Amphibulima browni
Encyclopedia
Amphibulima browni is a species
of air-breathing land snail
, a terrestrial
pulmonate gastropod mollusk in the family Orthalicidae
.
This rare tropical land snail is endemic to the West Indian island of Dominica
. The snail has been seen only very rarely since it was first discovered in the late 19th century, and it may eventually be listed as an endangered species
. The shell
of this snail is oblong and thin, but not fragile, and it has a large aperture
.
The status of this species, which is one of three species of Amphibulima on Dominica, has been somewhat doubtful for a long period, since this taxon has not been reported since its original description. The collection of a few live specimens during the recent surveys in the 2000s confirmed its presence, and although it appears rare, it seems to be less restricted in distribution than Amphibulima pardalina
.
Amphibulima browni is likely to meet the IUCN-criteria for listing as Endangered species
.
in 1899.
The shell
is oblong, thin, but not elastic or fragile, corneous-olivaceous, with numerous irregularly scattered reddish dots. The surface is somewhat wrinkled with growth-striae and showing numerous very low but coarse irregular spirals. The shell has 2½ whorls
. The apex
is decidedly raised. The suture of the last half whorl is rapidly descending. The spire
is rather slender and its length contained from 4½ to 4¾ times in that of the shell.
The aperture
is large, irregularly oblong. The outer lip is somewhat blunt, strongly arcuate above, retracted or waved backward at the position of the slight "shoulder" and somewhat effuse below. The columella is arcuate and thin.
The height of the shell is from 18.5 to 19 mm. The width of the shell is from 10 to 10.5 mm. The height of the aperture is 14.7–15 mm. The height of the spire is 3.8-4.3 mm.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of air-breathing land snail
Land snail
A land snail is any of the many species of snail that live on land, as opposed to those that live in salt water and fresh water. Land snails are terrestrial gastropod mollusks that have shells, It is not always an easy matter to say which species are terrestrial, because some are more or less...
, a terrestrial
Terrestrial animal
Terrestrial animals are animals that live predominantly or entirely on land , as compared with aquatic animals, which live predominantly or entirely in the water , or amphibians, which rely on a combination of aquatic and terrestrial habitats...
pulmonate gastropod mollusk in the family Orthalicidae
Orthalicidae
Orthalicidae are a family of tropical air-breathing land snails, terrestrial pulmonate gastropod mollusks are classified in the informal group Sigmurethra of the clade Stylommatophora...
.
This rare tropical land snail is endemic to the West Indian island of Dominica
Dominica
Dominica , officially the Commonwealth of Dominica, is an island nation in the Lesser Antilles region of the Caribbean Sea, south-southeast of Guadeloupe and northwest of Martinique. Its size is and the highest point in the country is Morne Diablotins, which has an elevation of . The Commonwealth...
. The snail has been seen only very rarely since it was first discovered in the late 19th century, and it may eventually be listed as an endangered species
Endangered species
An endangered species is a population of organisms which is at risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters...
. The shell
Gastropod shell
The gastropod shell is a shell which is part of the body of a gastropod or snail, one kind of mollusc. The gastropod shell is an external skeleton or exoskeleton, which serves not only for muscle attachment, but also for protection from predators and from mechanical damage...
of this snail is oblong and thin, but not fragile, and it has a large aperture
Aperture (mollusc)
The aperture is an opening in certain kinds of mollusc shells: it is the main opening of the shell, where part of the body of the animal emerges for locomotion, feeding, etc....
.
Distribution
Amphibulima browni is endemic to the West Indian island of Dominica. The type locality is Dominica, the altitude 330 m, "on bananas".The status of this species, which is one of three species of Amphibulima on Dominica, has been somewhat doubtful for a long period, since this taxon has not been reported since its original description. The collection of a few live specimens during the recent surveys in the 2000s confirmed its presence, and although it appears rare, it seems to be less restricted in distribution than Amphibulima pardalina
Amphibulima pardalina
Amphibulima pardalina is a species of tropical air-breathing land snail, a pulmonate gastropod mollusk in the subfamily Amphibuliminae.- Distribution :Amphibulima pardalina is endemic to Dominica...
.
Amphibulima browni is likely to meet the IUCN-criteria for listing as Endangered species
Endangered species
An endangered species is a population of organisms which is at risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters...
.
Description
Amphibulima browni was firstly collected by biologist A. D. Brown and it was originally described by an American malacologist Henry Augustus PilsbryHenry Augustus Pilsbry
Henry Augustus Pilsbry was an American biologist, malacologist and carcinologist, among other areas of study. He was a dominant presence in many fields of invertebrate taxonomy for the better part of a century...
in 1899.
The shell
Gastropod shell
The gastropod shell is a shell which is part of the body of a gastropod or snail, one kind of mollusc. The gastropod shell is an external skeleton or exoskeleton, which serves not only for muscle attachment, but also for protection from predators and from mechanical damage...
is oblong, thin, but not elastic or fragile, corneous-olivaceous, with numerous irregularly scattered reddish dots. The surface is somewhat wrinkled with growth-striae and showing numerous very low but coarse irregular spirals. The shell has 2½ whorls
Whorl (mollusc)
A whorl is a single, complete 360° revolution or turn in the spiral growth of a mollusc shell. A spiral configuration of the shell is found in of numerous gastropods, but it is also found in shelled cephalopods including Nautilus, Spirula and the large extinct subclass of cephalopods known as the...
. The apex
Apex (mollusc)
Apex is an anatomical term for the tip of the mollusc shell of a gastropod, scaphopod, or cephalopod mollusc.-Gastropods:The word "apex" is most often used to mean the tip of the spire of the shell of a gastropod...
is decidedly raised. The suture of the last half whorl is rapidly descending. The spire
Spire (mollusc)
A spire is a descriptive term for part of the coiled shell of mollusks. The word is a convenient aid in describing shells, but it does not refer to a very precise part of shell anatomy: the spire consists of all of the whorls except for the body whorl...
is rather slender and its length contained from 4½ to 4¾ times in that of the shell.
The aperture
Aperture (mollusc)
The aperture is an opening in certain kinds of mollusc shells: it is the main opening of the shell, where part of the body of the animal emerges for locomotion, feeding, etc....
is large, irregularly oblong. The outer lip is somewhat blunt, strongly arcuate above, retracted or waved backward at the position of the slight "shoulder" and somewhat effuse below. The columella is arcuate and thin.
The height of the shell is from 18.5 to 19 mm. The width of the shell is from 10 to 10.5 mm. The height of the aperture is 14.7–15 mm. The height of the spire is 3.8-4.3 mm.