Pseudoeurycea sp. – Cázares-Hernández et al. 2021.

Suggested English name: Jaguar Salamander.

Suggested Spanish name: Tlaconete jaguar.

MZFC-HE 28694. An adult male from El Mirador, Texhuacan Municipality, Veracruz, Mexico (18°38′04.8″N, 97°03′35.0″W, 2,367 m elevation, WGS84 datum), collected by Erasmo Cázares Hernández on 5 September 2015.

Seven. One male: MZFC-HE 35855 (10 September 2015); six females: MZFC-HE 35859 (10 September 2015), MZFC-HE 28686 (11 September 2015), MZFC-HE 35856–57 (14 September 2015), MZFC-HE 35858, 28685 (10 October 2015). Same locality as the holotype.

Assigned to the genus Pseudoeurycea based on the presence of a sublingual fold, comparatively short fifth toe compared to the fourth, limited foot webbing, relatively large size, and mitochondrial DNA sequences.

Morphologically, we distinguish the new species from the other salamanders that occur in the region and from the others of the genus Pseudoeurycea based on size of the body and tail, limb length, digit shape, shape and size of the head, and especially by external coloration (dorsal and ventral coloration of head, body and tail). Pseudoeurycea jaguar is easily distinguished from the other species of the genus Pseudoeurycea by its unique color pattern (Figs 1, 4).

Based on mtDNA, this new species is closely related to members of the P. juarezi group (sensuCanseco-Márquez and Parra-Olea 2003; Parra-Olea et al. 2004). It is distinguished from species of the P. juarezi group by its larger body size (SVL males: P. aurantiaSVL 40.2–45.0, P. jaguarsp. nov. 58.0–58.7 mm, P. juarezi 44.0–51.3 mm, P. ruficauda 24.2 mm, P. saltator 40.0–42.3 mm; females: P. aurantia 41.5–44.1 mm, P. jaguarsp. nov. 42.4–71.0 mm, P. juarezi 38.5–48.0 mm, P. ruficauda 38.2 mm, P. saltator 33.4–41.2 mm; Tables 1 and 2) and wider head (HW males: P. aurantia 9.9–11.2 mm, P. jaguarsp. nov. 13.7–15.1 mm, P. juarezi 10.0–12.6 mm, P. ruficauda 6.7 mm, P. saltator 9.5–10.3 mm; females: P. aurantia 10.3–10.7 mm, P. jaguarsp. nov. 11.0–17.6 mm, P. juarezi 9.4–12.5 mm, P. ruficauda 8.5 mm, P. saltator 3.8–9.1 mm. Females have a relatively longer tail (TL/SVL females: P. aurantia 0.86–0.90, P. jaguarsp. nov. 0.93–1.25, P. juarezi 0.70–1.12, P. ruficauda 0.99, P. saltator 0.88–0.92). Pseudoeurycea jaguarsp. nov. has more maxillary and premaxillary teeth (mean MT + PMT males: P. aurantia 69, P. jaguarsp. nov. 85.5, P. juarezi 73, P. ruficauda 31, P. saltator 67; females; P. aurantia 74, P. jaguarsp. nov. 92.6, P. juarezi 67, P. saltator 73) and vomerine teeth (mean VT males: P. aurantia 25, P. jaguarsp. nov. 30.5, P. juarezi 23.3, P. ruficauda 17, P. saltator 26; females; P. aurantia 22, P. jaguarsp. nov. 30.3, P. juarezi 22, P. saltator 22). The head of P. jaguar is longer and wider than that of other species (HL males: P. aurantia 9.9–11.2, P. jaguarsp. nov. 13.7–15.1 mm, P. juarezi 10.0–12.6 mm, P. ruficauda 6.7 mm, P. saltator 9.5–10.3 mm; females: P. aurantia 10.3–10.7 mm, P. jaguarsp. nov. 11.0–17.6 mm, P. juarezi 9.4–12.5 mm, P. ruficauda 8.5 mm, P. saltator 3.8–9.1 mm; HW males: P. aurantia 6.3–6.8, P. jaguarsp. nov. 9.8–10.3 mm, P. juarezi 6.2–7.9 mm, P. ruficauda 4.4 mm, P. saltator 6.3–6.7 mm; females: P. aurantia 6.1–6.7 mm, P. jaguarsp. nov. 7.8–12.0 mm, P. juarezi 5.9–7.8 mm, P. ruficauda 6.1 mm, P. saltator 5.4–6.7 mm). No other species of Pseudoeurycea from Veracruz or Puebla has such large, extensively webbed feet and long limbs.

