Dendrobates dorisswansoni, Rueda-Almonacid & Rada & Sánchez- Pacheco & Velásquez-Álvarez & Quevedo, 2006

Rueda-Almonacid, José Vicente, Rada, Marco, Sánchez- Pacheco, Santiago J., Velásquez-Álvarez, Álvaro Andrés & Quevedo, Alonso, 2006, Two new and exceptional poison dart frogs of the genus Dendrobates (Anura: Dendrobatidae) from the Northeastern Flank of the cordillera Central of Colombia, Zootaxa 1259, pp. 39-54 : 48-53

Dendrobates dorisswansoni new species

Holotype: An adult female deposited in the amphibian collection of the Instituto de Ciencias Naturales­Museo de Historia Natural de la Universidad Nacional de Colombia, Bogotá, ICN 53279, one of a series collected 12 June 2001 by Alonso Quevedo and Oscar Javier Gallego Carvajal.

Type locality: Colombia, Departamento de Tolima, Municipio de Falan, unpaved road between vereda El Llano and the ¨ Finca la Lulera ,¨ eastern flank of the Cordillera Central, 1780m, ca 5° 08´North, 74° 56´West

Paratopotypes: Adult males: MUJ 5019 (individual stained) MUJ 5021 , MUJ 5023 ; females MUJ 5020 , MUJ 5022 , MUJ 5024 , MUJ 5025 . CZUT­A 204 , CZUT­A 206 , CZUT­A 207 ; Juveniles MUJ 5026 , CZUT­A 205 . Locality data is the same as the holotype.

Etymology: This species is named after Doris Swanson of Spokane, Washington, in the United States of America. Doris is the wife of the late Dale Swanson, after whom the other species in this paper is named, and, like her husband, is a world traveler, dedicated conservationist, and wonderful friend. Her continued commitment to the cause of biodiversity conservation, and particularly her support for the conservation of Critically Endangered and Endangered species, is making a major difference in globally important hotspots like the Tropical Andes.

Definition and Diagnosis: A small dendrobatid frog having an adult average snout vent length of about 16.8 mm in males and 18.2 mm in females (maximum known SVL of 19.43 mm). The coloration pattern over the back and the limbs consists of irregular, red blotches, which are rounded and elongated, on a background of dark brown to black. The throat, chest, and the upper half of the belly have a design similar to the back (red blotches on a dark background).

This species can be distinguished from most of the members of this family (except D. daleswansoni ) by the fusion of the first toe to the adjacent digit, thus only four toes are visible externally in the hind limbs. Dendrobates dorisswansoni and D. daleswansoni are the only known dendrobatids with a reduction of the toes and the two can be distinguished by the differences in coloration, D. daleswansoni with a red ¨hood¨ and the posterior half an Antique Brown or Robin Rufous ( Smithe 1975) and Dendrobates dorisswansoni being dark brown or black with irregular red or orange blotches ( Figures 1 and 2); with regard to dorsal skin texture, in D. dorisswansoni is completely smooth and in D. daleswansoni has few small flat warts barely discernable in the sacro­coccigea region of the hind limbs; in D. daleswansoni the I and II toes are totally fused and in D. dorisswansoni they are partially or totally fused. Finally, the testes are dark brown in D. dorisswansoni and cream with fine brown reticulation in D. daleswansoni .

Dimension of the Holotype (mm): The holotype corresponds to an adult female with a snout vent length of 18.04; tibia length of 8.3; maximum body width of 7.35; head width of 6.05; interorbital distance of 2.19; cephalic distance of 4.68; distance between the snout and nares of 0.68; distance between the nares and the eye of 1.37; distance between the nares of 2.34; eye diameter of 2.04; tympanum diameter of 1.09; distance from the posterior corner of the jaw to the inferior edge of the tympanic ring of 0.58; hand length of 4.52; disc width in the third finger of 0.6; width of the third finger of 0.44; disc width in the third toe of 0.48; disc width in the fourth toe of 0.44; width of the fourth toe of 0.42.

The dimension and percentage relationships of the type specimens are presented in Tables 3 and 4.

Description of the type specimens: Based on 3 adult males and 8 adult females. The head is longer than wider and much narrower than the body in females, while males have the head somewhat wider than the body. Snout round in dorsal and lateral view. Prominent nares situated much closer to the end of the snout than to the eye, only visible in front and ventral view (not dorsal), ovoid form and directed posterolaterally. Canthus rostralis rounded, loreal region flat, vertical and weakly concave. Interorbital distance flat and wider than the width of the superior eyelid. Eye large and prominent with a maximum diameter of 12.9% (average) of the snout vent length, pupil horizontally elliptical. Distance between the nares and the eye between 58.82–62.06% of the diameter of the eye in adults ( Table 3 and 4). Tympanum and tympanic ring obscured and covered by skin in the posterodorsal region, ovoid and directed anteroventrally, with a maximum diameter taken diagonally, or in other words, at an anteroposterior angle, is 39.1% of the diameter of the eye. Supratympanic fold absent.

