burrows are U-shaped and can be up to 2m deep even below the waterline.
During the day, mud lobsters plug up their entrance with mud. In the evening,
these are opened and the mud lobsters may emerge. Mud lobsters prefer to
dig in intertidal and subtidal regions.
Mangrove Lobster/Large Mangrove
modest, shy creatures are responsible for the strange volcano-shaped
mounds that are commonly seen in the back mangroves.
Mud lobsters are believed to eat tiny organic titbits in mud. To get
enough nutrition, they have to process huge amounts of mud and sand.
Processed mud is piled around their burrows as they eat-and-dig through
the mud. Their mounds can reach 3m high.
and wetland wildlife at
Sungei Buloh Nature Park
with a long "tail", held curved under the thorax.
Peter Ng and N Sivasothi
Small triangular rostrum. The clawed legs are unequal
in size and the moveable finger (dactyl) is obviously
larger than the fixed finger (pollex). Grows to 30-60cm.
Status in Singapore: Common.
World distribution: South
Asia to Oceania. Indo-west pacific region
Classification: Family Thalassinidae.
Mud Lobsters are not lobsters and related to ghost shrimps
of the genus Callianasa.
Role in the habitat: Mud Lobster digging
helps the mangrove community by recycling material from deep in the mud,
loosening the mud and allowing air and oxygenated water to penetrate the
otherwise oxygen-poor soil. This facilitates the growth of mangrove seedlings.
Experiments show that seedlings of the Nipah
Palm (Nypa fruiticans), Bruguiera
and Ceriops grow more quickly on mud lobster-processed soil. Other
plants found commonly growing on the mounds include Sea
Holly (Acanthus spp.) and Blind
Your Eye (Exoecaria algallocha).
mounds also result in pools which at low tide, provide shelter for small
aquatic creatures. The mound is also a mini-habitat for a wide range of
creatures, many of which have adapted to live only in a "Mud Lobster
Condo". These include: an ant (Odontomachus malignus: its scientific
name comes from its vicious sting!); a spider (Idioctis littoralis);
the Mud Shrimp (Wolffogebia phuketensis: which lives permanently
in a burrow in the mound, paddling a current of nutrients into its burrow
at high tide).
creatures that make use of condo facilities include mudskippers,
water snakes (e.g., the File Snake, Acrochordus granulatus). The
Collared Kingfisher (Halcyon
chloris) sometimes nests in a large mound.
Status and threats: Mud lobsters are
widely harvested throughout the tropical Pacific as food, and a variety
of techniques have been developed for catching them. Fortunately, they are
not a popular dish elsewhere. But they are considered a pest by prawn and
fish farmers as their digging often undermines the bunds that form the foundation
of prawn and fish ponds.
- Peter K L Ng and N Sivasothi, "A Guide to the Mangroves of
Singapore II: Animal Diversity", Singapore Science Centre,
1999 (p. 86-87: description, habits, habitat, photos).
- Michael Mastaller,
"Mangroves: The Forgotten Forest Between Land and Sea",
Tropical Press, 1997 (p. 66-67: habits, habitat, diagram).
- Peter Widman (ed.),
"A Guide to the Ecosystem of Palawan, Philippines",
Times Edition, 1998 (p. 43: snippet on habit, photo).