Anderson's stream snake (''Opisthotropis andersonii''), also known commonly as Anderson's mountain keelback,Beolens, Bo; Watkins, Michael; Grayson, Michael (2011). ''The Eponym Dictionary of Reptiles''. Baltimore: Johns Hopkins University Press. xiii + 296 pp. . (''Opisthotropis andersonii'', p. 8; ''O. maxwelli'', p. 171). is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

snake Snakes are elongated limbless reptiles of the suborder Serpentes (). Cladistically squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales much like other members of the group. Many species of snakes have s ...

in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Colubridae Colubridae (, commonly known as colubrids , from , 'snake') is a family of snakes. With 249 genera, it is the largest snake family. The earliest fossil species of the family date back to the Late Eocene epoch, with earlier origins suspected. C ...

. The species is native to

Asia Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which ...

Etymology

The

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

, ''andersonii'', is in honor of Scottish herpetologist

John Anderson John Anderson may refer to: Arts and entertainment Music * John Anderson (jazz trumpeter) (1921–1974), American musician * Jon Anderson (John Roy Anderson, born 1944), lead singer of the British band Yes * John Anderson (producer) (1948–2024 ...

Geographic range

''O. andersonii'' is found in

Hong Kong Hong Kong)., Legally Hong Kong, China in international treaties and organizations. is a special administrative region of China. With 7.5 million residents in a territory, Hong Kong is the fourth most densely populated region in the wor ...

and

Vietnam Vietnam, officially the Socialist Republic of Vietnam (SRV), is a country at the eastern edge of mainland Southeast Asia, with an area of about and a population of over 100 million, making it the world's List of countries and depende ...

. www.reptile-database.org.

Habitat

The preferred natural

habitat In ecology, habitat refers to the array of resources, biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species' habitat can be seen as the physical manifestation of its ...

s of ''O. andersonii'' are

forest A forest is an ecosystem characterized by a dense ecological community, community of trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, ...

and freshwater

wetlands A wetland is a distinct semi-aquatic ecosystem whose groundcovers are flooded or saturated in water, either permanently, for years or decades, or only seasonally. Flooding results in oxygen-poor ( anoxic) processes taking place, especially ...

, at altitudes of .

Description

Dorsally Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position provi ...

, ''O. andersonii'' is blackish olive. Ventrally it is whitish, except for the chin and lower labials which are brown. The snout is short, broad, and depressed. There is a single

prefrontal Prefrontal may refer to: *Prefrontal bone, a skull bone in some tetrapods *Prefrontal cortex, a region of the brain of a mammal *Prefrontal scales The prefrontal scales on snakes and other reptiles are the scales adjacent and anterior to the fr ...

, and only one pair of

chin shield Chin shields or chinshields, genials scales on a snake are scales found on the underside of the snake's head towards the anterior and touching the lower labial scales. Chin shields to the front of the snake (towards the snout) are called anterio ...

s. Boulenger GA (1893). ''Catalogue of the Snakes in the British Museum (Natural History). Volume I., Containing the Families Colubridæ ...'' London: Trustees of the British Museum (Natural History). (Taylor and Francis, printers). xiii + 448 pp. + Plates I–XXVIII. (''Opisthotropis andersonii'', new combination, p. 284 + Plate XVIII, figures 3, 3a, 3b, 3c). The

dorsal scales In snakes, the dorsal scales are the longitudinal series of plates that encircle the body, but do not include the ventral scales. Campbell JA, Lamar WW (2004). ''The Venomous Reptiles of the Western Hemisphere''. Ithaca and London: Comstock Publis ...

, which are arranged in 17 rows throughout the entire length of the body, are smooth on the neck, feebly keeled at midbody, and strongly keeled on the tail. Adults of ''O. andersonii'' have a total length (including tail) of . The tail is 15–20 % of the total length.

Reproduction

''O. andersonii'' is

oviparous Oviparous animals are animals that reproduce by depositing fertilized zygotes outside the body (i.e., by laying or spawning) in metabolically independent incubation organs known as eggs, which nurture the embryo into moving offsprings kno ...

Etymology

Geographic range

Habitat

Description

Reproduction

References

Further reading