Mixophyes carbinensis, Mahony, Michael, Donnellan, Stephen C., Richards, Stephen J. & Mcdonald, Keith, 2006

Mahony, Michael, Donnellan, Stephen C., Richards, Stephen J. & Mcdonald, Keith, 2006, Species boundaries among barred river frogs, Mixophyes (Anura: Myobatrachidae) in north­eastern Australia, with descriptions of two new species, Zootaxa 1228, pp. 35-60 : 51-53

Mixophyes carbinensis new species (group I)

( Fig. 6A )

Holotype

QM J79552 , an adult male from Mt Lewis, Carbine Tableland, Queensland, Australia, 16° 31’ S, 145° 16’ E, collected by M. Mahony on 19 December 1993. Other material examined: see Appendix 1.

Diagnosis

Mixophyes carbinensis sp. nov. is distinguished from other members of the M. schevilli species complex by having uniformly dark posterior surface of thighs with numerous (9–35 per thigh) small (1–1.7 mm) rounded pale spots, versus in M. schevilli the presence on the posterior surface of each thigh of 1–13 symmetrical pale blotches bordered by a dark margin, diameter 1–6 mm and in M. coggeri posterior surface of thigh with 0–9 large irregular pale botches bordered by a dark margin, length of blotches 1–11 mm. In M. carbinensis , the spots are uniformly distributed along the length of thigh, whereas in the other two species the blotches are concentrated on distal section of the thigh towards the ventral edge and sometimes extend onto the ventral surface at the knee. The pattern on the dorsal and posterior surfaces of the legs in M. carbinensis sp. nov. is more distinct than in the other two taxa as the individual elements of the pattern have sharply demarcated edges and contrast markedly with the underlying ground color. In M. schevilli and M. coggeri sp. nov. the pattern is less distinct as the edges of the individual elements are less clearly demarcated and the color of the elements is less contrasting with the background color.

Description of Holotype

Head flattened, slightly broader than long (HL/HW = 0.81); snout prominent, gently rounded when viewed from above and in profile. Nostrils more lateral than superior, distance from snout greater than distance from eye (SN/EN = 1.5); distance between eye and naris approximately two­thirds of internarial span (EN/IN = 0.67); canthus rostralis well defined, straight; loreal region slightly concave below canthus rostralis, becoming convex towards upper lip. Eye relatively large, diameter larger than eye to naris distance (EY/EN = 1.57). Pupil shape when constricted not determinable. Tympanum large, conspicuous and oval with long axis angled slightly towards eye. Tympanum diameter slightly less than eye length (TY/E = 0.85). Vomerine teeth relatively long straight rows directed from anterior margin of choanae to midline between choanae. Tongue approximately rectangular, notched posteriorly. Fingers long, slender and unwebbed. Subarticular and palmar tubercules prominent, especially palmar tubercule at base of digit one; brown glandular nuptial pad on inner palmar tubercule and entire length of first digit except terminal disc. Relative length of fingers 3>4>1=2; hind limbs moderately long (TL/ SVL = 0.61). Toes fully webbed except distal phalanx of fourth toe, which is fringed with web. Webbing between fourth and third toes with exception of distal two phalanges of fourth toe, which is fringed with web. Webbing between third and second toe with the exception of distal phalanx of third toe, which is fringed with web. Webbing between second and first toes midway along distal phalanx of first toe to joint of distal phalanx of second toe. Sub­articular tubercules absent; inner metatarsal tubercule prominent, with well­developed outer edge; relative order of length of toes 4>5>3>2>1. Dorsum and venter smooth.

Dimensions of holotype (in mm): SVL, 70; TL, 42.5; HL, 23; HW, 30; EN, 6; IN, 8; E Y, 9; IO, 13; TY, 7.5; A, 14; F3, 21; F3D, 1; T4, 36; T4D, 1; MT, 3.5.

Color in preservative: Dorsum dark chocolate brown. Dark brown mid­dorsal stripe originates anteriorly as an inter­orbital bar and extends along mid­line of dorsum to midsacral region; lateral margins of stripe uneven and finely edged with black. Several smaller black­edged dark brown patches on dorsum lateral to mid­dorsal stripe; dark lateral head stripe commences at nares and extends over and around posterior margin of tympanum. Lateral edges of limbs scalloped with very dark, approximately triangular, patches. Dorsal surface of forelimbs and hindlimbs dark brown with distinct narrow darker brown transverse bars. Posterior surface of thighs uniformly dark with numerous (9–35 per thigh) small (1–1.7 mm) rounded pale spots. Palmar and plantar surfaces of feet and hands very dark.

Var ia t io n: SVL of males 59–72 mm and females 67–78 mm ( Table 3 ). Hind limbs long (TL/SVL, = 0.64 ± 0.02, range = 0.60–0.69). Head length less than head width (HL/HW, = 0.85 ± 0.05, range = 0.77–0.94), eye to naris distance usually less than internarial span (EN/IN, = 0.78 ± 0.09, range = 0.65–1.01). Pupil vertical when constricted. Mid­dorsal stripe narrow to moderately broad. Remainder of dorsal surface either sparsely flecked with small black spots or a few larger blotches. Dark lateral headstripe extends posteriorly along supratympanic fold sometimes reaching to above axilla, width variable. Bars on upper surface of limbs narrow and very dark. Posterior surface of thighs uniformly dark with numerous (9–35 per thigh) small (1–1.7 mm) rounded pale spots distributed evenly along thigh. Ventral surfaces except chin immaculate. Chin immaculate or dusky on lateral margins.

Color in life: Dorsal surfaces of body and limbs light fawn to rich copper brown. Middorsal stripe, other patches, bars on limbs, and area below eye dark chocolate brown, frequently accentuated by thin cream border. Lateral head stripe black, bordered by a fine cream or fawn line that is sharply demarked against black stripe but diffuses into surrounding ground color. Tympanum dark brown, not bordered by lighter line. Several small black blotches midway along upper lip, towards articulation of jaw and immediately below and adjacent to eye. A lateral triangular patch expanding from external nostril to front of jaw dark brown or black towards margin, with more diffuse lighter brown centre. Iris dark brown. Ventral surface of body and chin cream with diffuse grey mottling around margins of chin, and towards articulation of jaw and beneath shoulder. Laterally, brown of dorsum grades into lighter peach color, which then fades into cream ventral color. In some individuals, junction between ventral and lateral surface grey to black with a number of cream dots that tend to be more distinct towards groin region. Posterior surface of thigh dark grey to black with small round cream spots. Sides of limbs with roughly triangular dark brown to black patches. Ventral surfaces of limbs gray. Upper surfaces of fingers and toes same color as dorsum but webbing between toes black. In males, nuptial pad gray to brown.

Distribution

Known only from Carbine and Windsor Tablelands, northeastern Queensland.

Figures

FIGURES 6 A – C: Holotypes of Mixophyes species; A, M. carbinensis sp. nov. (QM J 79552), B, M. coggeri sp. nov. (QM J 79551), and C, M. schevilli (MCZ 18150).