''Compsodrillia acestra'' is a species of

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 ...

mollusc 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 esti ...

in the family

Pseudomelatomidae Pseudomelatomidae is a family of predatory sea snails, marine gastropods included in the superfamily Conoidea (previously Conacea) and part of the Neogastropoda ( Bouchet & Rocroi, 2005). In 1995 Kantor elevated the subfamily Pseudomelatomina ...

, the turrids and allies.

Description

The length of the shell attains 19 mm, its diameter 5.5 mm. (Original description) The shell is long and slender. It has a pale olive-color with a translucent white tip. It contains 9 whorls, with a smooth vitreous rounded two-whorled

protoconch A protoconch (meaning first or earliest or original shell) is an embryonic or larval shell which occurs in some classes of molluscs, e.g., the initial chamber of an ammonite or the larval shell of a gastropod. In older texts it is also called ...

. The fasciole is wide, steep, excavated and marked with close-set fine even spirals.;It is bounded behind by a sharply cut elevated thread, a little space in front of the suture. The whorl in front of the fasciole is covered with close-set, strong, subequal, flattish spirals, with narrow channelled interspaces. These spirals, from two on the four apical whorls, increase to seven on the penultimate whorl, and eleven (behind those on the

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 ...

) on the b ody whorl. Here they are a little more widely separated, and have one or two intercalary fine threads in the interspaces. On the siphonal canal there are six primary threads alternating with somewhat smaller secondary ones. The transverse sculpture consists of gently elevated ribs (eight on the penultimate whorl), which vary in different specimens as to elevation and strength. In the type specimen figured they begin at the fasciole and fade on the base. The varix is strong and protrudes. There is a touch of livid color in front of it, which is seen nowhere else on the shell. The aperture is whitish. The throat is slightly livid, not lirate. The notch is deep and strong. The outer lip is thin, contracted for the siphonal canal. The inner lip shows a thin elevated callus. The columella is straight. The siphonal canal is rather short, and recurved.

Distribution

''C. acestra'' can be found off the

Florida Keys The Florida Keys are a coral cay archipelago located off the southern coast of Florida, forming the southernmost part of the continental United States. They begin at the southeastern coast of the Florida peninsula, about south of Miami, and e ...

, in the Gulf of Mexico, off the coast of Eastern Brazil.Tunnell, John W., Jr., Felder, Darryl L., & Earle, Sylvia A., eds. ''Gulf of Mexico Origin, Waters, and Biota, Volume 1: Biodiversity.'' Texas A&M University Press, 2009. 669.

References

* Absalão, R. S.; Pimenta, A. D. & Caetano, C. H. S. 2007. Turridae (Mollusca, Neogastropoda, Conoidea) coletados no litoral sudeste do Brasil, Programa REVIZEE "Score" Central. Biociências (On-line) 13: 19-47

External links

*
Rosenberg, G.; Moretzsohn, F.; García, E. F. (2009). Gastropoda (Mollusca) of the Gulf of Mexico, pp. 579–699 in: Felder, D.L. and D.K. Camp (eds.), Gulf of Mexico–Origins, Waters, and Biota. Texas A&M Press, College Station, Texas
{{DEFAULTSORT:Compsodrillia Acestra acestra Gastropods described in 1889