The new species is further distinguished from all members of the juarezi group, as well as from all other species of Pseudoeurycea and all salamander species from central Veracruz, by color pattern. Pseudoeurycea jaguar has irregular yellow mottling on the dorsum on a brown or nearly black background. In P. aurantia the ground color is reddish brown with bright orange blotches or mottling present on the dorsum; these blotches coalesce on the tail (Fig. 1A), and some individuals have small dark spots on the tail and dorsum. Pseudoeurycea saltator has a uniformly dark gray-brown dorsal ground color that is invariably overlain by a paler yellow or golden mid-dorsal stripe (Fig. 1B). Pseudoeurycea juarezi typically has yellow-brown dorsal coloration on the head and forming a dorsal band to the tip of the tail, with scattered black spots on the dorsum and tail (Fig. 1C); the color pattern in this species can be variable, some specimens have small dark spots on a yellowish background (Fig. 1D) while others are darker brown or reddish-brown dorsally with yellow or golden mottling on the tail. Dorsal coloration in P. ruficauda is orange-tan with coppery-gold highlights that are mixed with black (Fig. 1E). The ventral part of the tail of P. jaguar is paler than the dorsal part (lead gray), darkening towards the tip, with very small and clear flecks evenly distributed along the median portion of the venter. Both P. melanomolga and P. gadovii have some version of yellowish spots on a dark background, but the spots in these species are arranged in regular rows unlike the mottling seen in P. jaguar. Pseudoeurycea lynchi has greenish, rather than yellow, blotches and mottling and tends to show less background color compared to P. jaguar. Pseudoeurycea nigromaculata also typically shows less background color and often is primarily yellowish on the tail, and P. granitum has irregular blotches and a pale interorbital bar that are lacking in P. jaguar.

A relatively large adult male (58.7 SVL), body slender, head relatively long and broad (HW/SVL = 0.17), wider than body, neck region well defined (Fig. 2A, B). Snout slightly truncate in dorsal view and rounded in lateral view, eyes moderate in size, slightly protruding, not exceeding margin of jaw in dorsal view. Nostrils small, oval. Nearly round and relatively prominent mental gland (2.4 mm wide) (Fig. 2B). Costal folds 13, counting one each in axilla and groin. Tail longer than body (TL/SVL = 1.15), tapering gradually along length, slender posteriorly ending in a point. Limbs long, overlap by 2 costal folds when appressed to side of body (Fig. 3D). Hands and feet broad, digits long and relatively slender, blunt with distinct subterminal pads. Hands and feet highly webbed compared to most other members of the genus (although only moderately webbed compared with species of Bolitoglossa or some Chiropterotriton), with webbing extending to the middle of the penultimate phalanx on third toe of foot. First toe short, fifth toe short compared to fourth long, 2.1 times larger than the first finger. Digits in order of decreasing length: III–II–IV–I on hands; III–IV–II–V–I on feet. Phalangeal formulae 1–2–3–2 for hands and 1–2–3–3–2 for feet (Fig. 2C, D). Teeth numerous: maxillary teeth 92 (45/47); premaxillary teeth 3, enlarged compared to maxillary teeth; vomerine teeth 36, arranged in two arcs (18/18) extending beyond the choanae. Nasolabial protuberances well developed.

Snout to posterior angle of vent (SVL) 58.7; head width 10.3; head length 14.8; head depth at angle of jaw 4.7; eyelid length 3.9; eyelid width 3.0; anterior rim of orbit to snout 4.9; eye diameter 4.4; interorbital distance 3.5; snout to forelimb 21.0; internarial distance 3.1; intercanthal distance 4.1; nostril diameter 0.4; snout projection beyond mandible 1.1; snout to anterior angle of vent 55.4; axilla to groin 29.4; tail length 67.6; tail width at base 4.3; tail depth at base 4.7; forelimb length 18.2; hind limb length 19; hand width 5.1; foot width 8.0; length of the longest (third) toe 2.5; length of fifth toe 0.8; mental gland width 2.4; mental gland length 2.3. Tooth counts: premaxillary 3; maxillary 45/47; vomerine 18/18.

The type series includes eight specimens, two males and six females. There is marked sexual dimorphism; adult females reach a larger size than males (SVL 42.4–71.0 mm in females vs. 58.0–58.7 mm in males), head relatively broad (9.8–12.0 mm in females and 9.8–10.3 mm in males) and have a more robust body compared to males (shoulder width 7.6–10.8 in females vs 7.2–7.3 mm in males). Adult males have a well-developed, nearly round mental gland (width 2.8 mm) (Fig. 3A) and few premaxillary teeth (3–4 vs.13–20 in females). Hands and feet are broader in females (foot width 7.7–8 mm in males and 8.3–9.3 in females) (Fig. 3B, C).

