Postembryonic ontogeny of the spadefoot toad,Scaphiopus intermontanus (Anura: Pelobatidae): Skeletal morphology

Postembryonic skeletal ontogeny of the pelobatid frog Scaphiopus intermontanus is described based on a developmental series of cleared-and-stained, whole-mount specimens. The focus is on laboratory-reared individuals fed a herbivorous diet as larvae. Although there is variation in the timing of ossification of individual skeletal elements relative to developmental stages based on external morphological criteria, the sequence of skeletal development generally is conservative. Compared with its close relative, S. bombifrons, ossifications that occur during prometamorphosis tend to be slightly delayed in S. intermontanus; however, cranial bones that ossify during late metamorphic climax in S. intermontanus are delayed until postmetamorphosis in S. bombifrons. The differences in timing between the two species are consistent, however, with differences observed between two developmental series of S. intermontanus raised at two different temperatures. Noteworthy features of skeletal development in S. intermontanus include: 1) presence of palatine ossifications that form from independent centers of ossification and soon fuse with the postnarial portion of the vomers to form the compound vomeropalatine bones; 2) compound sphenethmoid that may arise from four or more endochondral centers of ossification and one dorsal, dermal center of ossification; and 3) presence of transverse processes and vestigal prezygapophyses on the first postsacral vertebra. The morphology of the larval orbitohyoideus and interhyoideus muscles is compared. The record of skeletal ontogeny and muscle morphology presented herein for the herbivorous larval morph can serve as a baseline for comparisons with the ontogeny of the carnivorous larval morph of Scaphiopus. J. Morphol. 238:179–244, 1998. © 1998 Wiley-Liss, Inc.     

Skeletal development of the Mexican spadefoot, Spea multiplicata (Anura: Pelobatidae)

The larval chondrocranium of Spea multiplicata is described, as is the development and adult morphology of the skeleton. There are major modifications to the larval chondrocranium throughout development, including the presence of embryonic trabeculae in young tadpoles and significant reorganization of cartilaginous structures at metamorphosis. The first bone to ossify is the parasphenoid (Stage 35), followed by the presacral neural arches, ilium, and femur (Stage 36). By Stage 39, most of the postcranial elements have begun to ossify. Metamorphic climax is accomplished over three Gosner stages (39-41) and involves major modifications to the chondrocranium, as well as the appearance of three cranial elements (septomaxilla, nasal, and premaxilla). After metamorphosis, the exoccipital, vomer, dentary, angulosplenial, squamosal, pterygoid, sphenethmoid, ischium, and hyoid begin to ossify. The stapes, mentomeckelian, operculum, carpals, and tarsals do not appear until juvenile and adult stages. The development of the hyoid and cartilaginous condensations of the carpals and tarsals are described. In addition, phenotypic plasticity within the genus and the absence of a palatine (= neopalatine) bone are discussed.     

中国四川省蛙科一新种——南江臭蛙(两栖纲:无尾目)

对分布于四川、重庆市、贵州、湖北、湖南、安徽和福建的花臭蛙[Odorrana(Odorrana)schmackeri(Boettger,1892)]标本进行了形态比较,结果发现四川省南江和万源县的花臭蛙标本与其他产地的花臭蛙标本在形态特征上存在明显区别,主要是:1)成体雄雌体长之比值较小,约为1∶1.34;2)犁骨齿列短,两内侧间距宽,距内鼻孔远;3)背面深色斑点周围无浅色边缘;4)股后部深色斑大而稀疏;5)趾间蹼较弱,第四趾蹼达远端关节下瘤;6)腹内成熟卵的动植物极均为乳白色。故将四川省南江和万源的标本订为新种--南江臭蛙[Odorrana(Odorrana)nanjiangensis,sp.nov.]。     

Population size and survival of the Brazilian Torrent Frog Hylodes heyeri (Anura,Hylodidae)

Population dynamics are influenced by environmental variability and understanding the abundance and persistence of individuals and populations is a fundamental goal of population ecology. Thus, estimating demographic parameters to identify the factors important for population variability is required to understand temporal and spatial dynamics. The stream-living diurnal frog Hylodes heyeri is endemic to the Atlantic Forest of Brazil in the states of Paraná, São Paulo and Santa Catarina. Here we use capture-mark-recapture methods to estimate survival rates and population size of this Brazilian Torrent Frog in Pico do Marumbi State Park, Paraná. We used CJS models for an open population to estimate apparent survival, capturability and population size in two streams. The number of captures during each session was positively correlated with the minimum weekly temperature. Despite that correlation, the most parsimonious model of survival and capturability was the constant model for both parameters, resulting in a monthly survival rate of 0.38 (95% CI = 0.30–0.46). Thus, only the abundance of the frog differed in the two streams (79 vs. 36), with the population size estimate of 187 individuals. Reproduction is seasonal in the Brazilian Torrent Frog and so the low monthly survival rate suggests that animals move over time rather than die, because 38% month⁻¹ survival should result in <1% of the population remaining after 5 months. Thus, researchers must recognize that populations are labile and individuals often move or are washed downstream during heavy rainfall, generating apparently rapid local turnover that is unlikely to reflect true mortality.     

