Synapturanus artifex, Osorno-Muñoz & Gutiérrez-Lamus & Lynch & Keeffe & Caicedo-Portilla & Chan & Tonini & De Sá, 2023

Osorno-Muñoz, Mariela, Gutiérrez-Lamus, Doris L., Lynch, John, Keeffe, Rachel, Caicedo-Portilla, José Rancés, Chan, Kin Nok, Tonini, João F. R. & De Sá, Rafael O., 2023, Three new species of the Synapturanus rabus complex (Microhylidae: Otophryninae) in Colombia with a review of the genus Synapturanus, Zootaxa 5258 (2), pp. 151-196 : 163-168

Synapturanus artifex sp. nov.

Synapturanus sp. “ Amazonas ”

Holotype ( Fig. 6 ). SINCHI-A 6632 (SNC-H 405), adult male, collected at Departamento Amazonas, “area no municipalizada” La Chorrera, cabildo indígena Okaina, Comunidad de Puerto Oriente , Colombia (01°31′43.7″ S, 72°40′38.5″ W), 134 m., on October 18, 2019, by Marco Fidel Rochicón and Vitilio Iyokina.

Paratopotypes. Adult female SINCHI-A 6469 (MOM 7430), adult males SINCHI-A 6631 (SNC-H 404), SINCHI-A 6633 (SNC-H 406), and SINCHI-A 6518 (MOM 7479); all collected along with the holotype by Zabdiel Anderson Ciake, Alfredo Iyokina, Sofonias Iyokina, Diomedes Vigidima, and Epifanio Ciake.

Diagnosis: A species of Synapturanus diagnosed by the following combination of characters: 1) SVL small size, adult female SVL = 17.6 mm (n =1); adult males 15.2–15.9 mm (χ = 15.5 ± 0.1 mm, n = 4), 2) stout and body elongated, 3) head narrower than body, snout pointed in dorsal view, rounded in lateral view, and ventrally distinctly projecting beyond the edge of the anterior upper jaw, 4) symphysis of lower jaw with an unpigmented notch and external nares with a wide and unpigmented rim, 5) tympanum slightly visible, 6) vocal slits absent, 7) rounded choanae, about equal in diameter to the unpigmented edge of the external narin, 8) vomerine teeth absent, 9) hand formula III>IV>II>I, digits becoming thinner towards their distal ends, fingertips rounded or slightly pointed, fingers bordered by a thin fringe, interdigital membrane absent, 10) subarticular tubercles absent, thenar tubercle elongated, palmar tubercle rounded with undefined edges, 11) adult males with a protuberant and oval-shaped glandular area on the internal surface of distal forearm, extending from the wrist to the middle of the distal forearm and dorsally visible, 12) relative lengths of toes IV>III>V>II>I, toes are thin and subcylindrical with a distal rounded or lanceolate widening, with thin fringes extending from the base of the digits to their distal end, digits lack webbing, 13) inner metatarsal tubercle small and elongated, outer metatarsal tubercle absent, subarticular tubercles absent, unpigmented subarticular spots on toes, 14) knee, heel, and wrist with skin folds, 15) cephalic groove distinct, extending over the head and tympanum and reaching and extending beyond the lower jaw articulation and reaching or distinctly crossing over entire throat, 16) in life dorsal body surfaces dark brown, with or without pale dorsal spots, occipital groove area light brown, edge of tympanum with small orange spots, ventral area of flanks greyish, oblique light brown to orange stripe begins posterior to the eye and extends over the tympanum and broadening towards the arm, ventrally, 17) canthal stripe present or absent, if present poorly defined; canthal stripe formed by a series of small, and discontinuous cream spots, extending from the rostral tip and dorsal to the flank, 18) in life ventral surfaces dark brown on snout and on edges of throat and its anterior surface, lighter on the posterior half of the throat; chest with two triangular-shaped spots that do not meet medially, most of the belly surface translucent, lineae masculinae (Davis and Law, 1935) present, ventral surfaces of thigh light brown, the remaining of ventral leg surfaces dark brown, hands and feet dark brown, thenar and inner metatarsal tubercles, subarticular surfaces, and tip of digits unpigmented, 19) forearm gland cream-colored in preserved specimens.