Postrictal tubercle absent; rounded choanae, not visible in ventral view, as they are completely covered by the maxillary arch. Vomerine, maxillary and premaxillary teeth absent. Tongue elongated, almost two times longer than wider, the posterior margin not indented and posterior third not adhered to floor of mouth. Median lingual process absent (sensu Grant et al 1997).

ents MUJ MUJ MUJ ICN MUJ MUJ MUJ MUJ CZUT­ CZUT­ CZUT 5023 5019 5021 53279 5022 5025 5020 5024 A 204 A 206 ­A 207 SVL 16,28 16,9 17,1 18,04 17,55 19,43 18,23 17,54 17,75 17,6 17,71 TL 8,08 7,99 8,47 8,3 7,82 8,08 8,14 8,39 7,83 8,03 8,25 MBW 5,55 5,52 5,62 7,35 6,93 7,48 6,55 6,5 6,35 6,25 6,23 HW 5,78 5,81 5,93 6,05 5,94 5,8 5,14 5,47 5,66 5,54 5,65 IOD 2,11 2,1 2,25 2,19 2,22 2,9 2 2,43 2,26 2,25 2,24 CL 4,24 4,43 4,48 4,68 4,44 4,21 4,32 4,48 4,09 4,02 4,25 ST­CN 0,62 0,63 0,44 0,68 0,82 0,88 0,8 0,64 0,53 0,64 0,61 CN­E 1,34 1,45 1,52 1,37 1,43 1,47 1,44 1,48 1,53 1,5 1,51 IND 2,63 2,31 2,57 2,34 2,45 2,53 2,41 2,48 2,54 2,42

ED 2,38 2,38 2,2 2,04 2,39 2,61 2,36 2,49 2,01 2,1 2,39 DT 1,09 1,03 0,89 1,09 0,98 0,87 0,75 0,73 0,95 0,91 1,08 MC­T 0,65 0,71 0,6 0,58 0,58 0,53 0,62 0,48 0,67 0,61 0,77 HL ­ 4,34 4,52 4,52 4,16 4,22 4,12 ­ 4,1 4,71 4,41 DcW­IIIf 0,75 0,68 0,69 0,6 0,63 0,6 0,59 0,57 0,52 0,53 ­ W­IIIf 0,4 0,38 0,36 0,44 0,4 0,43 0,42 0,41 0,44 0,39 ­ DcW­IIIt 0,44 0,42 0,48 0,48 0,5 0,52 0,55 0,45 0,5 0,43 ­ DcW­IVt 0,45 0,54 0,51 0,44 0,4 0,51 0,66 0,52 0,45 ­ ­ W­IVt 0,41 0,38 0,46 0,42 0,38 0,41 0,4 0,39 0,39 ­ ­

*The abbreviations used are: SVL (snout­vent length), TL (tibia length), MBW (maximum body width), HW (head width), IOD (interorbital distance), CL (cephalic length), ST­CN (Snout tip— center of nare), CN­E (center of nare—edge eye), IND (internare distance), ED (eye diameter), DT (diameter of tympanum), MC­T (mouth corner­lower edge of tympanic ring), HL (hand length), DcW­IIIf (disc width on third finger), W­IIIf (width third finger), DcW­IIIt (disc width on third toe), DcW­IVt (disc width on fourth toe), W­IVt (width of fourth toe)

Hand relatively large, with a length equal to 23.45–26.43% of the snout vent length. The relative length of the fingers in increasing order of size is I<II<IV<III; the tip of the IV digit reaches the middle of the second to last phalange of the third digit and the distal extreme of the first digit does not reach the base of the disc of the second digit. Discs moderately expanded on all the digits of the hand with the distal edge truncated or undulated with the exception of the first digit, which is rounded. Outer metacarpal tubercle large, somewhat flat and rounded, located in the lower middle of the palm, internal metacarpal tubercle rounded and located at the base of the pollex. Paired dorsal pads on dorsal surfaces of the discs present. Basal subarticular tubercle rounded and flat over the fingers I and II, and two subarticular tubercles rounded and flattened over the III and IV digits ( Figure 3).

