Allobates paleovarzensis Lima, Caldwell, Biavati & Montanarin, 2010, sp. nov.
Creators: name: Lima, Albertina P.
name: Caldwell, Janalee P
name: Biavati, Graziela
name: Montanarin, Anelise
Publisher: name: Zenodo
Year: 2010
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Amphibia
Anura
Aromobatidae
Allobates
Allobates paleovarzensis

description: Allobates paleovarzensis, sp. nov.
Figures 1 A–1C and 2A–2B
Holotype. INPA-H 20904 (original field number APL 12650), adult male, collected on 27 April 2007 by Albertina P. Lima and Natan da Silva Melo, in the municipality of Castanho, near the town of Careiro da Várzea on the southern margin of Rio Amazonas (03°22’26.3’’S; 59°52’06.4’’W), elevation 50 m. The type locality is 34 km S Manaus on Highway BR 319. The specimen was taken from a small remnant of paleovárzea forest along the margin of a small river, the Paraná do Castanho.
Paratopotypes. Males, INPA-H 20876–20903 and INPA-H 20905, original field numbers APL 12098, 12100, 12102, 12105, 12106, 12108, 12111–12113, 12625–12629, 12635–12643, 12645–12649, 12651; females, INPA-H 20861–20875, original field numbers APL 12099, 12101, 12103, 12104, 12107, 12109, 12110, 12630–12634, 12644, 12652–12653, all collected by APL, Natan da Silva Melo, and Graziela M. Biavati on 15–16 March 2006, 5–13 March 2006, and 27 April 2007 from the type locality.
Etymology. The specific name refers to the paleovárzea habitat in which the species occurs. Paleovárzeas are ancient floodplains of the Amazon River and its tributaries that are no longer subject to seasonal inundation.
Diagnosis. The new species was assigned to the genus Allobates, based on the following characteristics. A cryptically colored, medium-sized species, mean SVL of males 20.1, range 18.3 to 22.4 mm; mean SVL of females 19.8, range 18.7 to 21.7 mm. Finger III of male weakly swollen, 0.12 mm wider than Finger III of female (Fig. 3 A). Dorsolateral stripe present in both sexes, less obvious in some individuals; ventrolateral stripe present, narrow, and distinct; oblique lateral stripe only in inguinal area, short, and diffuse (Fig. 1 C and 1F); male with gray to grayish-violet throat with a lighter center; female with yellowish throat (Fig. 2 D). Rudimentary webbing present only basally between Toes III and IV (Fig. 3 B); median lingual process absent; testes white in preservative, extending one-half length of kidney.
In addition, one presumed population of the new species was included in a molecular analysis by Grant et al. (2006, Fig. 73, new species = “SãoFrancisco”), which revealed that it is most closely related to an undescribed species of Allobates (“ReservaDucke”) from Reserva Ducke near Manaus, Brazil. The other three species from the same region as the new species are also included in the analysis and are genetically distinct (Allobates caeruleodactylus, Fig. 73; undescribed species “Manaus1,” Fig. 73; and Allobates nidicola, Fig. 72) from the new species.
Allobates paleovarzensis is distinguished from A. brunneus (Cope, 1887; Lima et al., 2009), A. gasconi (Morales, 2002 "2000"), and A. crombiei (Morales, 2002 "2000") by absence of a distinct dark diamondshaped or hourglass pattern on the dorsum. A. paleovarzensis differs from A. olfersioides in lacking an intercrossing "X" pattern on the dorsum. From A. trilineatus (Boulenger, 1883; Grant & Rodriguez 2001), A. conspicuus (Morales, 2002 "2000"), A. fuscellus (Morales, 2002 "2000"), A. sumtuosus (Morales, 2002 "2000"), A. caeruleodactylus (Lima & Caldwell, 2001), A. granti (Kok, et al. 2006), and A. subfolionidificans (Lima et al. 2007), A. paleovarzensis is distinguished by its larger SVL in both males and females (Allobates paleovarzensis is larger than 18.0 mm, whereas maximum SVL of adults of other species is smaller than 18.0 mm). The call of A. paleovarzensis is distinct from that of A. caeruleodactylus (Lima & Caldwell, 2001), A. granti (Kok, et al. 2006), A. subfolionidificans (Lima, et al. 2007), A. marchesianus (Caldwell et al. 2002a and b), and A. nidicola (Caldwell & Lima, 2003). A. paleovarzensis is distinguished from A. masniger by the absence of a dorsolateral stripe (present in A. paleovarzensis) and lack of swollen Finger III (weakly swollen in A. paleovarzensis). A. vanzolinius has a more elongate body form and less robust limbs than A. paleovarzensis.