Dorsum and dorsal surface of head solid dark chocolate brown with extensive yellow speckling or mottling; yellow specks small on head, becoming larger and mottled on the dorsum and even larger and more continuous on tail. Sides of head brown with yellow speckling, with the same proportion of yellow toward back of the head, mouth and dorsal surface of the head. Dorsal surface of tail same color as dorsum, with the yellow mottling more continuous, but reduced at tip. Sides of body dark brown above midline, with yellow flecks (small flecks combined with larger and elongated flecks) and slightly paler brown with limited yellow mottling below midline. Dorsal surface of limbs brown chocolate (same color as dorsal surface of head, body and tail) with yellow specks, which are larger and elongated on the hind limbs; dorsal surface of feet brown with small yellow specks. Ventral surface of body, limbs, gular region and tail pale brown with small yellow flecks. Iris dark brown with yellow specks around the pupil.

Dorsum nearly uniformly dark gray, including head and tail, hands, and feet. All irregular spots on body and specks on head cream. Ventral surface of body, limbs and gular region pale gray with numerous cream specks.

The color pattern is similar in most adult specimens. Irregular blotches on the body can vary in size and shape and can be yellow or orange, forming elongated or rounded patterns; they are smaller on the head and become larger along the dorsum and even larger on the tail, but their size varies from specimen to specimen (Fig. 4). Regardless of the size of the blotches on the dorsum, most specimens have a mottled pattern. There were two adult specimens, one female (MZFC-HE 35857, Fig. 4C) and one male, that were almost completely dark with small yellow blotches. There appears to be ontogenetic variation in color pattern. In juveniles, the dorsum is almost entirely dark brown or black, without the yellow mottling or blotches as in adults. Some of the smallest specimens (22 mm SVL) are almost totally black, with little or no yellow dorsal coloration (Fig. 4G, H). Slightly larger juveniles (30–40 mm SVL), show more yellow dorsal coloration (Fig. 4I, J).

Pseudoeurycea jaguarsp. nov. is known only from Sierra de Zongolica (Fig. 5A). It is found in a mature coniferous forest (Fig. 5B, C) at 2,360–2,367 m, which is dominated by Cupressus benthamii, Pinus patula, Alnus acuminata, and Saurauria leucocarpa with an understory of Fuchsia microphyla, Rubus sp., Licianthes synanthera; and herbaceus plants including Didymaea alsinoides, Chusquea mulleri and Begonia oaxacana. There is an abundant presence of epiphytes, including Tillandsia imperialis and Elaphoglossum paleaceum, with extensive growth of mosses.

Pseudoeurycea jaguarsp. nov. is mainly an arboreal species with nocturnal habits. The species was observed active at night on trees, shrubs, rocks, herbaceous plants, and moss and was also observed moving on the ground. Most of the trees where P. jaguar was observed contained layers of moss and bromeliads. By day, we found P. jaguarsp. nov. hidden behind or within the layers of moss that cover the trunks of the trees, in particular two species of moss (Ptychomitrium sp. and Anacolia menziesii).

Other species of plethodontids that share habitat with P. jaguarsp. nov. in the study site are Aquiloeurycea cafetalera, Chiropterotriton sp., Isthmura gigantea, Parvimolge townsendi, Thorius sp. and T. troglodytes.

Antagonistic behavior between individuals in a population has been described in several species of plethodontid salamanders (Jaeger and Forester 1993; Staub 1993; Lynn et al. 2019). However, this behavior has been little studied or observed in Mexican plethodontids. During our population study, we only found one individual of P. jaguar in each trap or tree studied. Initially, we collected some individuals, transported them to the laboratory, and took morphological measurements for mark-recapture studies. On the first sampling trip, we kept three containers with more than one individual, considering that each container represented a particular section of the study area. In the first one, we kept five immature individuals with a large adult, in the second container a pair of adult individuals, and in the third container two large adult individuals with a young adult. In all the containers there were signs of serious aggression. In the first, three of the five juvenile individuals disappeared; in the second, the female and male adults mutilated each other, leaving the male blind and the female with serious injuries to the body; in the third container, the youngest individual was killed. Some individuals of the population studied have regenerated or regenerating tails, indicating some level of predation or possibly agonistic interaction between them.

The specific epithet jaguar is a noun in apposition and refers to the similarity between the dorsal color pattern of the salamander and that of the jaguar (Panthera onca). In the last three years the presence of this endangered feline has been recorded in some places in the Sierra de Zongolica and it seems appropriate to honor this emblematic species in the region.