''Terebralia palustris'', commonly known as the giant mangrove whelk, is a species of brackish-water

snail A snail is a shelled gastropod. The name is most often applied to land snails, terrestrial molluscs, terrestrial pulmonate gastropod molluscs. However, the common name ''snail'' is also used for most of the members of the molluscan class Gas ...

, a

mollusk Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The ...

in the family

Potamididae ''Potamididae'', common name potamidids (also known as horn snails or mudwhelks) are a family (biology), family of small to large brackish water snails that live on mud flats, mangroves and similar habitats. They are amphibious gastropod mollusc ...

. This tropical species which inhabits

mangrove A mangrove is a shrub or tree that grows mainly in coastal saline water, saline or brackish water. Mangroves grow in an equatorial climate, typically along coastlines and tidal rivers. They have particular adaptations to take in extra oxygen a ...

environments of the Indo-West Pacific region,Houbrick R. S. (1999) Systematic review and functional morphology of the mangrove snails ''Terebralia'' and ''Telescopium'' (Potamididae; Prosobranchia). ''Malacologica'' 33: 289-338. has the widest geographic distribution amongst the potamidids Pape E., Muthumbi A., Kamanu C. P., Vanreusel A. (2008) Size-dependent distribution and feeding habits of ''Terebralia palustris'' in mangrove habitats of Gazi Bay, Kenya. ''

Estuarine, Coastal and Shelf Science ''Estuarine, Coastal and Shelf Science'' is a peer-reviewed academic journal on ocean sciences, with a focus on coastal regions ranging from estuaries up to the edge of the continental shelf. It's published by Elsevier on behalf of the Estuarine ...

'' 76: 797-808. extending from eastern Africa to northern Australia. ''Terebralia palustris'' is the largest mangrove gastropod, with a maximum shell length of 190 mm recorded from Arnhem Land,

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

Distribution

This species has the widest distribution range of any ''

Terebralia ''Terebralia'' is a genus of sea snails, marine gastropod mollusks in the family Potamididae. Species Species within the genus ''Terebralia'' include: * ''Terebralia palustris ''Terebralia palustris'', common name, commonly known as the g ...

'' species. Its Western

Pacific 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 the definition, to Antarctica in the south, and is bounded by the cont ...

distribution extends south from the

Ryukyus The , also known as the or the , are a chain of Japanese islands that stretch southwest from Kyushu to Taiwan: the Ryukyu Islands are divided into the Satsunan Islands ( Ōsumi, Tokara and Amami) and Okinawa Prefecture ( Daitō, Miyako, Y ...

to the

Philippines The Philippines, officially the Republic of the Philippines, is an Archipelagic state, archipelagic country in Southeast Asia. Located in the western Pacific Ocean, it consists of List of islands of the Philippines, 7,641 islands, with a tot ...

and across

Borneo Borneo () is the List of islands by area, third-largest island in the world, with an area of , and population of 23,053,723 (2020 national censuses). Situated at the geographic centre of Maritime Southeast Asia, it is one of the Greater Sunda ...

New Guinea New Guinea (; Hiri Motu: ''Niu Gini''; , fossilized , also known as Papua or historically ) is the List of islands by area, world's second-largest island, with an area of . Located in Melanesia in the southwestern Pacific Ocean, the island is ...

and tropical

. Eastwards, ''T. palustris'' is found as far as

Palau Palau, officially the Republic of Palau, is an island country in the Micronesia subregion of Oceania in the western Pacific Ocean. The Republic of Palau consists of approximately 340 islands and is the western part of the Caroline Islands ...

as well the

New Hebrides New Hebrides, officially the New Hebrides Condominium () and named after the Hebrides in Scotland, was the colonial name for the island group in the South Pacific Ocean that is now Vanuatu. Native people had inhabited the islands for three th ...

and

New Caledonia New Caledonia ( ; ) is a group of islands in the southwest Pacific Ocean, southwest of Vanuatu and east of Australia. Located from Metropolitan France, it forms a Overseas France#Sui generis collectivity, ''sui generis'' collectivity of t ...

