Ventral Coloration Research Articles

MORPHOLOGICAL VARIATIONS OF SUMATRAN TORENT FROGS, Huia sumatrana (Yang, 1991) AND H. modiglianii Doria, Salvidio and Tavan, 1999

Kurniati, H. 2009. Morphological variations of Sumatran Toren frogs, Huiasumatrana (Yang, 1991) and H. modiglianii Doria, Salvidio and Tavan, 1999. ZooIndonesia 18(1):9-20. Based on an examination specimens of the Sumatran TorrentFrog, Huia sumatrana in Museum Zoologicum Bogoriense (MZB), Indonesia, severalindividuals were found to possess morphological characters similar to those of H.modiglianii, including the number of crossbars on the thigh, snout morphology, anddorsal and ventral pattern and coloration. A similar degree of morphological variationin H. sumatrana that close to H. modiglianii tentatively is named as H. cf sumatrana.

Testing Species Boundaries within the Atractus occipitoalbus Complex (Serpentes: Dipsadidae)

The taxonomic status of Atractus occipitoalbus is revised on the basis of concordance between quantitative and qualitative analyses of morphological characters (meristic, morphometric, color pattern, and hemipenis). Atractus duboisi and A. orcesi are herein resurrected based on the number of ventral and subcaudal scales, number of postocular scales, head shape in lateral view, relative tail length, distinct color patterns, and hemipenial morphology. Additionally, a new species, closely related to A. occipitoalbus ,i s described from the Andean piedmont of Colombia. The new species, represented by a single female, is diagnosed from the A. occipitoalbus female populations on the basis of number of subcaudals, number postocular scales, and dorsal and ventral color patterns.

Biogeographical analysis of Cameroonian puddle frogs and description of a new species ofPhrynobatrachus(Anura: Phrynobatrachidae) endemic to Mount Oku, Cameroon

Patterns of species divergence amongst 13 species of Phrynobatrachus from Cameroon were analysed using phylogenetic analyses of mitochondrial DNA sequence data from 12S rRNA, valine-tRNA, and 16S rRNA. A clade endemic to the mountains of western Cameroon and eastern Nigeria, part of the geologic rift zone termed the Cameroon Volcanic Line, supports the view that montane regions have acted as centres of speciation. Bioko Island (Equatorial Guinea), located 32 km off the coast of Cameroon, is populated by three different lowland Phrynobatrachus species from the mainland. Two of these species, Phrynobatrachus auritus and Phrynobatrachus cornutus reach submontane elevations on Bioko Island (up to 1200–1300 m) but are present only at lowland elevations on mainland Cameroon. A new miniature species of puddle frog of the genus Phrynobatrachus restricted to Mt Oku in the Republic of Cameroon is diagnosed on the basis of morphological characters and molecular data. Unlike all other miniature Phrynobatrachus (snout–vent length < 20 mm), males of this species have unique ventral coloration characterized by a black throat, dark brown to black pectoral and abdominal regions, and a light or white area on the proximal hind limbs. Minute spines cover the venter in males, often appearing as white asperities. The description of this new species supports the significance of this montane ecoregion as a biodiversity hotspot for anurans.

Notoraja sapphira sp. nov. (Rajoidei: Arhynchobatidae), a new deepwater skate from the slopes of the Norfolk Ridge (South-West Pacific)

A new arhynchobatid skate of the genus Notoraja is described from five specimens collected on the slopes of the Norfolk Ridge between 1195 and 1313 m depth. The new species is distinct from its sibling species from southern Australian waters, the Blue Skate (N. azurea), by its smaller size, several morphometric and meristic characters, thorn pattern and dorsal and ventral coloration.

A New Species of Cryptotriton (Caudata: Plethodontidae) from Eastern Guatemala

A new species of lungless salamander (Plethodontidae) is described from the mountains of eastern Guatemala. The new species is distinguished from all other members of its genus by its yellow ventral coloration. It is geographically closest to its sister taxon, Cryptotriton veraepacis, from which it differs in several osteological features as well as nostril size and shape. Molecular analyses with allozyme loci and mitochondrial DNA also support its distinctiveness from C. veraepacis. This miniaturized species inhabits cloud forest habitats and has been found most commonly in bromeliads.

A new species of dink frog (Anura: Eleutherodactylidae: Diasporus) from Cordillera de Talamanca, Costa Rica

A new dink frog species of the genus Diasporus (Eleutherodactylidae) is described from the Cordillera de Talamanca in Costa Rica. The new species shows an amazing polymorphism in the dorsal and ventral coloration that varies from red to black and white that is unique in the genus. Here we include the description of its mating call, sexual dimorphism relative to coloration, and comments on its distribution and conservation status. In addition, molecular data that complement the morphological taxonomy are shown.

