Anfibios del Ecuador

Description
Diagnosis:Ameerega parvula is characterized by an incomplete light lateral stripe, differing from other members of the picta group. This species can also be distinguished from certain members of the group by its red dorsum in life and the presence of teeth. It differs from A. ingeri and A. picta by the usual absence of a light proximoventral calf-spot and from A. smaragdina by the presence of ventral marbling in life. This species can be further distinguished from A. picta by a strongly granular dorsum, the first finger being longer than the second and having maxillary and premaxillary teeth present (Silverstonei 1976).

A. parvula tadpoles are very similar to the geographically sympatric species A. bilinguis in size and coloration. The two can be distinguished by small differences in the length of the second lower tooth row (P-2). In A. parvula, the P-2 row is slightly longer than the P-1 row, whereas the converse is true for A. bilinguis tadpoles. Also, the two species can be distinguished by the relative width of their tail fins. The upper fin in A. parvula is slightly wider than the lower fin, while the upper fin in A. bilinguis tadpoles is slightly narrower than the lower fin. Both A. parvula and A. bilinguis tadpoles can be diagnosed from other sympatric species based on body color and oral disc characteristics, such as papillae dorsal gaps or jaw sheath shape (Poelman et al. 2010).

Description: A. parvula ranges from 17.5 mm to 24.0 mm in snout-vent-length. In males, the SVL ranges from 17.5 mm to 22.5 mm and in females 19 mm to 24 mm. Adult skin is strongly granular on the dorsum and on the dorsal surface of the hindlimbs (Silverstone 1976). Jungfer (1989) described the dorsal skin as densely covered in rounded or flattened, evenly distributed granules (Grant et al. 2006). The skin is smooth on the ventral surface of the hind limbs (Silverstone 1976). Maxillary and premaxillary teeth are present in this species. The first finger is longer than the second (Silverstone 1976), and the third finger of males is often swollen in frogs of this clade (Grant et al. 2006). Finger discs of adults in this clade are narrowly to moderately expanded. There is usually no toe webbing in adults of this clade, with at most basal webbing (Grant et al. 2006).

Coloration: Adult frogs have a ground color of black, with a spotted dark red dorsum. The underside of the body and limbs can be either black with blue marbling or a blue with black marbling. This marbling extends partially onto the side of the body. There is an incomplete light blue stripe extending from the forelimbs along the upper lip, ending next to the outside of the eye or nostril (Silverstone 1976). Distinct dorsolateral stripes are absent (Brown and Twomey 2009). Also usually absent are calf-spots. A yellow axillary spot is located on the upper arm and on the thigh. However this upper arm spot can also be blue and the thigh spot can be absent. Juveniles are blueish black on the dorsum, with less blue on the underside compared to the adults. Small juveniles may lack yellow arm and thigh spots (Silverstone 1976).

Live tadpoles have dark brown bodies, densely covered in darker brown to nearly black spots. The tail is pale brown at the body-tail junction, and fades to pale grayish tan at the tip. The tail musculature is covered in irregular small to medium-sized gray to dark brown specks. Dark brown spots may connect to create blotches, most often on the upper part of the tail musculature. The tail fin is transparent with many irregular dark grey flecks or spots. Tadpole hind legs are light tan, with irregular dark gray-brown flecks. The venter is transparent, and intestines are visible through the skin. The posterior end of the underside is slightly pigmented, with dark brown coloration on its anterior end (Poelman et al. 2010).

Coloration in Preservation: In preserved adults, the ground color is similar to live specimens or dark brown. The upper arm and thigh-spots, if present, are usually white in color. The lateral “stripe” usually disappears. The ventral marbling is not distinct and grey but, the marbling may disappear (Silverstone 1976).