Description of holotype. An adult male, 19.2 mm SVL (for all measurements, see Table 1); body slender; head slightly longer than wide, head width 93% of the head length, head width 28% of SVL; snout blunt, broadly rounded to nearly truncate in dorsal view (Figs. 1 A and 1D) and acutely rounded in lateral view (Figs. 1 C and 2A), extending past lower jaw (Fig. 1 B); snout 53.8% of head length; internarial distance 34% of head width; eye to nostril distance 72% of eye length; laterally placed nostrils slightly protuberant, opening posterolaterally; tympanum round, directed posterolaterally; tympanic membrane inconspicuous, 37.5% of eye length; posterodorsal part of tympanum partially concealed by slip of m. depressor mandibulae; tongue nearly twice as long as wide, attached anteriorly, rounded along posterior margin; median lingual process absent; vocal sac and vocal slits present (Fig. 1 C). Teeth on premaxilla and maxilla imperceptible under light microscope at 50x magnification.
Skin granular on dorsal surface, granules weakest on head; skin on dorsal surface of legs granular. Skin on ventral surfaces smooth. Forearm slender, 82% of upper arm; ulnar fold absent; HAND III length in males 19.7% of SVL; Finger I 0.9 mm longer than Finger II when fingers appressed; Finger II similar size to Finger IV; Finger IV extends midway to distal subarticular tubercle of Finger III; Finger III>I>II=IV (Fig. 3 A); basal webbing between fingers absent; palmar tubercle nearly round, 0.45 mm diameter, 12.1% of hand length; thenar tubercle oval, one-third diameter of palmar tubercle (Fig. 3 A); one subarticular tubercle present on Fingers I, II, and IV, two subarticular tubercles present on Finger III (Fig. 3 A); basal subarticular tubercles on Fingers I and II largest, nearly equal in size, basal subarticular tubercle on Finger III smaller than that on Fingers I and II, distal subarticular tubercle on Finger III and subarticular tubercle on finger IV smaller; nearly equal in size. Fingers lack fringes; discs on all fingers expanded; Finger III weakly swollen, width of disc on Finger III 0.70 mm, disc 0.25 mm wider than width of finger (Fig. 3 A).
Hindlimb robust; TL 46% of SVL; FL 38.6% of SVL; relative length of toes IV>III>V>II>I; basal webbing present only between Toes III and IV; lateral fringes absent on all toes, Toe I reaching distal edge of subarticular tubercle of Toe II when appressed; discs on Toes I, II, III, and IV larger than width of toes; disc on Toe V slightly larger than toe; disc width of Toe IV 0.60 mm; inner metatarsal tubercle oval; outer metatarsal tubercle round; median metatarsal tubercle absent. Metatarsal fold present, distinct proximally; tarsal fold absent, tarsal keel distinct, short, and elliptic. One subarticular tubercle on Toes I and II; two on Toes III and V; three on Toe IV. Basal subarticular tubercle on Toe IV poorly defined (Fig. 3 B).
Variation within type series. No significant difference was found in SVL or most other measurements of 30 males (including the holotype) and 15 females (SVL, t = 0.255, df = 43, P = 0.281). We therefore describe variation of all 45 specimens together regardless of sex unless otherwise noted. HW 26–31% of SVL, SL 41– 55% of HL; IN 31–41% of HW; EN distance 27–37% of HW; tympanic membrane inconspicuous, round, 33– 49% of EL; skin granular on dorsal surface, weaker on head; dorsolateral stripe present in most live specimens, absent or diffuse in preserved specimens; narrow ventrolateral stripe present in preserved and live specimens; oblique lateral stripe present only in inguinal area, diffuse, in some individuals consisting of tiny whitish spots (Figs. 1 F and 2C, 2E, and 2F).
