Pristimantis lassoalcalai, Barrio-Amorós, César L., Rojas-Runjaic, Fernando & Barros, Tito R., 2010

Barrio-Amorós, César L., Rojas-Runjaic, Fernando & Barros, Tito R., 2010, Two new Pristimantis (Anura: Terrarana: Strabomantidae) from the Sierra de Perijá, Venezuela, Zootaxa 2329, pp. 1-21 : 4-10

Pristimantis lassoalcalai sp. nov.

Fig 2

Holotype: MHNLS 18898, an adult female from Cerro Las Antenas, elevation 1827 m, 10°19’40.0”N- 72°35’27.0” W, Sierra de Perijá, Municipio Rosario de Perijá, Estado Zulia, Venezuela, collected on 29 March 2008, by Fernando Rojas-Runjaic, Edwin Infante, Paul Granado, Pio Colmenares and Pablo Velozo.

Paratypes: seven adult females: MHNLS 18460, with immature ova, collected by Gilson Rivas and Tito Barros on 31 March 2007; MHNLS 18877 collected on 29 March 2008, by Fernando Rojas-Runjaic, Edwin Infante, Pablo Velozo, and Paul Granado; MHNLS 18893-97, all collected in the type locality; six adult males ( MHNLS 18873, 18874, 18876, 18878, 18879 and 18900) collected on 29 March 2008, by Fernando Rojas- Runjaic, Edwin Infante, Pablo Velozo and Paul Granado, collected at the type locality.

Diagnosis. Pristimantis lassoalcalai is a small (SVL of males 21.3–23.2 mm [n=6], mean= 22.1 mm; SVL of females 23.2–27.4 [n=7], mean= 25.3 mm) member of the P. unistrigatus species group characterized by: (1) dorsal skin shagreen with a distinct to indistinct middorsal raphe; ventral skin areolate; cranial crests absent; (2) tympanum distinct, about ½ of ED; (3) snout subacuminate in dorsal view, subacuminate in profile; canthus rostralis distinct, rounded; (4) upper eyelid smooth, with small granules; (5) choanae small, round to oval; dentigerous processes of the vomers small, slightly oblique, with 3–4 teeth on each; tongue large, round, ½ free posteriorly; (6) vocal slits on males, single nuptial pads on thumb small, white; (7) Finger I shorter than II; (8) fingers without lateral keels; (9) ulnar tubercles absent; (10) tarsal tubercles absent, calcars usually absent, only apparent in life; (11) inner metatarsal tubercle indistinct and oval, outer small, protuberant; (12) toes without lateral keels; webbing absent; Toes III, IV and V with relatively broad disks, slightly smaller than those on Fingers III and IV; Toe V slightly longer than III; (13) colour in life golden brown to gray, with small irregular dark brown spots; dark brown canthal and supratympanic stripes; a narrow labial whitish stripe; hind limbs barred or not; hidden surfaces of hind limbs pale to dark brown, sometimes with small round white spots surrounded by dark brown. Throat light gray, chest, belly and inferior part of limbs light gray, dark brown marbled or reticulated. Iris metallic golden, finely black reticulated. In preservative, dorsal colour pale to dark grey or bronze, usually unpatterned or with a few irregular marks, including an ill defined interorbital bar; canthal, and supratympanic stripes wide and conspicuously dark grey to black; narrow dirty white labial stripe; ventrally dirty white marbled, spotted or reticulated with gray; in 30% of the individuals there are dirty white flash marks (pale yellow in life) surrounded by black in groin and on hidden surfaces of hind limbs.

Pristimantis lassoalcalai is unique among northern Andean Pristimantis in the following combination of characters: body and head slender, poorly defined marks on dorsum, marbled to reticulated venter; on 30% of the specimens there are pale (pale yellow in life) flash marks on the groin and on the hidden surfaces of the hind limbs; middorsal raphe and short anterior dorsolateral folds; cranial crests absent.

