Thamnophis validus (KENNICOTT, 1860)
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Higher Taxa | Colubridae (Natricinae), Colubroidea, Caenophidia, Alethinophidia, Serpentes, Squamata (snakes) |
Subspecies | Thamnophis validus celaeno (COPE 1861) Thamnophis validus isabellae (CONANT 1953) Thamnophis validus thamnophisoides (CONANT 1961) Thamnophis validus validus (KENNICOTT 1860) |
Common Names | E: West Coast Garter Snake G: Mexikanische Westküsten-Strumpfbandnatter S: Jarretera Mexicana del Pacifico |
Synonym | Regina valida KENNICOTT 1860: 334 Tropidonotus tephropleura COPE 1860 Tropidonotus quadriserialis FISCHER 1879 (fide SMITH 1976) Tropidonotus validus — BOULENGER 1893: 237 Natrix valida — VAN DENBURGH 1895: 152 Natrix valida — TAYLOR 1939 Natrix valida — CONANT 1946 Natrix valida valida — FUGLER & DIXON 1961 Natrix valida valida — HARDY 1969: 186 Natrix valida— SMITH & SMITH 1976 Nerodia valida — STEBBINS 1985: 244 Nerodia valida — MCCRANIE & MCALLISTER 1988 Nerodia valida — CHIASSON & LOWE 1989 Thamnophis validus — DE QUEIROZ & LAWSON 1994 Thamnophis valida — LINER 1994 Nerodia valida — HEATWOLE 1999 Thamnophis valida — LEMOS-ESPINAL et al. 2002 Thamnophis validus — WALLACH et al. 2014: 727 Thamnophis validus — HEIMES 2016: 385 Thamnophis validus celaeno (COPE 1861) Tropidonotus celaeno COPE 1861: 341 Natrix celaeno — VAN DENBURGH 1895: 154 Natrix valida celaeno — LEVITON & BANTA 1964 Nerodia valida celaeno — MCCRANIE 1988 Nerodia valida celaeno — SHINE 1994 Thamnophis validus isabellae (CONANT 1953) Natrix valida isabellae CONANT 1953 Nerodia valida isabellae — MCCRANIE 1988 Nerodia valida isabellae — SHINE 1994 Thamnophis validus thamnophisoides (CONANT 1961) Natrix valida thamnophisoides CONANT 1961: 2 Nerodia valida thamnophisoides — MCCRANIE 1988 Thamnophis validus thamnophisoides — ROSSMAN 1996: 39 Thamnophis validus thamnophisoides — LINER & CASAS-ANDREU 2008: 148 |
Distribution | Mexico (Baja California Sur, Chihuahua [LEMOS-ESPINAL et al. 2002, HR 33: 325], Jalisco, Sonora, Guerrero, Sinaloa, Nayarit, Oaxaca) Type locality: "Durango, Mexico," (in error). Unknown; corrected to Río Presidio or coastal plain of southern Mexico fide Conant (1969: 83). celaeno: Mexico (Baja California); Type locality: "Cape St. Lucas, Lower California", revised to "San Jose River, Cape San Lucas, Baja California, Mexico" by Cochran, 1961:222 isabellae: Mexico (Guerrero); Type locality: “Pie de la Cuesta, Laguna Coyuca, Guerrero." thamnophisoides: Mexico (Nayarit); Type locality: “along the Rio San Cayetano (Rio de Tepic on some maps and also known locally as the Rio Mololoa), approximately 3.5 miles south-east of Tepic, Nayarit, Mexico”. |
Reproduction | ovovivparous. |
Types | Holotype: USNM 1309, adult female (D.N. Couch). Holotype: ZMH R04345 [quadriserialis] Holotype: AMNH 84091, adult female, collected July 3 or 4, 1959 by Roger Conant; paratypes: CNHM [thamnophisoides] Holotype: AMNH 73171, adult collected October 1949, by Roger Conant. [isabellae] Holotype: USNM 1309 [validus] Holotype: USNM 341 [celaeno] Syntypes: USNM 4683, 131748 [Tropidonotus tephropleura] |
Diagnosis | Definition. A moderately sized, moderately stout (as an adult), semi-aquatic snake ranging in size from 165 mm in the smallest known newborn to about 1100 mm in the largest known specimen (adult males average significantly smaller than adult females). The head is distinctly wider than the neck and comparatively broad in mature adults. The eye width is usually less than its distance from the nostril in adults but in juveniles the two dimensions are about equal. The rostral is twice as wide as high. The internasals are longer than wide. The prefrontals are wider than long. The nasals are divided. The parietals are widest anteriorly. The mental is triangular and the posterior chin shields are longer than the anterior ones. There are 130-150 ventrals in males, 127-147 in females; 69-86 subcaudals in males, 61-78 in females; 19-21 (usually 19) keeled scale rows at midbody and usually 17 anteriorto base of tail; usually 8 supra labia Is (occasionally 7 or 9), the 4th and 5th normally entering the orbit; usually 10 infralabials (occasionally 9 or 11); 1-2 (usually 1) preoculars; 1-4 (usually 3) postoculars; normally one anterior temporal; 2-3 temporals in secondary row; loreal single; anal divided. Teeth number 23-27 in the maxillary, 12-15 palatine, 23-31 pterygoid, and 25-30 dentary (McCranie 1988). Coloration: The dorsal coloration is variable and may be brown, chocolate brown, dark brown, olive brown, gray to olive gray, or black. Four longitudinal rows of small black or dark brown spots are usually discernable except in the darkest specimens. These rows of spots are most conspicuous on the anterior or middorsal portions of the body. A pale middorsal stripe is present in one subspecies and pale lateral stripes may be present in most subspecies (McCranie 1988). DefInition (validus). A subspecies characterized by a gray to olive gray or brown dorsal coloration, lack of pale longitudinal stripes and by a high number of ventrals. The venter is immaculate with a pale grayish brown or dull yellowish coloration. There is a single preocular (rarely 2) and 3 postoculars (rarely 1, 2, or 4). There are 136-150 (mean 141.7) ventra Is in males, 132-147 (mean 140.3) in females; 70-86 (mean 77.8) subcaudals in males, 61-78 (mean 70.4) in females (McCranie 1988). Definition (celaeno). A subspecies characterized by lateral pale longitudinal stripes, involving the first and third rows of scales. The dorsal coloration is highly variable but primarily consists of dark and pale color phases. In the dark phase, the dorsum is very dark brown or black with little or no pattern except for pale and irregular lateral stripes. The venter is virtually uniform black or very dark brown. In the pale phase, the dorsal coloration is pale gray or brown with 75-97 (mean 86.7) dark spots in four rows similar to mainland N. v. valida. The venter is whitish or yellowish either immaculate or with a light washing or stippling of slightly darker pigment. There is a single preocular (rarely 2) and usually 3 postoculars (rarely 1, 2, or 4). There are 135-146 (mean 142.1) ventrals in males, 134-145 (mean 141.1) in females; 74-82 (mean 78.1) subcaudals in males, 67-75 (mean 71.0) in females (McCranie 1988). Definition (isabelleae). A subspecies characterized by a brown or chocolate brown dorsum, a pale stripe on the first two or three rows of dorsal scales on each side, a low number of ventral scutes, and a slightly higher mean number of subcaudals. The venter gradually changes from a dull yellow on the anterior portion to a pale pinkish posteriorly. There are usually four rows of dark spots on the dorsum, each spot occupying only the anterior edge of anyone scale. There is a single preocular and 3 postoculars. There are 131-137 (mean 134.0) ventrals in males, 130-138 (mean 133.7) in females; 76-81 (mean 78.3) subcaudals in males, 68-76 (mean 72.4) in females (McCranie 1988). Definition (thamnophisoides). A subspecies characterized by a prominent pale middorsal stripe and a pale area on the first two or three rows of scales which gives the effect of a pale lateral stripe on each side of the body. The dorsal coloration varies from brown to olive brown and the venter is usually pale yellow with no darkening. There is a single preocular (rarely 2) and 3 postoculars (rarely 2 or 4). There are 130-140 (mean 135.3) ventrals in males,127-139 (mean 133.6) in females; 69-80 (mean 74.3) subcaudals in males, 65-73 (mean 68.7) in females (McCranie 1988). |
Comment | Habitat: at least partially coastal and thus considered (partially) “marine” (according to WORMS). NCBI taxon ID: 426693 [celaeno] NCBI taxon ID: 426692 [isabellae] NCBI taxon ID: 174673 [thamnophisoides] NCBI taxon ID: 426691 [validus] |
Etymology | The name valida is derived from the Latin word validus, meaning powerful or strong. The subspecies celaeno was named after Greek “kelainos”, meaning black or dark, in reference to the dorsal coloration. T. v. isabelleae honors Isabelle Hunt Conant, who accompanied her husband Roger when the type specimen was collected. T. v. thamnophisoides refers to the garter snake genus Thamnophis, which this subspecies resembles (the subspecies was originally described in the genus Regina). |
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