Species boundaries among barred river frogs, Mixophyes (Anura: Myobatrachidae) in northeastern Australia, with descriptions of two new species
Author
Mahony, Michael
Author
Donnellan, Stephen C.
Author
Richards, Stephen J.
Author
Mcdonald, Keith
text
Zootaxa
2006
1228
35
60
journal article
10.5281/zenodo.172713
f2e44996-bfff-448f-afa2-bb62159b35e9
11755326
172713
Mixophyes schevilli
Loveridge, 1933
(group III)
(
Fig. 6C
)
Mixophyes fasciolatus schevilli
Loveridge, 1933
Mixophyes schevilli
Straughan, 1968
Holotype
MCZ
R18150, an adult female from Millaa Millaa, Queensland,
Australia
,
17° 31’ S
,
145° 37’ E
, collected by P. J. Darlington
1–9 April 1932
.
Diagnosis
Mixophyes schevilli
is distinguished from
M. carbinensis
sp. nov.
and
M. coggeri
sp. nov.
by having posterior surface of thighs with few (1–13 per thigh) pale blotches (diameter
1–6 mm
) bordered by a dark margin, versus in
M. carbinensis
a uniformly dark posterior surface of thigh with numerous (9–35 / thigh) small (
1–1.7 mm
) rounded pale spots, and in
M. coggeri
posterior surface of each thigh with 0–9 large (
1–11 mm
) irregular pale botches bordered by a dark margin.
Mixophyes schevilli
is further distinguished from a
M
.
coggeri
sp. nov.
by having a continuous middorsal stripe, versus a discontinuously linear series of large irregular shaped blotches along the middorsal region in
M. coggeri
. Both sexes of
M. schevilli
have a significantly smaller head than the comparable sex of
M. coggeri
.
Description of
holotype
Head flattened, approximately as long as broad (HL/HW = 0.92); snout prominent, gently rounded when viewed from above and in profile; nostrils more lateral than superior, distance from snout equal to that from eye; distance between eye and naris equal to internarial span (EN/IN = 1.07); canthus rostralis well defined and slightly concave; loreal region nearly flat and inclined laterally; eye relatively large (EY/EN = 1.3); pupil vertical when constricted; tympanum large, conspicuous, oval with vertical long axis. Tympanum length nearly two thirds eye diameter (TY/EY = 0.63); vomerine teeth relatively long, oblique rows angled from anterior margin of choanae to midline between choanae; tongue approximately rectangular, not notched posteriorly.
Fingers long, slender, unwebbed. Subarticular and palmar tubercles prominent; relative length of fingers 3> 1> 4> 2; hind limbs long (TL/SVL = 0.61); toes extensively webbed, webbing reaching discs on toes 1, 2, 3, and 5 and to second most distal joint of toe 4 (
Fig. 7
); subarticular tubercles oval; outer metatarsal tubercle absent; inner metatarsal tubercle prominent, with welldeveloped outer edge, approximately one half length of tip of toe 1 to junction with tubercle (MT/first toe length = 0.53); relative order of length of toes 4> 5> 3> 2> 1. Dorsum with small tubercules, venter smooth.
Dimensions of
holotype
(in mm):
SVL, 84; TL, 51; HL, 32; HW, 34; EN, 7; IN, 8; EY, 11; IO, 16; TY, 7; A, 21; F3, 21; F3D, 1.5; T4, 42; T4D, 2; MT, 5.
Color in preservative:
Dorsum brown with dark brown interorbital bar extending backward as a narrow middorsal stripe with irregular edges terminating in midsacral region, lateral margins uneven and discontinuously finely edged in black. Dark brown triangular patch anterior of nostril with an apex at nostril and one edge along upper lip. These patches almost meet on apex of snout. Dark brown streak between nostril and eye extends posteriorly over tympanum along flank to level of forelimb. Lighter brown patch about as wide as eye, extends from lower margin of eye to upper lip.
Forelimbs light brown with several dark transverse bars. Dorsal surface of hind limbs light brown with distinct narrow dark brown cross bars; bars much narrower than intervening lighter background, expanded anteriorly; posterior surface of thighs finely reticulated with dark brown pattern and with 1–13 symmetrical pale blotches (
1–6 mm
diameter) per side, each bordered by a dark margin; anterior lateral edge of shank and posterior lateral edges of arms, plantar surface of feet and of tarsus uniformly dark; lateral palmar surfaces of outer fingers dark; venter including throat and ventral surface of thighs immaculate and paler than rest of dorsum; lower jaw edged with dark brown.
Var ia t io n
: SVL of males
58–75 mm
and females
68–92 mm
(
Table 3
).
Hind
limbs long (TL/SVL, = 0.66 ± 0.03, range = 0.60–0.81). Head length approximates head width (HL/ HW, = 0.88 ± 0.04, range = 0.74–0.98), and eye to naris distance versus internarial span variable (EN/IN, = 0.84 ± 0.09, range = 0.63–1.18). The middorsal stripe may be narrow and end middorsally; may be broader and end in midsacral region, or may be very broad with irregularly and deeply dissected lateral edges (
Fig. 3
). Remainder of dorsal surface either sparsely flecked with small black spots or a fewer larger blotches. Posterior extension of dark lateral headstripe along supratympanic fold variable, sometimes reaching to above axilla, width variable. Dark bars on upper surface of limbs very narrow or broader with a fine white or black margin. Between 1 and 13 pale blotches,
1–6 mm
in diameter, on posterior surface of each thigh (
Fig. 4
). Blotches concentrated on distal section of thigh towards ventral edge and sometimes extending onto ventral surface at knee. Blotches always bordered by a dark margin that varies in intensity. Ventral surfaces immaculate except throat and chin that vary from immaculate to completely dusky. In some individuals, lateral margins of chin with coarse dark reticulum. Webbing between toes 1 and 2 variable. In males, brown glandular nuptial pad on proximal phalanx of first digit and inner palmar tubercle.
Color in life:
Dorsal surfaces of body and limbs vary from pale yellow through rich copper brown to dark brown. Middorsal stripe and patches, patch on face and bars on limbs darker brown than background, often darker towards margin. Head stripe black, bordered by fine cream or fawn line that is sharply demarcated against black stripe but diffuses into surrounding ground color. Tympanum same color as dorsum or darker brown not bordered by lighter line. Small dark brown to black blotches occur on upper lip and immediately below and adjacent to eye. Iris very dark brown. Ventral surface of body and chin cream, with grey wash towards margin of jaw. Brown coloration of dorsal surface merges laterally with cream ventral coloration. A number of irregular darker blotches may occur towards groin. Posterior surface of thigh brown to dark gray; large irregular shaped cream or offwhite blotches with a darker margin. Sides of limbs with roughly triangular dark brown to black patches. Ventral surfaces of limbs offwhite. Upper surfaces of fingers and toes same color as dorsum but webbing between toes black. In males, nuptial pad gray to brown.
Distribution
Known from three disjunct areas: Big Tableland, Thornton Peak, and the Atherton Tableland between Lamb Range in the north and Charmillan Creek in the south.