Synapturanus artifex sp. nov. can be differentiated from S. rabus (traits in parenthesis) in being somewhat smaller, SVL 17.6 mm in one female (vs. 17.2-19.0 mm) and SVL 15.2–15.9 mm in males (vs. 16.2-16.6 mm); two males have few and poorly defined pale spots on the back (absent in S. rabus ), S. artifex sp. nov. lacks irregular markings on the posterior limbs (most specimens have irregular spots on one or both legs in S. rabus ), gray flank, a light brown stripe runs obliquely posteroventral to the eye and broadening towards the arm (uniformly dark brown), entire belly, central area of chest, and proximal throat translucent gray, lacking brown pigmentation (only the central part of belly is translucent gray).

Synapturanus artifex males are smaller than S. danta (SVL 15.2-15.9 vs. 17.6-17.9). Synapturanus artifex sp. nov. is smaller than S. latebrosus sp. nov. (traits in parenthesis) SVL 17.6 mm in one female (vs. 20.0-22.0 mm) and SVL 15.2-15.9 mm in males (vs. 18.1-19.0 mm). Synapturanus artifex sp. nov. has a longer tibia, 42% of SVL (vs. 37%), and also larger eyes than S. latebrosus sp. nov. judging by the ED/END ratio, 0.7 in average for both sexes (vs. 0.6). Synapturanus artifex sp. nov. has a broad, unpigmented midventral area that extends over the chest and throat, whereas in S. latebrosus sp. nov. it is narrow and circumscribed to the belly. In S. artifex sp. nov. the cephalic groove crosses over the entire throat whereas in S. latebrosus sp. nov. it slightly extends beyond the lower jaw.

Synapturanus artifex sp. nov. differs from S. sacratus sp. nov. (traits in parenthesis) in being slightly larger, SVL 17.6 mm in one female (vs. 16.9, 17.3 mm in two females) and SVL 15.2 -15.9 mm in males (vs. 14.0, 15.0 mm in two males). Synapturanus artifex sp. nov. exhibits a poorly defined faint canthal line when present (vs. a conspicuous and continuous canthal stripe that becomes discontinuous over the body flanks); in life, S. artifex sp. nov. has a thick, light brown to orange stripe running obliquely over the tympanum toward the ventral arm (vs. not evident in S. sacratus sp. nov.); cephalic groove distinctly crosses over the entire throat (vs. cephalic groove slightly extends beyond the lower jaw).

Synapturanus artifex sp. nov. with SVL 15.2-15.9 mm in males is clearly smaller than S. mirandariberoi (SVL 27.0– 31.7 mm in males), S. salseri , (SVL 23.7-26.4 mm in males), S. zombie (SVL 37.0- 40.6 mm in males), S. mesomorphus (SVL 22.9-26.0 mm in males), and S. ajuricaba (SVL 29.3-33.2 mmv in males). Synapturanus artifex sp. nov. lacks any pattern of speckles, spots or blotches on the back present to a greater or lesser extent in the above-mentioned species, although the holotype and another male of S. artifex sp. nov. shows few whitish spots of diffuse contours. In S. artifex sp. nov., the forearm gland is scattered and reaches up to the middle vs. protruding and concentrated towards the wrist in S. salseri .

