Hyla Research Articles

Effects of Snake Predation on Aggregation and Metamorphosis of Pacific Treefrog (Hyla regilla) Larvae

OVASKA, K. E., AND J. CALDBECK. 1997a. Courtship behavior and vocalizations of the frogs Eleutherodactylus antillensis and cochranae in the British Virgin Islands. J. Herpetol. 31:149-155. ,AND . 1997b. Vocal behaviour of the frog Eleutherodactylus antillensis on the British Virgin Islands. Anim. Behav. 54:181-188. , AND J. LAZELL, JR. 1998. Eleutherodactylus schwartzi. (NCN). Reproduction. Herpetol. Rev. 29:97.

Una nueva especie de rana arborícola (Amphibia: Hylidae: Hyla) de un bosque nublado del oeste de Venezuela

It is described a new species of treefrog of the genus Hyla, H. amicorum, from the Cerro Socopo, state of Falcon, western Venezuela. This new taxon can be differentiated from the congeners reported from Venezuela by the combination of characteristics as follow: small size (22.6 mm, in male), vestigial webbing between toes II and III, belly strongly areolated, skin dorsally smooth, vent covered totally by a skin fold, no pattern on dorsum, dentigerous processes of the vomer arranged forming a wide U, located slightly behind and between the choanae. Intrageneric relationships of this new species are obscure, but a close relationships with those groups of H. minuta or H. microcephala groups would not be discarded, nevertheless as long as show unique combination of morphological characteristics, suggesting probably a different phylogenetic origin.

The identity and distribution of Hyla rossalleni Goin

The identity and distribution of Hyla rossalleni Goin

Description of the Tadpole of Hyla plicata with Comments on the Taxonomic Value of the Larval Internal Oral Morphology

behavior of the iguanid lizard Sceloporus jarrovi. Copeia 1978:430-438. . 1981. Phenotypic correlates of male reproductive success in the lizard Sceloporus jarrovi. pp. 96-107 in R. D. Alexander and D. W. Tinkle (eds.), Natural Selection and Social Behavior. Clarion Press, New York. SINERVO, B. 1990. Evolution of thermal physiology and growth rate between populations of the western fence lizard (Sceloporus occidentalis). Oecologia (Berlin) 83:228-237. AND S. C. ADOLPH. 1989. Thermal sensitivity of growth rate in hatchling Sceloporus lizards: Environmental, behavioral and genetic aspects. Oecologia (Berlin) 78:411-419. AND S. C. ADOLPH. 1994. Growth plasticity and thermal opportunity in Sceloporus lizards. Ecology 75:776-790. SMITH, D. C. 1981. Competitive interactions of the striped plateau lizard (Sceloporus virgatus) and the tree lizard (Urosaurus ornatus). Ecology 62:679-687. SMrrH, G. R. 1995. Within-population life history and demographic variation in the striped plateau lizard, Sceloporus virgatus. Unpubl. Ph.D. Dissertation, Univ. Nebraska, Lincoln. . 1996. Habitat use and fidelity in the lizard, Sceloporus virgatus. Amer. Midi. Natur. 135:68-80. AND R. E. BALLINGER. 1994. Thermal ecology of Sceloporus virgatus, from southeastern Arizona, and comparison with Urosaurus ornatus. J. Herpetol. 28:65-69.

Hybridization between tetraploid and diploid species of treefrogs (Genus hyla).

An indirect analysis of female meiotic mechanisms in the tetraploid (4n = 48) grey treefrog, Hyla versicolor, was performed by examining artificially produced hybrids. First generation hybrids between a H. versicolor female from Canada (4n = 48) and a H. arborea male from France (2n = 24) were all triploid and appeared to contain two sets of chromosomes from H. versicolor and one set from H. arborea. Males and females were produced in equal numbers but testes in general were more completely developed than ovaries. Electrophoretic analysis of selected allozyme loci suggested that gene products from the two parents were not equally expressed. Backcross hybrids were triploid, tetraploid, and pentaploid but did not appear to contain recognizable chromosomes from the H. arborea grandparent. Allozymes from these hybrids indicated that only H. versicolor alleles were expressed, as none of the distinctive H. arborea alleles present in the triploid male parent were present in the offspring. It was concluded that preferential pairing of chromosomes and gene regulatory biases may help to explain factors that relate to the ability of tetraploids to hybridize with even distantly related taxa and may be involved in the rediploidization process that usually follows polyploidization.

