Bioacoustics of Colleeneremia pyrina

Habitat and ecology. Litoria pyrina sp. nov. is commonly recorded via FrogID (>15,000 records from 10 November 2017 – 30 July 2023 ), and is frequently heard calling in disturbed areas, with 30% of FrogID records from suburban or urban habitats and 47% of records in rural areas. Litoria pyrina sp. nov. has been detected calling in all months via the FrogID project but has a core calling season from September to April, with a peak in November and December. Litoria pyrina sp. nov. breeds primarily in lentic waterbodies, with the majority of FrogID records of this species documented by users as being at small ponds (32%), flooded areas (15%) and large ponds (27%). It is absent from extensive areas of subtropical ( Meyer et al. 2001 ) and tropical rainforests ( Meyer et al 2001 ; Williams & Hero 1998 ; Hoskin & Hero 2008 ; Meyer et al. 2020 ;) and from undisturbed wallum (e.g. the sand islands) in south-eastern Queensland ( Hines & Meyer 2011 ).

Comparison with other species. Litoria pyrina sp. nov. is sympatric with L. balatus , L. dentata , and L. electrica but is allopatric with the other members of the L. rubella species group - L. rubella in central and northern Australia and southern New Guinea , L. quiritatus in south-eastern New South Wales, L. congenita and L. pygmaea in New Guinea and L. capitula on the Tanimbar Islands, Indonesia ( Menzies 2006 ; Rowley et al. 2021 ). Litoria pyrina sp. nov. can be distinguished from L. balatus and L. dentata by the absence of a continuous, irregularly edged, dark brown dorsal band (versus presence) and having a more robust body. It can be distinguished from L. electrica by the absence versus presence of chocolate-coloured bars across the dorsum. No morphological characters are known to reliably diagnose L. pyrina sp. nov. from the L. rubella population in central Queensland and New South Wales. Litoria pyrina sp. nov. can be distinguished often from parapatric L. rubella by call, having a higher dominant frequency (1.75–2.97 kHz versus 1.29–2.07 kHz) resulting in an audibly higher-pitched call.

