Amphidromus perversus
Encyclopedia
Amphidromus perversus is a species
of air-breathing land snail
, a terrestrial
pulmonate gastropod mollusk in the family Camaenidae
.
Amphidromus perversus is the type species
of the genus Amphidromus, by the subsequent designation of Eduard von Martens
(1860).
and Java
to Borneo
, Sulawesi
and Bali
.
Absent from the Mentawi Chain and Panaitan Island. Its occurrence on Sumbawa
needs confirmation. Probably it has been introduced into Singapore
. Subspecies recognized here are from Great Natuna, Bawean
, Kangean Islands
and Riau Islands.
In Amphidromus perversus and most other thick-shelled Amphidromus species, the lip is internally thickened, forms a "roll" in its expansion, and has a very heavy parietal callus
.
The shell is solid, polished, amphidromine, moderately large (45-55 mm) high, usually with a dark varix. Lip and callus white; ground color white, orange, yellow, or yellowish-green. Many specimens with interrupted or continuous radial brownish streaks covering part or all of the whorls on the lower spire and body whorl
.
Amphidromus perversus undoubtedly offers the greatest array of discretely variable color combinations of any species of Amphidromus.
Color variation of Amphidromus perversus perversus include 12 forms:
. Collected by Hoogerwerf on August 20, 1954.
Description: A brilliantly colored series of populations with highly polished shell surface. The general intensity of the coloration and the strong polish are the only features separating this race from the other subspecies.
Remarks: The problem of how to treat insular populations which show minor divergence from the main stocks is far from being satisfactorily settled. The intense coloration of the Kangean populations shows a minor difference from the main populations and Laidlaw & Solem (1961) have recognized it with a subspecific name. For purposes of future reference, we they selected as holotype a shell with a color pattern
quite distinct from any which have been named. Thus, the name butoti can at least be used for the color variation if it is decided to include the Kangean populations in the nominate form of perversus. Besides the nominate color pattern of butoti, shells referable to the infraviridis, infrapictus, rufocinctus, sultanus and typical perversus pattern were seen on Kangean Island.
Paratypes: Specimens were seen from several localities on Kangean Island. The shells from Sepandjang are in Chicago Natural History Museum, no. 97808, in the Zoological Museum in Amsterdam, and in Butot
; Djukung specimens are in the Zoological Museum in Amsterdam; and topotypes from Bajutan are in Chicago Natural History Museum, no. 97806, and in Butot and the Zoologisch Museum, Amsterdam, Some additional material from Kangean Island (USNM 468416, Paravicini!) was seen after the description had been written.
Remarks: The shell is white with rather numerous brown flammulations that become confluent on the base, elongate, and quite slender. Apparently it is a white derivative from the interruptus stock, which may have a definite geographic separation in Bali and Java. Material from Kedewan, East Java (Butot, Chicago Natural History Museum 72404) ranged from 43.5 to 48 mm in height.
near Singapore and possibly Perak
and Biliton Island off Borneo.
Remarks: The purple apex
, the numerous wavy brown flammulations that are partially interrupted by a yellow peripheral color band, and the solid shell are characteristic. This variety is similar to sultanus, but has only partial interruption of the stripes by the color band and has the purple apex. The Biliton record from the early Samarang voyage is questionable, and it is quite possible that the Perak records of De Morgan are in error. The only certain localities are the Singapore area and Riau Archipelago.
The yellow peripheral band of melanomma is absent; otherwise this is close to the Riau population. Amphidromus perversus natunensis is quite variable in color, ranging from white to dark (see Pilsbry 1900, pp. 162-163). Possibly some of the material that Jacobi (1895) dissected under the names Amphidromus interruptus and Amphidromus chloris belongs here, but the shells were not figured and their location is unknown. The South Natuna Island record needs confirmation, while specimens from Siantan, Anamba Islands (CNHM 72427), are referred by Laidlaw & Solem (1961) with some hesitation.
.
This weakly characterized race differs primarily by its intense color, strong color zone, and slight white margin at the suture. Of seventeen shells collected in May, 1954, by Hoogerwerf at Telaga Kastoba, Bawean Island, ten were dextral and seven sinistral. Three lacked a varix, one was grass green in color, three were whitish, and thirteen had yellow ground color. The name sankapurus Fruhstorfer, 1905, refers to white shells with a very dark color band. This variation is similar to Amphidromus perversus butoti.
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 Camaenidae
Camaenidae
Camaenidae is a family of air-breathing land snails, terrestrial pulmonate gastropod mollusks in the superfamily Helicoidea.This is one of the most diverse families in the clade Stylommatophora....
.