The late replication banding patterns of chromosomes are highly conserved in the genera Rana, Hyla, and Bufo (Amphibia: Anura)

The late replication banding patterns of chromosomes are highly conserved in the genera Rana, Hyla, and Bufo (Amphibia: Anura)

A New Species of Frog of the Genus Hyla from the Cordillera Oriental in Northern Colombia with Comments on the Taxonomy of Hyla minuta

A new species of Hyla is described from the eastern slope of the Andes in northern Colombia. This species can be distinguished from Hyla minuta osteologically, but it cannot be placed in any of the presently recognized species groups of Hyla based on morphological characters. In spite of its resemblance to H. minuta, H. stingi and H. minuta are not close relatives. It is shown that dorsal pattern and color is not an autapomorphy in H. minuta, and therefore lacks any use for taxonomic purposes in that species. It is suggested H. minuta is a complex of species. RESUMEN. - Se describe una nueva especie de Hyla de la vertiente oriental de los Andes en norte Colombia. En el presente, esta especie solo puede ser distinguida de Hyla minuta usando caracteres osteologicos. Esta especie no puede ser asignada a ninguno de los grupos de especies de Hyla actualmente reconocidos, basandome en caracteres morfologicos. A pesar de su parecido con H. minuta, H. stingi e H. minuta no estan cercanamente relacionades. Se muestra que el patron y color dorsal no es una autapomorfia de H. minuta, y por lo tanto no son buenos caracteres para ser usados con fines taxonomicos en esa especie. Se sugiere que H. minuta es un complejo de especies.

New Species of Tree Frog of the Genus Hyla (Anura: Hylidae) from Northern Honduras

fin osteology in gobioid fishes with comments on gobioid relationships. Bull. Mar. Sci. 42:174-214. HOESE, D. F. 1984. Gobioidei: relationships, p. 588591. In: Ontogeny and systematics of fishes-an international symposium dedicated to the memory of Elbert Halvor Ahlstrom. H. G. Moser, W. J. Richards, D. M. Cohen, M. P. Fahay, A. W. Kendall, Jr., and S. L. Richardson (eds.). 15-18 Aug. 1983, La Jolla, California, American Society of Ichthyologists and Herpetologists (ASIH), Gainesville, Florida. , AND G. R. ALLEN. 1987. New Australian fishes part 10. A new genus and two new species of freshwater eleotridid fishes (Gobioidei) from the Kimberley region of Western Australia. Mem. Mus. Victoria 48:35-42.

Predation on Hyla versicolor and Pseudacris crucifer during Reproduction

Note sur la predation exercee sur les rainettes Hyla versicolor et Pseudoacris crucifer lors de la periode de reproduction, notamment par un insecte aquatique (Lethocerus americanus) et une grenouille (Rana catesbeiana).

Histological Structure of the Lungs of the Loggerhead Turtle, Caretta caretta, before and after Hatching

Ross, M. A., AND J. L. HARPER. 1972. Occupation of biological space during seedling establishment. J. Ecol. 60:77-88. SAS INSTITUTE INC. 1987. SAS/STATtm guide for personal computers. Version 6. SAS Institute Inc., Cary, North Carolina. SEALE, D. B., AND N. BECKVAR. 1980. The comparative ability of anuran larvae (genera Hyla, Bufo, and Rana) to ingest suspended blue-green algae. Copeia 1980:495-502. WILBUR, H. M., AND R. A. ALFORD. 1985. Priority effects in experimental pond communities: responses of Hyla to Bufo and Rana. Ecology 66:11061114. WRIGHT, A. H., AND A. A. WRIGHT. 1949. Handbook of frogs an toads. 3rd d. Cornell University Press, Ithaca, New York.

