''Bostryx fragilis'' is a species of tropical air-breathing

land snail A land snail is any of the numerous species of snail that live on land, as opposed to the sea snails and freshwater snails. ''Land snail'' is the common name for terrestrial gastropod mollusks that have shells (those without shells are known as ...

, a

pulmonate Pulmonata or pulmonates, is an informal group (previously an order, and before that a subclass) of snails and slugs characterized by the ability to breathe air, by virtue of having a pallial lung instead of a gill, or gills. The group includ ...

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 in the family Bulimulidae. The

specific epithet In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

''fragilis'' is from the Latin language and means "fragile", it refers to the thin shell.

Distribution

* Peru The type locality is Quebrada Santa Maria, 03°40’53’S 080°26’10’W, 25 m, Tumbes Region, Peru.

Description

''Bostryx fragilis'' is characterized by the whitish lines on the thin, translucent shell, the tawny-brownish upper whorls and the prominent last whorl. The shell up to 18.9 mm in height, two times as long as wide, narrowly perforate, elongate, with hardly convex sides and fragile. Colour is whitish on a translucent background, the upper whorls are becoming gradually tawny-brown towards the apex. The surface is slightly shining, the incrassate growth striae overlaid on the last whorls by whitish, low, axial costulae, which are partly forked and do not always cover the whole whorl, but may end in between the sutures or shell base. Upper whorls are with fine, interrupted spiral threads.

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 ...

is with wrinkles, mostly broken into granules and crossed by finely incised spiral lines. The shell has 6.8 whorls, that are hardly convex. The suture is slightly impressed. The aperture is elongate-subovate, 1.61 times as long as wide, 0.40 times the total height. Peristome is thin and simple. Columellar margin is nearly straight, very narrowly dilated above. The shell has 6.6-7.1 whorls. The width of the shell is 8.0-9.2 mm. The height of the shell is 16.9-18.9 mm. The width of the aperture is 4–5 mm. The height of the aperture is 6.6-8.2 mm. The height of the last whorl is 9.2-11.9 mm. The holotype has 6.8 whorls and dimensions of the holotype are as follows: The width of the shell is 8.7 mm. The height of the shell is 18.0 mm. The width of the aperture is 4.5 mm. The height of the aperture is 7.3 mm. The height of the last whorl is 11.3 mm. ''Bostryx fragilis'' is closely allied to ''

Bostryx juana ''Bostryx'' is a genus of air-breathing land snails, terrestrial pulmonate gastropod mollusks in the family Bulimulidae.Breure A. S. H. & Romero P. (2012). "Support and surprises: molecular phylogeny of the land snail superfamily Orthalicoidea u ...

'' (Cousin, 1887) from which it differs by (1) being smaller, (2) slightly more slender and (3) lacking the tawny-brown spiral bands. ''Bostryx fragilis'' further resembles ''

Bostryx alausiensis ''Bostryx'' is a genus of air-breathing land snails, terrestrial pulmonate gastropod mollusks in the family Bulimulidae.Breure A. S. H. & Romero P. (2012). "Support and surprises: molecular phylogeny of the land snail superfamily Orthalicoidea u ...

'' (Cousin, 1887), also described from southern Ecuador. It differs by being (1) smaller, (2) stouter, and (3) having a larger aperture. Finally, it may be compared to ''

Bostryx delicatulus ''Bostryx'' is a genus of air-breathing land snails, terrestrial pulmonate gastropod mollusks in the family Bulimulidae.Breure A. S. H. & Romero P. (2012). "Support and surprises: molecular phylogeny of the land snail superfamily Orthalicoidea ...

'' (Philippi, 1867) from which it differs by (1) being stouter, (2) the brownish upper whorls and (3) the simple peristome. There is a morphological resemblance between the species mentioned above and some ''

Bulimulus ''Bulimulus'' is a genus of small to medium-sized tropical or sub-tropical, air-breathing land snails, pulmonate gastropod mollusks in the subfamily Bulimulinae within the family Bulimulidae.Breure A. S. H. & Romero P. (2012). "Support and su ...

'' species occurring in the same region, e.g. ''

Bulimulus inconspicuus ''Drymaeus inconspicuus'' is a species of tropical air-breathing land snail, a pulmonate gastropod mollusk in the family Bulimulidae.MolluscaBase eds. (2020). MolluscaBase. Drymaeus inconspicuus (Haas, 1949). Accessed through: World Registe ...

'' Haas, 1949, both in general shell shape and - superficially - also in protoconch sculpture. The relationships and phylogeography of these two genera in this region warrant further study.

References

This article incorporates CC-BY-3.0 text from the reference {{Taxonbar, from=Q4948309 Bulimulidae Gastropods described in 2010