Kaloula mediolineata

Vassilieva, Anna B., 2021, Larval morphologyof three syntopic species of Kaloula Gray (Anura: Microhylidae) from Vietnam, Zootaxa 4952 (1), pp. 71-86 : 77-78

Kaloula mediolineata

Tadpole description. External larval morphology of Kaloula mediolineata is described based on eight tadpoles (Stages 37–38) from Binh Chau–Phuok Buu NR (ZMMU A-7571) and shown in Fig. 3 A,B ; the main morphometric characters and body proportions are given in Table 3 .

In dorsal view ( Fig. 3A ), body broadly oval, with the maximum width at the gills level; snout bluntly rounded. In lateral view ( Fig. 3B ), body depressed dorsoventrally, especially in its rostral part. Eyes lateral, relatively small; pupils oriented laterally. Nostrils closed at the stages under description. Very thin nasolacrimal groove extending laterally from the narial protuberances to the anteroventral margin of the orbit. Spiracle ventral, medial, transversal, located at the rear part of the belly; relatively wide, slit-like ( Fig. 5B ). Vent tube medial, oblique; vent opening located at the ventral edge of the ventral fin. Tail moderately long, lanceolate, with a rather broadly tapering, rounded tip. Tail musculature rather weakly developed. Tail fins tall, reaching their maximum height at the medium third of its length. Dorsal fin originating slightly anterior to the body-tail junction, on the rear dorsum, nearly equal to or slightly lower than the ventral fin. Small patch (1.2–1.5 mm in length) of thickened skin visible on the base of dorsal fin posterior to body-tail junction. Mouth slightly upturned, dorsoterminal, without keratinized elements. Upper labium short, arched, deeply concave from the dorsal view, with a medial notch; lateral flaps slightly projecting forwards beyond the snout edge. Lower labium inverted W-shaped, with two smooth semicircular lateral flanges fringed with a row of short delicate papillae ( Fig. 6B ).

Coloration. Vital coloration is almost uniformly light-brown above, with a delicate darker marbled pattern; belly and spiracle membrane are transparent; tail axis is darkly pigmented, dorsal fin has scarce brownish-grey speckling, ventral fin is almost transparent. Iris is black, with a thin golden rim around the pupil. In preservative, the brown tints fade to yellowish-grey.

Geographic variations. In comparison with tadpoles from Binh Chau NR, the larvae from Yok Don NP have slightly longer tails with more developed musculature (wider tail base) and lower tail fins; the slit-like spiracle of these tadpoles is located somewhat rostrally and has a shorter covering membrane.

Metamorphs. Young metamorphs of Kaloula mediolineata ( Fig. 3C ) have stocky appearance, finely granular skin and bulging, lateral eyes. Limbs are slender, digits are thin, delicate, without enlarged tips. Ground coloration is dark brown, with distinct light-brown or yellowish dorsolateral stripes and a transversal stripe on the rostral part of the head; short light medial stripe is seen on the rear back; the upper arms and dorsal surface of the thigh are with pinkish or orange patches. Undersides are brownish-grey with whitish marbling. SVL 8.60–13.10 (10.90 ± 1.30) mm (n = 14).

Coexisting tadpoles. In Binh Chau–Phuok Buu NR and Yok Don NP, tadpoles of Kaloula mediolineata were observed in temporary ponds with larvae of K. pulchra and other frog species: Glyphoglossus molossus Günther , G. guttulatus , Microhyla heymonsi , M. mukhlesuri , M. pulchra (Microhylidae) ; Polypedates megacephalus (Rhacophoridae) ; and “ Hylarana ” lateralis ( Ranidae ).

Figures

FIGURE 3. External morphology of a Kaloula mediolineata tadpole from Binh Chau–Phuok Buu NR (ZMMU A-7571), Stage 36, TL 27 mm, (A) dorsal view, (B) lateral view, and (C) a young metamorph, St. 46, SVL 10.8 mm. Abbreviations: sp spiracle, v vent. Photo by V. Trounov.

FIGURE 5. Spiracle morphology, in ventral view: (A) Kaloula indochinensis ZMMU A-7570, (B) K. mediolineata ZMMU A-7571, and (C) K. pulchra ZMMU A-7575. Abbreviations: sp spiracle, v vent.

FIGURE 6. Mouthparts morphology, in dorsal view: (A) Kaloula indochinensis ZMMU A-7570, (B) K. mediolineata ZMMU A-7571, and (C) K. pulchra ZMMU A-7575. Abbreviations: llab lower labium, ulab upper labium, pap papillae.