Forearm slightly longer than upper arm; HAND III, on average, 21% of SVL; basal webbing between fingers absent in all specimens; palmar tubercle nearly round, average diameter 0.47, 12% of HAND III; subarticular tubercles on fingers similar in size and number to the holotype in all specimens. No fringes on fingers; all discs on fingers expanded; Finger III weakly swollen in all males, width of middle of the third phalange on Finger III in males (mean 0.44 ± 0.05) significantly greater than in females (mean 0.31 ± 0.04 mm; t = 8.2, df = 43, P <0.000).
TL 41–49% of SVL. Ratio of FL to SVL in males (mean 0.39 ± 0.03) significantly (t = 3.04, df = 43, P = 0.004) greater than in females (mean 0.37 ± 0.01); FL 46% of SVL in males and 45% in females; basal webbing between Toes III and IV present in all specimens; disc width on Toe IV 0.50; in all specimens inner metatarsal tubercle oval, outer metatarsal tubercle round, median metatarsal tubercle absent; metatarsal fold weak, present in all specimens; tarsal keel distinct, short, and curved. Subarticular tubercles on toes as in holotype.
Color of adults in life. Color in life of the holotype is shown in Figures 2 A–B. Background color of dorsum uniform light brown, becoming slightly darker on head. Some specimens have dark brown markings on the head, extending in a few specimens onto the dorsum (Figs. 2 C and 2E). The tan dorsolateral stripe appears more distinct in those specimens with a dark brown dorsum (Fig. 2 E). Tips of the granules on the dorsum are dark brown, contrasting with the lighter brown background in many specimens. Upper surface of arm orange-brown with some irregular light brown blotches. Dorsal surface of leg light brown with darker brown granules. Some individuals have a thin dark brown vertical stripe on the middle of tibia and the foot. Reproductive males have a grayish-violet throat, lighter in center, and upper chest with melanophores dispersed on the vocal sac, whitish belly, and yellow flank and ventral surface of the upper thigh (Fig. 2 B and 2D); adult females have a light yellow throat and chest, and a deeper yellow belly; in females the leg has a yellow wash and lacks melanophores (Fig. 2 D). Both sexes have a continuous narrow white ventrolateral stripe beginning on the upper lip or below the eye and extending to the groin; below the ventrolateral stripe, the side is flesh with evenly scattered white flecking. The base of the thigh has a cream crescent-shaped mark; ventral surface of the hand and foot is brown (Fig. 2 D).
Color of adults in preservative. The color in preservative of the holotype is shown in Figures 1 A–1C. The following description of color in preservative was based on 44 specimens. In 23 specimens, the surface of the dorsum is generally uniform dark brown (as in Fig. 4 E–4G). In these specimens, the dorsolateral stripe is distinct and extends from the snout and above the eye to the tip of the urostyle. In 21 specimens, the dorsum is pale brown with scattered darker brown granules. In these specimens, the head is darker than the rest of the body, and the dorsolateral stripe is inconspicuous (similar to the holotype, Fig. 1 A, and a female, Fig. 1 D, and to specimens in Figs. 4 A–4C). The upper surface of the arm is cream with dark brown flecks. The upper surface of the leg is pale brown with a narrow dark brown stripe on the tibia in 27 specimens. In 15 specimens, the foot is pale brown with distinct dark brown blotches; these blotches are diffuse in 29 specimens. The white ventrolateral stripe begins below the eye, extending below the tympanum and above the arm insertion to the groin. The lateral surface below the ventrolateral stripe is cream with scattered light brown flecks. A distinct dark brown lateral band extends from the tip of the snout through the eye to the vent and increases in width from snout to vent. The oblique lateral stripe is present inguinally in the lateral dark brown band, and is short and diffuse, containing small whitish spots in some specimens. The tympanum is dark brown above and white below where it converges with the ventrolateral stripe in all specimens. The ventral coloration, although sexually dimorphic in live individuals, fades in preserved specimens (Fig. 1 B and E). Reproductive females have a cream throat, chest, and belly without melanophores; males have a light to medium gray vocal sac and upper chest (Fig. 5). A crescent-shaped paracloacal mark is present in all specimens (Fig. 4).
