Jorge Valencia - Academia.edu (original) (raw)
Papers by Jorge Valencia
Describimos una especie nueva de Pristimantis verde de la ladera occidental de los Andes de Ecuad... more Describimos una especie nueva de Pristimantis verde de la ladera occidental de los Andes de Ecuador en el Distrito Metropolitano de Quito
(DMQ). La especie nueva se distingue por su coloración dorsal verde e iris con tres anillos de colores en vida, piel del dorso y flancos areolados, y por
carecer de procesos odontóforos vomerinos. Es asignada tentativamente al grupo de especies de Pristimantis unistrigatus y es comparada con Pristimantis
ornatissimus (Despax), la segunda especie de llamativa coloración verde en la región. La nueva especie forma parte del ensamblaje de ranas de los
bosques altimontanos del DMQ. La descripción de esta especie nueva ratifica la importancia de la conservación de la diversidad biológica del DMQ.
Many snakes are able to use their chemosensory system to detect scent of conspecifics, which is i... more Many snakes are able to use their chemosensory system to detect scent of conspecifics, which is
important in many social contexts. Age discrimination based on chemical cues may be especially important to
ensure access to sexually mature potential partners. In this study, we used 24 individual Boa constrictor snakes
(12 adults mature and 12 non-mature individuals) that had been captured in different areas of Ecuador, and were
maintained in captivity at the Vivarium of Quito. We used tongue-flick experiments to examine whether these
snakes were able to discriminate between scents from mature and non-mature individuals. Results showed that
B. constrictor snakes used chemical cues to recognize conspecifics and that the scent of individuals of different
ages elicited chemosensory responses of different magnitudes. The scents from adult conspecifics elicited the
quickest and highest chemosensory responses (i.e., short latency times and high tongue-flick rates), although
we did not find differential responses to scent of males and females. The magnitude of the responses was lower
to scent of sub adult individuals, and then even lower to scent of juvenile snakes, but in all cases the scent of
snakes was discriminated from a blank control. We discuss the potential chemical mechanisms that may allow
age recognition and its implications for social and sexual behavior of this snake species. Rev. Biol. Trop. 60 (4):
1603-1611. Epub 2012 December 01.
Most snakes have the chemosensory ability to identify chemical cues from conspecifics, which is u... more Most snakes have the chemosensory ability to identify chemical cues from conspecifics, which is useful in many social
and sexual behaviors. This has been especially well studied in European and North American snake species. In contrast,
there is a general lack of knowledge on the biology and especially on the use of chemical signals by most Neotropical
snake species. Here, we explored the existence of intraspecific recognition by chemical cues in several snake species
from Ecuador within the families Boidae (Boa constrictor constrictor, Boa constrictor imperator, Corallus hortulanus, and
Epicrates cenchria) and Colubridae (Lampropeltis triangulum micropholis) by using experiments of tongue-flicking
discrimination. Results showed that individuals of all species tested showed higher chemosensory responses to odors
from conspecific individuals when compared to odors from individuals of other species, suggesting intraspecific
chemosensory recognition in these snake species. In contrast, there was not chemosensory recognition between the two
subspecies of B. constrictor. We show that some Neotropical snake species are able to use chemical cues of conspecifics in
intraspecific recognition, but further studies are needed to analyze the role of chemical signals in their biology and
social behavior.
We describe a new species of Atractus from Cordillera de los Guacamayos in the Andes of Ecuador. ... more We describe a new species of Atractus from Cordillera de los Guacamayos in the Andes of Ecuador. This new species is the largest known species of Atractus, reaching almost 120 cm in total length with a robust habitus. We also use multivariate statistical analyses of morphometric data to look into the taxonomic confusion involving other large, banded/blotched, species of Atractus in Western Amazonia. We show that A. snethlageae has a widespread distribution in Amazonia and has been repeatedly confused with A. major in Ecuador owing to its color polymorphism. Our multivariate statistical analyses support previous suggestions to recognize A. snethlageae as a distinct species relative to A. flammigerus. Taxonomic accounts are provided for both A. major and A. snethlageae including detailed color pattern descriptions. We also find that there are no valid morphological differences to support recognizing A. arangoi as a separate species from A. major; consequently we synonymize the former name with the latter.