Description of holotype . Adult female ( Fig. 13 ); moderate body size ( 33.73 mm SUL); body moderately flattened and wide; head small (HDL/SUL = 0.26), flattened (HD/SUL = 0.14), and narrow (HDW/SUL = 0.29); head length approximately equal to width (HDL/HDW = 0.90); snout triangular in dorsal view, tip of snout blunt, rounded in profile; canthus rostralis rounded; loreal region steep, concave when considered in conjunction with upper labial margin; crown of head flat; nares ovate, on anterolateral edge of snout, oriented dorsolaterally; eyes small (EYE/HDL = 0.30), pupils oriented horizontally; eye to naris distance 1.2 X eye diameter; tympanum circular with raised annulus; well-developed supratympanic fold angling posteroventrally towards attachment of arm; tympanum and eye subequal in diameter (TMP/EYE = 0.79); arms moderate ([UAL+LAL]/SUL = 0.32), thin; fingers with basal webbing; relative length of fingers I<II<IV<III; tips of fingers with well-developed discs, distinct circum-marginal grooves and narrow fringing, discs relatively wide compared to width of the penultimate phalanx (third finger disc width 1.8 X third finger width); subarticular tubercles rounded; metacarpal tubercles ovate; hindlimbs short (TIB/SUL = 0.39); relative length of toes I<II<III<V<IV; tips of toes with well-developed discs, distinct circum-marginal grooves and narrow fringing; discs slightly smaller than those of fingers (fourth toe disc width 1.1 X toe width); subarticular tubercles distinct, rounded; inner metatarsal tubercle distinct, spatulate; outer metatarsal tubercle absent; toes partially webbed, extending beyond distal tubercle of all toes except IV, where webbing extending between distal and penultimate tubercles. Skin of dorsal surface smooth, lacking dorsolateral folds, parotoid glands and ridges; glandular tissue located between mouth and arm; ventral surface of body granular, smooth on limbs. Colour in preservative. Dorsal background colour pale brown. Wide dark brown lateral head stripe, beginning on snout and wrapping around nares, continuing along loreal region, through eye and tympanum, angling posteroventrally and terminating at the pelvis; between the naris and eye, darker pigment of canthal stripe demarcates loreal region from top of snout; hiatus of pigment on tip of snout forming a V-shape. Ventral surfaces, other than gular region, cream. Posterior surfaces of thighs lack pattern. Measurements (mm) of holotype . SUL 33.7, FOL 19.8, TIB 13.2, FEL 12.3, LAL 6.1, UAL 4.8, HDW 9.8, DFE 6.0, IOD 3.9, IND 1.8, HDL 8.8, HD 4.9, SNT 4.3, EN 3.2, NS 0.8, EYE 2.6, TEY 1.0, TMP 2.1, 3TL 8.2, 3FDW 1.6, 3FW 0.9, PL 10.1, 4TDW 1.3, 4TW 1.2, IMT 1.5. Variation. Morphometric data presented in Table 5 for 10 adult females and 24 adult males reveals considerable variation among vouchered specimens, mostly independent of sex. Females (SUL 30.1–36.5 mm ; mean 33.4 mm ) tended to be longer than males (SUL 27.3–36.0) mm; mean 32.1 mm ); females did not appear more rotund when gravid (though low sample size was small; n = 10); within sexes body shape varied from gracile to robust dependent on preservation. Body width usually wider than head width in females; in males, body width equal to or slightly wider than head width; body moderately flattened to slightly robust. Annulus of tympanum raised relative to skin of temporal region. Moderately-developed to well-developed terminal discs on digits; relative width of finger discs 1.1–2.2 times wider than finger width, and toe discs 1.1–1.8 times wider than toe width, some of which is attributable to artefacts of preservation. Dorsal skin smooth to slightly granular, ventral skin smooth to granular. Colour. Colour variation is described from photographs of six animals taken in life ( Fig. 15 ) and in situ observations. Dorsal colouration broadly uniform across head, body and outer surface of limbs; across individuals dorsal colouration can be fawn, cream, brown, rich chocolate-brown, red-brown, brick-red, grey, or a metallic grey, sometimes whitish in the day; irregular dark brown pigmentation may be present on dorsal surface and appendages, often forming small specks or marbling, extent highly variable. Darker dorsolateral streak occasionally present, generally stronger in inguinal region. Ventral surface uniformly cream, always lighter than dorsal surface; gradual to sharp contrast between dorsal and ventral colouration over dorsolateral region, generally coincides with lateral head stripe when present. Pale patch below eye, variable in lightness and extent among individuals. Distinctly darker lateral stripe originating from a V-shape hiatus on tip of snout, wrapping around nares, passing through eye and tympanum, dissipating variably from above attachment of arm to more posteriorly towards groin, generally more diffuse posteriorly; stripe contrast and intensity varies from well-defined and dark to pale and poorly contrasted. Posterior of thighs and inguinal region pale yellow to dull red extent and saturation variable between individuals, sometimes with spots similar to the dorsal colour. Iris golden to copper-brown; male gular pigmentation dark brown; nuptial pads light to dark brown. In preservative, reddish hues over body tend to be lost, colour and contrast of dorsolateral stripe usually fades, colour of thighs tends to be lost, colour of iris lost. Embryos. Mean diameter of 13 ova (stage 11) from Townsville, Qld was 1.0 mm (0.9–1.1); mean capsule diameter was 2.4 mm (2.1–2.7). Tadpole body and tail shape . Lateral view ( Fig. 8F ): Body and tail shape as for general description. Mid-dorsal profile not typically convex in shape and rises slightly to tail/body junction. Dorsal fin begins just before tail/body junction and rises to its maximum height over middle of tail. Tadpole colour in life. Dorsal view ( Fig. 8G ): Colour varies from darker over eyes, brain, abdomen and vertebral region in small tadpoles, to generally golden, dull golden-brown or grey-brown from early limb development stages, most commonly with a broad, darker mid-dorsal patch. Some develop diffuse, fine darker mottling or a few scattered darker spots from about stage 35 onwards ( Figs 8F, G ). From about stage 40 a broad darker mid-dorsal patch extends down body, bordered on either side by paler continuous irregular band. Dorsal tail muscle usually with fine darker melanophores, sometimes forming transverse bands. Lateral view ( Fig. 8F ): Dorsal pigment merges over sides of body with opaque white and copper sheen. Eyes opaque copper-gold. Tail muscle usually pale with fine melanophores (less numerous posteriorly) or with a darker line along the middle which continues to tip. Fins clear in small tadpoles, finely stippled mainly anteriorly in fully grown tadpoles. Two leucistic tadpoles at stages 33 and 37 were observed from Bluewater, north of Townsville with silver-white body and tail, pink pupil and golden iris. Very fine melanophore stippling just visible over dorsum and hind limb buds. Metamorphs. A sample of seven metamorphs from Mareeba and Charters Towers, north Qld ranged from 14.5– 15.5 mm (mean 14.9) and one from near Julatten, Atherton Tablelands was 16.0 mm. Metamorphs mostly resemble adults and are reddish-brown, with a slight short streak on each side of mid-vertebral region in some and a dark patch in each inguinal region. As in adults, a broad, dark brown lateral stripe extends from snout to groin with a white stripe beneath it from snout to armpit. The specimen from near Julatten ( Fig. 8M had a more distinct, broad dark middorsal band down body dissected by a fine, faint cream vertebral line; sides of body paler sides above dark lateral stripe. Iris coppery red. One leucistic tadpole metamorphosed with normal but paler adult pigmentation. Advertisement call. Call descriptions are based on the calls of 24 males ( Table 4 , Fig. 5 ). The advertisement call of L. pyrina comprises a single, highly pitched multi-pulsed note ( Fig. 6 ). Individuals had a mean call duration of 0.39–0.82 seconds and an average of 21–48 uniformly spaced pulses repeated at a rate of 35.9–105.0 pulses/s. The dominant frequency was 1.75–2.97 kHz.