Limnodynastes terraereginae ( Fry, 1915 )

Parkin, Tom, Rowley, Jodi J. L., Gillard, Grace L., Sopniewski, Jarrod, Shea, Glenn M. & Donnellan, Stephen C., 2024, Systematics and Taxonomy of the Northern Banjo Frog (Anura: Limnodynastidae: Limnodynastes terraereginae) and Allied Taxa, Ichthyology & Herpetology 112 (1), pp. 76-105 : 95-99

Limnodynastes terraereginae ( Fry, 1915)

Figures 16, 17

Suggested common name: Superb Banjo Frog

Holotype.— AMS R4525 (adult female) collected from Somerset , Cape York Peninsula , Far North Queensland, Australia (10.758S, 142.588E) by Charles Hedley and Allan Riverstone McCulloch in 1907.

Material examined.— See Supplementary Table S1 (see Data Accessibility) for full list of specimens used in morphometric analyses.

Revised diagnosis.— Limnodynastes terraereginae can be distinguished from all species in the L. dorsalis group by a combination of: (1) large adult body size ( SVL for males 65–66 mm; females 73–94 mm), (2) excessively robust build, (3) vestigial-moderate trace of webbing on the hind foot ( Fig. 10 ), (4) presence of magenta suffusions in the groin, (5) pale, immaculate ventral surface, edged with yellow ( Fig. 11A ), (6) advertisement call with a moderately high dominant frequency (0.6–1.1 kHz, mean 0.8 kHz), and (7) genetically by 16 apomorphic nucleotide states on the ND4 gene (Table 4).

Holotype measurements (mm).— SVL 73.4; FOL 44.5; TIB 27.1; THL 30.2; HW 32.9; IOD 6.5; DFE 11.8; IND 6.4; NS 6.7; EN 6.4; ED 8.5; HDD 14.6; SL 13.0; HL 26.4; UAL 12.7; LAL 17.7; HAL 17.3; AL 32.7; FL 31.1; IMT 6.0; TEY 3.9; Fin3W 1.9; Toe4W 2.1.

Redescription of holotype.— Habitus excessively stout. Dorsum textured with irregular tubercles, ventral surface smooth.

Head large, broadest at tympanum, wider than long (HW/HL 1.25). Head appears rounded from above and in lateral profile. Nostrils slightly raised, outward-facing and not prominent in profile. Eyes large, bulbous and protruding, pupil round and tympanum indistinct. Arms and legs short and powerfully built, tibial gland prominent, oval-shaped and approximately 57% length of tibia. Four fingers and five toes, all rounded, thick-set and tapering without terminal discs. Webbing on fingers absent and with moderate trace on toes ( Fig. 10 ), prominent distended finger spatulae on 2 nd fingers indicating specimen is female. Subarticular tubercles prominent on fingers and toes, metacarpal tubercles prominent, inner-metatarsal tubercle also prominent, wedge-shaped and longer than the 1 st toe. Soles of feet smooth. Numerous raised scattered tubercles present on posterior edge of thighs and around cloaca.

Color in preservative.— Described after more than 115 years in preservative, dorsum base color a fairly uniform creambrown with irregularly scattered large dark brown blotches and spots, tending to become darker and denser posteriorly. Distinct yellow vertebral stripe extending from rostrum to vent. Pattern becomes more dispersed laterally and is replaced by a fairly uniform cream-yellow base which transitions to a slightly lighter and immaculate cream-yellow on the ventrum. Subaural gland cream-yellow, with darker brown banding running through eye. Upper surface of arms cream-yellow with faded mottling. Lower surface of arms and legs plain cream-yellow.

Variation.— A summary of variation in morphometric characters for each sex is presented in Table 6 and Figure 6 .

Color and pattern (in life).— Ventral surface plain, unpatterned cream to pearl and edged by yellow. Vocal sac dark brown to orange and mottled in breeding males. Distinct magenta patches in inguinal region and legs. Dorsum with light brown base with strong dark brown to black blotching ( Fig. 17 ). Yellow vertebral stripe can be distinct, broken, faded, or absent. Lateral zone with dark brown base and yellow-orange mottling or stippling. Posterior thigh flash black with scarlet to orange blotching. Soles of feet dark brown with light speckling and lateral edge of foot often with yellow stripe. Shoulder with yellow-orange patch, forearm mottled with gray, brown, white, to pearl fingers and toes. Distinct yellow to orange subaural gland with darker brown to black stripe running from rostrum, through eye and usually fading into the lateral zone.

