Opalinidae (Slopalinida) in Madagascan Anura: Zelleriella Metcalf, 1920 and Protoopalina Metcalf, 1918

Between January and April, 1995, 142 Madagascan anurans collected at nine sites and comprising 61 species in three families were checked for opalinids in the cloaca. Zelleriella madagascariensis n. sp. was found in two of three Dyscophus insularis (Microhylidae) from Morondava; Protoopalina devinckae n. sp. in one Ptychadena mascareniensis (Ranidae) from Morondava; P. primordialis (Awerinzew, 1913) in two Ptychadena mascareniensis from Antananarivo; P. drachi Tuzet & Knoepffler, 1968 in three of seven Ptychadena mascareniensis from Antananarivo and Andasibe; P. legeardi n. sp. in one Mantidactylus lugubris (Ranidae) and one of two M. grandidieri both from Andasibe; P. grolleaui n. sp. in one Scaphiophryne marmorata (Microhylidae) from Andasibe; P. charvisi n. sp. in two S. calcarata from Morondava; and P. perantonii n. sp. in three Aglyptodactylus madagascariensis (Ranidae) from Andasibe. The biogeographical significance of these findings is discussed.     

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.     

Helminth infracommunities in Litoria genimaculata (Amphibia: Anura) from Birthday Creek, and upland rainforest stream in Northern Queensland, Australia

The helminth fauna of Litoria genimaculata, a rainforest frog from northern Queensland, was quantified from 53 adult male frogs collected at monthly intervals between April 1990 and March 1991. The helminth fauna of this species was depauperate (6 species: Mesocoelium sp., Parapolystoma bulliense, Austraplectana sp., Onchocercidae gen. sp., Cosmocerca sp. and an unidentified nematode larva). The most commonly encountered species was P. bulliense, but the intestinal infracommanity was dominated by the digenean Mesocoelium sp. Fifty-five per cent of frogs were infected with only 1 helminth species and only 1 frog had more than 2 species, resulting in low diversity values. These results support previous studies which indicate that amphibians have depauperate helminth communities.     

Chromosome banding in Amphibia. XXIV. The B chromosomes of Gastrotheca espeletia (Anura,Hylidae)

The mitotic chromosomes of an Ecuadorian population of the marsupial frog Gastrotheca espeletia were analyzed by means of banding techniques and fluorescence in situ hybridization. This species is characterized by unusual supernumerary (B) chromosomes. The maximum number of B chromosomes is 9 and they occur in three different morphological types. Banding analyses show that the B chromosomes are completely heterochromatic, consist of AT base pair-rich repeated DNA sequences, replicate their DNA in very late S-phase of the cell cycle, and are probably derived from a centromeric or paracentromeric region of a standard (A) chromosome. Exceptionally, the B chromosomes carry 18S + 28S ribosomal RNA genes and the conserved vertebrate telomeric DNA sequence appears to be underrepresented. Flow cytometric measurements of the nuclear DNA content differentiate between individuals with different numbers of B chromosomes. Significantly more B chromosomes are present in female than in male animals.     

Chromosome banding in Amphibia. XXII. Atypical y chromosomes in Gastrotheca walkeri and Gastrotheca ovifera (Anura,Hylidae)

The chromosomes of the rare South American marsupial frogs Gastrotheca walkeri and G. ovifera were extensively reexamined with various banding techniques. The karyotypes of both species are distinguished by a new category of XY female symbol /XX male symbol female sex chromosomes. The unusual Y chromosomes are characterized by containing the least amount of constitutive heterochromatin in the karyotypes. This is in contrast to all previously known amphibian Y chromosomes and does not fit the evolutionary model of early XY differentiation in vertebrates. In male meiosis, the heteromorphic XY chromosomes of both species still exhibit the same pairing configurations as the autosomes. DNA flow cytometric measurements show the nuclear DNA amount of G. walkeri to be 10.90 pg. The significance of the XY/XX sex chromosomes of these marsupial frogs, the various classes of constitutive heterochromatin detected, and the data obtained from meiotic analyses are discussed in detail.     

