Soft Shelled Crab

Soft Shell Crab is a unique and exciting food. During its lifetime the Blue Swimmer Crab will go through several growth stages. In order for a Blue Swimmer Crab to lose its shell, the body of the crab physically grows 30%. When the crab outgrows its shell, it backs out of its shell and in a 90 minute period, the skin underneath hardens into it’s new shell.

Watermark Soft Shell crabs are grown specifically to produce a soft shell crab which is full in flavour and meat - this sounds obvious, however, in the wild, when the crab is moulting, it is in both poor condition and is typically found in brackish water - as a result the flesh of the wild crabs imported from South East Asia oftem eat soft and mushy, lacking the sweetness of Watermark crabs.

Until now, commercially harvesting soft-shell crabs has been possible only with round-the-clock surveillance, seven days a week during the crab-shelling season. After catching the wild soft-shell crabs have traditionally been placed in holding pens and watched to find that 90 minute window after crabs shed their old, hard shells and before the new coat starts to harden. As the crabs utilse calcium found in the water to assist in the production of the new shell, removal from the water during these 90 minutes stops the shell hardening process.

Watermark have developed an innovative robotic system that can replace the traditional method. The project has taken years to devise the automated technology, that not only replaces the essential husbandry required in growing the crabs from an egg, but it also detects when a crab has molted and mechanically harvests it.After breeding the crablets from eggs in a hatchery, they are transferred into the grow-out system.The grow out system, is a multi tiered miniature aquatic apartment building, which holds approximately 40,000 crabs. Each crab has their own pot because of their cannibalistic nature.At this stage the robotic management on the farm takes over, constantly monitoring water quality and temperature but importantly, managing the welfare of each individual crab. Feed, waste removal and finally the robotic sensors detect the exact moment when the crab throws its shell. The importance of this is that there is a 90 minute window from when a crab throws it’s shell to the skin underneath calcifying, or becoming “paper”. The sooner the newly moulted crab is detected, the softer the new skin/shell. In addition, the sooner the newly moulted crab is detected, the better the quality of the meat, as the crab imbibes vast amounts of water to expand its body mass prior to forming it’s new shellThe majority of crabs imported from Asia are soft shell mud-crabs, mostly they carry a distinctive brackish aroma and flavour.

Through the development of the Watermark programme,a range of species were considered but after many trials, and taste tests, Watermark settled on a species of crab endemic to Australia – the Blue Swimmer Crab (portenus pelagic), which delivered both production efficiencies and culinary excellence. The species developed is unique to Watermark, it’s unique colouration and flavour
reflecting the Watermark breeding programme.Watermark also developed proprietary feeds. Originally based on Japanese Kuruma Prawn feeds the development team focused on the final eating quality of the finished crabs.

The result is a full, sweet and delicious soft shell crab, unlike any from around the world.Watermark crabs are fully prepared, the abdomen, gills ( dead mans fingers) and beak have been removed. The “mustard” is left in, this may or may not be removed peding the culinary preferance.