Austrodromidia australis belongs to the Dromiidae family, commonly known as the sponge crabs. These unique creatures actually carry a well-fitting camouflage cap of living sponge or ascidian (sea squirt) over their back which they trim and keep tidy. As well as camouflaging the crab, the sponge can often taste bad, making potential predators reluctant to eat it. The sponge or other encrusting animal on the back of the Dromiid can often be larger than the crab itself.
The Western Australian Museum is the repository for the State’s collection of both natural and social heritage. The Museum's collections require varying amounts of care to preserve. Some artefacts or specimens can simply be kept dry. Most of the Crustacean Collection however is wet-preserved in ethanol and stored in jars and housed in our wet store. Unluckily, not all crustaceans can fit into our jars and some larger specimens are stored in drums, which again, sadly, don’t fit in our wet store.
The Western Australian Department of Fisheries has issued an alert after the Asian Paddle Crab, Charybdis japonica, was caught by a recreational crabber near Mosman Park on 19 October. Fishers and divers in the Swan and Canning Rivers as well as the greater Cockburn Sound area are urged to report any unusual crabs to FishWatch reporting line on 1800 815 507 or email biosecurity@fish.wa.gov.au.
Sometimes at the museum we come across a species that can be baffling. This crab with its pock-marked, lumpy and misshapen carapace is a bizarre sight. The row of circular pits on the pincers reminded us of a harmonica, which is why we are dubbing this species the Harmonica Pebble Crab. This species was first reported in Australian waters in 2004 from the Dampier Archipelago at a depth of 40 m.
Two curious looking ‘stones’ collected from a dam near Lake Yindarlgooda out in the Goldfields were brought into the Museum by inquisitive members of the public. These mushroom shaped stones are made of calcium carbonate, the main mineral in human bones, coral skeletons and the shells of oysters and abalone.
Last week this 20 cm long monster was brought into the Museum by a curious member of the public who had managed to collect it while fishing in the Gulf of Carpentaria. With lightning-quick reflexes, frighteningly long, sharp spines and incredible vision this is an animal not to be handled with bare hands!
Crustaceans such as crabs, lobsters and prawns are a major component of peoples’ diets around the world with eleven million tonnes caught or cultured annually. Despite a considerable diversity of crustacean species in Australia, only a handful of species are harvested as part of commercial or recreational fisheries. In Western Australia there are only about a half-dozen crab species that are commonly seen in seafood restaurants or fish markets, with the blue swimmer and mud crabs being the most common.
Even the biggest animals have fleas, and the mighty whale shark is no exception. Pandarus rhincodonicus, is a small crustacean, barely reaching one centimetre in length, belonging to a group of crustaceans known as copepods which are normally known to be free-living and a dominant group within planktonic communities. However, many species are bottom dwellers or parasites of other marine animals, particularly fish. Pandarus rhincodonicus was first discovered in WA and was only named and formally described in 2000.
On the tropical reefs of Western Australia the stunning Neopetrolisthes maculatus is always found living on or around large sea anemones. Like the clown fish, these spotty little crabs are protected from potentail predators by the stinging tentacles of the sea anemone. Only a single pair of crabs can be found on each host as the crabs will defend their territory from rivals. Despite their impressive claws these are not used for capturing food, but are probably used fend off potential home invaders.
This large and colourful species of swimming crab is wide ranging in the tropical Indo-West Pacific from East Africa the Persian Gulf through to Indonesia and Japan, and throughout most of Australia. The crucifix crab lives in shallow sandy or rocky areas. In parts of its range, such as India, the crucifix crab forms a substantial commercial and recreational fishery but in Australia this species is quite rare and isn’t caught in large numbers by Australian crabbers.
If you’ve ever walked along the many miles of beach in Western Australia, you may have seen large burrows high up on the shore, near the high tide line and beyond into the dunes. During the day you would be unlikely to find the animal responsible for these, unless you carried out some serious excavating yourself. At dusk, however, you may see the culprits emerge.
Fight Club: the Peacock Mantis Shrimp Odontodactylus scyllarus (Linneaus, 1758)
Mantis Shrimp belong to a group of crustaceans, called stomatopods, only distantly related to shrimps and prawns you would normally see on your dinner plate. They get their common name from the enlarged second limb, referred to as the claw, which is very reminiscent of the front legs of the praying mantis. Much like the praying mantis in your back garden, mantis shrimp also use these limbs for capturing prey, with which they launch lightning fast attacks.