A Molecular Phylogeny for the Frog Genus Limnodynastes (Anura: Myobatrachidae)

Members of the genus Limnodynastes are a prominent and widespread feature of the Australian frog fauna. Yet despite their potential to be informative about biogeographic history and mechanisms of speciation, the relationships among these taxa are not well known. We investigated phylogenetic relationships within the genus Limnodynastes via sequencing of mitochondrial (mt)DNA from current members of the genus Limnodynastes and the monotypic genus Megistolotis. a 450-bp fragment of the 16S rRNA gene and a 370-bp fragment of the protein-coding gene ND4 were used to infer a molecular phylogeny. We revise traditional species groupings and now recognize four species groups within Limnodynastes: the L. ornatus group (L. ornatus and L. spenceri), the L. peronii group (L. peronii, L. tasmaniensis, L. fletcheri, the L. depressus), the L. salmini group (L. salmini, L. convexiusculus, and L. lignarius), and the L. dorsalis group (L. dorsalis, L. terraereginae, L. dumerilii and L. interioris). The L. ornatus species group forms a highly distinctive clade that is a sister group to the other Limnodynastes groups. Pending broader phylogenetic studies it could be removed from the genus Limnodynastes. Our results concur with previous suggestions that Megistolotis lignarius is nested within Limnodynastes, and we therefore reclassify this species as Limnodynastes lignarius. Furthermore, specimens identified as L. depressus form a mtDNA lineage distinct from other species in the genus, confirming the validity of the species. Specimens of species from the L. dorsalis group (L. dorsalis, L. dumerilii, L. interioris, and L. terraereginae) are closely related such that L. dumerilii is paraphyletic with two other species. Finally, our study provides broad support for previous phylogenies based on microcomplement fixation.     

Territoriality and Male Mating Success in the Dart-poison Frog,Epipedobates femoralis (Dendrobatidae,Anura)

The social and reproductive behaviour of the dart-poison frog, Epipedobates femoralis, was studied in Amazonian Peru for 14 months. Males defended territories with advertisement calls and, ultimately, fighting. Territory size ranged from 0.25 to 26 m² and was positively correlated with duration of residence and calling activity of the owner. Females were not territorial and were never attacked when approaching calling males. Males and females only mated once and females sampled calling males before mating. Male mating success was closely correlated with territory size and calling activity. No correlation was found between male body size and mating success. Territories provide residents with sufficient space for mate attraction and reproduction without interference from rivals. Since territory size is dependent on calling activity which involves high energetic costs, it is suggested that territory size reveals male quality.     

厄瓜多尔西部新热带蛙(两栖纲: 无尾目:细趾蟾科)的分布特征及生态习性

Leptodactylus labrosus属于陆地坐-等型的捕食者,其食物包括地表的、掘地的及飞行昆虫,其中蚂蚁数量最多。曾有报道Bothrops asper是其天敌。L.labrosus主要栖息于落叶及半落叶林潮湿的环境中,偶尔也栖息于常绿林中。L.labrosus分布于厄瓜多尔西海岸的北部、中部、南部;秘鲁西海岸的北部、中部,分布地海拔可达600 m;及位于南厄瓜多尔和北秘鲁海拔高达1 300 m的干燥的安第斯山谷。其分布地区包括了厄瓜多尔和秘鲁海岸的潮湿的、季节性干燥的森林。在安第斯山脉斜坡的潮湿地带,L.labrosus与其他3种细趾蟾科的分布区重叠,但表现为生境分离。其分布特征与其他几种活动区域受限的两栖动物相似。Tumbesian地区应被认为是地方特有两栖动物的分布区。Choco和Tumbesian的中间区域是L.labrosus与其他细趾蟾科的生境分布重叠区,其生态及气候特征使其形成了独特的动物区系,包括几种地方特有物种。因此该地区应被划为西厄瓜多尔地方种区域。     

Comparative skeletogenesis of the Oriental Tree Frog Hyla orientalis (Anura: Hylidae)

The ontogeny of skeletal development of the Oriental Tree Frog, Hyla orientalis (Bedriaga, 1890), is followed from tadpole to froglet and compared with four other hylid species i.e., Hypsiboas lanciformis, Hypsiboas pulchellus, Phyllomedusa vaillanti and Pseudis platensis. Our analysis and comparison is based on cleared and double-stained specimens. The parasphenoid is the first skeletal element that ossified in Hyla orientalis is followed by the exoocipital, prootic, axial and appendicular skeletal elements, frontoparietal, nasal, upper jaw, squamosal, pterygoid, lower jaw, vomer and quadratojugal. Ossification initiated at early Stage 33 in Hyla orientalis whereas in other hylids it begins after Stage 37. Major transformations of the larval jaw were visible after Stage 42. Cranial ossifications were completed after appendicular and axial ossifications of Hyla orientalis. All skeletal elements ossified before the end of the metamorphosis, a unique feature of Hyla orientalis in comparison to the other hylids studied here.     