Pristimantis lassoalcalai (characters in parentheses) is here compared with species from cloud forest and paramo in Venezuela and adjacent Colombia (including two species inhabiting paramo in the Sierra de Perijá). The only two paramo-dwelling species in Perijá are known from the Colombian side, though their presence on the Venezuelan side is possible. Pristimantis cuentasi is a paramo dweller with short legs, shank 32.7–39% of SVL (49.6%), can be distinguished by snout rounded in profile (subacuminate), and fingers without distinct disks (moderately large). Pristimantis reclusus , another paramo dweller, robust (slender), with disks on fingers only slightly more expanded than digit (Finger III twice width of adjacent phalanx), and a row of low ulnar tubercles (absent). Pristimantis lassoalcalai is compared with species from the Sierra de Santa Marta in Colombia, the closer Cordillera Oriental de Colombia, Cordillera de Mérida and Sierra de Perijá that lack cranial crests and/or have pale flash marks in the groin and on the hidden surfaces of hind limbs. Pristimantis carmelitae (Ruthven, 1917) has a finger IV reaching the proximal edge of the disc of FIII (shorter, reaching only the proximal edge of the intercalary cartilage), smooth skin on venter (areolate), males lack vocal slits (present), and is a larger species, males 29.9–39.2 mm; females 36.4–48.8 mm (males 21.3–23.2 mm; females 23.2–27.4 mm). Pristimantis insignitus (Ruthven, 1917) has occipital folds (absent), skin on venter smooth (areolate), and first finger longer than second (shorter). Pristimantis megalops (Ruthven, 1917) has shagreen dorsum skin with enlarged warts (warts absent), finger and toes with lateral fringes evident at their bases (absent), and the posterior surfaces of the thighs reticulated (grey with pale spots). Pristimantis sanctamartae (Ruthven, 1917) lack nuptial pads (present), has large pads on outer fingers (moderate), lateral keels on fingers and toes (absent) and ulnar and tarsal tubercles (absent). Pristimantis douglasi ( Lynch, 1996) is a member of the Pristimantis galdi species group ( P. unistrigatus species group), with females having crests (absent), but males lack them and are quite similar in general appearance; P. douglasi , from the northernmost Cordillera Oriental de Colombia, have fingers and toes with fleshy lateral keels (absent), inner tarsal fold (absent), a labial white stripe (absent or ill defined), dark brown venter sometimes with white large spots (dirty white to marbled, spotted or reticulated with gray), usually a narrow white vertebral stripe (absent in the type series of P. lassoalcalai ) and cream lines on canthus, eyelids and back of scapula (absent), iris greenish yellow with a red horizontal streak (metallic golden with greenish tonalities). Rivero (1982) diagnosed his " Eleutherodactylus lentiginosus " group from the Cordillera de Mérida as having cream or yellow spots in the groin and on the anterior and posterior surfaces of the thigh (this is a variable character and its presence or absence is not necessarily diagnostic, CLBA pers. obs.). Pristimantis mondolfii (Rivero, 1982) has a large tympanum, ½ of ED (½), angular canthus rostralis (round), distinct, round outer metatarsal tubercle (indistinct), small plantar supernumerary tubercles (absent), and is larger, females up to 48 mm (KU 181021) (females up to 27.4 mm). Pristimantis melanoproctus (Rivero, 1982) has a large tympanum, ½ of ED (½), lacks vocal slits (present), fingers and toes with lateral fringes (absent), and has basal webbing (absent). Pristimantis lentiginosus (Rivero, 1982) has a large tympanum, ⅔of ED (½), a rounded snout dorsally (subacuminate), and an inner tarsal fold (absent). Pristimantis vanadisae ( La Marca, 1984) has prominent tubercles on eyelids (only small granules), and prominent ulnar, tarsal, and heel tubercles (very low to indistinct). The sympatric P. rivasi sp. nov. is a larger species, females reaching 41 mm in SVL (maximum adult female SVL 27.4); with cranial crests (absent); subacuminate snout in profile (acuminate), truncate snout in dorsal view (subacuminate); broadly expanded finger disks (moderately expanded), and without flash marks in groin or on hidden surfaces of hind limbs (present). Other Perijá species without cranial crests are P. prolixodiscus , P. fasciatus and P. yukpa . Pristimantis prolixodiscus is a member of the P. lacrimosus species group ( P. unistrigatus species group), and is herein reported from The Sierra de Perijá, therefore compared with P. lassoalcalai since it does not bear cranial crests; it has a snout with a pointed papilla at tip (lacking papilla), discs on digits longer than wide (wider than long), fingers and toes with lateral fringes (absent), heel lacking conical tubercle (present in living specimens), venter white (dirty white to marbled), and green on the dorsum (never green); furthermore, P. prolixodiscus is a bromeliad inhabitant (never found in bromeliads) Pristimantis fasciatus has fingers with lateral fringes and basal webbing (absent), toes with lateral fringes and basally webbed (absent), tympanum annulus completely exposed (its posterodorsal section hidden under a supratympanic fold), skin on dorsum finely granular (shagreen), a striped pattern (never striped in the known series). Pristimantis yukpa has lateral fringes on fingers II and III (absent), webbing between toes IV and V (absent), toe V much longer than III, surpassing distal tubercle on TIV (slightly longer, reaching penultimate subarticular tubercle on TIV), an immaculate white venter (white background with grey spots or reticulations) and no inguinal marks surrounded by black (present in many individuals).