Systematic Implications of Hybridization Experiments with Some Eurasian Treefrogs (Genus Hyla)

Thirteen kinds of interspecific and intraspecific crosses were performed with Eurasian treefrogs of the genus Hyla. Progeny of eight kinds of interspecific crosses (between females of H. japonica and males of H. hallowellii, H. chinensis, H. suweonensis, H. savignyi, H. meridionalis, H. arborea arborea and H. arborea sarda and between a female of H. suweonensis and males of H. japonica and H. hallowellii) metamorphosed into froglets. The results are consistent with other lines of evidence that indicate close phylogenetic relationship among these Eurasian species. At metamorphosis, all of the hybrids had either nearly normal testes or abnormal ovaries. Sex ratio differed significantly from a 1:1 ratio among progeny in five kinds of interspecific crosses; most of the control froglets had normal ovaries or testes in nearly equal proportion. Gonadal structures in hybrids after one year were also abnormal, suggesting that fertility of adults would be very low, if not absent. The presumed low hybrid fertility supports the specific status of H. japonica, which has often been treated as a subspecies of H. arborea. It also supports the specific status of H. suweonensis, which was distinguished originally on the basis of its characteristic vocalization. This study also suggests specific status of H. savignyi and some genetic divergence between H. japonica of Japan and Korea.

Low Cutaneous Evaporative Water Loss in Arboreal Frogs

Rates of cutaneous evaporative water loss were measured in seven arboreal and 11 nonarboreal anuran species under controlled environmental conditions. Areaspecific rates of cutaneous evaporative water loss of arboreal species (genera Hyla and Osteopilus) were 47% lower than those of nonarboreal species (genera Acris, Atelopus, Bufo, Gastrophryne, Rana, Scaphiopus, and Xenopus). Body and skin temperatures of arboreal species averaged 4.4 C higher than those of nonarboreal ones. Boundary layer resistance was similar in both groups of frogs and averaged 0.80 s cm⁻¹; skin resistance averaged 0.05 s cm⁻¹ in nonarboreal frogs and was 41 times higher in arboreal ones. The results of this study conflict with those of previous studies and emphasize the need for careful control of animal posture and water vapor density when measuring evaporative water loss.

Gene dosage effects on MDH isozyme expression in diploid, triploid, and tetraploid treefrogs of the genus Hyla.

Electrophoretic staining intensities at a polymorphic malate dehydrogenase locus (MDH-1) in the tetraploid treefrog Hyla versicolor and diploid Hyla chrysoscelis were compared using intraspecific and interspecific crosses. Gene dosage levels within the three ploidies were additive for the expression of isozymes encoded by this locus. Using densitometry, phenotypes from intraspecific tetraploid progeny conformed to a tetraploid gene dosage model, while phenotypes from interspecific hybrids conformed to a triploid gene dosage model. Intra- and interspecific progeny phenotypes and ratios agree with theoretical models predicting differences in such phenotypes and ratios, depending on the ploidy of the parents involved. Heterozygous phenotypes revealed that diploid crosses produced only symmetrically heterozygous progeny while tetraploid crosses produced two classes of asymmetrically heterozygous progeny in addition to symmetrically heterozygous progeny. Interspecific crosses produced only asymmetrically heterozygous progeny. Interspecific crosses involving a homozygous diploid genotype and symmetrically heterozygous tetraploid genotype produced three progeny phenotypes, while the reciprocal cross produced only two progeny phenotypes. the value of interspecific crosses between diploids and tetraploids in determining gene silencing at duplicated loci is considered.

