Bothrolycus
Encyclopedia
Günther's Black Snake, Bothrolycus ater, is a species
of poorly-known colubrid
snake
endemic to central Africa. It is the only member
of the genus
, Bothrolycus. This snake is notable as one of the few snakes with notable sexual dimorphism
(males have 17 scale-rows, females have 19), as well as possessing a small pit anterior to the eye. While superficially similar to the thermal pits of vipers, the function remains unknown.
, Equatorial Guinea
, Gabon
and the Democratic Republic of Congo (Zaire).
Dorsally blackish brown. Head paler. Lips and chin with a few whitish, black-edged dots. Ventrally pale brown, with whitish dots or short streaks.
Adult females may attain a total length of 46 cm (18 inches), with a tail 4 cm (1½ inch) long.
Females: Dorsal scales smooth, arranged in 19 rows. Ventrals 147-148; anal plate entire; subcaudals 18-22, divided.
Males: Smooth dorsal scales in 17 rows. Anal plate entire; subcaudals divided.
Snout projecting, obliquely truncate; loreal region vertical. Rostral slightly broader than high, not visible from above. Internasals much shorter than the prefrontals. Frontal 1½ times as long as broad, as long as its distance from the end of the snout, as long as the parietals. Loreal elongate, entering the eye. Two postoculars. Temporals 1+2. Seven upper labials, third, fourth, and fifth entering the eye. Four lower labials in contact with the anterior chin shield. Two pairs of chin shields, the anterior pair as long as or slightly longer than the posterior pair.
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 poorly-known colubrid
Colubrid
A colubrid is a member of the snake family Colubridae. This broad classification of snakes includes about two-thirds of all snake species on earth. The earliest species of the snake family date back to the Oligocene epoch. With 304 genera and 1,938 species, Colubridae is the largest snake family...
snake
Snake
Snakes are elongate, legless, carnivorous reptiles of the suborder Serpentes that can be distinguished from legless lizards by their lack of eyelids and external ears. Like all squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales...
endemic to central Africa. It is the only member
Monotypic
In biology, a monotypic taxon is a taxonomic group with only one biological type. The term's usage differs slightly between botany and zoology. The term monotypic has a separate use in conservation biology, monotypic habitat, regarding species habitat conversion eliminating biodiversity and...
of the genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
, Bothrolycus. This snake is notable as one of the few snakes with notable sexual dimorphism
Sexual dimorphism
Sexual dimorphism is a phenotypic difference between males and females of the same species. Examples of such differences include differences in morphology, ornamentation, and behavior.-Examples:-Ornamentation / coloration:...
(males have 17 scale-rows, females have 19), as well as possessing a small pit anterior to the eye. While superficially similar to the thermal pits of vipers, the function remains unknown.
Geographic range
It is found in CameroonCameroon
Cameroon, officially the Republic of Cameroon , is a country in west Central Africa. It is bordered by Nigeria to the west; Chad to the northeast; the Central African Republic to the east; and Equatorial Guinea, Gabon, and the Republic of the Congo to the south. Cameroon's coastline lies on the...
, Equatorial Guinea
Equatorial Guinea
Equatorial Guinea, officially the Republic of Equatorial Guinea where the capital Malabo is situated.Annobón is the southernmost island of Equatorial Guinea and is situated just south of the equator. Bioko island is the northernmost point of Equatorial Guinea. Between the two islands and to the...
, Gabon
Gabon
Gabon , officially the Gabonese Republic is a state in west central Africa sharing borders with Equatorial Guinea to the northwest, Cameroon to the north, and with the Republic of the Congo curving around the east and south. The Gulf of Guinea, an arm of the Atlantic Ocean is to the west...
and the Democratic Republic of Congo (Zaire).
Description
Maxillary teeth 20, forming a continuous series, the six anterior teeth strongly enlarged. Anterior mandibular teeth strongly enlarged. Head distinct from neck. Eye rather small, with round pupil. Loreal region deeply concave, the pit entering the eye. Body short, cylindrical; tail very short. Dorsal scales smooth, without apical pits, in 19 [or 17] rows. Ventrals rounded; subcaudals in two rows. Vertebral column with hypapophyses developed throughout.Dorsally blackish brown. Head paler. Lips and chin with a few whitish, black-edged dots. Ventrally pale brown, with whitish dots or short streaks.
Adult females may attain a total length of 46 cm (18 inches), with a tail 4 cm (1½ inch) long.
Females: Dorsal scales smooth, arranged in 19 rows. Ventrals 147-148; anal plate entire; subcaudals 18-22, divided.
Males: Smooth dorsal scales in 17 rows. Anal plate entire; subcaudals divided.
Snout projecting, obliquely truncate; loreal region vertical. Rostral slightly broader than high, not visible from above. Internasals much shorter than the prefrontals. Frontal 1½ times as long as broad, as long as its distance from the end of the snout, as long as the parietals. Loreal elongate, entering the eye. Two postoculars. Temporals 1+2. Seven upper labials, third, fourth, and fifth entering the eye. Four lower labials in contact with the anterior chin shield. Two pairs of chin shields, the anterior pair as long as or slightly longer than the posterior pair.