Limnodynastes grayi ( Steindachner,1867 )

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 : 90-93

Limnodynastes grayi ( Steindachner,1867)

Figures 12 , 13

Suggested common name: Scarlet-sided Banjo Frog

Holotype.— NHMW 4695 (adult male) collected in the vicinity of Rockhampton, Queensland (previously stated as Neu-S ud-Wales € ¼ NSW in the original description). Presumably collected by German natural history collector Eduard Dämel in 1866 (see Appendix 1).

Material examined.— Heliorana grayi type examined from high-resolution images. For full list of specimens examined in morphometric analyses see Supplementary Table S1 (see Data Accessibility).

Revised diagnosis.— Limnodynastes grayi is diagnosed from all species in the L. dorsalis group by a combination of: (1) medium-large adult body size ( SVL for males 47–78 mm; females 55–75 mm), (2) robust build, (3) vestigial-moderate webbing trace on the feet ( Fig. 10 ), (4) the presence of scarlet suffusions in the groin, (5) pale and immaculate ventral surface ( Fig. 11B ), (6) advertisement call with a moderately high dominant frequency (0.6–1.3 kHz, mean 0.9 kHz), and (7) genetically by five apomorphic nucleotide states on the ND4 gene (Table 4).

Redescription of the holotype.— We redescribe the holotype based on high-resolution images of the preserved specimen after more than 155 years in preservative. Habitus stout and robust. Dorsum and ventral surface smooth. Head large, broadest at tympanum and wider than long. Head appears rounded from above and largely flat in profile, sloping more steeply at snout. Nostrils slightly raised and forward-facing. Tympanum indistinct. Subaural gland distinct and extending from below eye to above shoulder. Eyes large and concealed. Arms and legs relatively short and powerfully built, tibial gland prominent, oval-shaped and approximately 56% the length of tibia. Four fingers and five toes, all rounded, and tapering without terminal discs. Webbing on fingers absent but moderately developed on toes ( Fig. 10 ). Subarticular tubercles prominent on fingers and toes, metacarpal tubercles prominent, inner-metatarsal tubercle also prominent, wedge-shaped and approximately the same length as the first toe. Soles of feet smoothly textured.

Color in preservative.— Uniform dark brown dorsally without patterning, transitioning to stippled cream-yellow laterally and completely plain cream-yellow ventrally. Prominent cream-yellow subaural gland and pale raised spots around cloaca and posterior edge of thighs.

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

Color and pattern variation (in life).— Variation in color is described from images of genotyped specimens taken in life. Ventral surface plain, unpatterned translucent pearl to cream, sometimes edged with gray, cream, yellow, or orange. Vocal sac often darker and mottled in males. Dorsal surface plain brown to gray sometimes with dark or light blotches and mottling. Orange-yellow vertebral stripe may be distinct, broken, faded, or absent. Lateral zone gray with yellow, orange, scarlet, black, or white mottling, reticulations, or stippling. Scarlet patches or mottling usually present in the inguinal region, upper thigh, and medial tibia. Posterior thigh flash black with gray-scarlet mottling or blotching becoming lighter toward anterior edge of thigh. Soles of feet brown-gray and with black, white, gray speckling and yellow stripe on lateral edge of foot. Shoulders with yellow-orange patch and remaining arm gray and mottled with black or white. Hands lighter white, cream, or gray. Prominent yellow-cream subaural gland with darker gray, black, or brown stripe running from rostrum, through eye to edge of subaural gland.

Advertisement calls.— The advertisement call description of L. grayi is based on the calls of 41 individuals sampled throughout the species’ distribution, including the holotype locality (Rockhampton, QLD). The advertisement call consists of a single, resonant note. Individuals had a mean dominant frequency of 0.6–1.3 kHz, and a mean fundamental frequency of 0.4–0.7 kHz. On average, advertisement calls had a duration of 0.05– 0.14 s ( Table 7; Fig. 8 ).

Distribution.— Widely distributed across an area spanning approximately 550,000 km 2 from central western NSW to northern QLD. In the southernmost extent of its range, L. grayi is absent largely from higher altitude areas of the Great Dividing Range ( GDR), occurring mostly on the slopes and plains to the west, as far south as Tomingley, Central West NSW. East of the GDR, L. grayi extends as far south as Coffs Harbour on the north coast. In QLD, L. grayi occurs throughout south-eastern coastal regions including several islands (i.e., Fraser, Moreton, Stradbroke, and Whitsunday Islands), extending continuously along the coast up to Bowen. In north QLD, L. grayi primarily occurs in upland areas such as the Atherton Tablelands, Hervey and Paluma Ranges, with the northernmost extent of its range appearing to be the western edge of the Carbine Uplands. The range of L. grayi also extends into inland QLD as far as Mungalalla in the south, and Carnarvon National Park, Torrens Creek, up to Blackbraes and Undara National Parks in the north.

Habitat.— Occurs in a variety of habitats including sclerophyll and open woodland, Melaleuca wetlands, brigalow, coastal heathland, urban, and agricultural areas. Usually found in association with sandy and sometimes granitic substrates, basalt plains, sandstone hills, and plains.

Conservation status.— Given its substantially widespread distribution (. 550,000 km 2) and lack of evidence for population fragmentation or decline, L. grayi likely qualifies for the listing of Least Concern under the IUCN Red List Criteria ( IUCN Standards and Petitions Committee, 2022).

Ecology.— Breeding occurs in static or slow-flowing aquatic habitats such as ponds, dams, road-side ditches, swamps, and wallums ( Anstis, 2017; T. Parkin, pers. obs.). Males typically call from concealed positions amongst vegetation or floating in water. According to FrogID data, the species is most often recorded calling from dams, ponds, and flooded areas, particularly within rural and natural landscapes. The male calling period is from November to February, with some calling activity in September, October, and March. Tadpole development detailed by Davies (1992) and Anstis (2017). Tadpoles are highly acid-tolerant, withstanding a range from circumneutral–pH 3.0 ( Hines and Meyer, 2011; Hird et al., 2022).

Figures

FIG. 12. Holotype of Heliorana grayi, NHMW 4695. (A) Left-side profile, (B) hind foot, (C) dorsal profile, (D) ventral profile. Images copyright Alice Schumacher, NHM Vienna.

FIG. 13. Images in life of Limnodynastes grayi. (A) AMS R.188151, female, Dirty Creek, north coast, NSW. (B) AMS R.188350, female, Tyndale, north coast, NSW. (C) AMS R.185843, male, Yetman, Northern Tablelands, NSW. (D) QM J97851, male, Watsonville, Atherton Tablelands, Qld. (E) QM J97848, male, Hervey Range, Qld. (F) QM J97857, female, Mount Carbine, Qld.

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. 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.