Description of the holotype: an adult female, of 26.2 mm of SVL. Body slender; head slightly longer than wide, HW 38.16% of SVL. Snout subacuminate in profile ( Fig. 3 a), subacuminate in dorsal view ( Fig. 3 b); EN slightly shorter than ED; nostrils non- protuberant, directed dorsolaterally; canthus rostralis distinct, rounded; loreal region slightly concave. Upper eyelid without tubercles or warts. Cranial crests absent. Tympanum distinct, 33.3% of ED, surrounded by a tympanic annulus, with a supratympanic fold covering a small portion of its posterodorsal section. Choanae small, round, not concealed by palatal shelf of maxillary arch; vomerine dentigerous processes small, slightly oblique, bearing 4 teeth each, posterior and medial to choanae. Tongue round, slightly notched posteriorly, posterior one third free.

Dorsal skin shagreen ( Fig. 3 c); one large tubercle posteroventral to tympanum present; occipital ridges poorly-defined; middorsal raphe only present, but difficultly detectable, on the head; dorsolateral folds present on the anterior half of the body, low and indistinct. Throat and chest smooth, belly and ventral surfaces of thighs areolate ( Fig. 3 d); posterior surfaces smooth. Ulnar, tarsal, and heel tubercles absent.

Relative lengths of adpressed fingers III>IV>II>I; when adpressed, Finger I not reaching disk on Finger II. Finger disks much broader than long, disk on Finger III twice width of adjacent phalanx; oval except on Finger II, which is rounded; disk on thumb round, not distinctly expanded. Finger II disk on right hand 1.5 times wider than adjacent phalanx. Lateral fringes on fingers absent; webbing absent. Bifid palmar tubercle, and ovoid thenar tubercles low, indistinct; subarticular tubercles protuberant, single, round; supernumerary tubercles protuberant, in rows under each finger ( Fig 3 e).

Hind limbs moderately short; shank 49.6% of SVL. Relative lengths of appressed toes IV>V>III>II>I. Disk on Toe IV slightly smaller than disk on Finger III. Toes without lateral fringes, unwebbed. Disks slightly wider than long, wider than phalanges, horizontally oval, except on Toe I, which is round. Inner metatarsal tubercle oval, indistinct; outer small, protuberant, round; subarticular tubercles protuberant, single, round; four supernumerary tubercles distinguishable under left plant ( Fig 3 f).