Variation in Propagule Size as a Function of Environmental Uncertainty for Tree Frogs

Predictions concerning egg size and the associated within-clutch variability component were tested with tropical treefrogs, genus Hyla. It was expected that species breeding in temporary versus permanent aquatic breeding sites would exhibit significant differences in clutch parameters as a result of differing selective forces in these contrasting environments. Although the intraclutch variability in egg size, as measured by CV, was not significantly different between the two groups, there was a significant difference in the shape of the distribution of values around the mean, as measured by kurtosis values (g2). The clutches from species breeding in temporary ponds tended towards platykurtosis; this distribution is interpreted as "bet-hedging" as a response to environmental uncertainty. The clutches from species breeding in permanent ponds tended towards leptokurtosis; this distribution is interpreted to be the result of stabilizing selection around an optimal egg size in the more predictable environment. I wish to stress that although these two groups are significantly different from each other in their distributional trends, most of the distributions are not significantly different from normal. In other words, there is a range of egg size, rather than one optimal egg size, in both environments. Numerous factors, including stochastic environmental effects, probably influence egg size in ways that are not necessarily synergistic and unidirectional. The central limit theorem (relative to all the selective and proximate factors affecting egg size) is invoked as an explanation for the fact that nearly all clutches exhibit a normal distribution of egg sizes.

Mating Calls of Treefrogs (Genus Hyla) in the Far East, with Description of a New Species from Korea

Mating calls of treefrogs (genus Hyla) from Japan, Korea and Taiwan are characterized and compared. The calls of H. japonica and H. hallowelli are a series of notes consisting of many fine pulses, whereas the note of H. chinensis consists of a few discrete pulses. Note length and note interval are inversely correlated with air temperature in H. japonica and H. hallowelli, and their regressions resemble those of western Asian H. savignyi and European H. meridionalis, respectively. H. suweonensis, a new species described from Korea, differs phonetically from sympatric H. japonica especially in frequency distribution. It differs also in calling behavior, some morphometric characters and serum proteins. Its karyotype (2n = 24) is similar to many other hylids. Acoustic characteristics of the Holoarctic hylids suggest that H. japonica, H. hallowelli and all European and western Asian species are related to, and probably derived from, the H. eximia group of North America. H. suweonensis and H. chinensis seem to belong to two different phyletic lines.

Acute toxicity of methyl fluorosulfonate (Magic Methyl).

Methyl fluorosulfonate (Magic Methyl), an active methylating agent used by research chemists, was studied for acute oral toxicity, acute inhalation toxicity, ocular irritation, and dermal irritation. This compound is very hazardous and may have been responsible for at least one human death. The results of these studies confirmed that Magic Methyl is markedly toxic by all routes studied and particularly by the inhalation route since the LC50 value for rats was found to be between 5 and 6 ppm.

Evolutionary Genetics of Diploid-Tetraploid Species of Treefrogs of the Genus Hyla

Evolutionary Genetics of Diploid-Tetraploid Species of Treefrogs of the Genus Hyla