Measurements Gender N Average +/­ Standard deviation RANGE

SVL Males 3 16,76 0,43 16,28­17,1 Females 8 17,98 0,63 17,54­19,43 TL/SVL Males 3 0,49 0,60 0,47­0,49 Females 8 0,45 0,33 0,42­0,48 HW/SVL Males 3 0,35 0,19 0,34­0,35 Females 8 0,31 0,46 0,28­0,34 CN­E /DE Males 3 0,62 0,90 1,54­1,74 Females 8 0,64 0,23 1,31­1,75 DcW­IIIf / W­IIIf Males 3 1,87 2,00 1,79­1,92 Females 7 1,38 2,00 1,18­1,41 HL/SVL Males 2 0,26 0,30 0,25­0,26 Females 7 0,24 0,36 0,22­0,27

HL / HW Males 2 0,76 1,62 0,75­0,76 Females 7 0,76 0,79 0,70­0,80

Hind limbs relatively short, when these are extended forward along the body the heel reaches the center of the eye; when the thigh is flexed perpendicular to the sagittal line and the legs are extended backwards, the heels barely overlap. The relative length of the toes is IV > III > V >II. First toe totally reduced and fused to the second in two specimens or with the disc barely visible in the remaining specimens ( Figure 5) .

Discs of the toes much smaller than the hand, rounded, slightly wider than the digits. Toe II with a basal, subarticular tubercle not protuberant, toes III and V with two subarticular tubercles and toe IV with three subarticular tubercles. Supernumerary plantar tubercles absent. Web toe formula absent. External metatarsal tubercle protuberant, elongated, flattened and smaller than the inner metatarsal tubercle, which is conical. A small and slight tarsal fold over the inner edge of the third distal of the tarsus. Skin of the back, belly and flank is smooth.

Color in life: Body with coloration pattern of irregular red or yellow­orange blotches on a background of dark brown or black over the back, the limbs are black or sepia and can have (or not) round, red or dark red spots. The throat, chest, and the upper half of the belly are like the back (red blotches on a dark background). Invariably all individuals present a bright red band over the upper lip, which extends from the tip of the snout to the base of insertion of the arm.

Color in preservative (ethanol 70%): The surfaces that are red in life become white, the dark portions (brown or black) maintain their color or become slightly paler. Males with testes uniform dark brown. Eggs are brown.

Sexual Dimorphism: Among the most notable characteristics to differentiate adult D. dorisswansoni males from females are the following: the presence of vocal slits, smaller body size and wider disc on the third finger. According to the measurements taken males have a cephalic width slightly larger than the abdominal width and have thinner bodies than the females.

Distribution: Species known in the cloud forests of the northern cordillera Central, in the departamento de Tolima, Colombia.

Natural History: Dendrobates dorisswansoni was a relatively abundant species on the forest floor when the typical series was captured and despite its small size it is easily observable in daytime hours and/or often hidden in bromeliads located 1.5– 2m high. Some of the females in the type series possess 5 or 6 eggs in each ovary. These are brown and have a diameter of approximately 1.96–2.08 mm.

In the type locality, the landscape is dominated by two kinds of habitat: cattle pastures and small patches of native forest surrounded by crops. The majority of water bodies are covered by secondary vegetation where the canopy reaches 10 or 15 m, with trees of 3–4m below and abundant heliconias and ferns in the underbrush. The ground is wet sand covered with a thick layer of decomposing organic material. Some areas of the forest are recovering from logging.

According to the Holdridge Life Zones (1967), the type locality is located in premontane wet forest (bh­PM), with the following climatic characteristics: annual temperature between 12–18 °C, precipitation between 1000 and 2000 mm /year, with a bimodal seasonal pattern of precipitation, and dense fog frequently forms.

Comments: The taxonomic classification of dendrobatids has experienced many changes and corrections in nomenclature in the last 25 years as a result of the use of molecular analysis technique, analysis of alkaloids produced by their skin and the use of mitochondrial DNA sequencing ( Myers, 1987; Myers & Daly 1976a; 1976b; 1980; Vences et al 2000; 2003). A new proposal regarding the phylogeny and classification of the family Dendrobatidae is being developed by Taran Grant and colleagues at the American Museum of Natural History. Currently, 10 genera and over 186 species are recognized within this family, of which, 73 species are found in Colombia, distributed as 47 Colostethus , 14 Dendrobates , 8 Epipedobates , 3 Phyllobates and 1 Allobates ( Frost, 2006) .

Of all the dendrobatids currently described and recognized, none has been associated with the reduction and loss of one of the phalanges of the toe and/or the fusion of the first toe with the second. This evolutionary tendency, which has appeared independently in no fewer than 8 genera of anurans and 33 genera of salamanders ( Alberch & Gale, 1985), follows a defined pattern, which always occurs in anurans that have lost a phalange, of the reduction and loss of the first toe, as has occurred in Geobatrachus walkeri , Atopophrynus syntomopus , Syncope antenori and S. carvalhoi and the species described here.

The particular modification of the toe morphology in Dendrobates daleswansoni and D. dorisswansoni is a exceptional feature and could be a cause to create a new genus within the Dendrobatidae family, however, we have refrained from adopting such a decision, waiting for anatomical and molecular study in order to clarify the taxonomic position and the phylogenetic relationships of this species.