Pleurodema kriegi ( Müller, 1926 ), Muller, 1926

Valetti, Julián A., Salas, Nancy E. & Martino, Adolfo L., 2009, A new polyploid species of Pleurodema (Anura: Leiuperidae) from Sierra de Comechingones, Córdoba, Argentina and redescription of Pleurodema kriegi (Müller, 1926), Zootaxa 2073, pp. 1-21 : 10-13

Re-description of Pleurodema kriegi ( Müller, 1926)

Fig. 8

Paludicola kriegi Müller, 1926 .

Pleurodema kriegi di Tada, Salusso and Martori, 1976.

Material. Neotype. FML 20460, adult male ( Fig. 8 ) near La Posta (31º36'46'' S, 64º52'29'' W, approximately 2151 m elevation), Pampa de Achala, Córdoba province, Argentina ( Fig. 1 ), collected during the night of 17 January 2006 by Julián A. Valetti.

Referred specimens. (17 specimens). FML 20459, 20461, 20463–20471, 20474-20476, fourteen adult males and FML 20462, 20472–20473, three adult females, all collected with the neotype.

Diagnosis. A small species of Pleurodema (33.24 mm SVL), characterized by: (1) relatively small size; (2) snout short, canthus rostralis rounded in dorsal view and truncate in profile; (3) lumbar glands present, 1 ½ eye diameter; (4) round tympanic annulus, almost concealed; (5) tympanum length half of the eye diameter; (6) vomerine teeth absent, (7) comissural gland prominent; (8) brilliant red-orange spots on the groin and around lumbar glands; (9) ploidy level 2n= 4x =44; (10) axillary amplexus; (11) egg deposition in gelatinous nest attached to vegetation; (12) compound advertisement call with tri-pulsed pulse groups, average dominant frequency 1823 Hz.

According to external morphology, Pleurodema kriegi , Pleurodema bibroni and the new species described below are cryptic and the properties of their advertisement calls are similar (see above). Pleurodema kriegi differs from the new allopatric species from Sierra de Comechingones by having tetraploid chromosomic complement (octoploid in the new species) and by having a lower pulse rate (55.9 pulses/sec in Pleurodema kriegi and 65.7 pulses/sec in the new species). Pleurodema kriegi and Pleurodema bibroni are the only tetraploid species of the genus. They are morphologically very similar and although Laurent (1975) found some morphological differences between these entities, an unequivocal distinction between these taxa is not possible. The advertisement call of Pleurodema kriegi is similar to Pleurodema bibroni , too. Barrio (1977) detected difference in the pulse rate between these taxa, although the temperatures of recording are different and this environmental variable can affect this temporal variable of the call; Kolenc et al. (2009) found no acoustic differences between these two species. Barrio and Rinaldi de Chieri (1970) found secondary constriction chromosomes 12 only in Pleurodema kriegi . Ultimately, Pleurodema kriegi and P. bibroni were considered as distinct species by Barrio (1977) based mostly on biogeographic and ecologic differences.

Pleurodema kriegi is distinguished markedly from P. tucumanum , P. nebulosum , P. guayapae , P. marmoratum and P. diplolister by the presence of lumbar glands (lumbar glands absent in these species); from P. bufoninum , P. borellii , P. cinereum and P. thaul by the presence of advertisement call compound by tripulsed pulse groups (absent in P. bufoninum, Duellman & Veloso 1977 ; formed by a single pulse group in P. borellii and P. cinereum, McLister et al. 1991 ; and formed by pulse groups of 5-6 pulses in P. thaul, Barrio 1977 ); from P. brachyops by having lumbar glands bigger than eye diameter (smaller in P. brachyops ), yellow lumbar glands with black central ocellus (black lumbar glands with whitish central blotchs in P. brachyops ), tympanum size half of the eye diameter (smaller than half eye diameter in P. brachyops ).

Description of the neotype. The neotype (FML 20460, Fig. 8 ) is an adult male of 34.4 mm, body robust; head triangular, slightly wider than long; snout short, canthus rostralis rounded and vertically truncated. Eyes protuberant; eye diameter larger than interocular distance; interocular distance larger than internarinal interval. Round tympanic annulus almost concealed, approximately half the size of eye diameter. Commissural glands present, oval, approximately the same size of eye diameter. Vomerine teeth absent. Dark vocal sac. Fingers free; relative length of fingers: 3>4>1>2; two not-darkened palmar tubercles ( Fig. 8 ). Femur length less than tibia length; sum of femur length and tibia length longer than foot length. Toes free with cutaneous edge and rudimentary interdigital basal membrane; two metatarsal tubercles, inner metatarsal tubercle pointed and outer metatarsal tubercle shovel-shaped ( Fig. 8 ); relative length of toes: 4>5=3>2>1. Lumbar glands large, oval, one and a half times the size of eye diameter. Vocal sacs single, median and subgular. In life, dorsally brownish with large almost symmetrical dark spots. Dark transverse bands on upper surface of arms and legs. Yellow lumbar glands with a black central ocellus covering 60% of the gland. Brilliant red-orange spots on the groin and around lumbar glands. Dark palms and soles, with whitish palmar tubercles. Dark vocal sac with the rest of ventral body surface whitish and mild dotted dark. Iris gold with black reticulations. The neotype is ventrally very infected by the sub-cutaneous acari Hannemania achalai Alzuet and Mauri, 1987 .

Morphometric measures of neotype (mm): Snout-vent length 34.4; maximal head width 13.6; head length 11.5; snout-eye distance 5.0; internarinal distance 1.9; interocular distance 2.7; eye-narinal distance 2.7; rostronarinal distance 3.2; eye diameter 3.6; arm length 16.1; length of 3rd finger 4.6; femur length 15.0; tibia length 15.8; foot length (including tarsal length) 22.5; length of 3rd toe 5.2; length of 4th toe 9.1.

Distribution. The species is currently known from Pampa de Achala, Córdoba province ( Fig. 1 ) (see Barrio 1977, Kolenc et al. 2009) and cited to near Alpa Corral, Córdoba province by Ávila and Priotto (1995). However, the last record should be corroborated because the locality is to the south of the new species with octoploid chromosomic complement and the specimens could be octoploid, too.

Ecology. Pleurodema kriegi males were acoustically active from the first rains of austral spring (November) to March from 21.00 hs. to 3.00 hr. (sunset time: 21.00 – 21.30 hr) Pleurodema kriegi breeds in temporary and semipermanent ponds with vegetation at the edges, or aquatic vegetation, and 10 to 40 cm deep ( Fig. 9 ). The males emit their calls floating in the surface of the water or underground near the edge of ponds. The eggs are deposited in semisubmerged eggs-masses and adhered to the aquatic vegetation. The amplexus is axillary. This species was observed in sympatry with Rhinella achalensis , and in syntopy with R. arenarum , Odontophrynus achalensis and Hypsiboas cordobae .

The tadpole of Pleurodema kriegi was recently redescripted by Kolenc et al. (2009) and a comparison with Pleurodema bibroni was performed.

Figures

FIGURE 1. Geographic position of type locality of Pleurodema sp. nov. (Estancia Los Tabaquillos; asterisk) and locality of specimens of Pleurodema kriegi used in the redescription (La Posta, Pampa de Achala; circle).

FIGURE 8. Pleurodema kriegi, neotype (FML 20460, SVL 34.4 mm), (A) dorsal view of specimen; ventral views of (B) hand and (C) foot. Photograph by J. Valetti.

FIGURE 9. Typical habitat of Pleurodema kriegi. La Posta, Pampa de Achala. Córdoba province, Argentina. Photograph by J. Valetti and A. Martino.