''Nassodonta insignis'' is a species of brackish water snail, with gills and an operculum, a

gastropod The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...

mollusk Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is e ...

in the family

Nassariidae The Nassariidae, Nassa mud snails (USA), or dog whelks (UK), are a taxonomic family of small to medium-sized sea snails, marine gastropod mollusks in the clade Neogastropoda. "Dog whelk" also refers to ''Nucella lapillus''. Shell description T ...

. ''Nassodonta insignis'' is the

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...

of the genus ''Nassodonta''.Strong, E. E., Galindo, L. A., & Kantor, Y. I. (2017). "Quid est ''Clea helena''? Evidence for a previously unrecognized radiation of assassin snails (Gastropoda: Buccinoidea: Nassariidae)". ''PeerJ'' 5: e3638. . This species distributed in the brackish water habitats of southwest coast of India.

Distribution

Apparently confined to the southern coasts of India inshallow, brackish water. Reported by Preston from Cochin (

Kochi Kochi (), also known as Cochin ( ) ( the official name until 1996) is a major port city on the Malabar Coast of India bordering the Laccadive Sea, which is a part of the Arabian Sea. It is part of the district of Ernakulam in the state of K ...

) backwaters near

Ernakulam Ernakulam () is the Central Business District of the city of Kochi in Kerala, India and has lent its name to the Ernakulam district. Many major establishments, including the Kerala High Court, the office of the Kochi Municipal Corporation a ...

. Smith (1895) pointed out that the original locality indication of ''Nassodonta insignis'' was “Peiho river, China”, and stated that on the label accompanying the type is written “Peihoi, fresh water, Calvert, with genus ''Velorita''”. Smith further pointed out that the genus ''Velorita'' ('' Villorita cyprinoides'', Gray, 1825) occurs only on the west side of the Indian Peninsula, in the neighbourhood of Cochin, and in the estuary of the river Kundapur, (where it is largely eaten by natives), and that it has never been found in China, and that “Peihoi” could be some small village on the Malabar coast. The present study suggests that ''“Peiho river”'' may be ''“Periyar'' river''”_.'' the largest river in the south west coast of India that feeds Cochin (Kochi) backwaters.

Description

Shell up to 12.0mm in length, ovate and solid, some specimens broader than others, teleconch of only 3-3 ½ convex whorls, protoconch of 1 ½ embryonic whorls, partly macroscopically axially striate; shell smooth except for very fine axial growth lines and a heavy, flattish spiral cord at base of body whorl. Aperture moderately narrow, outerlip thickened but not strongly variced, interior with 4-5 denticles decreasing in size anteriorly. Columella concave and with a moderately broad and thick callus, a strong fold at the anterior end and occasionally with another weak plication; siphonal notch deep and broad, parietal denticle swollen, anal canal distinct. Color fawn to brown, last whorl decorated with a moderately broad, interrupted brown subsutural band and a broad dark brown band on the posterior half. Aperture white but occasionally stained with brown. Smith (1895) correctly transferred the species from the

Buccinidae The Buccinidae are a very large and diverse taxonomic family of large sea snails, often known as whelks or true whelks.Bouchet, P.; Gofas, S. (2010). Buccinidae. In: Bouchet, P.; Gofas, S.; Rosenberg, G. (2010) World Marine Mollusca database. A ...

to the Nassariidae, based on the presence of multicuspidate rachidian tooth of radula. Operculum thick, roundish, exceptional for the family

, two vertical teeth.

References

{{Taxonbar, from=Q41008084 Nassariidae Gastropods described in 1867