Portunidae these are the swimming crabs, which characteristically have the last pair of legs as swimming paddles. The crab's tough shell and spines provide some defense against predators. Smaller juvenile flower crabs (1-2cm) may have a wide variety of colours and patterns including bold bars and blotches. It is particularly active at night. There was some interesting information about how to stop the spread of the green crab but I feel there has to be a lot more education to the public in order for it even to begin to show results. They were contacted according to the snowball technique , in … The Surf Crab is commonly found on ocean beaches between the high- and low-tide marks. Birds will eat them, fish will eat them, even people will eat them. The cheliped (pincer) is usually sharply spined. Velvet Swimming Crab (Necora puber ... Class Crustacea Order Decapoda Family Portunidae Genus Necora ARKive ARKive Statistics, Behaviour & Habitat A large, active and highly aggressive crab. In other parts of the world, it has been reported to eat mostly slow moving, bottom-dwelling creatures such as snails and clams, and worms. The Surf Crab belongs to the family Portunidae, known as swimming crabs because their back legs are modified into paddles. Decapods occur in all oceans, in fresh water, and on Most species are efficient swimmers and aggressive predators. Portunidae Family. crabscoastal a guide to the crabs of New Zealand Version 1, 2015 Serena Wilkens Shane Ahyong. The Blue Swimmer Crab, formerly known as Portunus pelagicus but now known as Portunus armatus, is a member of the Portunidae family.This family includes other large, edible crabs found in Australia, such as the Mud Crab. They can communicate by drumming or waving their pincers. They are also good at hiding during daylight hours and at low tide. For crabs, the bite is fatal, paralyzing the crab so that it no longer uses its pinchers to thrash, allowing the octopus a tasty crab leg dinner. The Surf Crab is commonly found on ocean beaches between the high- and low-tide marks. The blue swimmer crab belongs to the family Portunidae, or swimming crabs, which have characteristically flattened hind legs used as paddles for swimming.The blue swimmer male has a bright bluish colouration whereas the female, or jenny, is less brightly coloured with smaller claws and a more rounded abdominal flap than males. The respondents were fishermen of both genders, specialists in gathering mangrove crabs Goniopsis cruentata, swimming crabs (Portunidae), and land crabs Ucides cordatus and Cardisoma guanhumi. Some crabs, notably the Portunidae and Matutidae, are also capable of swimming, the Portunidae especially so as their last pair of walking legs is flattened into swimming paddles. The flower crab is a predator. Velvet Swimming Crab (Necora puber) Facts Also known as: Velvet swimmer crab, Devil crab and witch crab Previously known as: Macropipus puber Kingdom Animalia Phylum Arthropoda Class Crustacea Order Decapoda Family Portunidae Genus Necora ARKive ARKive Statistics, Behaviour & Habitat A large, active and highly aggressive crab. Crabs from this family can usually be recognised by their flat, disc-shaped hind legs, used as paddles for swimming. about this guide about crabs morphology index species index species pages icons glossary 2 about this guide Crabs are a group of common marine invertebrates that inhabit our coastlines and our harbours, from the intertidal zone down to the continental shelf. The family also includes other large, edible crabs found in Australia, such as mud crabs. The Surf Crab belongs to the family Portunidae, known as swimming crabs because their back legs are modified into paddles. Some crabs, notably the Portunidae and Matutidae, are also capable of swimming, the Portunidae especially so as their last pair of walking legs is flattened into swimming paddles. Caption: A Blue Swimmer Crab underwater Credit: WA Museum . Features: Body width 5-7cm. What do Crabs Feed On? What does it eat? Most crabs are omnivores, although some families have a more specialized diet.In the case of the species pertaining to the Portunidae family, they are known by being mainly carnivorous, preying on slow-moving invertebrates such as mollusks and crustaceans. This bright red swimming crab is commonly seen on many of our shores, especially near reefs and coral rubble. During my observations when conducting my research, I found there was a lot of research on what the green crabs may eat but not what can eat it. Macrophthalmidae commonly known as fiddler, sentinel or ghost crabs. First, the octopus catches the crab by landing on top of it, then uses the suction discs to capture it and finally bite into its hard shell.