''Zeatrophon ambiguus''

common name In biology, a common name of a taxon or organism (also known as a vernacular name, English name, colloquial name, country name, popular name, or farmer's name) is a name that is based on the normal language of everyday life; and is often contrast ...

the large trophon, is a species of large predatory

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 Marine is an adjective meaning of or pertaining to the sea or ocean. Marine or marines may refer to: Ocean * Maritime (disambiguation) * Marine art * Marine biology * Marine debris * Marine habitats * Marine life * Marine pollution Military * ...

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 Muricidae, the rock snails or murex snails.Marshall, B.; Rosenberg, G. (2014). Zeatrophon ambiguus (Philippi, 1844). Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=598755 on 2015-01-08

Description

The length of the ashell attains 56 mm, its diameter, 31 mm. (Described as ''Trophon ambiguus'') The fusiform shell is not very thick, usually with an umbilical chink, turriculate, reticulated by spiral and axial ribs. The sculpture consists of two spiral ridges on the spire-whorls, the upper of which is on the carina of the whorls. The interstices show an occasional finer ridge. The

body whorl The body whorl is part of the morphology of the shell in those gastropod mollusks that possess a coiled shell. The term is also sometimes used in a similar way to describe the shell of a cephalopod mollusk. In gastropods In gastropods, the b ...

has numerous unequal spirals, some of which are usually more prominent than the others. There is a distinct fasciole along 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 ...

. The axial sculpture is formed by subequal sharp varices on the spire-whorls, very inequidistant and often almost obsolete on the body whorl. The points of intersection, especially on the carina of the whorls, are nodulous, or produced into short hollow spines. The colour of the shell is white or yellowish. Inside it is white, greenish, or light brown. The spire is conical, shorter than the aperture with the siphonal canal. The

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 ...

consists of 2J convex and smooth whorls, the nucleus is minute and rounded. Whorls 1 to 8 with a broad, flat, and but slightly sloping shoulder, lightly convex below it. The base is contracted towards the siphonal canal. The suture is not much impressed. The aperture is ovate, broadly angled above, produced below into a moderately long and open siphonal canal, which is recurved and bent to the left. The outer lip is usually thin and sharp, but in old specimens it is often much thickened inside. It is generally finely crenulated, but sometimes almost smooth. It is distinctly angled above, contracted on approaching the siphonal canal. The columella is vertical, somewhat excavated. Inner lip thin, extending a short distance beyond the columella, and has a well-defined margin. It forms a more or less thick callous layer on the concave parietal wall, and is narrowed below to a fine and sharp ridge. The fasciole is well defined and lamellar. The umbilical chink is mostly distinct. The operculum has the nucleus subapical. Dentition: The central tooth is transverse, with 5 cusps, of which the median and externals are much larger, but all 5 are united at the base. The laterals are angled and unicuspid. Suter H. (1913-1915), Manual of New Zealand Mollusca; Wellington, N. Z. :J. Mackay, govt. printer,1913-1915
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Distribution

This marine species is endemic to New Zealand.

References

* Fleming, C.A. (1943). Tertiary Mollusca from Dannevirke Subdivision. Transactions of the Royal Society of New Zealand. 73: 193–208. * * Powell A W B, ''New Zealand Mollusca'', William Collins Publishers Ltd, Auckland, New Zealand 1979

External links

Philippi, R. A. (1842-1850). Abbildungen und Beschreibungen neuer oder wenig gekannter Conchylien unter Mithülfe mehrerer deutscher Conchyliologen. Cassel, T. Fischer: Vol. 1: 1-20

Reeve, L. A. (1847-1848). Monograph of the genus Fusus. In: Conchologia Iconica, or, illustrations of the shells of molluscous animals, vol. 4, pls 1-21 and unpaginated text. L. Reeve & Co., London

Marwick, J. (1928). The Tertiary Mollusca of the Chatham Islands, including a generic review of the New Zealand Pectinidae. Transactions of the New Zealand Institute. 58: 431-506

Adams, H. & Adams, A. (1864). Descriptions of new species of shells, chiefly from the Cumingian collection. Proceedings of the Zoological Society of London. 1863: 428-435.

Spencer H.G., Willan R.C., Marshall B.A. & Murray T.J. (2011). Checklist of the Recent Mollusca Recorded from the New Zealand Exclusive Economic Zone.

Beu, A.G. 2011 Marine Molluscs of oxygen isotope stages of the last 2 million years in New Zealand. Part 4. Gastropoda (Ptenoglossa, Neogastropoda, Heterobranchia). Journal of the Royal Society of New Zealand 41, 1–153
{{Taxonbar, from=Q14525768 Pagodulinae Gastropods of New Zealand Gastropods described in 1844 Taxa named by Rodolfo Amando Philippi