Tadpoles in preservation generally have a light tan body and tail. The body color gradually darkens as it develops. The tail has grayish brown to dark gray flecks, but sometimes has pale brown flecks. The body has many uniform dark brown spots on its dorsal side. There is little adult coloration in preserved tadpoles, such as pale red to orange brown markings on the dorsal side. The ventral side can have a pale blue-black flecked pattern that becomes bright blue and black in adults. The ventral, posterior side of the body has a moderate amount of pigment. The ventral, anterior side is transparent with few pale and dark gray spots. Because of the transparency of its venter, guts can be seen on the ventral side. Developing legs are dark gray, darkest at the tibia (Poelman et al. 2010).

Tadpole Morphology: Tadpole total length ranges from 12.10 to 27.13 mm in stages 25-40. The body shape is depressed. The upper fin is deeper than the lower fin, and starts 0.11 mm posterior to where the body and tail meet. The tail is wide and deep at the body’s base, narrows slightly at the middle point (1.98 mm deep), then continues to decrease towards the slender, rounded tip. Eyes are located on the dorsal surface. The snout is narrow and rounded on the dorsal side, whereas on the ventral side, the snout is broad and rounded. Nostrils are tiny and not easily seen, located anterodorsally. On the ventral surface, the spiracle is sinistral and the vent is dextral (Poelman et al. 2010).

The tadpole mouth is located on the ventral side. Oral discs are present, and are normal and emarginate (Grant et al. 2006). Marginal papillae are small, and of equal size, with 6 papillae located laterally on each side of the mouth and 25 located ventrally. However, there is a good deal of variation in papillae number (ranging from 12 to 78). This variation may be due to observations of tadpoles at different stages of development. Papillae are consistently absent on the upper lip, around the dorsal gap of tooth row A-1. An A-2 gap is also present, roughly one-third the total length of the tooth row. The lower jaw sheath is V-shaped, and the upper jaw sheath is mostly straight, but can be slightly V-shaped. Jaw sheaths are finely serrated (Poelman et al. 2010).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Colombia, Ecuador, Peru

View distribution map using BerkeleyMapper.

A. parvula inhabits the forests of the Amazon drainage in Columbia, in Ecuador in the Napo Province (Poelman et al. 2010) and in Peru’s Santiago Valley, east of the Andes (Silverstone 1976; Icochea 2010). The species is found in terrestrial habitats including lowland tropical/subtropical forests; in addition, they can be found in permanent wetland habitats such as rivers, streams, creeks, and waterfalls. They have also been found in old secondary forests (Icochea 2010). As of 1976, elevation records were from 330 to 1000 meters above sea level (Silverstone 1976).

Life History, Abundance, Activity, and Special Behaviors
Wevers (1988) reports that A. parvula is a diurnal species (Lindquist and Hetherington 1996). This species is found on the ground in leaf litter near bodies of water, such as rivers (Poelman et al. 2010). Males have been observed by Wevers (1988) to undergo "foot-waving" for visual communication, possibly as a display of aggression towards other males, or for courtship (Lindquist and Hetherington 1996). Tadpoles are usually found in puddles or pools on the ground (Poelman et al. 2010). These bodies of water are usually partially covered by the tree canopy (Poelman et al. 2010). Males carry the tadpole clutch on their backs from the terrestrial nets to water sources (such as puddles or slow-moving rivulets) in order to provide food for them (Poelman et al. 2010; Icochea 2010).

A. parvula has bright, aposematic coloration and produces toxic compounds. Its skin can produce lipophilic alkaloids, as can other species of the Dendrobatidae family (Darst et al. 2005).

Trends and Threats
This species is widespread, and its population is stable. There are no major threats; large areas of suitable habitat remain. Human activity, such as agriculture (crops, livestock, etc.) has led to some local areas of habitat loss. It is potentially threatened by an increase in the pet trade (Icochea 2010). In Ecuador, A. parvula inhabits five protected areas, including Parque Nacional Yasuní, Parque Nacional Sangay and Limoncocha Reserva Biológica. A. parvula is also present in Peru’s Santiago Comaina Reserved Zone (Icochea 2010).