Description of Holotype. An adult male with a protruding and elongated glandular surface, broader near the wrist, on the inner distal forearm; the glandular area extends over the middle of the forearm and is dorsally visible; body smooth, ovoid in dorsal view, small (SVL = 15.5 mm); head triangular, almost as wide as long (HL = 4.2, HW = 4.1), snout tip acuminate, snout projects beyond the anterior edge of the upper jaw (SL/SW= 0.7); nostrils with a distinct light colored rim, directed laterally; the eye–nostril distance is slightly greater than the eye diameter (END = 1.5 mm, ED = 1.2 mm), canthus rostralis defined, loreal region concave below marked by a distinct groove that reaches from the antero–ventral edge of eye to the posteroventral edge of nostril, interorbital area concave, IOD = 2.2 mm, without occipital fold, a distinct shallow cephalic groove extending over the tympanum and barely exceeding the level of the lower jaw; tympanum visible, TD = 0.9 mm; vocal slits absent, tongue less wide than the oral cavity, tongue thin on posterior free edges; vomerine teeth absent; rounded choanae widely separated. Anterior and posterior limbs robust and short, hands without webbing, finger relative lengths III>IV>II>I, hand digits distally pointed, with narrow fringes on digits, subarticular tubercles absent, subarticular surfaces light colored, small and oval thenar tubercle located at the base of finger I, palmar tubercle rounded with poorly defined edges; distinct folds on knee and heel, less distinct on wrist and metatarsal area; toes lack webbing, toes subcylindrical and slightly expanded distally, distal tips lanceolate and flat in lateral view, except toe I that is distally pointed, toes with narrow fringes along their length, external edge of toe I reaches the ventral edge of the internal metatarsal tubercle; subarticular tubercles absent, inner metatarsal tubercle elongated, small, at the base of toe I; toes relative lengths IV>III>V>II>I; tibia length TBL = 6.7 mm, about 43% of snout–vent length.

Live coloration. Dorsal body surfaces dark brown with few and poorly defined whitish spots, ventral flank gray, light brown band extends from behind the eye and broadening towards the arm, iris dark brown, dorsal articular surfaces and distal tips of fingers and toes unpigmented. Ventrolateral surfaces of throat dark brown distally as well as the snout, surfaces of hands and feet, forelimbs, tibia, and feet, light brown on medial and proximal areas of throat, as well as two separate patches on chest; edges of belly and thighs translucent gray, translucent, whitish central belly without brown pigmentation as in medial area of chest and over the fold between the throat and chest, lineae masculinea visible. Subarticular surfaces of fingers and toes unpigmented.

Coloration of Preserved Specimens. Dorsally dark brown, with diffuse white to cream dots, ventral flanks and post-ocular band broadening towards the arm cream, the translucent ventral areas in life turn into light cream. Articular surfaces on fingers and toes cream.

Measurements of Holotype (mm). SLV 15.5; HL 4.2; HW 4.1; HL/ESD 1.8; SL/SW 0.7, TD 0.9, ESD 2.3, END 1.5, ED 1.2, ED/END 0.8, TBL 6.7, IOD 2.2, TBL/SVL 0.4.

Variation in the type series. Measurement data for the type series are given in Table 2 and Table S2 . The canthal stripe is present in the female and two males; in the female SINCHI-A 6469 it is barely visible, discontinuous, and reaches the flank; in male SINCHI-A 6631 is distinct, discontinuous, and extends only to the area above the insertion of the forearm; in male SINCHI-A 6518 consists of dots over the posterior part of the canthus rostralis and over the eyelid, in male SINCHI-A 6633, as well as on the holotype, the canthal stripe is absent. The posterior surface of the throat can be translucent; the translucent belly can bear areas of small brown dots. Female SINCHI-A 6469 has two visible eggs (3.5 and 1.6 mm) at their longest side.

Etymology. A Latin noun in aposition meaning artist, in allusion to the skills and extraordinary designs that Okaina, Uitoto, Bora, and Muinane indigenous peoples capture in their basketry in which they depict their life in nature.

Distribution ( Fig. 4 ). Synapturanus artifex sp. nov. is known only from the type locality.