Molecular phylogeny and biogeography of West Indian toads (Anura: Bufonidae)

Toads of the Bufo peltocephalus Group (Anura: Bufonidae) occur throughout the Greater Antilles (Cuba to the Virgin Islands), a geographic region of relatively high endemicity. Previous morphological and immunological studies suggested that the West Indian toads are a monophyletic lineage derived from Neotropical Bufo but were unable to clarify relationships within the group. We examined the evolutionary relationships and biogeography of this group of frogs by collecting approximately 2 kb of mitochondrial DNA sequence data from eight West Indian species and selected non-West Indian species from the New World and the Old World. Our analyses support the monophyly of native West Indian toads and a New World origin for the group. Relationships among the West Indian species are less certain, but a Cuban lineage is defined in most analyses.     

Ontogeny of the Thyroid Glands During Larval Development of South American Horned Frogs (Anura,Ceratophryidae)

The role of thyroid hormone (TH) in anuran metamorphosis has been documented from a variety of approaches, but the sequence of morpho-histological development of the thyroid glands that produce the secretion of the hormone was assumed invariant from studies of relatively few species even when the effects of environmental influences on larval development and metamorphosis have been largely documented. There are anurans in which developmental and growth rates diverge, and the resulting heterochrony in growth and development produces giant/miniature tadpoles, and or rapid/delayed metamorphosis suggesting changes of the activity of the thyroid glands during larval development. Herein, we analyze the morpho-histological variation of the thyroid glands in larval series of Ceratophrys cranwelli, Chacophrys pierottii, Lepidobatrachus laevis and L. llanensis that share breeding sites along semiarid environments of the Chaco in South America, belong to a monophyletic lineage, and present accelerated patterns in growth and development in order to have a morphological evidence about a possible shift of TH physiology. We describe gross morphology and histology of the thyroid glands and find features shared by all studied species such as the presence of supernumerary heterotopic follicles; changes in the volume and number of follicles towards the metamorphic climax, and cuboidal epithelia with occasional intra-cellular vacuoles as signs of low glandular activity without a manifest peak at the climax as it was assumed for anurans. We discuss different lines of evidence to interpret sources of extra supplement of TH to support the rapid metamorphosis. These interpretations highlight the necessity to design a research program to investigate the endocrine variation during development of ceratophryids taking in account their morphology, physiology and ecology in order to learn more about the effects of environmental and developmental interactions involved in the anuran evolution.     

Temporal and Geographic Variation in the Advertisement Call of the Booroolong Frog (Litoria booroolongensis: Anura: Hylidae)

The mechanisms that underlie sexual selection rely upon within‐ and among‐individual variability in the targeted traits. In this study, we examined variation in the advertisement call of the booroolong frog (Litoria booroolongensis) at several different levels: between populations, between breeding seasons in the same population, among males within a population, within males between nights and within males in a single calling bout. The call of L. booroolongensis has multiple notes with a pulsed structure. We detected considerable variation in advertisement call structure between breeding seasons and between populations. The measured call properties ranged from static to dynamic; however, most properties were intermediate between the criteria that have been traditionally used to define call traits as static or dynamic (≤5 and ≥12% respectively). We compared actual and relative repeatabilities and found that the temporal call properties associated with the structure of the note had the highest values, suggesting that these characters in particular may respond to selection. We argue that relative repeatabilities are a particularly useful measure of the potential for evolutionary response to selection as they account for an individual's relative performance during the period of assessment in an ever‐changing breeding arena.     

Intraspecific Polymorphism of Rice Frog,Fejervarya multistriata(Anura: Ranidae),in Lingnan,Huangshan,China

Many anuran species exhibit striking color and/or pattern polymorphisms.We sampled 599 adult rice frogs,Fejervarya multistriata,from a rice paddy in the periphery of the Lingnan Nature Reserve(Huangshan,Anhui).We recognized ten morphs based on three relatively stable and distinct morphological characters: dorsal ground color(green or gray),middorsal stripe(absence,wide,or narrow),occipital rusty spot(absence or presence).The grey individuals are more common and larger than the green individuals(frequency 88.1 vs.11.9%,respectively) and(SVL 39.4–36.6 vs.35.7–34.6 mm,respectively).There is a higher proportion of individuals with a middorsal stripe(59.7%) while absence of the occipital rusty spot is more common in the population(82.3%).We expect additional studies in different habitat types would help build our understanding of the relationship between color polymorphism and habitat,geography,and climate.     