Advertisement call.— The advertisement call description of L. terraereginae is based on the calls of five individuals from Cape York Peninsula. The advertisement call consists of a single, resonant note. Individuals had a mean dominant frequency of 0.6–1.1 kHz, and a mean fundamental frequency of 0.5–0.6 kHz. On average, advertisement calls had a duration of 0.08– 0.12 s ( Table 7; Fig. 8 )

Distribution.— Restricted to the eastern coast of the Cape York Peninsula Bioregion in far north QLD, from Cooktown in the south to Somerset at the tip of Cape York, encompassing an area of approximately 36,000 km 2. Recorded from Jardine-Pascoe Sandstones, Coen-Yambo Inlier, Laura Lowlands, and Starke Coastal Lowlands subregions.

Habitat.— Occurs in Melaleuca woodlands, ephemeral swamps, littoral monsoon forest, vine thicket, coastal heath, and riparian habitats with clay or sandy substrate.

Conservation status.— AOO and EOO were calculated for this taxon at 204 km 2 and 59,565 km 2, respectively. The estimate of AOO potentially qualifies the taxon for Endangered; however, the EOO estimate does not meet any risk category. There is currently inadequate data available to assess whether populations of this taxon are fragmented, have declined, or have fluctuated severely and so a listing of Least Concern is appropriate until further information becomes available.

Ecology.— The peak calling period is from January to March. According to FrogID data, the species is most often recorded calling from streams, creeks, and flooded areas in natural landscapes. Males have been recorded calling in closedcanopy, flooded littoral monsoon forest near Cooktown in May 2021, elevation 12 m a.s.l. (T. Parkin, pers. obs.). Significant rainfall (. 250 mm) had fallen in the region over the preceding week associated with tropical cyclone Niran. Several males were observed calling from exposed positions beside the water’s edge, air temperature 26.58C. Tadpoles and reproductive biology not recorded.

Figures

FIG. 10. Illustration of hind foot webbing extent, a useful diagnostic character for identification of the Limnodynastes dorsalis group. (A) Well-developed webbing (extends to beyond half-way between the 1st subarticular tubercle and tip of Toe 1), (B) moderate webbing (extends one-quarter to half-way between the 1st subarticular tubercle on Toe 1), (C) vestigial webbing (does not or only slightly extends beyond the 1st subarticular tubercle on the 1st Toe). Illustration copyright Alana de Laive.

FIG. 11. Examples of typical ventral color pattern, a useful diagnostic trait between members of the eastern Limnodynastes dorsalis group. (A) Limnodynastes terraereginae (CYP lineage), (B) L. grayi (WS lineage), (C) L. superciliaris (EC lineage), (D) L. dumerilii dumerilii, (E) L. dumerilii insularis, and (F) L. interioris. Specimen registration labels represent 25 mm.

FIG. 6. Comparison of morphological measurements between adult specimens of the Limnodynastes dorsalis group lineages redescribed herein.

FIG. 17. Images in life of Limnodynastes terraereginae. (A) QM J97862, female, Cooktown, Qld. (B) QM J97860, male, Cooktown, Qld. (C) QM J97861, male, Cooktown, Qld. (D) Unvouchered individual, Kutini-Payamu (Iron Range) National Park, Qld (photo copyright: Stephen Zozaya).

FIG. 8. Comparison of the male advertisement calls of (A) WS lineage—Rockhampton, QLD (FrogID 312613), (B) EC lineage—Harrington, NSW (AMS R.188164), (C) CYP lineage—Finch Bay, Cooktown, QLD (QM J97862), (D) Limnodynastes dumerilii dumerilii—Tenterfield Creek, NSW (AMS R.188096), and (E) L. interioris —Narrandera, NSW (FrogID 276467). Audiospectrograms and oscillograms were produced in Raven Pro 1.6 with a fast-Fourier transformation of 512 points, and 50% overlap.