Colour in life ( Fig 2a ). Dorsum golden brown with small scattered irregular dark brown spots; head slightly lighter, especially over the external borders of the upper eyelids and snout; with two dark brown stripes, one interorbital, another transversal irregular black bar anterior to the upper eyelids; dark brown canthal and supratympanic stripes; a narrow labial stripe interrupted by lighter transverse intersections. Ill defined dark brown transverse bars on anterior limbs; on hind limbs little more defined over a light grey background; hidden surfaces of hind limbs grey with small round white spots surrounded by dark brown. Throat light grey, chest belly and inferior part of limbs light grey spotted with white. Iris metallic golden with greenish tonalities and finely black reticulated.

Colour in preservative. Dorsum grey, with small black spots irregularly spread along dorsum; on the head, an irregular black, broken interorbital bar, and another transversal irregular black bar anterior to the upper eyelids ( Fig. 3 b). Canthal stripe black, wide, covering nare; supratympanic stripe black, covering upper half of tympanum and turning behind tympanum towards the upper arm; a narrow longitudinal labial grey stripe on each side. Transverse dark bars on hind limbs only on shanks and tarsi. Anterior surface of thighs with pale spots surrounded by dark grey. Throat grey, chest, belly and ventral surfaces of arms dark grey with white marbling ( Fig 3 d); downsides of shanks and tarsi dark grey with white round little spots.

Measurements of holotype (in mm): SVL: 26.2; ShL 13; HeL: 10.3; HW: 10; InD: 2.4; EN: 3; ED: 3.6; TD: 1.2; ETS: 4.7; FD: 1.2; T4D: 1; 1FiL: 3; 2FiL: 3.8.

Variation: Females are consistent in the majority of characters with the female holotype. Some variation can be seen in the shape of the middorsal raphe (distinct on MHNLS 18460, 18894, 18895, present but indistinct on MHNLS 18877, 18893, 18897). The two dorsolateral folds are present on all females although they are low and ill-defined; they are completely indistinct on 18460 due to its bad preservation state. There also is consistently present a tubercle posteroventral to the tympanum. Small calcars are present at least in two specimens photographed in life (a male MHNLS 18878, Fig. 2a ; a female MHNLS 18877, Fig. 2 b) but not appreciable in preservative; small ulnar and tarsal tubercles are also appreciable in the male MHNLS 18878 ( Fig 2a ), but are indistinct in preservative. Appendix II shows the dorsal pattern variation of the type series. Males dorsally can be dark grey (MHNLS 18878), pale grey (MHNLS 18879, 18873–74), to bronze (MHNLS 18876), with transverse bars on the limbs, a W postoccipital mark, irregular spotting on dorsum, and a well defined black interorbital bar. The paler specimens (MHNLS 18879, 18873–74) have a uniform dorsum, with no spotting at all, except a few small irregular marks on the head of MHNLS 18876. The most appreciable variation is on ventral pattern and disposition of spots on the groin and on the hind limbs ( Fig. 4 a–d).

On all females but MHNLS 18894 the belly is patterned with dark grey marbled with white large mostly round spots. On MHNLS 18894 the pattern is discernible but paler. On females MHNLS 18460 and 18894 there are many pale spots surrounded by black on the groin ( Fig 4 a), anterior and posterior surfaces of the thighs, as is characteristic for the species in the lentiginosus group of Rivero (1988). Variation on the belly pattern is as follows: MHNLS 18876 is the paler, with an almost unpatterned belly ( Fig 4 b), MHNLS 18873 and 18874 have a pale reticulation; MHNLS 18879 has a spotted belly, without marbled or reticulation; MHNLS 18900 has a mostly white belly with irregularly scattered small round spots; and MHNLS 18878 has a dark grey belly with a few whitish small spots; the most patterned belly is on MHNLS 18877 ( Fig. 4 c). Males accord with all characters with females, and there is not a clear sexual dimorphism in pattern. The male MHNLS 18878 has also a profusion of white round spots on the groin and posterior side of the thighs ( Fig.4 d). Sexual dimorphism is only evident by the smaller size, presence of vocal slits and single white nuptial pads on males.