Description of vocalization. The call of this species consisted of groups of single notes separated by intervals with a mean of 1.8 seconds. The notes within each call were separated by intervals of 0.113 seconds (Fig. 6). The mean number of notes produced per call was 11.5 ± 4.5 and varied from 3 to 21 notes. The mean number of calls per 1 min section was 17.2 and varied from 12 to 24. Twenty-one to thirty-six notes and internote intervals (3 per call) per male were measured per 1 min period. The mean note duration for the 8 males was 0.043 ± 0.007 and varied from 0.025 to 0.060 s. The inter-note intervals within calls of the 8 males had a mean of 0.113 ± 0.030 s and a range of 0.065 to 0.266 s. The duration of calls had a mean of 1.65 ± 0.55 s (range 0.72 to 3.02 s), and calls were separated by intervals of 1.8 ± 0.58 s (range 0.26 to 3.65 s).
Considerable variation occurred in the spectral parameters within 1-minute sections of individual calls, but the frequency distribution was normal. We used the mean maximum and minimum values to characterize the maximum, high, and low frequency traits for the 8 males. Because the spectral parameters were correlated [maximum and high (r = 0.82), maximum and low (r = 0.67), low and high (r = 0.63)], we present maximum frequency to illustrate individual variation in detail (Table 2). A sub-sample of 21 to 36 notes emitted during a period of 1 minute was analyzed for each male. For the 8 males combined, the means for low, high, and maximum frequency were 4.13 kHz (range 3.51–4.58 kHz), 4.72 kHz (range 4.20–5.10 kHz), and 4.45 kHz (range 4.05–4.93 kHz), respectively (Fig. 6).
Description of tadpole. Descriptive statistics for 10 characters were based on 119 tadpoles from stages 25 to 41 (Table 3). The following description is based on a sample of 32 tadpoles in stage 39 from lot INPA-H 20916 (Table 3). Tadpoles in this lot were collected from clutches in stage 25 and reared to stage 39 before preservation.
Body ellipsoid in dorsal view (Fig. 7 A) and flattened in lateral view (Fig. 7 B). Body and tail 36.0% and 64.0%, respectively, of TL; body wider than deep; BH 67.4% of BW at level of spiracle; BW at level of eyes 80.4% of BW at level of spiracle; snout bluntly rounded in dorsal and lateral views; END 0.66 ± 0.04, 62.4% of ED; eyes dorsal and directed laterally; ED 1.07 ± 0.04; IOD 27.3% of HW at level of eyes. Small naris located dorsolaterally and directed anterolaterally; internarial distance 1.74. Sinistral spiracle a free tube, directed dorsolaterally, 1.1, located slightly posterior to mid-body and below lateral midline (Fig. 7 C). Vent tube 1.10 ± 0.19 long, dextral. Caudal musculature deeper than dorsal and ventral fins. Upper fin deeper than lower fin, 0.11 ± 0.01 at midtail. Upper fin originates 0.22 ± 0.02 posterior to junction of body and tail.
Oral apparatus emarginate, located anteroventrally, 0.186 ± 0.01 in width (Figs. 8 A and 8B); anterior labium with large papillae only on lateral margin, 4 on each side; posterior labium entirely surrounded by 16 to 19 papillae; papillae on posterolateral margin same size as the posteromedial papillae (Fig. 8 A); submarginal papillae absent; lower jaw sheath V-shaped, deeper than upper jaw sheath; transverse width of upper sheath 0.80 ± 0.004, or 43% of oral disc width. Upper and lower sheaths serrated; serrations extend entire length of sheaths; labial tooth row formula 2(2)/3(1); tooth row A-1 complete, 1.4 ± 0.07; tooth row A- 2 interrupted medially, consisting of two widely separated rows at level of upper jaw sheath, segment 0.43 ± 0.05 in length, with gap of 0.56 ± 0.06. Lower tooth rows shorter than A-1; P-2 (1.32 ± 0.06) slightly longer than P-1 (1.30 ± 0.08) and P-3 (0.93 ± 0.06) shorter in length than P-1 or P-2 (Fig. 8 B).