We describe a new species of Siphlophis from the Amazonian slopes of the Ecuadorian Andes, in the... more We describe a new species of Siphlophis from the Amazonian slopes of the Ecuadorian Andes, in the provinces of Azuay, Tungurahua, and Zamora Chinchipe. This is the third species of Siphlophis known from Ecuador and the seventh species in the genus. The new species of Siphlophis is distinguished from all other Siphlophis by characters of external morphology and coloration. Furthermore, phylogenetic analysis of molecular characters places it in Siphlophis and strongly supports our assessment that the species is new and valid. A key to the species of Siphlophis is provided.
We describe a new species of Enyalioides from lowland cloud forests in southwestern Ecuador. This... more We describe a new species of Enyalioides from lowland cloud forests in southwestern Ecuador. This represents the third species in the genus known to occur west of the Andes in South America; the other two species are E. heterolepis and E. oshaughnessyi. Among other characters, the new species can be distinguished from other members in the genus by having small, keeled, paravertebrals; a series of skin folds on the lateral aspects of body and neck; size-homogeneous scales on body and limbs; distinct caudal segments; and an extensive dark patch on the gular region of adult males. Morphological similarity suggests that the new species, which we call E. touzeti, is closely related to E. oshaughnessyi.
the name Herpetodryas reticulata Peters, 1863, is revalidated and assigned to the snakes of the g... more the name Herpetodryas reticulata Peters, 1863, is revalidated and assigned to the snakes of the genus Mastigodryas from the dry forests of central and southwestern ecuador. Mastigodryas reticulatus (Peters, 1863) is characterized by the presence of a striped dorsal pattern, with the upper light lateral stripe formed by two scale rows (4 and 5); dorsal scales with dark apical edges; a light, immaculate throat and venter; a higher number of ventral scales; an elongate and nude region on the base of the hemipenis; and thin, enlarged spines located lateral to the sulcus spermaticus on the distal region of the body of the hemipenis. this species is a member of the M. boddaerti Group, along with M. boddaerti and M. heathii.
We describe a new species of Atractus from Cordillera de los Guacamayos in the Andes of Ecuador. ... more We describe a new species of Atractus from Cordillera de los Guacamayos in the Andes of Ecuador. This new species is the largest known species of Atractus, reaching almost 120 cm in total length with a robust habitus. We also use multivariate statistical analyses of morphometric data to look into the taxonomic confusion involving other large, banded/blotched, species of Atractus in Western Amazonia. We show that A. snethlageae has a widespread distribution in Amazonia and has been repeatedly confused with A. major in Ecuador owing to its color polymorphism. Our multivariate statistical analyses support previous suggestions to recognize A. snethlageae as a distinct species relative to A. flammigerus. Taxonomic accounts are provided for both A. major and A. snethlageae including detailed color pattern descriptions. We also find that there are no valid morphological differences to support recognizing A. arangoi as a separate species from A. major; consequently we synonymize the former name with the latter.
We describe a new species of the diverse genus Pristimantis. The new species is characterized by ... more We describe a new species of the diverse genus Pristimantis. The new species is characterized by having a green dorsum with reddish marks, acuminate snout with papilla at tip, conical ulnar and tarsal tubercles, and by lacking cranial crests. The new species inhabits the northwestern Andean slopes of Ecuador.
We describe a new species of Pristimantis from evergreen lowland forest in the Amazon Basin of Ec... more We describe a new species of Pristimantis from evergreen lowland forest in the Amazon Basin of Ecuador. We observed all specimens to be active at night, located over leaves of shrubs in both primary forest and in the edge of forest clearings. The new species is tentatively assigned to Pristimantis (Pristimantis) frater group based on its small size (17.0-22.1 mm in snout-vent length of four males and 24.1 mm in a single female), relatively narrow head, short and subacuminate snout, lack of canthal stripes and labial bars, moderately long limbs, Finger I shorter than Finger II, and Toe V longer than Toe III. The new species differs from other congeneric species in Amazonia by possessing dense black reticulations on upper and lower borders of the iris, a dorsum that is orange or dark reddish brown without distinct pattern in life, a tympanic membrane not differentiated but ventral part of the tympanic annulus visible, and a small tubercle on each heel and eyelid.