Protein Variation in Several Species of Hyla

Case, S. M., Haneline, P. G., and M. F. Smith (Museum of Vertebrate Zoology, University of California, Berkeley, California 94720) 1975. Protein variation in several species of Hyla. Syst. Zool. 24:281-295.-Allelic variation at fourteen loci coding for ten enzymes was studied in seventeen populations of Hyla regilla and in H. eximia, H. wrightorum, H. cadaverina, and H. euphorbiacea. Heterozygote deficiencies were found at several loci in several populations of H. regilla and possible reasons are suggested. The proportion of polymorphic loci and average individual heterozygosity were typical of other vertebrates with some exceptions: (1) the Lee's Camp, Oregon population; (2) the Santa Cruz Island population; (3) the three San Diego Co. populations; (4) the Sierra San Pedro Martyr population; and (5) the three populations in southern Baja California. Measures of genetic similarity (S) and genetic distance (D), as well as patterns of variation in allele frequencies at PGI and IDH-2, suggested three groups within Hyla regilla. These were: (1) the four Oregon populations; (2) the three central California populations; and (3) the ten southern California and Baja populations. The proportion of major alleles shared indicated Hyla eximia and H. wrightorum, are very closely related and that H. wrightorum is not a subspecies of H. regilla; H. eximia and H. wrightorum are also closely related to H. euphorbiacea. Hyla regilla and H. cadaverina are more closely allied to each other than they are to the other three forms. A strong correlation (r = 0.93) between genetic relatedness as measured by immunological comparisons of albumin and that measured by electrophoretic studies of many proteins was found, although immunological techniques cannot be used to study taxa which are very closely related (D = 0.25 or less). [Proteins; genetics; Hylidae] Since the pioneering work of Lewontin & Hubby (1966) attention has been focused on the amount and significance of genic variation in local populations. Subsequently electrophoresis has been used to study various aspects of local population genetics and the relationships among species (see Selander & Johnson, 1973 for a review). A number of electrophoretic studies of anurans have been conducted (Dessauer & Nevo, 1969; Gartside, 1972; Guttman & Wilson, 1973; Maxson & Wilson, 1974a; Platz & Platz, 1973; Rogers, 1973a and b; Salthe, 1969; Salthe & Nevo, 1969). The scope of these works is wide, ranging from an analysis of variation at a few loci as a method of assessing amounts of introgression to a survey of variation at a large number of loci in an effort to determine the overall level ' California Academy of Sciences, San Francisco, California; Present address: Department of Amiphibians and Reptiles, Museum of Comparative Zoology, Harvard University, Cambridge, Massachusetts 02138. of genic variation and to examine genetic relationships between two or more forms. No detailed study of the latter type has been done with any members of the genus Hyla. The main purpose of this study was to determine the amount of genic variation within and the genetic distance between populations of Hyla regilla. This is of particular interest since this species ranges from British Columbia to the tip of Baja California and has been divided into ten subspecies by Jameson, et al. (1966) on the basis of a discriminate analysis of morphological characters. Maxson & Wilson (1974b) have compared the serum albumins of eight of these subspecies using the method of microcomplement fixation. Electrophoretic estimates of genetic distance can provide an independent method for detecting subgroups within this wide-ranging species. In addition, several other members of the Hyla eximia group, in which H. regilla

Convergent morphological evolution detected by studying proteins of tree frogs in the Hyla eximia species group.

Protein studies have uncovered an apparent case of convergent evolution among North American tree frogs. The species Hyla eximia and Hyla regilla are so similar in external morphology that the "wrightorum" subspecies is assigned by some authorities to H. eximia and by others to H. regilla. Yet microcomplement fixation experiments show that "wrightorum" albumin, though virtually indistinguishable from authentic H. eximia albumin, differs as much from H. regilla albumin as from albumins of species outside the genus Hyla, such as Acris crepitans. The morphological resemblance of "wrightorum" to H. regilla is thus probably due to convergence.

An Osteological Analysis of Holarctic Tree Frogs, Family Hylidae

Holarctic hylids are currently grouped into 4 genera: Hyla, Acris, Pseudacris, and Limnaeodus. A complete osteological analysis of 32 species of holarctic hylids was performed to discover if systematic skeletal differences supported recognition of these taxonomic groups. Detailed examinations of their skeletons revealed that the species differed in 20 osteological characters. Simple matching similarity coefficients were calculated for all of the species and a phenogram was constructed using the weighted pair group method of averages. The osteological analysis suggests that the 32 species form 5 clusters: 1) 7 species of Pseudacris; 2) two species of Acris; 3) Limnaeodus ocularis; 4) Hyla crucifer; and, 5) 21 species of Hyla. Both Acris and Limnaeodus are distinctive osteologically, and both genera appear to be valid. Osteologically, Hyla crucifer appears to be a connecting link between Pseudacris and other Hyla, and literature reports of hydridization studies also suggest that H. crucifer is equally related to both Pseudacris and other holarctic Hyla. Present data, then, suggest that the recognition of Pseudacris as a separate genus is unwarranted, and the species so designated probably represent species within the genus Hyla.