Amphidromus perversus is the type species
Type species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...
of the genus Amphidromus, by the subsequent designation of Eduard von Martens
Eduard von Martens
Eduard von Martens sometimes known as Carl or Karl Eduard von Martens, was a German zoologist.Born in Stuttgart in 1831, von Martens attended universities in Tübingen, Stuttgart and Munich, graduating from the University of Tübingen in 1855. In 1860, he set off as part of an expedition to the Far...
(1860).
Subspecies
There are six subspecies of Amphidromus perversus:- Amphidromus perversus perversus (Linnaeus, 1758)
- Amphidromus perversus butoti Laidlaw & Solem, 1961
- Amphidromus perversus emaciatus (von Martens, 1867)
- Amphidromus perversus melanomma (Pfeiffer, 1852)
- Amphidromus perversus natunensis Fulton, 1896
- Amphidromus perversus rufocinctus Fruhstorfer, 1905
Distribution
Distribution of Amphidromus perversus include SumatraSumatra
Sumatra is an island in western Indonesia, westernmost of the Sunda Islands. It is the largest island entirely in Indonesia , and the sixth largest island in the world at 473,481 km2 with a population of 50,365,538...
and Java
Java
Java is an island of Indonesia. With a population of 135 million , it is the world's most populous island, and one of the most densely populated regions in the world. It is home to 60% of Indonesia's population. The Indonesian capital city, Jakarta, is in west Java...
to Borneo
Borneo
Borneo is the third largest island in the world and is located north of Java Island, Indonesia, at the geographic centre of Maritime Southeast Asia....
, Sulawesi
Sulawesi
Sulawesi is one of the four larger Sunda Islands of Indonesia and is situated between Borneo and the Maluku Islands. In Indonesia, only Sumatra, Borneo, and Papua are larger in territory, and only Java and Sumatra have larger Indonesian populations.- Etymology :The Portuguese were the first to...
and Bali
Bali
Bali is an Indonesian island located in the westernmost end of the Lesser Sunda Islands, lying between Java to the west and Lombok to the east...
.
Absent from the Mentawi Chain and Panaitan Island. Its occurrence on Sumbawa
Sumbawa
Sumbawa is an Indonesian island, located in the middle of the Lesser Sunda Islands chain, with Lombok to the west, Flores to the east, and Sumba further to the southeast. It is in the province of West Nusa Tenggara....
needs confirmation. Probably it has been introduced into Singapore
Singapore
Singapore , officially the Republic of Singapore, is a Southeast Asian city-state off the southern tip of the Malay Peninsula, north of the equator. An island country made up of 63 islands, it is separated from Malaysia by the Straits of Johor to its north and from Indonesia's Riau Islands by the...
. Subspecies recognized here are from Great Natuna, Bawean
Bawean
Bawean is an island of Indonesia located approximately 150 km north of Surabaya in the Java Sea, off the coast of Java. It is administered by Gresik Regency of East Java province. It is approximately 15 km in diameter and is circumnavigated by a single narrow road. Bawean is dominated by...
, Kangean Islands
Kangean Islands
The Kangean Islands form an archipelago part of Indonesia, are located in the Java Sea approximately north of Bali and 120 km east of Madura Island. The islands are administratively a part of Sumenep Regency within East Java province.The largest island, at about 490 km², is Kangean Island...
and Riau Islands.
Shell description
Amphidromus perversus are amphidromine (left-handed and right-handed snails occur in the population).In Amphidromus perversus and most other thick-shelled Amphidromus species, the lip is internally thickened, forms a "roll" in its expansion, and has a very heavy parietal callus
Parietal callus
A parietal callus is a feature of the shell anatomy of some groups of snails, i.e. gastropods. It is a thickened calcareous deposit which may be present on the parietal wall of the aperture of the adult shell. The parietal wall is the margin of the aperture and part of the wall of the body whorl...
.
The shell is solid, polished, amphidromine, moderately large (45-55 mm) high, usually with a dark varix. Lip and callus white; ground color white, orange, yellow, or yellowish-green. Many specimens with interrupted or continuous radial brownish streaks covering part or all of the whorls on the lower spire and body whorl
Body whorl
Body whorl is part of the morphology of a coiled gastropod mollusk.- In gastropods :In gastropods, the body whorl, or last whorl, is the most recently-formed and largest whorl of a spiral or helical shell, terminating in the aperture...
.
Amphidromus perversus undoubtedly offers the greatest array of discretely variable color combinations of any species of Amphidromus.
Color variation of Amphidromus perversus perversus include 12 forms:
- Amphidromus perversus perversus f. aurea Dillwyn, 1817 (not Martyn, 1784), is usable for the orange-colored (instead of yellow) monochrome shells found on Java and Celebes. Apparently an individual variation.