Color of tadpole in life. Dorsal and lateral surfaces of the body are yellow-brown with scattered irregular dark brown flecks (Fig. 8 C). All specimens have a distinct dark brown bar extending from snout through eye to approximately midbody. The ventral surface is transparent with intestines, heart, and other organs visible though skin (Fig. 8 D). The anteroventral surface has a transverse irregular line of dark brown and white flecking; white flecking is present elsewhere on venter. The tail musculature is light yellowish brown, similar to the body. The fins are transparent with tiny irregularly scattered black flecks.
Color of preserved tadpoles (INPA-H 20916). The dorsal and lateral areas of the body are light grayish brown with dark brown flecks that give a mottled appearance (Figs. 8 C and 8D). All specimens have a brown dorsolateral stripe from the snout through the eyes to approximately midbody. The anteroventral surface of the body is grayish, opaque; the remainder of the ventral surface is transparent and immaculate; the heart and intestines are visible though the skin. The tail muscle is grayish brown; tail fins are opaque with irregular brown reticulations.
Comparison with other species. The free-swimming tadpoles of Allobates caeruleodactylus and A. marchesianus differ from those of A. paleovarzensis in having many fewer papillae on the lower labium; in addition, the papillae on these two species are much longer. Both these species have distinct bars on the tail (Caldwell et al., 2002a). Labial tooth rows P-1, P-2, and P-3 of the free-swimming tadpole of A. subfolionidificans are subequal, in contrast to A. paleovarzensis, in which P-3 is shorter than P-1 and P-2 (Lima et al., 2007). A. paleovarzensis has a distinct dark brown bar from the snout through the eye to midbody, which is lacking in the free-swimming tadpole of A. brunneus (Lima et al., 2009). The tadpole of Allobates nidicola is endotrophic and develops entirely in a terrestrial nest; this highly modified tadpole lacks an oral disc and a spiracle.
Natural history. Allobates paleovarzensis occurs in paleovárzea forest near streams. Like other species of Allobates in the region, individuals are most active in early morning and late afternoon. Males typically call from 0 530 to 0 830 h, and again from 1630 h until dusk. On rainy or heavily overcast days, males can be heard calling throughout the day. While generally living in leaf litter on the forest floor, males select calling positions a few centimeters above the litter, such as on leaves or atop small twigs or branches. Calling and reproductive activity occur from the middle of October, depending on timing of the onset of the rainy season, until the dry season starts around the beginning of June.
During reproduction, the male sits on the female and grasps her in cephalic amplexus (Fig. 9 A). Clutches of eggs were typically found in leaf litter on small cup-shaped leaves sheltered by overhanging leaves that formed a roof. Of 21 nests that we located, mean clutch size was 25.5 ± 8.5 eggs (range, 9–47). After development in the nest, tadpoles were transported by males to pools near the streams inhabited by the frogs.
We witnessed many fights between males. When we played a recorded advertisement call to 7 males, they advanced toward the microphone; thus, it appears that males of this species, like closely related species, defend territories. We did not see aggressive interactions between females.
We observed courtship in two pairs of frogs. Males began calling about 0 530 h. After 20 minutes in the first case and 90 minutes in the second, a female approached the male. In both cases, the males hopped slowly toward nest sites and the females followed. Once at the nest, the males continued calling and mounted the females, grasping them in cephalic amplexus (Fig. 9 A). During amplexus, the male stroked the female’s back and head with his hands. After 50 minutes for the first pair and 30 minutes for the second, males left the nests and began calling approximately 50 and 100 cm from the nest. Females remained in the nest and began depositing eggs, straddling them as they were deposited (Fig. 9 B). The female of the first pair took 60 minutes to deposit 16 eggs, whereas the female of the second pair took 50 minutes to deposit 25 eggs; after egg deposition, both females left the nests. After about 110 minutes, the males returned to the nests and sat on the eggs for about 10 minutes, apparently releasing sperm over them (Fig. 9 C). An unusual aspect of the clutches of this species is that the gelatinous capsules surrounding the eggs are opaque (Fig. 9 D). In clutches of most other species we have observed, the gelatinous capsules are transparent.
description: Published as part of Lima, Albertina P., Caldwell, Janalee P, Biavati, Graziela & Montanarin, Anelise, 2010, A new species of Allobates (Anura: Aromobatidae) from Paleovárzea Forest in Amazonas, Brazil, pp. 1-17 in Zootaxa 2337 on pages 3-15, DOI: 10.5281/zenodo.193229