Helophis schoutedeni
| Helophis schoutedeni | ||||||||||||
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| Systematics | ||||||||||||
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| Scientific name of the genus | ||||||||||||
| Helophis | ||||||||||||
| de Witte & Laurent , 1942 | ||||||||||||
| Scientific name of the species | ||||||||||||
| Helophis schoutedeni | ||||||||||||
| ( de Witte , 1922) |
Helophis schoutedeni is a snake from the family of snakes . It is the only species in the genus Helophis . This genus cannot currently beassigned toany subfamily .
distribution
Helophis schoutedeni is common in the Democratic Republic of the Congo and in the Republic of the Congo in the catchment area of the Congo River.
The nine known sites (Tondu, Kinshasa , Kwamouth, Bokoro, Bamania, Boteka, Wafanya, Boende, Bumba) are all in the area of the Eastern Congo swamp forests.
features
The maximum head-trunk length of Helophis schoutedeni is 482 mm in males and 655 mm in females, the maximum tail length in males 100 mm and in females 102 mm. Females therefore have relatively shorter tails than males ( sexual dimorphism ).
The head is short and hardly separates from the trunk. The eyes are small, the pupils are, typical of snakes , round. There are 16 to 17 small teeth on the upper jaw. All teeth are the same size, have the same shape and are evenly distributed in the jaw. The trunk is cylindrical and strongly built. The tail is short, cylindrical, and tapers to a clearly pointed end. The upper side of the body is colored vividly maroon and shows large black spots, often arranged in transverse bands. The abdomen is colored black.
Scaling
The scales on the top of the body are clearly keeled. The genus Helophis has 23 rows of dorsal scales in the middle of the body . The 153 to 180 ventral scales in males and 156 to 169 in females are unkeeled. The anal shield is divided. This is followed by subcaudalia, usually in pairs, in males 38 to 59 and in switches 36 to 46 . Only in the rearmost area can some subcaudalia be unpaired.
The head shields of Helophis schoutedeni are dark red, the seams between them appear black. The rostral shield is small, rounded, and wider than it is long. A narrow part of it is just visible from above. The internasalia form two right triangles. The seam between the two is slightly deeper than that between the two prefrontalia. The latter are also wider than long. The frontal shield (frontal) is significantly longer than it is wide and a little longer than its distance from the tip of the snout. The two parietals are long and wide, together they are wider than long. The seam between them is only slightly shorter than the forehead shield. The nostrils point upwards, they lie between the two nasalia , the prenasal and the postnasal , which is shorter in Helophis schoutedeni .
Similar species
Helophis schoutedeni differs significantly from all other adders and was therefore placed in its own genus from the start. It comes closest to the Hydraethiops melanogaster from the subfamily of water snakes, which occurs in the same Central African distribution area . It differs from it in the larger number of teeth on the upper jaw and in its nostrils located between two head shields.
Research history
Little is known about the way of life, distribution and relationships of this snake species, as only four specimens were scientifically examined between 1921 and 2012. There were no photos of living specimens up to this point. During an expedition to the Democratic Republic of the Congo in June / July 2012, a single individual was caught in Kinshasa near the Congo River. During the handling, the snake showed a calm behavior with no defensive reactions, but it tried to escape. Thus the first photos of a living specimen could be taken.
Additional specimens were also discovered in the herpetological collection of the Royal Museum for Central Africa (RMCA), four of which were collected in the 1950s and 1960s, and another 32 specimens in the 1980s. As a result, new information on species diagnosis and distribution could be obtained.
Molecular genetic studies are missing, so that Helophis schoutedeni could not be classified in any of the numerous subfamilies of the adder.
Taxonomy
The Belgian herpetologist Gaston-François de Witte first described the snake in 1922 under the name Pelophis schoetedeni . 20 years later de Witte had to change the generic name because there was already the generic name Pelophis Fitzinger , in 1843, for some species of the water snake.
The species name was chosen by de Witte in honor of the Belgian zoologist Henri Schouteden , who discovered two specimens of this snake in what was then the Belgian Congo in 1921 .
Individual evidence
- ↑ a b c d e f g Zoltán T. Nagy, Vázlav Gvoždík, Danny Meirte, Marcel Collet & Olivier SG Pauwels: New data on the morphology and distribution of the enigmatic Schouteden's sun snake, Helophis schoutedeni (de Witte, 1922) from the Congo Basin. Zootaxa, 3755, 1, pp. 96-100, 2014
- ^ World Wildlife Fund: Eastern Congolian swamp forests . The Encyclopedia of Earth, 2012. Available from: http://www.eoearth.org/view/article/151901
- ↑ a b c Gaston-François de Witte: Description d'un ophidien nouveau récolté au Congo par le Dr. Schouteden . Revue de Zoologie Africaine, 10, 2, pp. 318-319, 1922
- ^ Gaston-François de Witte: Contribution à la Faune Herpétologique du Congo belge . Revue de zoologie et de botanique africaines, 36, 2, pp. 101-115, 1942
literature
- Gaston-François de Witte: Description d'un ophidien nouveau récolté au Congo par le Dr. Schouteden . Revue de Zoologie Africaine, 10, 2, pp. 318-319, 1922 (first description, scan ).
- Gaston-François de Witte & R. Laurent: Contribution à la Faune Herpétologique du Congo belge . Revue de zoologie et de botanique africaines, 36, 2, pp. 101–115, 1942 (renaming of the genus)
- Zoltán T. Nagy, Vázlav Gvoždík, Danny Meirte, Marcel Collet & Olivier SG Pauwels: New data on the morphology and distribution of the enigmatic Schouteden's sun snake, Helophis schoutedeni (de Witte, 1922) from the Congo Basin. Zootaxa, 3755, 1, pp. 96-100, 2014