Tadpole ( Fig. 7 ). During a sampling at Comunidad San Rafael del Caraparaná, “área no municipalizada El Encanto”, on April, 2022, one clutch, with two larvae was found in the soil, when removing the rootlets layer. The two larvae at stage 35 ( Gosner 1960) have a total length of 11.9 and 10.4 mm, a body width of 4.2 mm and a tail length of 6.4 and 5.7 mm respectively. Each larva is embedded in a viscous and translucent jelly about 9.5 mm in diameter and the complete posture contained in its hole in the ground measures about 19 mm. The larvae were pinkish in life, cream in preservative, with fine brown marbling on the head and along the dorsal midline extending up to the tail proximally. No opercular folds are visible. The tail is oval in cross section, without fins, and it is 54% of the total length.

Advertisement Call ( Fig. 8 ). Calls of Synapturanus artifex sp. nov. were recorded from two individuals. The first individual recorded on October 19, 2019 at 20:00 hrs., air temperature of 26.9°C, and 91% relative humidity was not possible to collect with SINCHI-A 6631(https://doi.org/10.6084/m9.figshare.16943425). It was recorded from Puerto Oriente, at 134 m., “área no municipalizada” La Chorrera (1°31’43.7″S, 72°40’38.5″W), Departamento Amazonas, Colombia. The second individual corresponds to voucher SINCHI-A 7110 ( Fig. 8 ), (https://doi. org/10.6084/m9.figshare.16943425) recorded on August 30, 2021 at 21:30 hrs., air temperature of 25.6°C, and 81% relative humidity recorded from Puerto Oriente, at 134 m., “área no municipalizada” La Chorrera (2°31′43.7″S, 72°39′53.6″W), Departamento Amazonas , Colombia ( Table 3 ) .

The call of Synapturanus artifex sp. nov. (n = 3) consists of single (one pulsed note, Guild C sensu Emmrich et al. . 2020) tonal notes (mean note length 0.040, range 0.029 -0.052 seconds, SD=0.007) and interval between notes between 5.35 and 17.54 seconds (χ = 7.52), dominant frequency between 1639 and 2224 Hz (χ = 1904 Hz, SD=216.9). The calls have a descendent modulation frequency.

Natural History. In 2019, specimens were collected in a secondary forest during nights with light rain; we found them by gently removing the thick layer of rootlets of the floor, below the leaf litter. In 2021, specimens were collected on a night with no rain, but after a heavy downpour in the afternoon. They were calling everywhere and the caller specimen SINCHI-A 7110 ( Table 3 ) was collected in an “indigenous chagra” (traditional crop system), about half a hectare in size, with no trees to shade the ground in the daytime. According to the owner of the “chagra” this forest named “monte bravo” was cut down to make the settlement 40 years ago, this “chagra” area has been cut and burned several times, most recently a year ago. The male was singing in the root of a bush about 10 cm depth under the rootlets. In 2022, specimens were collected in a secondary forest which was used as a cattle breeding pasture in the 70’s. The adults were found under the rootlets, about 10 cm depth; in the same microhabitat where the adults were found, one postures with two larvae was collected in a small hollow in the soil.

Figures

FIGURE 4. Current known distribution of new species of Synapturanus; symbols with black edges and a black dot identify type localities; the pentagon corresponds to S. sp. “Colombia” (Fouquet et al.. 2021a) which was homogenized as S. latebrosus in this study.

FIGURE 6. Synapturanus artifex sp. nov. Preserved holotype male SINCHI-A 6632 (SVL=15.5mm), (A) dorsal, (B) ventral, (C) lateral views; holotype in life, (D) dorsolateral, and (F) ventral views; alive paratopotype female SINCHI-A 6469, (E) lateral, and (G) ventral views.

FIGURE 7. (A) Synapturanus artifex nest in a shallow hole under rootlets, Departamento, Amazonas “área no municipalizada” San Rafael de Caraparaná, (B) Tadpoles close up.

FIGURE 8. Advertisement call of Synapturanus atifex sp. nov. (SINCHI-A 7110, male, SVL= 15.45 mm). (A) spectrogram, (B) oscilogram, (C) power spectrum.