قراءة كتاب A Review of the Frogs of the Hyla bistincta Group
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A Review of the Frogs of the Hyla bistincta Group
dorsal surfaces; flanks and anterior surfaces of thighs pale creamy yellow with purplish brown reticulations; posterior surfaces of thighs tan with yellow spots; ventral surfaces yellow; iris pale copper-color.
Variation.—There is little variation in structure. The total number of vomerine teeth varies from 6 to 14. In some individuals the supratympanic fold covers the upper part of the tympanum, but at least the lower part of the tympanum is always visible. The extent of the webbing between the toes varies from three-fourths to two-thirds complete. Usually the web extends to some point on the antepenultimate phalanx of the fourth toe, but in some specimens the web extends to the base of the penultimate phalanx.
In the large series of specimens from Uruapan, Michoacán, the coloration of the flanks and anterior surfaces of the thighs varies from nearly uniform creamy yellow with only fine dark reticulations to bold reticulations enclosing yellow spots. Some specimens from Oaxaca and Veracruz have slightly different markings on the flanks; in these the dark pigment is in the form of irregular spots or dashes, instead of reticulations.
There is considerable variation in color in the living frogs. The dorsum varies from greenish tan and pale yellowish tan to reddish brown, and some individuals are dark chocolate brown.
Remarks.—Shannon (1951:470) named Hyla bistincta labeculata on the basis of a single male from San Lucas Camotlán, Oaxaca; he diagnosed the subspecies as differing from Hyla bistincta bistincta by having "the gray reticulation of the sides entirely broken up into elongate black blotches; tarsal fold moderately elevated." The condition of the tarsal fold is characteristic of the species. The dispersion of dark pigment on the flanks is variable. The type of Hyla bistincta labeculata (USNM 123689) is extreme in the development of dark dashes on the flanks, but this condition is approached in several specimes from Oaxaca and Veracruz. For example, in some specimens from Cumbres de Acultzingo, Veracruz, the mottling on the flanks is bold; in others the flanks are reticulated. The specimen from San Vicente, Oaxaca, has black dashes on the flanks (Smith and Williams, 1963:23), whereas a specimen from Cerro San Felipe, Oaxaca, has no pattern on the flanks. In general, specimens from western México have reticulate mottling on the flanks as compared with the marbling on the flanks in specimens from eastern México. On the basis of available data, the recognition of subspecies in Hyla bistincta is unwarranted.
The tadpoles of this species described by Duellman (1961:47) are like those of Hyla robertsorum in having ⅔ tooth-rows, peglike serrations on the beaks, and long, rounded tails. At Uruapan tadpoles were found in a rocky stream on April 24, 1956, and metamorphosing young were found there on August 2, 1956. A completely metamorphosed juvenile has a snout-vent length of 24.8 mm.
Hyla bistincta is found only along streams, where individuals can be seen clinging to vines and other vegetation closely over-hanging fast-moving parts of the stream.
Distribution.—Hyla bistincta occurs at elevations from 1400 to 2600 meters in the mountains of the Sierra Madre Occidental in western Jalisco southward through the Cordillera Volcánica in Michoacán, México, and Morelos, the Sierra de Coalcomán in Michoacán, and the Sierra Madre del Sur in Guerrero and Oaxaca, and thence northward in the Sierra Madre Oriental to central Veracruz (Fig. 2).
Specimens examined.—Guerrero: Omiltemi, UIMNH 38023-5. Jalisco: 25 km. SE Autlán, UMMZ 102076. Mexico: 19 km. W Villa Victoria, UIMNH 28162, USNM 114513. Morelos: Cuernavaca, USNM 121523; 3 km. N Cuernavaca, UIMNH 28168-70. Michoacan: Cerro San Andrés, UMMZ 102075; Dos Aguas, UMMZ 119193; 12.5 km. ENE Dos Aguas, UMMZ 119194; Los Conejos, UMMZ 94238-40; Uruapan, KU 68077-8, 69093 (skeleton), UIMNH 20457, 28167, UMMZ 85452-3, 112838, 112839 (16), 115231 (tadpoles), 115232, 115233 (12), 121515, S-1699 (skeleton), S-1826 (skeleton), USNM 114514-5, 114517-24. Oaxaca: Cerro San Felipe, UIMNH 28163; Pluma Hidalgo, AMNH 13447; San Lucas Camotlán, USNM 123689; San Vincente, UIMNH 51346 (Smith and Williams, 1963:23). Veracruz: no specific locality, USNM 32261; Cumbres de Acultzingo, CNHM 105482-3, UIMNH 28164-6, 49133-4, USNM 114525.
Fig. 2. Map showing locality records for Hyla bistincta and Hyla charadricola.]Holotype.—University of Kansas Museum of Natural History No. 58414 from the Río Totolapa, 14.4 kilometers by road west of Huachinango, Puebla, México, 2280 meters; obtained by John Wellman on June 8, 1960.
Paratypes.—KU 58415-58423, same data as holotype, and UIMNH 50966, obtained at the type locality by William E. Duellman on February 11, 1961.
Diagnosis.—Maximum snout-vent length in males, 45 mm.; snout in dorsal profile truncate; tarsal fold short and weak; inner metatarsal tubercle moderately large, elliptical, and flat; outer metatarsal tubercle minute, round, and indistinct; webbing extending to base of terminal phalanx of fourth toe; nuptial spines on thumb absent; thoracic fold absent; anal opening at level of middle of thigh; dorsum olive-green with black reticulations; venter cream color with brown flecks on chin; flanks pale grayish green with brown spots; anal stripe absent; row of white flecks above and a row below anus; vocal slits absent.
Description of Holotype.—Adult male having a snout-vent lenth of 44.4 mm.; tibia length, 22.2 mm., 50 per cent of snout-vent length; foot length (measured from proximal edge of inner metatarsal tubercle to tip of longest toe), 20.4 mm.; greatest width of head, 14.0 mm., 31.5 per cent of snout-vent length; head length, 13.6 mm., 30.6 per cent of snout-vent length; diameter of eye, 5.0 mm.; diameter of tympanum, 1.6 mm., 32.0 per cent of diameter of eye. Snout in lateral profile bluntly rounded, in dorsal profile truncate (Fig. 3); canthus pronounced, rounded, not angular; loreal region slightly concave; lips thick, rounded, not flaring; nostrils slightly protuberant; internarial distance, 3.7 mm.; interorbital distance, 4.1 mm., somewhat broader than width of eyelid, 3.3 mm. A heavy dermal fold from posterior corner of eye above tympanum and then to insertion of forearm; tympanum round, its diameter three-fourths its distance from eye. Forearm rather slender; a short axillary membrane; no fold on wrist; no nuptial excrescence or spines on enlarged prepollex; subarticular tubercles moderately small, round; none bifid; few supernumerary tubercles on proximal segments of digits; large, flat palmar tubercle present; fingers long and slender; length of fingers from shortest to longest, 1-2-4-3; discs moderately large, that on third finger about equal to diameter of tympanum; rudimentary web between first and second fingers; web between third and fourth fingers extending to about one-fifth length of fourth finger (Fig. 1). Heels overlap by about one-third length of tibia when hind limbs adpressed; tibiotarsal articulation extends to middle of eye; tarsal fold weak, extending from moderately large, flat, elliptical inner
