Elachistocleis ovale ovale (Schneider, 1799)

Jowers, Michael J., Othman, Siti N., Borzée, Amaël, Rivas, Gilson A., Sánchez-Ramírez, Santiago, Auguste, Renoir J., Downie, J. Roger, Read, Morley & Murphy, John C., 2021, Unraveling unique island colonization events in Elachistocleis frogs: phylogeography, cryptic divergence, and taxonomical implications, Organisms Diversity & Evolution (New York, N. Y.) 21 (1), pp. 189-206 : 196-197

Elachistocleis ovale ovale —Parker 1927:4 Elachistocleis ovalis — Kenny 1969:68

Holotype: UWIZM 2016.22 .56, a female from Trinidad, West Indies. 7.7 km SE of Arima; along Cumuto Tamana Road , at construction site (10.58664° N, 61.23144° W) collected 1 June 2016 by Alvin Braswell, John Murphy, Mike Rutherford. In amplexus with UWIZM 2016.22 .55. Photographs taken and tissues collected.

Referred material: Trinidad: Aripo Savanna UWIZM .2011.20.7, UWIZM. 2015.18.14, Arena Forest , Cumoto Rd. UWIZM . 2016.22.62, UWIZM. 2017.5.4 ; Nariva Swamp CAREC .A.22, CAREC.A.33.

Diagnosis: A medium-sized Elachistocleis, SUL 28.3– 32.8 mm in four males, 34.8–41.9 mm in four females, characterized by head length about equal to head width, HW about 0.99 (r = 0.89–1.12, n = 4) of length in females and HW 1.09 (r = 1.02–1.11, n = 4) of HL in males (x = 8.62; SD = 5.6; n = 4); the fold of skin on the back of the head extends to the shoulder and then runs along the ventrolateral surface to just in front of the hind leg (may not be present in preserved material) the postcommisural gland is present and obvious in live specimens; tympanum indistinct; dorsum smooth; in preservative black with few minutes scattered white to gray spots; an indistinct, pale vertebral line, from snout to vent; ventral surface is brown-gray with minute pale stippling. There is an abrupt transition from dorsal coloration to ventral coloration ventrolaterally; no spots or coloration in the axillae or groin region; a narrow well-defined red or orange (cream in preserved material) band on the posterior surface of the thighs; the gular region is jet black, the chest and abdomen are gray with fine yellow to cream stippling that extends to the ventral surface of the thighs but not to the tibia or foot which are black. The tips of the digits on the hands tend to be cream, and the toes tend to have cream tips plus off-white marking at the joints of the phalanges. Rear legs 1.02–1.17× the body length.

Holotype measurements: SUL 32.77, HL 10.86, HW 9.12, IND 1.96, END 2.88, IOD 4.48, HAL 6.95, THL 10.49, TL 8.85, FL 17.23. Measurements for referred material are given in Supplementary material Table 4.

Description of holotype: Body ovoid, head small, triangular, slightly longer than broad, head length 119% of head width and 0.33 of SUL. Snout subelliptical in dorsal view, protruding in profile. Nostrils small, not protuberant, directed anterolaterally, closer to tip of snout than to eye, internarial distance is 1.96 mm, eye orbit diameter in two females 2.14 mm. Canthus rostralis rounded; loreal region flat, sloping and rounded to the upper lip; lips not flared. Eyes small, dorsolateral, only slightly protruding. Interorbital space slightly convex, about half the head width. No cranial crests. A well-defined transverse skinfold across back of the head, joints fold around body bending downwards slightly behind the eyes to the shoulder and extends posteriorly to the femoral axial region. Tympanum concealed, supratympanic fold absent. Lower jaw with truncate, fold on posterior edge. Tongue large, oval, heart-shaped with a slight notch on posterior bor- der. Choanae large, subcircular, widely separated. Premaxillary, maxillary, and vomerine odontophores absent. A weak skinfold crossing the chest between axillae. Arms moderately robust, no tubercles, or crests on forearm; a pair of palmar tubercles on base of palm; fingers slender, free, with subarticular tubercles developed, rounded; fingers round not flattened or expanded; terminal grooves absent. Relative lengths of fingers, 1<2>4>3. Prepollex not evident. Legs short, robust. Thigh length longer than tibia, tibia about 0.84 of the femur, and about 0.51 of the foot. Back leg length longer (112% of the SUL). Toes slender, free, not fringed; supranumerary tubercles absent; tips of toes rounded, not flattened, or expanded; terminal grooves absent. Relative lengths of toes, 2<3<1<4<5. (See Table 2 for morphological comparison to all other 19 Elachistocleis species. )

Skin smooth above and beneath. Anal opening not modified, para-anal tubercles absent. In life ( Fig. 7 ), dorsum and dorsal surfaces of limbs grayish brown, pale medial stripe; distinctive mid-dorsal light cream stripe, from between the eyes to the urostyle; a gradation of color and pattern laterally between the dorsal and ventral regions is mostly black with some gray reticulations; venter dark gray, mottled with light gray and yellow; throat dark gray to black with fine white spots; axial region have no flash colors; tiny orange flecks on base of thigh and groin spots on axillae and groin; a well-defined red stripe on the posterior surface of thighs.

Variation in referred material: The variations in body measurements are in Supplementary material 4. The variation in E.

Figures

Fig. 7 a An Elachistocleis nigrogularis in amplexus. b Elachistocleis surinamensis in amplexus. Photography JCM