A new species of Oreophrynella (Anura: Bufonidae) from the Pantepui region of Guyana, with notes on O. macconnelli Boulenger, 1900

Oreophrynella seegobini sp. nov. is described from 2088 m elevation on Maringma tepui in the Pakaraima Mountains of Guyana, at the Guyana-Brazil border. The new species is mainly distinguished from known congeners by small size, indistinct frontoparietal crests, prominent postorbital crests, prominent suborbital crests, well-developed webbing on hand and foot, dorsal skin minutely spiculate with scattered medium to large elevated tubercles, ventral skin anteriorly rugose with few flat granules, posteriorly tuberculate, blackish brown dorsal colour, and dark brownish orange ventral colour. Data on four specimens of O. macconnelli collected on the southeast slope of the tepui are provided.

A New Species ofLeptolalax(Amphibia, Anura, Megophryidae) from Peninsular Malaysia

A new megophryid species, Leptolalax kecil, is described from the Cameron Highlands of Peninsular Malaysia on the basis of acoustic and morphological characteristics. It has an advertisement call dissimilar to that of other, congeneric species, and is the smallest of the known Leptolalax. It is similar to L. pluvialis from Vietnam in small body size, but differs from it in ventral color, and in the size and color of the pectoral gland. The distributional pattern of the new species Is discussed.

Revalidation of Phrynobatrachus maculiventris Guibé & Lamotte, 1958 and description of its aposematic coloured tadpole

Phrynobatrachus maculiventris Guibé & Lamotte, 1958 is a valid species. Herein we clarify its taxonomic status, re‐describe it, and provide the first description of its tadpole. The tadpoles’ specific identity was assessed through DNA barcoding. Phrynobatrachus maculiventris adults differ from all other West African Phrynobatrachus species by a combination of smooth dorsal skin and a peculiar ventral colouration. The analysis of mitochondrial 16S rRNA revealed that P. maculiventris differs from other West African species of the genus by at least 4.7 % genetic differences. Their tadpoles are unmistakable due to their aposematic black and yellow colour pattern. Cardioglossa liberiensis Barbour & Loveridge, 1927 is a synonym of P. maculiventris. Phrynobatrachus maculiventris has priority over C. liberiensis as the genus Phrynobatrachus has a species named P. liberiensis Barbour & Loveridge, 1927, that was described earlier than C. liberiensis.

Using image analysis on the ventral colour pattern in Salamandrina perspicillata (Amphibia: Salamandridae) to discriminate among populations

The ventral colour pattern in Salamandrina perspicillata is characteristic of each individual and remains invariant throughout the salamanders' life. The present study aimed to determine, using statistical methods applied to quantitative image analysis, whether the coloration pattern is population-specific. The images of ventral colour pattern of 180 salamanders belonging to five populations were analysed. The images were previously warped by geometric morphometry. To our knowledge, this is the first study to use an approach based on geometric morphometrics to standardize ventral shapes. This technique is useful for eliminating form distortions. The results of an analysis of similarities recognized more coloration similarity among individuals of the same population than among individuals from different populations. Analysis by partial least squares correctly classified the 88.88% of individuals into the correct population. The similarities or differences among individuals of different populations are not related to the geographical distances. The results obtained showed that the coloration of the ventral side of the head of the salamanders can be used for discriminating among populations. (C) 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 96, 35-43.

The largest blindsnake in Mesoamerica: a new species of Typhlops (Squamata: Typhlopidae) from an isolated karstic mountain in Honduras

A distinctive new species of Typhlops is described from Parque Nacional Montaña de Santa Bárbara, 1550 m elevation, Departamento de Santa Bárbara, Honduras. The holotype and only known specimen of this new taxon is the largest specimen of the genus thus far reported from Mexico and Central America, and is further differentiated from all other Mesoamerican Typhlops by having 22–22–22 scales around the body and by having a dark brownish gray dorsum with a well-defined pale yellowish gray to immaculate white ventral coloration. This species is a member of the Caribbean Arc Group of Typhlops. An updated key to the Typhlopidae of Mesoamerica is provided.

Ventral colour polymorphism correlates with alternative behavioural patterns in female common lizards (Lacerta vivipara)

In the common lizard, female competition for resources is likely to be a strong selective pressure that has enhanced the evolution of conspicuous traits. Female common lizards display a polymorphism in ventral colour correlated with differences in reproduction, dispersal, and susceptibility to resource competition. We tested the hypothesis that this polymorphism is correlated with differences in behaviour in a social context. We studied the agonistic behaviour (aggression and avoidance) and social stress of females of different colours during laboratory-staged encounters with a limiting resource. We found that the behaviour of females was affected by their own colour, or the colour of their opponent, or both. Such alternative behavioural patterns might reflect differences in competitive ability. Orange females were the least aggressive and the most likely to avoid social interactions, and thus could be a weaker competitor. Yellow females were rarely exposed to aggression and often made their opponents flee, and thus might have higher resource-holding potential. Mixed females were aggressive but were also often exposed to aggression, and displayed the highest stress level, which could be characteristic of an intermediate or condition-dependent resource-holding potential. The possibility that ventral colour is used in social interactions to signal resource-holding potential is discussed.

