Iwasaki's snail-eater (''Pareas iwasakii'') is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

snake Snakes are elongated, Limbless vertebrate, limbless, carnivore, carnivorous reptiles of the suborder Serpentes . Like all other Squamata, squamates, snakes are ectothermic, amniote vertebrates covered in overlapping Scale (zoology), scales. Ma ...

in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Pareidae Pareidae is a small family of snakes found largely in southeast Asia, with an isolated subfamily endemic to southwestern India. It encompasses 42 species in four genera divided into two subfamilies: Pareinae and Xylophiinae. Both families are tho ...

. The species is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to the

Yaeyama Islands The Yaeyama Islands (八重山列島 ''Yaeyama-rettō'', also 八重山諸島 ''Yaeyama-shotō'', Yaeyama: ''Yaima'', Yonaguni: ''Daama'', Okinawan: ''Yeema'', Northern Ryukyuan: ''Yapema'') are an archipelago in the southwest of Okinawa ...

in the southern

Ryukyu Islands The , also known as the or the , are a chain of Japanese islands that stretch southwest from Kyushu to Taiwan: the Ōsumi, Tokara, Amami, Okinawa, and Sakishima Islands (further divided into the Miyako and Yaeyama Islands), with Yonaguni ...

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

Etymology

The specific name, ''iwasakii'', is in honor of

Japanese Japanese may refer to: * Something from or related to Japan, an island country in East Asia * Japanese language, spoken mainly in Japan * Japanese people, the ethnic group that identifies with Japan through ancestry or culture ** Japanese diaspor ...

meteorologist A meteorologist is a scientist who studies and works in the field of meteorology aiming to understand or predict Earth's atmospheric phenomena including the weather. Those who study meteorological phenomena are meteorologists in research, while t ...

Takuji Iwasaki.

Ecology

''Pareas iwasakii'' is a snail-eating specialist; even newly hatched individuals feed on snails. It has asymmetric jaws, with more teeth on the right (about 25 teeth compared to 15 teeth on the left) which facilitates feeding on snails with dextral (clockwise coiled) shells. A consequence of this asymmetry is that ''Pareas iwasakii'' is much less adept at preying on sinistral (counterclockwise coiled) snails. It systematically directs its attack on snails from the right in order to insert its lower jaw into the shell opening. The selection pressure of this predator on snails of the genus

Satsuma Satsuma may refer to: * Satsuma (fruit), a citrus fruit * ''Satsuma'' (gastropod), a genus of land snails Places Japan * Satsuma, Kagoshima, a Japanese town * Satsuma District, Kagoshima, a district in Kagoshima Prefecture * Satsuma Domain, a sou ...

(en) has led to a significant increase in the proportion of snails with left-facing shells, known as levogyres, compared to snails with right-facing shells, known as dextrogyres, because the two forms have difficulty mating with each other. This proportion is a local originality, the levorotatory form being very rare on a worldwide scale.

Taxonomy

Originally described as ''Amblycephalus formosensis iwasakii'' by Moichirō Maki, it is currently placed in the genus ''

Pareas ''Pareas'' is a genus of Asian snakes in the family Pareidae. All species in the genus ''Pareas'' are harmless to humans. Species ''Pareas'' contains the following species: (''Pareas menglaensis'', new species). (''Pareas kaduri'', new species) ...

''.

Etymology

Ecology

Taxonomy

References

Further reading