Optimal temperatures see a 70% survival through the first zoeal stage which is greatly reduced to a 30% survival in the second zoeal and Megalopa stages. They then have to twist off the legs by hand and pick out the meat. Chefs steam these giants over large pots of boiling water with their legs outstretched. As you might imagine they are difficult to cook and prepare due to their size. This is much warmer than the waters at depths below 200m where adults are found, with waters steadily around 10 ☌. The Japanese Spider Crab is considered to be a delicacy in Japan. This surface water ranges between 12 ☌ and 15 ☌ during the hatching season (January to March). During the larval stages, Macrocheira kaempferi is found near the surface as the planktonic forms drift with ocean currents. Colder water is associated with longer durations in each stage. At these temperatures the zoeal stages can last anywhere from 7 to 18 days, with the megalopa stage lasting anywhere from 25 to 45 days. It is thought that the optimum rearing temperature for all larval stages is between 15 ☌ and 18 ☌, with survival temperatures ranging from 11 ☌ to 20 ☌. Each of these stages is influenced greatly by temperature, both in terms of survival and stage length. As an animal professional Im committed to improving relationships between people and animals to bring them more happiness. Macrocheira Kaempferi undergoes two zoeal stages and a megalopa stage before it reaches adulthood. Japanese Spider Crabs Red Rock Crabs Sally Lightfoot Crab About Joanne Spencer Ive always been passionate about animals which led me to a career in training and behaviour. They look very different than their parents at this stage, with small, transparent bodies. The first, or prezoeal stage lasts only a matter of minutes, with most molting within 15 minutes to enter the first zoeal stage. Once hatched, these larvae undergo four stages of development before they mature into adulthood. They can lay up to 1.5 million eggs per season, and these eggs will hatch in 10 days on average. This crab specimen from the American Museum of Natural History measures 3.8 metres (12 ft) across its outstretched legsįemale crabs carry fertilized eggs attached to their abdominal appendages until they hatch into tiny planktonic larvae.
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