The

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or approximately 20% of the water area of Earth#Surface, Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia (continent), ...

occurrence of ''Terebralia palustris'' includes mangrove habitats throughout

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania, between the Indian Ocean, Indian and Pacific Ocean, Pacific oceans. Comprising over List of islands of Indonesia, 17,000 islands, including Sumatra, ...

and regions of

South East Asia Southeast Asia is the geographical United Nations geoscheme for Asia#South-eastern Asia, southeastern region of Asia, consisting of the regions that are situated south of China, east of the Indian subcontinent, and northwest of the Mainland Au ...

including

India India, officially the Republic of India, is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area; the List of countries by population (United Nations), most populous country since ...

and

Ceylon Sri Lanka, officially the Democratic Socialist Republic of Sri Lanka, also known historically as Ceylon, is an island country in South Asia. It lies in the Indian Ocean, southwest of the Bay of Bengal, separated from the Indian subcontinent, ...

. The species has also been reported from the

Andaman Islands The Andaman Islands () are an archipelago, made up of 200 islands, in the northeastern Indian Ocean about southwest off the coasts of Myanmar's Ayeyarwady Region. Together with the Nicobar Islands to their south, the Andamans serve as a mari ...

, Nicobar, the

Maldives The Maldives, officially the Republic of Maldives, and historically known as the Maldive Islands, is an Archipelagic state, archipelagic country in South Asia located in the Indian Ocean. The Maldives is southwest of Sri Lanka and India, abou ...

Mauritius Mauritius, officially the Republic of Mauritius, is an island country in the Indian Ocean, about off the southeastern coast of East Africa, east of Madagascar. It includes the main island (also called Mauritius), as well as Rodrigues, Ag ...

, the

Seychelles Seychelles (, ; ), officially the Republic of Seychelles (; Seychellois Creole: ), is an island country and archipelagic state consisting of 155 islands (as per the Constitution) in the Indian Ocean. Its capital and largest city, Victoria, ...

, the Amirantes and

Madagascar Madagascar, officially the Republic of Madagascar, is an island country that includes the island of Madagascar and numerous smaller peripheral islands. Lying off the southeastern coast of Africa, it is the world's List of islands by area, f ...

. ''Terebralia palustris'' also occurs along the tropical and subtropical East African coastline including

Kenya Kenya, officially the Republic of Kenya, is a country located in East Africa. With an estimated population of more than 52.4 million as of mid-2024, Kenya is the 27th-most-populous country in the world and the 7th most populous in Africa. ...

Tanzania Tanzania, officially the United Republic of Tanzania, is a country in East Africa within the African Great Lakes region. It is bordered by Uganda to the northwest; Kenya to the northeast; the Indian Ocean to the east; Mozambique and Malawi to t ...

and

Mozambique Mozambique, officially the Republic of Mozambique, is a country located in Southeast Africa bordered by the Indian Ocean to the east, Tanzania to the north, Malawi and Zambia to the northwest, Zimbabwe to the west, and Eswatini and South Afr ...

. The southern global distribution limit for this species is along the eastern subtropical coastline of

South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic O ...

. The northward extension of the African distribution is as far as the

Red Sea The Red Sea is a sea inlet of the Indian Ocean, lying between Africa and Asia. Its connection to the ocean is in the south, through the Bab-el-Mandeb Strait and the Gulf of Aden. To its north lie the Sinai Peninsula, the Gulf of Aqaba, and th ...

Description

Shell

The shell is generally described as elongate, thick, solid and turreted. It comprises as many as 20 flat-sided

whorl A whorl ( or ) is an individual circle, oval, volution or equivalent in a whorled pattern, which consists of a spiral or multiple concentric objects (including circles, ovals and arcs). In nature File:Photograph and axial plane floral diagra ...

s with the early whorls being sculptured with strong colabral axial ribs. Spiral incised lines appear on the ninth or tenth whorl. These gradually increase in number to three. Growth is determinate for this species and full maturity is indicated by a thickened

aperture In optics, the aperture of an optical system (including a system consisting of a single lens) is the hole or opening that primarily limits light propagated through the system. More specifically, the entrance pupil as the front side image o ...

margin. The size of mature adult snails varies between populations and in some cases maturity has been reported for individuals at only 45 mm total shell length.