Books by Jorge Valencia
Describimos una especie nueva de Pristimantis verde de la ladera occidental de los Andes de Ecuad... more Describimos una especie nueva de Pristimantis verde de la ladera occidental de los Andes de Ecuador en el Distrito Metropolitano de Quito
(DMQ). La especie nueva se distingue por su coloración dorsal verde e iris con tres anillos de colores en vida, piel del dorso y flancos areolados, y por
carecer de procesos odontóforos vomerinos. Es asignada tentativamente al grupo de especies de Pristimantis unistrigatus y es comparada con Pristimantis
ornatissimus (Despax), la segunda especie de llamativa coloración verde en la región. La nueva especie forma parte del ensamblaje de ranas de los
bosques altimontanos del DMQ. La descripción de esta especie nueva ratifica la importancia de la conservación de la diversidad biológica del DMQ.
Many snakes are able to use their chemosensory system to detect scent of conspecifics, which is i... more Many snakes are able to use their chemosensory system to detect scent of conspecifics, which is
important in many social contexts. Age discrimination based on chemical cues may be especially important to
ensure access to sexually mature potential partners. In this study, we used 24 individual Boa constrictor snakes
(12 adults mature and 12 non-mature individuals) that had been captured in different areas of Ecuador, and were
maintained in captivity at the Vivarium of Quito. We used tongue-flick experiments to examine whether these
snakes were able to discriminate between scents from mature and non-mature individuals. Results showed that
B. constrictor snakes used chemical cues to recognize conspecifics and that the scent of individuals of different
ages elicited chemosensory responses of different magnitudes. The scents from adult conspecifics elicited the
quickest and highest chemosensory responses (i.e., short latency times and high tongue-flick rates), although
we did not find differential responses to scent of males and females. The magnitude of the responses was lower
to scent of sub adult individuals, and then even lower to scent of juvenile snakes, but in all cases the scent of
snakes was discriminated from a blank control. We discuss the potential chemical mechanisms that may allow
age recognition and its implications for social and sexual behavior of this snake species. Rev. Biol. Trop. 60 (4):
1603-1611. Epub 2012 December 01.
Most snakes have the chemosensory ability to identify chemical cues from conspecifics, which is u... more Most snakes have the chemosensory ability to identify chemical cues from conspecifics, which is useful in many social
and sexual behaviors. This has been especially well studied in European and North American snake species. In contrast,
there is a general lack of knowledge on the biology and especially on the use of chemical signals by most Neotropical
snake species. Here, we explored the existence of intraspecific recognition by chemical cues in several snake species
from Ecuador within the families Boidae (Boa constrictor constrictor, Boa constrictor imperator, Corallus hortulanus, and
Epicrates cenchria) and Colubridae (Lampropeltis triangulum micropholis) by using experiments of tongue-flicking
discrimination. Results showed that individuals of all species tested showed higher chemosensory responses to odors
from conspecific individuals when compared to odors from individuals of other species, suggesting intraspecific
chemosensory recognition in these snake species. In contrast, there was not chemosensory recognition between the two
subspecies of B. constrictor. We show that some Neotropical snake species are able to use chemical cues of conspecifics in
intraspecific recognition, but further studies are needed to analyze the role of chemical signals in their biology and
social behavior.
We describe a new species of Atractus from Cordillera de los Guacamayos in the Andes of Ecuador. ... more We describe a new species of Atractus from Cordillera de los Guacamayos in the Andes of Ecuador. This new species is the largest known species of Atractus, reaching almost 120 cm in total length with a robust habitus. We also use multivariate statistical analyses of morphometric data to look into the taxonomic confusion involving other large, banded/blotched, species of Atractus in Western Amazonia. We show that A. snethlageae has a widespread distribution in Amazonia and has been repeatedly confused with A. major in Ecuador owing to its color polymorphism. Our multivariate statistical analyses support previous suggestions to recognize A. snethlageae as a distinct species relative to A. flammigerus. Taxonomic accounts are provided for both A. major and A. snethlageae including detailed color pattern descriptions. We also find that there are no valid morphological differences to support recognizing A. arangoi as a separate species from A. major; consequently we synonymize the former name with the latter.
