MANNA FROM HEAVEN
Blue swimmer crabs, sometimes known as blue manna or ‘blueys’, are surprisingly simple to prepare and have sweet, moist flesh that is easily enhanced with aromatics and flavoursome stock.
Blue swimmer crabs have sweet, moist flesh that is easily enhanced with aromatics and flavoursome stock.
Innovative celebrity chef Heston Blumenthal once remarked about one of his foodie forays into the unknown: “It was quite a challenge to make people eat crab ice cream.” But if he’d served it up to the average Kiwi and called the dish ‘Paddling with a Bluey’, many probably would have been tempted to sample a spoonful or three.
Blue swimmer crabs, sometimes known as ‘blueys’ and ‘blue manna’, are generally thought to be one of the best crabs for eating. Prized for their firm, sweet flesh, their broad carapaces and impressive pincers make them the ideal candidates for a crustacean feast.
MOST LIKELY TO FIND THEM
Blueys are found around the top the North Island of New Zealand, the gulfs of Western and Southern Australia, and from Northern Queensland down to southern NSW. They come out at sunset to feed and can also be caught around high or low tide, during the period of slack water, when they forage for food.
DESCRIPTION
Blue swimmer crabs are not all blue – the females, known as ‘jennies’, are a duller greenish brown than their bright-blue male counterparts. Both are decorated with white spots and have nine spikes either side of their eyes along their carapace, called horns. Their distinctive paddle-shaped back legs make them very good swimmers. They live for about three years and grow very fast from ‘zoea’ stage through to maturity in about a year. Their large carapaces can grow from 20-25cm wide and their large pincers have a claw span of up to 80cm. The average bluey weighs about 500 grams, but whoppers can weigh up to a full kilogram.
WHAT DO THEY EAT?
Known as opportunistic scavengers, juvenile blue swimmer crabs feed on small crustaceans, molluscs and other invertebrates found on the sea floor. They also eat worms and occasionally seagrass and algae. Adults graduate to larger prey such as small fish and bristle worms.
HOW TO STORE
Blue swimmer crabs can’t live out of the water as long as some other species, but they can be stored for up to 24 hours if they are handled properly. The best method of storing them is in an ice box full of ice kept in a cool, dark place, but it is advisable to cook them as soon as possible. The cooked crab meat can be stored in an airtight container in the fridge for up to three days, or wrapped in freezer wrap or placed in airtight containers and frozen for two to three months.
HOW TO COOK
The old days of plunging live crabs in a pot of boiling water are long gone. The accepted method is to put them in the freezer for about 20 minutes until they are no longer moving – secure the pincers first if this has not already been done. When they are inert, you can flip them on their backs and stab up under the carapace top and bottom to kill them. Boil crabs for 6-7 minutes – be careful not to overcook them. Depending on what you are making, you may want to just dismantle the crab to make eating easier, or completely strip the meat. The legs and pincers should be twisted from the carapace, which is then opened with a sharp knife. Inside you will find a yellowy-green substance called tomalley – some people discard this, others treat it as a delicacy and use it to add flavour to sauces. If you are going to make a cold dish, it is probably easier to buy cooked crab. However, if you are making a hot dish, you’ll get the most flavour from buying live crabs.
The blue swimmer’s meat has a delicate, unique taste that lends itself to spicy dishes – try a crab curry or chilli crab and get a flavour rush as you suck on the claws and legs. Use a cracker to break up the shell. Crab is also great for pasta dishes, such as ravioli, and is fabulous in salads with mango or papaya and chilli, or you can simply sling one on the barbie … the list goes on.
WHICH FLAVOURS WORK WITH BLUEYS?
A squeeze of lemon or lime may be all you need to savour a bluey. Vinegar-based dipping sauces highlight flavours; and chilli, basil, roasted garlic, mint, spicy coconut cream and tomato-based sauces are all a good match.
HEALTH BENEFITS
Crab is a calorie-counter’s dream and one of the healthiest seafoods you can eat. It’s full of protein, as well as some essential vitamins and minerals. It’s an excellent source of vitamins A, C and B, as well as copper, zinc and chromium, which enhances the action of insulin. Almost all seafood contains varying levels of mercury, and it is found in higher quantities in longerlived large fish such as tuna, swordfish and orange roughy. Crab has much lower levels of the toxin and is a better option for pregnant women, nursing mothers and young children.