Testosterone stimulates the expression of a social color signal in Yarrow's Spiny Lizard, Sceloporus jarrovii

The sex steroid testosterone has been shown to regulate the development of male-specific coloration in many organisms that exhibit sexual dichromatism, but the role of testosterone is less certain for species in which both sexes express bright coloration. Lizards in the genus Sceloporus possess bright blue patches on their throats and abdomens. These patches, which are used in social signaling, are often regulated by testosterone and are consequently expressed only in males of most species. However, Yarrow's Spiny Lizard (Sceloporus jarrovii, Cope 1875) exhibits a derived condition in which both sexes express bright blue ventral patches despite dramatic sexual differences in circulating testosterone levels throughout postnatal ontogeny. In this study, we used surgical castration and hormone replacement in juvenile males to test the hypothesis that testosterone stimulates the expression of blue ventral coloration in S. jarrovii. In two separate experiments conducted in captivity and the natural field environment, we found that surgical castration decreased the hue and saturation while increasing the brightness of blue throat and abdominal patches. Castration also decreased the amount of black pigment bordering the blue throat patch. Treatment of castrated males with exogenous testosterone restored all aspects of ventral coloration to values similar to those of intact control males. Early organizational effects of testosterone during prenatal development may lead to the expression of blue coloration in both sexes, but the results of our present experiments indicate that subsequent effects of testosterone during sexual maturation further enhance the coloration of males.

FEMALE PREFERENCES FOR APOSEMATIC SIGNAL COMPONENTS IN A POLYMORPHIC POISON FROG

Aposematic signals may be subject to conflicting selective pressures from predators and conspecifics. We studied female preferences for different components of aposematic coloration in the polymorphic poison frog Oophaga pumilio across several phenotypically distinct populations. This frog shows striking diversity in color and pattern between geographically isolated populations in western Panama. Results indicate that male dorsal color is the most important determiner of female preferences. We did not find consistent evidence for effects of other signal components, such as spotting pattern or ventral color. Females in two populations showed assortative preferences mediated by male dorsal coloration. In a third population we found incomplete color-assortative preference behavior, with females exhibiting strong discrimination toward one novel color but not another. These results hint at a possible interaction between sexual and natural selection: female tolerance of unfamiliar coloration patterns could facilitate the establishment of novel phenotypes that are favored by other selective pressures (e.g., predator biases). Furthermore, our study suggests that specific components of the aposematic signal (i.e., dorsal color, ventral color, and spotting pattern) are affected differently by natural and sexual selection.

Three new species of leaflitter frogs from the upper Amazon forests: cryptic diversity within Pristimantis "ockendeni" (Anura: Strabomantidae) in Ecuador

We describe three new species of Pristimantis leaflitter frogs from the upper Amazon basin of Ecuador: Pristimantis achuar, Pristimantis altamnis, and Pristimantis kichwarum. Each of these new species was previously considered to be part of a single species, formerly known as Eleutherodactylus ockendeni (Boulenger) morph B. However, analysis of DNA sequences together with examination of the morphology of more than 600 specimens from Ecuador reveals that multiple species were confused under the same name. The morphological differences among the three new species are subtle but consistent: presence or absence of a black canthal stripe and/or supratympanic ridge, snout-vent length, and ventral colouration. The three species are generally allopatric and geographically restricted, although at some localities two of the species occur sympatrically.Describimos tres especies nuevas de ranas del sotobosque de la cuenca Amazónica Ecuatoriana: Pristimantis achuar, Pristimantis altamnis y Pristimantis kichwarum. Estas especies fueron consideradas antes como una sola especie bajo el nombre Eleutherodactylus ockendeni (Boulenger) morfo B. Sin embargo, el análisis de secuencias de ADN y la examinación de la morfología de más que 600 especímenes Ecuatorianos indican que en realidad existen tres especies. Sus diferencias morfológicas son sutiles pero constantes: presencia o ausencia de una raya cantal negra y/o de un pliegue supratimpánico y su coloración ventral. Las tres especies tienen distribuciones alopátricas y distintas aunque en algunas localidades se puede encontrar dos de las tres especies juntas.

