Southern rock lobster, Red rock lobster, Spiny rock lobster
Jasus edwardsii, the southern rock lobster, red rock lobster, or spiny rock lobster, is a species of spiny lobster found throughout coastal waters of southern Australia and New Zealand including the Chatham Islands. It is commonly called crayfish in Australia and New Zealand and kōura in Māori. They resemble lobsters, but lack the large characteristic pincers on the first pair of walking legs.
Spiny rock lobsters are carnivorous, leaving their rock cover to venture out to feed during the night. They live in and around reefs at depths ranging from 5–200 metres (16–660 ft) deep at the continental shelf. They can be dark red and orange above with paler yellowish abdomens or grey-green brown with the paler underside. The more tropical animals tend to have the brighter colours. Adult carapaces can grow up to 230 millimetres (9.1 in) in length and can often exceed 8 kilograms (18 lb) in underfished areas.
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ScavengerScavengers are animals that consume dead organisms that have died from causes other than predation or have been killed by other predators. While sc...
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OviparousOviparous animals are female animals that lay their eggs, with little or no other embryonic development within the mother. This is the reproductive...
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starts withMaximum total body length is 58 cm (males), and 43 cm (females); maximum carapace lengths 23.5 cm (males), 18 cm (females); minimum legal carapace lengths 10 cm (males), and 9 cm (females).
Jasus edwardsii is found around most of the coast of New Zealand, including the three main islands, the Three Kings Islands, the Chatham Islands, the Snares Islands, the Bounty Islands, the Antipodes Islands and the Auckland Islands. This last locality is the southernmost place where spiny lobsters occur in the world. In Australia, J. edwardsii is found around the southern coast, from central New South Wales to southern Western Australia, including Tasmania.
NIWA used primarily brine shrimp to feed the juvenile lobsters, but little is known about a preferred food source. Chopped up mussel flesh has been used previously in Japan. Both these techniques carry some potential disadvantages – brine shrimp can introduce disease, and mussels deteriorate once introduced to the water, giving bacteria an environment to grow on. A study has shown that mussels provide the best food along with a carbohydrate source in the form of agar, allowing faster grow rates in the lobster.
Adults are sexually mature at between 7 and 11 years, mating occurs during late summer and autumn. Eggs develop on females, which carry between 100,000 and 500,000 eggs which are fertilised and held below the tail on hairs on the female's abdomen. The eggs develop here for 3 to 5 months. Eggs then metamorphose into naupliosoma larva which leave the female and are free swimming plankton which migrate towards the surface where they moult into a phyllosoma larva.
The rock lobster has among the longest larval development known for any marine creature. The phyllosoma (Greek for "leaf-like") larvae spend between 9 months to 2 years in oceanic waters before metamorphosing to the post larval stage, known as the puerulus, which then swims towards the coast to settle.
