driftfishes, are a family of percomorph fishes found in tropical and subtropical waters throughout the world. The family includes about 16 species. The largest species, such as the Cape fathead, Cubiceps capensis, reach 1 m in length.
The louvar or luvar is a species of perciform fish, the only extant species in the genus Luvarus and family Luvaridae. It is closely related to the surgeonfish. The juvenile form has a pair of spines near the base of the tail, like the surgeonfish, though they are lost in the adult.
Phyllorhiza punctata is a species of jellyfish, also known as the floating bell, Australian spotted jellyfish, brown jellyfish or the white-spotted jellyfish. It is native to the western Pacific from Australia to Japan, but has been introduced widely elsewhere. It feeds primarily on zooplankton. P. punctata generally can reach up to 50 centimetres (20 in) in bell diameter, but in October 2007, one 72 cm (28 in) wide, perhaps the largest ever recorded, was found on Sunset Beach, North Carolina.
The imperial blackfish, Schedophilus ovalis, is a medusafish of the family Centrolophidae found in the eastern Atlantic and the Mediterranean Sea, and occasionally western Atlantic (Bermuda). It occurs at depths of between 70 and 700 m. In its juvenile stage it is often found finding shelter amongst of the tentacles of floating jellyfish, including the Portuguese man o' war. It grows to 100 cm (39 in) total length.
The Tasmanian ruffe, Tubbia tasmanica, is a medusafish of the family Centrolophidae, found in temperate waters in the Indian and southwest Pacific Oceans, at depths of between 700 and 850 m. Its length is up to 67 cm.
The Gobiiformes are an order of fish that includes the gobies and their relatives. The order, which was previously considered a suborder of Perciformes, is made up of about 2,211 species that are divided between seven families. Phylogenetic relationships of the Gobiiformes have been elucidated using molecular data. Gobiiforms are primarily small species that live in marine water, but roughly 10% of these species inhabit fresh water. This order is composed chiefly of benthic or burrowing species; like many other benthic fishes, most gobiiforms do not have a gas bladder or any other means of controlling their buoyancy in water, so they must spend most of their time on or near the bottom. Gobiiformes means "Goby-like".
Porpita porpita, or blue button, is a marine organism consisting of a colony of hydroids found in the warmer, tropical and sub-tropical waters of the Pacific, Atlantic, and Indian oceans, as well as the Mediterranean Sea and eastern Arabian Sea. It was first identified by Carl Linnaeus in 1758, under the basionym Medusa porpita. In addition, it is one of the two genera under the suborder Chondrophora, which is a group of cnidarians that also includes Velella. The chondrophores are similar to the better-known siphonophores, which includes the Portuguese man o' war, or Physalia physalis. Although it is superficially similar to a jellyfish, each apparent individual is actually a colony of hydrozoan polyps. The taxonomic class, Hydrozoa, falls under the phylum Cnidaria, which includes anemones, corals, and jellyfish, which explains their similar appearances.
Trachurus lathami is a species of fish in the family Carangidae and the genus Trachurus, the jack mackerels. Common names include rough scad and horse mackerel in English, as well as chinchard frappeur (French), chicharro garretón (Spanish), jurel, and carapau, garaçuma, surel, and xixarro. It is native to parts of the western Atlantic Ocean, including seas off the eastern coasts of North and South America and the Gulf of Mexico.
Cyanea nozakii or Cyanea nozaki (misspelling), commonly known as the ghost jellyfish, is a species of jellyfish found in the northern Pacific Ocean near the coasts of China and Japan. Along with other species of large jellyfish, it is showing a greater tendency to appear in large numbers and cause blooms.