A new species of Bryophryne (Anura: Strabomantidae) from southern Peru

A new species of Bryophryne from southern Peru (Cusco Region) is described. Specimens were found in the leaf litter of cloud forest at elevations of 2350–3215 m. The new species has a maximum snout-vent length of 21.9 mm in adult females, 18.9 mm in adult males and is the smallest species of the genus. It lacks a tympanum and dentigerous processes of vomers, has dorsolateral folds, and males without vocal slits and without nuptial pads. The new species is most similar to B. bustamantei but differs in being smaller, having discontinuous dorsolateral folds, the males lacking vocal slits, and an overall darker ventral coloration. Bryophryne contains three species all of which lack a tympanum. The deep valley of the Río Apurímac as a distributional barrier separating Phrynopus from Bryophryne is discussed.

Colour variation in female common lizards: why we should speak of morphs, a reply to Cote et al.

AbstractFemale common lizards display variation in their ventral colour, ranging from pale yellow to bright orange. In a previous study, we proposed a discrete classification of this variation into three colour classes: yellow, orange and mixed. However, a recent study reported on continuity of reflectance spectra and plastic change in spectrum components in female common lizards, which made the authors question the validity of a discrete classification of colour patterns in this species. Here, we discuss the relevance of discrete, eye‐based colour classification for understanding the ecological processes that shape the social structure of common lizard female populations. First, as the mixed colour class is characterized by heterogeneous distribution of colour, we explain that it cannot be reliably described by localized spectrophotometer measurements. On the contrary, the classification of colour into three discrete classes is consistent with the description of three alternative strategies in female common lizards. Then, although we support the ecological importance of colour plasticity in this species, we refute the hypothesis of a condition‐dependent signal, which is not supported by experimental data. At last, we explain that colour plasticity, and in particular hormone‐mediated plasticity is compatible with genetic inheritance of colour and the evolution of alternative strategies. Indeed, the genetic background and the environment, especially the social environment, are expected to interact adaptively to modulate the expression of colour signals and alternative strategies.

Environmentally induced changes in carotenoid‐based coloration of female lizards: a comment on Vercken et al.

Colouration may either reflect a discrete polymorphism potentially related to life-history strategies, a continuous signal related to individual quality or a combination of both. Recently, Vercken et al. [J. Evol. Biol. (2007) 221] proposed three discrete ventral colour morphs in female common lizards, Lacerta vivipara, and suggested that they reflect alternative reproductive strategies. Here, we provide a quantitative assessment of the phenotypic distribution and determinants of the proposed colour polymorphism. Based on reflectance spectra, we found no evidence for three distinct visual colour classes, but observed continuous variation in colour from pale yellow to orange. Based on a 2-year experiment, we also provide evidence for reversible colour plasticity in response to a manipulation of the adult population sex ratio; yet, a significant portion of the colour variation was invariant throughout an adult female's life. Our results are thus in agreement with continuous colour variation in adults determined by environmental factors and potentially also by genetic factors.

A NEW ENDEMIC SPECIES OF LIOLAEMUS (IGUANIA: LIOLAEMIDAE) FROM THE MOUNTAIN RANGE OF TANDILIA, BUENOS AIRES PROVINCE, ARGENTINA

Liolaemus gracilis was cited in the categorization of the reptile habitat associations of Buenos Aires province in Argentina as the only Liolaemus lizard inhabiting the rocky grounds of the Tandilia System. We describe a new species of the genus Liolaemus which was previously confused with the widely ranging L. gracilis from the population of this mountain range. We examined samples of populations from coastal sand dunes and from the mountain range of Tandilia. Morphological characters and measurements were taken from specimens of both populations. We recorded ecological and life history notes of the saxicolous form in the field. The new species is an endemic and saxicolous form from Tandilia that can be distinguished from L. gracilis by indistinct or absent light dorsolateral stripes, small and segmental paravertebral spots, and by a throat with a denser, fine and diffuse spotted pattern. The ventral coloration is grayish plumb. Temporal scales are keeled or slightly keeled and the auricular scale is less differentiated. Morphometrically, the new species is larger in snout–vent length and head width but smaller in maximum body width and tail length than L. gracilis. The new species is oviparous and insectivorous.

Morphology of larvae of the family Mytilidae (Bivalvia) from the north-western part of the Sea of Japan

The larval shell morphology of 10 bivalve species of the family Mytilidae (Adula falcatoides,Crenella decussata,Crenomytilus grayanus,Modiolus kurilensis,Musculista senhousia,Mytilus coruscus,Mytilus galloprovincialis,Mytilus trossulusandSeptifer keenae, and an unidentified species Mytilidae indeterminate) from the Sea of Japan is described. The following morphological features were comparatively examined: larval shell outlines including shape and size of umbones, and anterior, posterior and ventral margins, hinge morphology, ligament location, sculpture, colour, and eye-spot outlines. Some dimensional parameters of larval shells are given. The time interval of occurrence of larvae in the plankton, water temperature in this period, and shell length of competent larvae are presented. It is demonstrated that, in spite of sometimes similar external morphological characters, identification of mytilid larvae creates no difficulties if all distinguishing characters are used.