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Tri color Hognose, Boicora' (Lystrophis matogrossensis)

SPECIES:

Lystrophis matogrossensis

SYNONYMS:

Heterodon semicinctus DUMÉRIL, BIBRON & DUMÉRIL 1854
Heterodon pulcher JAN 1863
Lystrophis semicinctus - BOULENGER 1894
Lystrophis semicinctus - CEI 1993

SUBSPECIES:

NONE

FAMILY:

Serpentes: Colubridae

DISTRIBUTION:

Restricted to Mato Grosso and Mato Grosso del sul, Brazil with the westernmost known locality in Caceres, Brazil. Recent discovery of a specimen in Sandoval, Santa Cruz, Bolivia.

COMMENT:

Synonymy after CEI 1993 (but see entry for L. pulcher).

As with its North American cousins, South American Lystrophis prefer sandy soils with shortgrass growth. All members of Lystrophis are burrowers and spend much of their time beneath the surface in search of lizards, toads and small reptile eggs.

DEFINITION:

Lystrophis matogrossensis differs from all other species in the genus by having several distinct characters. It is a small robust species with males ranging from 16 up to 24 inches snout to vent length. The species possesses a short, rounded tail and its head is small and not distinct from the neck.

The dorsal ring coloration forms a pattern of red, black, white, black, red; black rings total 9 to 15 pairs. The head is dorsally black with two white bands; the first follows the frontal-prefrontals and prefrontal-supraocular sutures, expanding into the loreals and posterior part of the nasals and reaching the three first suprlabials. The second band follows the first temporal-postocular suture, expanding on the lateral side of the parietals and is interrupted at the dorsum. There may be a white spot between the parietals and the supralabials are generally variegated. Ventrally the head is almost white as is most of the ventral surface, the exception being the tail.

Red, white and black bands form on the dorsum. The black bands are in pairs, with a white band between them. Each pair of black bands is separated from the other by a red area. The scales in the red and white areas have a free black tip; these black spots are smaller in the central dorsal white areas. The scales in the lateral portion of the black areas are spotted with white in the center.

The rostral is well developed, keeled dorsally, and upturned. Internasal scales are separated by the postero-dorsal portion of the rostral. The irregular prefrontals are in contact and not separated by an antefrontal shield in most cases. The frontal is as long as it is broad with a groove from the half of the anterior side to approximately the center of the scale. One preocular and two postocular scales are present. There is one loreal, and temporals measure 1 and 2. There are eight supralbials with the fourth and fifth entering the orbit. Of the ten infralabials, the first through the fourth are in contact with the first pair of chin shields. There are between 122 and 141 ventral scales in females and 128 to 138 in males. The ventral plate is divided. Subcaudal scales measure 21-33 in females and 26-34 in males. Dorsal scales measure 21-21-17.

This snake is entirely inoffensive and will not bite unless seriously provoked. When handled the snake may actually gape at the attacker appearing much larger than it actually is. More often than not, the snake will simply rattle its tail back and forth, imitating a rattlesnake. Although this snake is rear fanged, the toxicity of its venom is unkown. As with Lystrophis semicinctus, L. mattogrossensis feeds on small amphibians & reptiles including reptile eggs, and as neonates, occasionally insects. Breeding season begins in September with parturition occurring from November to December whereupon the snake lays approximately 10 eggs, which hatch in January or February. Commonly preyed upon by raptors, small mammals and ophiophagus (snake eating) snakes.

REFERENCES:

Scrocchi-G-J. Druz-F-B. (1993)
Description of a new species of the genus Lystrophis Cope and a revalidation of Lystrophis pulcher (Jan, 1863), (Serpentes; Colubridae).
PAPEIS AVULSOS DE ZOOLOGIA (SAO PAULO). 1993. vol. 38, no. 10, pp. 171-185.

DUMÉRIL, A.M.C., G. BIBRON & A.H.A. DUMÉRIL (1854)
Erpétologie générale ou Histoire Naturelle complète des Reptiles. Vol. 7 (partie 1).
Paris, xvi + 780 S.

GIRAUDO, A. R. 1997. Geographic Distribution. Serpentes: Lystrophis >matogrossensis. Herpetol. Review, 28 ( 3 ): 159.