Natural history: One of the localities at Cerro Las Antenas corresponds to a section of a narrow rapid creek at 1780 m, surrounded by a dense primary cloud forest. At this site 18 specimens were collected and two more observed during the expedition of March 2008 (end of the dry season); all were found on different bush leaves in the creekside foliage, rocks in the creek’s bed, and in sympatry with Cryptobatrachus remotus Infante-Rivero, Rojas-Runjaic & Barrio-Amorós, 2008 , Cochranella sp., and Hyalinobatrachium tatayoi Castroviejo-Fischer, Ayarzagüena & Vila, 2007 . The other locality is a secondary low forest, at the summit of Cerro Las Antenas, at 1933 m, with a high density of arboreal ferns, vines and Cecropia . At this site Pristimantis lassoalcalai was found in sympatry with P. rivasi sp. nov.

During the expedition of March 2008 many males were heard vocalizing profusely between 1600 and 1900 h, from leaves, usually exposed. All specimens seen or collected were at less than 1 m over the ground; several called from dry folds of Cecropia leaves. After 1900h the call activity declined abruptly and only a few males called sporadically until 2100h. During July 2008 many vocalizing males were heard calling profusely in the early morning hours (around 0800h) in a clear day near the summit of Cerro Las Antenas.

The vocalization of P. lassoalcalai consists of single notes emitted every few seconds to every few minutes. The call remains a lament and could be described onomatopoeically as “nheek, nheek, nheek”.

Distribution: ( Fig. 5 ). Pristimantis lassoalcalai is only known from two localities on Cerro Las Antenas, from 1827 to 1950 m. It is expected to occur throughout similar environments and elevation in the Sierra de Perijá.

Etymology: The species epithet is a patronymic for Oscar Lasso-Alcalá, ichthyologist at Museo de Historia Natural La Salle, for his continued support and friendship.

Remarks: Pristimantis lassoalcalai fits almost entirely in what Lynch & Duellman (1997) defined as the Pristimantis unistrigatus group in that it has an areolate skin on the belly, Finger I shorter than II, and a V Toe longer than III, but with the disk on Toe V not reaching the anterior edge of the distal subarticular tubercle of Toe IV. This last character should be contrasted with the state “disk on Toe V reaching the anterior edge of the distal subarticular tubercle of Toe IV” as in P. rivasi sp. nov., which unequivocally belongs into the unistrigatus species group; the difference could be of taxonomic importance, but to our knowledge this has been not tested.

Figures

FIGURE 3. Pristimantis lassoalcalai sp. nov. MHNLS 18898, holotype. A: Lateral view and B: Dorsal view of the head; C: Dorsal view and D: ventral view of the preserved specimen. Scales equal to 5 mm. E: Palmar view of the right hand and F: Plantar view of the left feet. Scales equal to 2 mm.

FIGURE 4. Details on pattern of Pristimantis lassoalcalai sp. nov. A: Posterior spotting of female MHNLS 18894; B: minimum ventral pattern marking, MHNLS 18876; C: maximum ventral pattern marking, MHNLS 18877; D: groin spotting of male MHNLS 18878.

FIGURE 5. Map of NW Venezuela, showing major physiographic elements: Maracaibo Lake, Sierra de Perijá to the west, and Cordillera de Mérida to the south east. Type locality and known distribution of Pristimantis lassoalcalai sp. nov. is shown by a white rhomb. Pristimantis rivasi sp. nov. distribution is shown by white circles; that to the north correspond to the type locality.

FIGURE 2. A: Pristimantis lassoalcalai sp. nov. A: MHNLS 18878, male paratype in life. B: MHNLS 18877, female paratype in life. Photos by P. Velozo.