Tri color Hognose (Lystrophis semicinctus)

SPECIES:

Lystrophis semicinctus

SYNONYMS:

Heterodon semicinctus DUMÉRIL, BIBRON & DUMÉRIL 1854
Heterodon pulcher JAN 1863
Lystrophis semicinctus - BOULENGER 1894
Lystrophis semicinctus wesieri -MULLER, 1928

Lystrophis semicinctus - CEI 1993

SUBSPECIES:

NONE

FAMILY:

Colubridae

DISTRIBUTION:

Buenos Aires, Catamarca, Córdoba, Chubut, Entre Ríos, La Pampa, La Rioja, Mendoza, Neuquén, Río Negro, San Luis and Tucumán. Also in western Bolivia (Scrocchi & Cruz, 1993). Monte, Espinal, Pampeana and Patagónica provinces.

COMMENT:

Synonymy after CEI 1993 (but see entry for L. pulcher). Formerly, authors considered a greater distribution because of the confusion with L. pulcher.

HABITAT:

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.

 

HABITS:

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. This snake is rear fanged, the toxicity of its venom is unkown. Lystrophis semicinctus 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.

DEFINITION:

Members of the Genus Lystrophis belong to the Subfamily Xenodontinae Large, bladelike posterior maxillary teeth, a large adrenal gland, and several other characters. Two of the genera, Lystrophis and Heterodon, have pointed, recurved, digging snouts not seen in Xenodon. A small robust species with males ranging from 16 up to 24 inches snout to vent length. The species possesses a short tail and its head is not distinct from the neck.

Lystrophis semicinctus is predominately yellowish in coloration, with the pale areas between the black being of equal width. The width of the black and white rings remains constant to adulthood. Black rings vary from 14 to 22 pairs on the body and from 2 to 41/2 pairs on the tail.

The rostral is well developed, keeled dorsally, and upturned. Internasal scales are separated by the postero-dorsal portion of the rostral. Prefrontals are generally separated by an antefrontal shield in most cases; few individuals do not possess the antefrontal. The frontal is as long as it is broad. One preocular and two postocular scales are present. There is one loreal, and temporals measure 1 and 2. There are eight supralabials 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 147 and 171 ventral scales; between153 and 167 ventral scales in females and 151 to 171 in males. The ventral plate is divided. Subcaudal scales measure 22-34 in females and 28-37 in males. Dorsal scales measure 21-21-17.

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.
Giambelluca, Luis Alberto. 1999. Lystrophis semicinctus (Ophidia: Colubridae) nueva cita para la provincia de Chubut (Argentina). Boletín de la Asociación Herpetológica Española. (10):19. [Instituto de Neurociencia (CONICET), Ciudad Universtiaria F. C. E. y N., Pabellón II, Capital Federal (1428), Argentina]