Molecular phylogeny and biogeography of West Indian frogs of the genus Leptodactylus (Anura, Leptodactylidae)

Three endemic species of the aquatic-breeding frog genus Leptodactylus are recognized from the West Indies: Leptodactylus albilabris (Puerto Rico and the Virgin Islands), Leptodactylus dominicensis (Hispaniola), and Leptodactylus fallax (Lesser Antilles). DNA sequences were obtained from several mitochondrial genes to resolve taxonomic questions involving these species and to provide insights into their origin and distribution in the islands. We found low levels of sequence divergence between L. dominicensis and L. albilabris, supporting morphological evidence that the former species is a junior synonym of the latter species. Phylogenetic analysis supported previous species-group allocations, finding that L. albilabris is a member of the fuscus group and L. fallax is a member of the pentadactylus group. Molecular time estimates for the divergence of L. albilabris from its closest relative in South America (24-58 million years ago, Ma) and for L. fallax from its closest relative in South America (23-34Ma) indicate that they colonized the West Indies independently by over-water dispersal in the mid-Cenozoic. The absence of detectable sequence divergence between the two extant populations of L. fallax (Dominica and Montserrat), a species used for human food and now critically endangered, suggests that one or both arose by human introduction from an island or islands where that species originated. The relatively minor genetic differentiation of populations of L. albilabris can be explained by vicariance and dispersal in the Pleistocene and Holocene, although human introduction of some populations cannot be ruled out.     

Integrative Taxonomic Approach for Describing a New Cryptic Species of Bush Frog (Raorchestes: Anura: Rhacophoridae) from the Western Ghats,India

A new cryptic species of bush frog Raorchestes honnametti sp. nov. is described from the south-eastern part of the Western Ghats, India. This newly described species belongs to the Charius clade and is morphologically similar to other clade members—R. charius and R. griet. Therefore, an integrative taxonomic approach based on molecular and bioacoustic analysis along with morphology was used to delimit the new species. Raorchestes honnametti sp. nov., is currently known only from Biligiri Rangaswamy Temple Tiger Reserve, a part of Biligiri Rangaswamy horst mountain range (a mountain formed due movement of two faults) formed during the Late Quaternary period (1.8–2.58 Ma). Discovery of cryptic species from a highly speciose and well-studied genus Raorchestes hints at the possible existence of several more cryptic species in this genus. We discuss the possible reasons for crypsis and emphasize the need for continued systematic surveys of amphibians across the Western Ghats.     

Enzymhistochemical Localization of Alkaline Phosphatases in Germinal Cysts of the Testis of the Frog Rana temporaria (Anura)

Alkaline phosphatases have been demonstrated enzymhistochemically in the testis of the common frog Rana temporaria, caught in the month of January. The follicle cells in the cyst walls and the lamina propria of the seminiferous tubules showed strong enzymatic activity; also a weak activity was observed in the peripheral region of some of the germinal cells lying within the cysts. The possible interaction of alkaline phosphatases in the transport processes across the cyst walls has been discussed.     

Effects of hind limb denervation on the development of appendicular ossicles in the Dwarf African Clawed Frog,Hymenochirus boettgeri (Anura: Pipidae)

Sesamoids and other appendicular ossicles are common in other classes of vertebrates but comparatively rare in amphibians. The pipid frog Hymenochirus boettgeri (Boulenger, G. A. 1899. On Hymenochirus, a new type of aglossal batrachians. – Annals of the Magazine of Natural History Series 7: 122–125) is unusual among anurans in having seven (or more) appendicular ossicles in each hind limb. Sesamoids are often associated with muscles and tendons, and their development is usually regarded as mediated by or correlated with function. This study investigated the effects of paralysis (loss of function) on development of ossicles in the hind limb of Hymenochirus. Complete denervation of the right sciatic nerve was performed at developmental stages 63 and 66, and the animals maintained for a further 6–7 or 12–13 weeks. Specimens were cleared and double stained for cartilage and bone. There were no gross morphological differences between control and sham operated groups. The lunulae were not affected by paralysis, whereas the fabella arose later and/or regressed in some specimens. The distal os sesamoides tarsalia (OST) was shorter in paralysed individuals, and both the distal OST and cartilagines plantares showed delayed maturation. Denervation of the hind limb thus affected the timing of appearance, maintenance and rate of maturation of some sesamoid bones in Hymenochirus, but had no effect on others.