We describe a new species of Siphlophis from the Amazonian slopes of the Ecuadorian Andes, in the... more We describe a new species of Siphlophis from the Amazonian slopes of the Ecuadorian Andes, in the provinces of Azuay, Tungurahua, and Zamora Chinchipe. This is the third species of Siphlophis known from Ecuador and the seventh species in the genus. The new species of Siphlophis is distinguished from all other Siphlophis by characters of external morphology and coloration. Furthermore, phylogenetic analysis of molecular characters places it in Siphlophis and strongly supports our assessment that the species is new and valid. A key to the species of Siphlophis is provided.
We describe a new species of Enyalioides from lowland cloud forests in southwestern Ecuador. This... more We describe a new species of Enyalioides from lowland cloud forests in southwestern Ecuador. This represents the third species in the genus known to occur west of the Andes in South America; the other two species are E. heterolepis and E. oshaughnessyi. Among other characters, the new species can be distinguished from other members in the genus by having small, keeled, paravertebrals; a series of skin folds on the lateral aspects of body and neck; size-homogeneous scales on body and limbs; distinct caudal segments; and an extensive dark patch on the gular region of adult males. Morphological similarity suggests that the new species, which we call E. touzeti, is closely related to E. oshaughnessyi.
the name Herpetodryas reticulata Peters, 1863, is revalidated and assigned to the snakes of the g... more the name Herpetodryas reticulata Peters, 1863, is revalidated and assigned to the snakes of the genus Mastigodryas from the dry forests of central and southwestern ecuador. Mastigodryas reticulatus (Peters, 1863) is characterized by the presence of a striped dorsal pattern, with the upper light lateral stripe formed by two scale rows (4 and 5); dorsal scales with dark apical edges; a light, immaculate throat and venter; a higher number of ventral scales; an elongate and nude region on the base of the hemipenis; and thin, enlarged spines located lateral to the sulcus spermaticus on the distal region of the body of the hemipenis. this species is a member of the M. boddaerti Group, along with M. boddaerti and M. heathii.
We describe a new species of Atractus from Cordillera de los Guacamayos in the Andes of Ecuador. ... more We describe a new species of Atractus from Cordillera de los Guacamayos in the Andes of Ecuador. This new species is the largest known species of Atractus, reaching almost 120 cm in total length with a robust habitus. We also use multivariate statistical analyses of morphometric data to look into the taxonomic confusion involving other large, banded/blotched, species of Atractus in Western Amazonia. We show that A. snethlageae has a widespread distribution in Amazonia and has been repeatedly confused with A. major in Ecuador owing to its color polymorphism. Our multivariate statistical analyses support previous suggestions to recognize A. snethlageae as a distinct species relative to A. flammigerus. Taxonomic accounts are provided for both A. major and A. snethlageae including detailed color pattern descriptions. We also find that there are no valid morphological differences to support recognizing A. arangoi as a separate species from A. major; consequently we synonymize the former name with the latter.
We describe a new species of the diverse genus Pristimantis. The new species is characterized by ... more We describe a new species of the diverse genus Pristimantis. The new species is characterized by having a green dorsum with reddish marks, acuminate snout with papilla at tip, conical ulnar and tarsal tubercles, and by lacking cranial crests. The new species inhabits the northwestern Andean slopes of Ecuador.
We describe a new species of Pristimantis from evergreen lowland forest in the Amazon Basin of Ec... more We describe a new species of Pristimantis from evergreen lowland forest in the Amazon Basin of Ecuador. We observed all specimens to be active at night, located over leaves of shrubs in both primary forest and in the edge of forest clearings. The new species is tentatively assigned to Pristimantis (Pristimantis) frater group based on its small size (17.0-22.1 mm in snout-vent length of four males and 24.1 mm in a single female), relatively narrow head, short and subacuminate snout, lack of canthal stripes and labial bars, moderately long limbs, Finger I shorter than Finger II, and Toe V longer than Toe III. The new species differs from other congeneric species in Amazonia by possessing dense black reticulations on upper and lower borders of the iris, a dorsum that is orange or dark reddish brown without distinct pattern in life, a tympanic membrane not differentiated but ventral part of the tympanic annulus visible, and a small tubercle on each heel and eyelid.