Moreton Bay Bug

Thenus australiensis (Sand Bug)
Thenus indicus (Mud Bug)



Available wild-caught, it is a marine crustacean with a reddish-brown shell, broad flat head with eyes at either edge of the shell, short narrow tail and 5 pairs of small legs. Found on muddy or sandy bottoms at 10-60m, north from northern NSW to Shark Bay in WA, though caught primarily between Cairns and Bundaberg as bycatch of Prawn and Scallop fisheries. They often bury themselves in sand or mud during the day and become active after dark. Thenus orientalis can be distinguished from Thenus indicus by the spots on its legs and a brown tail fan (T.indicus has no spots and a yellow tail fan).

Other Names

Baylobster, Bay Bobster, Bug, Flathead Lobster, Gulf-lobster, Mudbug, Northern Baylobster, Northern Bay Lobster, Sandbug, Shovelnose Lobster, Shovel-nosed Lobster, Slipper Lobster, Squat Lobster, Squilla.


Scyllaridae (Shovel-nosed/Slipper lobsters).


Available year round, although supply is affected by the seasonality of northern Prawn fisheries (peaking in autumn).

Size and Weight

Average 250g, but commonly 120-380g with 8-12cm wide head.


Medium-high priced, more expensive in areas where they are caught as they are familiar and popular.


Balmain Bug, Rock Lobsters, Slipper Lobsters. Most easily distinguished from similar species by the position of the eyes on the outer edge of the shell; Balmain Bugs’ eyes are located in the centre of the shell and those of Slipper Lobsters are closer to the edges but not on the actual edge as with Moreton Bay Bugs. Balmain Bugs also have a wider body.

There has been recent research that suggests that similar Asian Bugs may be different species, this may lead to a change in scientific name of the Australian species in the future.

To Buy

Sold whole, sometimes live (and frozen whole, tails and as meat). Look for brightly coloured, firm, intact, lustrous shells, without any discolouration, particularly at joints, and a pleasant fresh sea smell.

To Store

Wrap whole Bugs or meat in plastic wrap or place in an airtight container. Refrigerate for up to 3 days or freeze for up to 3 months below -18ºC.

To Cook

Average yield is 30%, the edible flesh is only in the tail and larger Bugs have a lower yield due to their head size. Have a medium, sweet, rich flavour (milder than Balmain Bug but stronger than Rock Lobster), low oiliness and dry, firm flesh.

To remove meat from shells, either split Bug lengthwise, or, to keep meat in one piece, remove head, turn tail over and cut down either side of the tail using kitchen scissors, peel underside of tail back and remove meat.

Do not recook cooked Bugs. Eat cold in salads or with a dipping sauce.

The most humane, and easiest, method of killing any crustacean is to chill it in the freezer for about 45 minutes until it becomes insensible (but not long enough to freeze it). Once chilled, it should be killed promptly by splitting in half. See NSW Department of Primary Industries or RSPCA for more details.

Cooking Methods

Steam, poach, deep-fry, pan-fry, stir-fry, grill, barbecue. Excellent cold as part of a seafood platter. To BBQ, cut in half lengthwise and cook in the shell. The firm flesh holds together well in soups, curries and casseroles and can be cubed for kebabs.