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Accueil du site → Master → Etats Unis → 1970 → The distribution and variation of the shovel-nosed snake Chionactis palarostris with the description of a new subspecies from coastal Sonora, Mexico

University of Arizona (1970)

The distribution and variation of the shovel-nosed snake Chionactis palarostris with the description of a new subspecies from coastal Sonora, Mexico

Blake, Richard Anthony

Titre : The distribution and variation of the shovel-nosed snake Chionactis palarostris with the description of a new subspecies from coastal Sonora, Mexico

Auteur : Blake, Richard Anthony

Université de soutenance : University of Arizona

Grade : Master of Science (MS) 1970

Résumé
A comparison of samples of known populations of Chionactis palarostris (Klauber, 1937) indicates that it is desirable to recognize three subspecies : (X palarostris (Klauber, 1951), jx organica (Klauber, 1951), and a new subspecies, C_. £. seri, from the coast of Sonora, Mexico. Five characters were utilized : (1) the number of scales between the paired parietals and the first black band (parictal- 1st band), (2) the total number of black bands, (3) the percentage of black bands completely encircling the body, (4) the ventral + caudal counts (v + c), and (5) the relative widths of the mid-body black bands and the adj acent interspaces (bw/iw). Chionactis |K palarostris differs from jx organica and jx seri by having more scales between the parietals and first band, a fewer number of bands, and a lower mid-body band and interspace widths ratio. Chionactis jx organica differs from jx seri by having a higher mid-body band and interspaces widths ratio, a higher percentage of bands complete, and a lower ventral-caudal count. Chionactis jx organica appears to be geographically isolated from both (% jx palarostris and £. ]x seri and has been recorded only from Organ Pipe Cactus National Monument, Pima County, Arizona. Chionactis p. palarostris has been recorded between Hermosillo and Guaymas, Sonora, Mexico. Chionactis p. seri has been recorded from Kino Bay to 40 miles north of El Desemboque del Rio San Ignacio, between Kino Bay and Hermosillo, and 8-20 miles north of Hermosillo. Specimens recently collected near Altar, Sonora, seem to be intermediate between C. £. organica and . seri.

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