Possible reasons for amphibian decline

General habitat alteration and loss
Intentional mortality (over-harvesting, pet trade or collecting)

Comments
Species Authority: This species was first described by Boulenger (1882), as Dendrobates parvulus. Phylogeny: In 1989, Jungfer determined Ameerega parvula to be a different species than A. bilinguis, a morphologically and geographically similar species, based on its vocalizations and adult morphology (Poelman et al. 2010). A. parvula thought to be the sister species to A. bilinguis, and both are in the subfamily Colostethinae (Grant et al. 2006; Poelman et al. 2010).

Etymology: The name parvula derives from the Latin word parvulus, meaning young or small.

References

Ananjeva, N. B., Borkin, L. J., Darevsky, I. S., and Orlov, N. L. (1988). Dictionary of Amphibians and Reptiles in Five Languages: Amphibians and Reptiles. Russky Yazuk Publishers, Moscow.

Boulenger, G.A. (1882). Catalogue of the Batrachia Salientia s. Ecaudata in the Collection of the British Museum, Ed. 2. Taylor and Francis, London.

Brown, J. L., and Twomey, E. (2009). ''Complicated histories: three new species of poison frogs of the genus Ameerega (Anura: Dendrobatidae) from north-central.'' Zootaxa, 2049, 1-38.

Darst, C. R., Menendez-Guerrero, P. A., Coloma, L. A., and Cannatella, D. C. (2005). ''Evolution of dietary specialization and chemical defense in poison frogs (Dendrobatidae): A comparative analysis.'' The American Naturalist, 165, 56-69.

Grant, T., Frost, D. R., Caldwell, J. P., Gagliardo, R., Haddad, C. F. B., Kok, P. J. R., Means, D. B., Noonan, B. P., Schargel, W. E., and Wheeler, W. C. (2006). ''Phylogenetic systematics of dart-poison frogs and their relatives (Amphibia: Athesphatanura: Dendrobatidae).'' Bulletin of the American Museum of Natural History, (299), 1-262.

Icochea, J., Coloma, L. A., Ron, S., Jungfer K.-H., and Cisneros-Heredia, D. (2004). Ameerega parvula. In: IUCN 2010. IUCN Red List of Threatened Species. Version 2010.4. www.iucnredlist.org.

Jungfer, K.-H. (1989). '' Pfeilgiftfrosche der Gattung Epipedobates mit rot granuliertem Rücken aus dem Oriente von Ecuador und Peru.'' Salamandra, 25, 81-98.

Lindquist, E. D., and Hetherington, T. E. (1996). ''Field studies on visual and acoustic signaling in the ''earless'' Panamanian Golden Frog, Atelopus zeteki.'' Journal of Herpetology, 30(3), 347-354.

Poelman, E. H., Verkade, J. C., van Wijngaarden, R. P. A., and Félix-Novoa, C. (2010). ''Descriptions of the tadpoles of two poison frogs, Amereega parvula and Ameerega bilinguis (Anura: Dendrobatidae) from Ecuador.'' Journal of Herpetology, 44(3), 409-417.

Silverstone, P.A. (1976). ''A revision of the poison arrow frogs of the genus Phyllobates Bibron in Sagra (Family Dendrobatidae).'' Natural History Museum of Los Angeles County Science Bulletin, 27, 1-53.

Walls, J. G. (1994). Jewels of the Rainforest: Poison Frogs of the Family Dendrobatidae. J.F.H. Publications, Neptune City, New Jersey.

Wever, E. G. (1985). The Amphibian Ear. Princeton University Press, Princeton, New Jersey.

Species Account Citation: AmphibiaWeb 2012 Ameerega parvula: Ruby Poison Frog <http://amphibiaweb.org/species/1668> University of California, Berkeley, CA, USA. Accessed Jun 19, 2018.

Citation: AmphibiaWeb. 2018. <http://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 19 Jun 2018.

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