''Thalassina'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

of mud lobsters found in the mangrove swamps of the

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or ~19.8% of the water on Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia to the east. To the south it is bounded by t ...

and western

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the contin ...

. Its nocturnal burrowing is important for the recycling of nutrients in the mangrove ecosystem, although it is sometimes considered a pest of

fish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of ...

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 Rostrum may refer to: * Any kind of a platform for a speaker: **dais **pulpit * Rostrum (anatomy), a beak, or anatomical structure resembling a beak, as in the mouthparts of many sucking insects * Rostrum (ship), a form of bow on naval ships * Ros ...

. The tail is long and thin, and, like many burrowing decapods, the

uropod Uropods are posterior appendages found on a wide variety of crustaceans. They typically have functions in locomotion. Definition Uropods are often defined as the appendages of the last body segment of a crustacean. An alternative definition sugge ...

s are reduced in form, and do not form a functional tail fan with the

telson The telson () is the posterior-most division of the body of an arthropod. Depending on the definition, the telson is either considered to be the final segment of the arthropod body, or an additional division that is not a true segment on accou ...

. Various rows of

seta In biology, setae (singular seta ; from the Latin word for " bristle") are any of a number of different bristle- or hair-like structures on living organisms. Animal setae Protostomes Annelid setae are stiff bristles present on the body. ...

e on the legs and

gill A gill () is a respiratory organ that many aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow respiration on land provided they are ...

s 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.

Distribution

''Thalassina'' is found along the coast of the

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an are ...

n mainland from

Kerala Kerala ( ; ) is a state on the Malabar Coast of India. It was formed on 1 November 1956, following the passage of the States Reorganisation Act, by combining Malayalam-speaking regions of the erstwhile regions of Cochin, Malabar, South ...

India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...

Vietnam Vietnam or Viet Nam ( vi, Việt Nam, ), officially the Socialist Republic of Vietnam,., group="n" is a country in Southeast Asia, at the eastern edge of mainland Southeast Asia, with an area of and population of 96 million, making i ...

, including Sri Lanka and the

Andaman and Nicobar Islands The Andaman and Nicobar Islands is a union territory of India consisting of 572 islands, of which 37 are inhabited, at the junction of the Bay of Bengal and the Andaman Sea. The territory is about north of Aceh in Indonesia and separated f ...

. It is also found throughout most of

Maritime Southeast Asia Maritime Southeast Asia comprises the countries of Brunei, Indonesia, Malaysia, the Philippines, Singapore, and East Timor. Maritime Southeast Asia is sometimes also referred to as Island Southeast Asia, Insular Southeast Asia or Oceanic Sout ...

and the

Ryukyu Islands The , also known as the or the , are a chain of Japanese islands that stretch southwest from Kyushu to Taiwan: the Ōsumi, Tokara, Amami, Okinawa, and Sakishima Islands (further divided into the Miyako and Yaeyama Islands), with Yona ...

, and its range extends south to most of

Australia's Australia, officially the Commonwealth of Australia, is a sovereign country comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands. With an area of , Australia is the largest country by a ...

north coast (from the

North West Cape North West Cape is a peninsula in the north-west of Western Australia. Cape Range runs down the spine of the peninsula and Ningaloo Reef runs along the western edge. It is in the Gascoyne region and includes the town of Exmouth. History In 16 ...

Western Australia Western Australia (commonly abbreviated as WA) is a state of Australia occupying the western percent of the land area of Australia excluding external territories. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to th ...

Central Queensland Central Queensland is an ambiguous geographical division of Queensland ( a state in Australia) that centres on the eastern coast, around the Tropic of Capricorn. Its major regional centre is Rockhampton. The region extends from the Capricorn Coas ...

), and east to Fiji and

Samoa Samoa, officially the Independent State of Samoa; sm, Sāmoa, and until 1997 known as Western Samoa, is a Polynesian island country consisting of two main islands ( Savai'i and Upolu); two smaller, inhabited islands ( Manono and Apolima); ...

Ecology and behaviour

''Thalassina'' lives in burrows up to deep, and is active at night. Its burrowing fulfils an important rôle in the mangrove

ecosystem An ecosystem (or ecological system) consists of all the organisms and the physical environment with which they interact. These biotic and abiotic components are linked together through nutrient cycles and energy flows. Energy enters the syste ...

bringing organic matter up from deep sediments. The animal's output forms large volcano-like mounds which can reach heights of and are vital to many other species such as '' Odontomachus malignus'' (an

ant Ants are eusocial insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from vespoid wasp ancestors in the Cretaceous period. More than 13,800 of an estimated total of ...

), '' Episesarma singaporense'' (a crab), '' Wolffogebia phuketensis'' (another mud shrimp), '' Idioctis littoralis'' (a

spider Spiders ( order Araneae) are air-breathing arthropods that have eight legs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude silk. They are the largest order of arachnids and rank seventh in total species ...

), '' Acrochordus granulatus'' (a

snake Snakes are elongated, limbless, carnivorous reptiles of the suborder Serpentes . Like all other squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales. Many species of snakes have skulls with several more j ...

), ''

Excoecaria agallocha ''Excoecaria agallocha'', a mangrove species, belongs to the genus '' Excoecaria'' of the family Euphorbiaceae. The species has many common names, including blind-your-eye mangrove, blinding tree, buta buta tree, milky mangrove, poisonfish tree ...