- Amphidromus perversus perversus f. aureus Martyn, 1784 — It still have not been reported from a precise locality. It was based on three shells collected by Sir Joseph BanksJoseph BanksSir Joseph Banks, 1st Baronet, GCB, PRS was an English naturalist, botanist and patron of the natural sciences. He took part in Captain James Cook's first great voyage . Banks is credited with the introduction to the Western world of eucalyptus, acacia, mimosa and the genus named after him,...
, supposedly on Pulau Panaitan. The only Amphidromus found there, Amphidromus banksi Butot, is quite different and the actual locahty of aureus is still unknown. The shells have a wide, white zone below the suture as in the Amphidromus atricallosusAmphidromus atricallosusAmphidromus atricallosus is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Camaenidae.- Subspecies :* Amphidromus atricallosus atricallosus...
complex and the lower parts of the whorls are yellow, with or without narrow, wavy, reddish-brown flammulations. The original specimens in the Natural History MuseumNatural History MuseumThe Natural History Museum is one of three large museums on Exhibition Road, South Kensington, London, England . Its main frontage is on Cromwell Road...
appear to be a form of Amphidromus perversus, but the locality remains a mystery. Note: Martyn's work was invalidated by action of the International Commission on Zoological NomenclatureInternational Commission on Zoological NomenclatureThe International Commission on Zoological Nomenclature is an organization dedicated to "achieving stability and sense in the scientific naming of animals". Founded in 1895, it currently comprises 28 members from 20 countries, mainly practicing zoological taxonomists...
, varietal names are not accorded legal status and the use of aureus is as a convenient term of reference. - Amphidromus perversus perversus f. borneensis Pilsbry, 1900, is based on a stout variant of the interruptus pattern, whitish in background color, and rather similar to the Javanese subspecies, emaciatus. It was described from South Borneo in the Bandjermassin District (Chicago Natural History Museum 63377), but there are specimens in the NaturalisNaturalisNaturalis is the national natural history museum of the Netherlands, based in Leiden. It originated from the merger of the Rijksmuseum van Natuurlijke Historie and the Rijksmuseum van Geologie en Mineralogie in 1984. In 1986 it was decided that the museum had to become a public museum and a new...
, Leiden from East Borneo. The flammulations above the periphery are reduced in number. Possibly this may prove to be a subspecies, but not enough data are available. - Amphidromus perversus perversus f. infrapictus von Martens, 1867, was considered by Pilsbry (1900) to be identical with interruptus Müller, 1774. At best it might be considered a slightly different stage in an almost continuous series of variations.
- Amphidromus perversus perversus f. infraviridis von Martens, 1867, probably is a derivative of the Celebesian infrapictus. Instead of flammulations and a basal purplish zone it has a pale green or greenish-yellow base which is only slightly darker than the greenish-yellow or citron-colored spireSpire (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...
. It is most similar to typical perversus but differs in the darker basal portion. - Amphidromus perversus perversus f. interruptus Müller, 1774, has a purplish or brownish zone on the base, a yellow or whitish patch near the columella, and brownish flammulations that are somewhat interrupted on the periphery and do not reach the suture above.
- Amphidromus perversus perversus f. mitra von Martens, 1867, is an unfigured variety from Bali and seems to be intermediate between interruptus and sultanus.
- Amphidromus perversus perversus f. niveus P. & F. Sarasin, 1899 is snow-white with a black varix and black mark behind the peristome. It is an "albino" perversus which is common in the Celebes and sporadically seen from Java and Borneo.
- Amphidromus perversus perversus f. obesus von Martens, 1867, is an unfigured variety which probably can be equated with squat individuals of the typical perversus pattern.
- Amphidromus perversus perversus f. perversus Linnaeus, 1758, is a solid yellow shell with black varix and narrow black band behind the peristome. It is known from the whole range of the species.
- Amphidromus perversus perversus f. strigosus von Martens, 1867, has continuous, rather narrow, straight brown bands running from the suture to the bottom of the whorl. It is known from Bali, Borneo, and Celebes.
- Amphidromus perversus perversus f. sultanus Lamarck, 1822, has wavy brown bands running over the entire whorl. The bands are interrupted in the middle of the whorl by a narrow spiral band of the ground color. This variation is found in all parts of the species range.
Amphidromus perversus butoti
Holotype: Zoological Museum in Amsterdam. The type locality is Bajutan, Kangean IslandsKangean Islands
The Kangean Islands form an archipelago part of Indonesia, are located in the Java Sea approximately north of Bali and 120 km east of Madura Island. The islands are administratively a part of Sumenep Regency within East Java province.The largest island, at about 490 km², is Kangean Island...
. Collected by Hoogerwerf on August 20, 1954.
