''Gemmula hastula'' is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

sea snail Sea snail is a common name for slow-moving marine gastropod molluscs, usually with visible external shells, such as whelk or abalone. They share the taxonomic class Gastropoda with slugs, which are distinguished from snails primarily by the ...

, a marine

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 Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Turridae Turridae is a taxonomic family name for a number of predatory sea snails, marine gastropod mollusks in the superfamily Conoidea. MolluscaBase (2018). Turridae H. Adams & A. Adams, 1853 (1838). Accessed through: World Register of Marine Specie ...

, the turrids.

Description

The length of the shell varies between 25 mm and 39 mm. (Original description by Reeve) The small and slender has an elongate-fusiform shape with a long, almost straight

siphonal canal The siphonal canal is an anatomical feature of the shells of certain groups of sea snails within the clade Neogastropoda. Some sea marine gastropods have a soft tubular anterior extension of the mantle called a siphon through which water is ...

. This species is chiefly characterized by the stout double ridge that encircles each whorl near the suture, and by the central ridge that is formed in place of the slit as the shell advances in growth. The whitish shell is axially marked and diffused with yellowish-brown spots. (Description by Melvill) An elegant tornate species, with produced siphonal canal, and spiral ribbing somewhat similar to that of '' Tomopleura nivea'' (Philippi, 1851), but more regular. The shell is white, tinted yellowish around the upper double carinae of each whorl. Just below the sutures these carinae are spirally deeply punctulate, an item omitted in the original description. As regards the nuclear whorls, the first two are vitreous, globular, smooth, and shining, the two next, also vitreous, but spirally nodulous. Melvill J.C., 1917. A revision of the Turridae (Pleurotomidae) occurring in the Persian Gulf, Gulf of Oman and north Arabian Sea as evidenced mostly through the results of dredgings carried out by Mr F. W. Townsend, 1893~1914. Proc. Malac. Soc. Lond. 12: 140-201, pls. 8-10

Distribution

This marine species occurs in the

Persian Gulf The Persian Gulf ( fa, خلیج فارس, translit=xalij-e fârs, lit=Gulf of Persis, Fars, ), sometimes called the ( ar, اَلْخَلِيْجُ ٱلْعَرَبِيُّ, Al-Khalīj al-ˁArabī), is a Mediterranean sea (oceanography), me ...

, the

Arabian Sea The Arabian Sea ( ar, اَلْبَحرْ ٱلْعَرَبِيُّ, Al-Bahr al-ˁArabī) is a region of the northern Indian Ocean bounded on the north by Pakistan, Iran and the Gulf of Oman, on the west by the Gulf of Aden, Guardafui Channel ...

and off the

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 ...

References

External links

Gastropods.com: ''Gemmula (Unedogemmula) hastula''

Tucker, J.K. 2004 ''Catalog of recent and fossil turrids (Mollusca: Gastropoda)''. Zootaxa 682:1-1295
{{DEFAULTSORT:Gemmula Hastula

hastula ''Hastula'' is a genus of sea snails, marine gastropod mollusks in the family Terebridae, the auger snails. Distribution Species in this genus can be found in the Indo-Pacific Region, Australia and Tasmania. Habitat and feeding habits These are ...

Gastropods described in 1843