Thalassina

Thalassina is a genus of mud lobsters found in the mangrove swamps of the Indian Ocean and western Pacific Ocean. Its nocturnal burrowing is important for the recycling of nutrients in the mangrove ecosystem, although it is sometimes considered a pest of fish and prawn farms.

==Description== Thalassina is a lobster-like animal which grows up to long, but is more typically long. Its colour ranges from pale to dark brown and brownish green. The carapace is tall and ovoid, extends over less than one third of the animal's length, and projects forward into a short rostrum. The tail is long and thin, and, like many burrowing decapods, the uropods are reduced in form, and do not form a functional tail fan with the telson. Various rows of setae on the legs and gills are used to prevent sediment from reaching the gills and for expelling any which does reach them. Thalassina also makes use of "respiratory reversal" to keep the gills free of dirt.