Anatomy

The head and foot are typically dark brown while the snout and tips of the

cephalic A head is the part of an organism which usually includes the ears, brain, forehead, cheeks, chin, eyes, nose, and mouth, each of which aid in various sensory functions such as sight, hearing, smell, and taste. Some very simple animals may no ...

tentacles In zoology, a tentacle is a flexible, mobile, and elongated organ present in some species of animals, most of them invertebrates. In animal anatomy, tentacles usually occur in one or more pairs. Anatomically, the tentacles of animals work main ...

are black. In females, a

ciliated The cilium (: cilia; ; in Medieval Latin and in anatomy, ''cilium'') is a short hair-like membrane protrusion from many types of eukaryotic cell. (Cilia are absent in bacteria and archaea.) The cilium has the shape of a slender threadlike pr ...

groove on the right side of the foot leads to a large, bulbous white

ovipositor The ovipositor is a tube-like organ used by some animals, especially insects, for the laying of eggs. In insects, an ovipositor consists of a maximum of three pairs of appendages. The details and morphology of the ovipositor vary, but typica ...

which is situated internally near the base of the foot. The

hemocyanin Hemocyanins (also spelled haemocyanins and abbreviated Hc) are proteins that transport oxygen throughout the bodies of some invertebrate animals. These metalloproteins contain two copper atoms that reversibly bind a single oxygen molecule (O2 ...

of this species was analyzed by Lieb et al. in 2010.Lieb B., Gebauer W., Gatsogiannis C., Depoix F., Hellmann N., Harasewych M. G., Strong E. E. & Markl J. (2010). "Molluscan mega-hemocyanin: an ancient oxygen carrier tuned by a ~550 kDa polypeptide". ''Frontiers in Zoology'' 2010, 7:14. . Its mega-hemocyanin have unusually high

oxygen Oxygen is a chemical element; it has chemical symbol, symbol O and atomic number 8. It is a member of the chalcogen group (periodic table), group in the periodic table, a highly reactivity (chemistry), reactive nonmetal (chemistry), non ...

affinities.

Ecology

It lives in the mud in

mangrove forest Mangrove forests, also called mangrove swamps, mangrove thickets or mangals, are productive wetlands that occur in coastal intertidal zones. Mangrove forests grow mainly at tropical and subtropical latitudes because mangrove trees cannot withsta ...

s. ''Terebralia palustris'' is a predominantly

-associated species.Zvonareva S., Kantor Yu., Li X. & Britayev T. (2015). "Long-term monitoring of Gastropoda (Mollusca) fauna in planted mangroves in central Vietnam". ''

Zoological Studies ''Zoological Studies'' is a peer-reviewed open access scientific journal covering zoology, with focuses on animal behavior, comparative physiology, evolution, ecology, systematics and biogeography. It is published by the Biodiversity Research Cente ...

'' 54: 39. .

References

* Dautzenberg, Ph. (1929). ''Contribution à l'étude de la faune de Madagascar: Mollusca marina testacea.'' Faune des colonies françaises, III(fasc. 4). Société d'Editions géographiques, maritimes et coloniales: Paris. 321–636, plates IV-VII pp. * Steyn, D.G. & Lussi, M. (1998) ''Marine Shells of South Africa. An Illustrated Collector’s Guide to Beached Shells.'' Ekogilde Publishers, Hartebeespoort, South Africa, ii + 264 pp. page(s): 38 * Reid, D.G., Dyal, P., Lozouet, P., Glaubrecht, M. & Williams, S.T. (2008) ''Mudwhelks and mangroves: the evolutionary history of an ecological association (Gastropoda: Potamididae).'' Molecular Phylogenetics and Evolution 47: 680-699

External links

* {{Authority control Potamididae Gastropods described in 1767 Taxa named by Carl Linnaeus