Description: A brilliantly colored series of populations with highly polished shell surface. The general intensity of the coloration and the strong polish are the only features separating this race from the other subspecies.
Remarks: The problem of how to treat insular populations which show minor divergence from the main stocks is far from being satisfactorily settled. The intense coloration of the Kangean populations shows a minor difference from the main populations and Laidlaw & Solem (1961) have recognized it with a subspecific name. For purposes of future reference, we they selected as holotype a shell with a color pattern
quite distinct from any which have been named. Thus, the name butoti can at least be used for the color variation if it is decided to include the Kangean populations in the nominate form of perversus. Besides the nominate color pattern of butoti, shells referable to the infraviridis, infrapictus, rufocinctus, sultanus and typical perversus pattern were seen on Kangean Island.
Paratypes: Specimens were seen from several localities on Kangean Island. The shells from Sepandjang are in Chicago Natural History Museum, no. 97808, in the Zoological Museum in Amsterdam, and in Butot
Butot
Butot is a commune in the Seine-Maritime department in the Haute-Normandie region in northern France.-Geography:A small farming village situated in the Pays de Caux some north of Rouen, at the junction of the D54 and the D467 roads.-Population:...
; Djukung specimens are in the Zoological Museum in Amsterdam; and topotypes from Bajutan are in Chicago Natural History Museum, no. 97806, and in Butot and the Zoologisch Museum, Amsterdam, Some additional material from Kangean Island (USNM 468416, Paravicini!) was seen after the description had been written.
Amphidromus perversus emaciatus
Range: Central and East Java, possibly Bali.Remarks: The shell is white with rather numerous brown flammulations that become confluent on the base, elongate, and quite slender. Apparently it is a white derivative from the interruptus stock, which may have a definite geographic separation in Bali and Java. Material from Kedewan, East Java (Butot, Chicago Natural History Museum 72404) ranged from 43.5 to 48 mm in height.
Amphidromus perversus melanomma
Range: Riau ArchipelagoRiau Archipelago
Not to be confused with Riau Islands Province, a province of Indonesia.The Riau Archipelago is the core group of islands within the Riau Islands Province in Indonesia, and located south of Singapore...
near Singapore and possibly Perak
Perak
Perak , one of the 13 states of Malaysia, is the second largest state in the Peninsular Malaysia bordering Kedah and Yala Province of Thailand to the north, Penang to the northwest, Kelantan and Pahang to the east, Selangor the Strait of Malacca to the south and west.Perak means silver in Malay...
and Biliton Island off Borneo.
Remarks: The purple 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...
, the numerous wavy brown flammulations that are partially interrupted by a yellow peripheral color band, and the solid shell are characteristic. This variety is similar to sultanus, but has only partial interruption of the stripes by the color band and has the purple apex. The Biliton record from the early Samarang voyage is questionable, and it is quite possible that the Perak records of De Morgan are in error. The only certain localities are the Singapore area and Riau Archipelago.
Amphidromus perversus natunensis
Range: Great Natuna Islands; possibly the South Natuna and Anamba Islands also.The yellow peripheral band of melanomma is absent; otherwise this is close to the Riau population. Amphidromus perversus natunensis is quite variable in color, ranging from white to dark (see Pilsbry 1900, pp. 162-163). Possibly some of the material that Jacobi (1895) dissected under the names Amphidromus interruptus and Amphidromus chloris belongs here, but the shells were not figured and their location is unknown. The South Natuna Island record needs confirmation, while specimens from Siantan, Anamba Islands (CNHM 72427), are referred by Laidlaw & Solem (1961) with some hesitation.
Amphidromus perversus rufocinctus
Range: Bawean Island, JavaJava
Java is an island of Indonesia. With a population of 135 million , it is the world's most populous island, and one of the most densely populated regions in the world. It is home to 60% of Indonesia's population. The Indonesian capital city, Jakarta, is in west Java...
.
This weakly characterized race differs primarily by its intense color, strong color zone, and slight white margin at the suture. Of seventeen shells collected in May, 1954, by Hoogerwerf at Telaga Kastoba, Bawean Island, ten were dextral and seven sinistral. Three lacked a varix, one was grass green in color, three were whitish, and thirteen had yellow ground color. The name sankapurus Fruhstorfer, 1905, refers to white shells with a very dark color band. This variation is similar to Amphidromus perversus butoti.
External links
- Amphidromus perversus natunensis at National Center for Biotechnology InformationNational Center for Biotechnology InformationThe National Center for Biotechnology Information is part of the United States National Library of Medicine , a branch of the National Institutes of Health. The NCBI is located in Bethesda, Maryland and was founded in 1988 through legislation sponsored by Senator Claude Pepper...
(NCBI) - photos of shells of Amphidromus perversus