'' (a

mangrove A mangrove is a shrub or tree that grows in coastal saline or brackish water. The term is also used for tropical coastal vegetation consisting of such species. Mangroves are taxonomically diverse, as a result of convergent evolution in severa ...

) and

termite Termites are small insects that live in colonies and have distinct castes (eusocial) and feed on wood or other dead plant matter. Termites comprise the infraorder Isoptera, or alternatively the epifamily Termitoidae, within the order Blatto ...

s. The burrowing activity can cause ''T. anomala'' to be seen as a pest where it weakened the

bunding Bunding, also called a bund wall, is a constructed retaining wall around storage "where potentially polluting substances are handled, processed or stored, for the purposes of containing any unintended escape of material from that area until ...

that surrounds prawn farms or fish farms. The small-eyed goby, a species of herbivorous

goby Goby is a common name for many species of small to medium sized ray-finned fish, normally with large heads and tapered bodies, which are found in marine, brackish and freshwater environments. Traditionally most of the species called gobies have b ...

specialising in feeding on seagrass, shares the burrows of mud lobsters of the genus ''Thalassina''.

Use as food

In parts of its range, including

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...

Philippines The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no), * bik, Republika kan Filipinas * ceb, Republika sa Pilipinas * cbk, República de Filipinas * hil, Republ ...

New Guinea New Guinea (; Hiri Motu: ''Niu Gini''; id, Papua, or , historically ) is the world's second-largest island with an area of . Located in Oceania in the southwestern Pacific Ocean, the island is separated from Australia by the wide Torr ...

and Fiji, the

claw A claw is a curved, pointed appendage found at the end of a toe or finger in most amniotes (mammals, reptiles, birds). Some invertebrates such as beetles and spiders have somewhat similar fine, hooked structures at the end of the leg or tarsus ...

s of ''Thalassina'' are eaten, but the meat is bland and it is never very popular. In powdered form or steeped in alcohol, it is used in

Thailand Thailand ( ), historically known as Siam () and officially the Kingdom of Thailand, is a country in Southeast Asia, located at the centre of the Indochinese Peninsula, spanning , with a population of almost 70 million. The country is b ...

as a remedy for

asthma Asthma is a long-term inflammatory disease of the airways of the lungs. It is characterized by variable and recurring symptoms, reversible airflow obstruction, and easily triggered bronchospasms. Symptoms include episodes of wheezing, co ...

Fossil record

Fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

s of ''Thalassina'' are encountered "in countless numbers", and extend back as far as the

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

. They are generally preserved in a hard phosphatic nodule which is believed to be the animal's moulting position.

Storm A storm is any disturbed state of the natural environment or the atmosphere of an astronomical body. It may be marked by significant disruptions to normal conditions such as strong wind, tornadoes, hail, thunder and lightning (a thunderstorm), ...

s may trap the animals in their burrows, and the

mineral In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. (2 ...

-rich nature of the

sediment Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, sa ...

s leads to very rapid fossilisation. The presence of ''Thalassina'', together with other warm-water species in the Miocene of Japan (outside the current range of the species) is taken as confirmation of a period of increased temperatures .

Taxonomy

''Thalassina'' is the only genus in the family Thalassinidae (=Scorpionoidae Haworth, 1825). For many years, only a single species, ''Thalassina anomala'', was recognised, but a 2009 revision by Nguyen Ngoc-Ho and

Michèle de Saint Laurent Michèle de Saint Laurent (December 9, 1926 – July 11, 2003) was a French carcinologist. She spent most of her career at the ' in Paris, working on the systematics of decapod crustaceans; her major contributions were to hermit crabs and Thala ...

increased the number of extant species to eight, including one fossil species. Thalassinidae is classified in the infraorder

Gebiidea Gebiidea is an infraorder of decapod crustaceans. Gebiidea and Axiidea are divergent infraoders of the former infraorder Thalassinidea. These infraorders have converged ecologically and morphologically as burrowing forms.Dworschak, Peter C. ( ...

, alongside the families Upogebiidae, Axianassidae and Laomediidae. The extant species are: *'' Thalassina anomala'' Herbst, 1804 – Indo-West Pacific, synonym ''T. maxima'' *'' Thalassina gracilis'' Dana, 1852 – Thailand, Singapore, Indonesia and north-western Australia *'' Thalassina kelanang'' Moh & Chong, 2009 – Malaysia *'' Thalassina krempfi'' Ngoc-Ho & de Saint Laurent, 2009 – Vietnam, Singapore and Indonesia *'' Thalassina pratas'' Lin, Komani & Chan, 2016 – China *'' Thalassina spinirostris'' Ngoc-Ho & de Saint Laurent, 2009 – Singapore, Malaysia *'' Thalassina spinosa'' Ngoc-Ho & de Saint Laurent, 2009 – Indonesia, India and Papua New Guinea *'' Thalassina squamifera'' de Man, 1915 – Thailand, Philippines, Singapore, Indonesia, Papua New Guinea, Solomon Islands, Fiji, northern Australia The fossil species, '' Thalassina emerii'', is known from northern Australia, Papua New Guinea and Indonesia.

References

{{Taxonbar, from=Q2698435 Thalassinidea Edible crustaceans Extant Miocene first appearances