Evolution of reproduction in the Rhacophoridae (Amphibia, Anura)

Rhacophorid treefrogs have different reproductive modes: some go through a tadpole stage and some have direct development, and the adults of some species produce foam nests. Philautus is the only genus characterized by direct development. The production of foam nests has been reported in the genera Polypedates, Rhacophorus, Chiromantis and Chirixalus. Recent molecular studies did not provide a robust hypothesis concerning the origin of these reproductive modes in the Rhacophoridae. In order to better understand the evolution of these reproductive modes, we tried to clarify relationships within this group, using DNA sequencing. Our data set consists in a large number of new sequences (1676 base pairs corresponding to threee genes) for five outgroup ranoids and 48 Rhacophoridae, including 16 undescribed species from Sri Lanka and southern India, and all homologous data available in Genbank. After the inclusion of Philautus from India, our data show that the separation of Philautus into clades does not coincide with their geographic distribution. Our data point to the existence of a clade, including the genera Rhacophorus, Polypedates, Chiromantis and Chirixalus, which confirms the results of Wilkinson et al. (2002) and suggests that the ability to produce foam nests has emerged only once in the Rhacophoridae, as already stated by these authors.     

Chromosome banding in Amphibia. XV. Two types of Y chromosomes and heterochromatin hypervariabilty inGastrotheca pseustes (Anura,Hylidae)

The chromosomes of the newly discovered South American marsupial frogGastrotheca pseustes were analyzed by conventional methods and by various banding techniques. This species is characterized by XY/XX sex chromosomes and the existence of two different morphs of Y chromosomes. Whereas in type A males the XY^A chromosomes are still homomorphic, in type B males the Y^B chromosome displays a large heterochromatic region at the long arm telomere which is absent in the X. In male meiosis, the homomorphic XY^A chromosomes exhibit the same pairing configuration as the autosomal bivalents. On the other hand, the heteromorphic XY^B chromosomes form a sex bivalent by pairing their short arm telomeres in a characteristic end-to-end arrangement. Analysis of the karyotypes by C-banding and DNA base pair-specific fluorochromes reveals enormous interindividual size variability of the autosomal heterochromatin.     

Chromosomal rearrangements as the source of variation in the number of chromosomes in Pseudis (Amphibia, Anura)

A cytogenetic study of Pseudis specimens from three localities in Rio Grande do Sul State, the southernmost Brazilian, was performed to identify karyotypic characteristics that could account for differences in vocalization pattern and body size. Individuals from around Tainhas were compared to those of São Jerônimo and Eldorado do Sul. Specimens from these latter two localities were identified as Pseudis minuta, while those from the former were classified as Pseudis sp. (aff. minuta). The populations from São Jerônimo and Eldorado do Sul had 2n?=?24 chromosomes, classified as metacentric, submetacentric and subtelocentric. The population from Tainhas had 2n?=?28 chromosomes, with four pairs of telocentric chromosomes. Modelling of these 28 chromosomes and testing for fusion in the centromeric/telomeric regions yielded a karyotype of 2n?=?24 chromosomes, similar to that of the other populations. The similarity was reinforced by the location of the NORs and heterochromatin. The Tainhas population showed an increase in heterochromatin, as seen by the presence of additional C-bands, especially in the telocentric chromosomes. These data suggest that the two karyotypes described in this work had a common ancestry. There is evidence that the differentiation of these karyotypes may have occurred by chromosome fission and heterochromatin addition. Based on the present karyotype (2n?=?28) and on morphological and vocalization studies by other researchers, we conclude that the Tainhas population may represent a new species.     

Age Determination of Frogs and Toads (Amphibia, Anura) from North-western Europe

Age was determined in three anuran species inhabiting a temperate oceanic climate ( Rana temporaria, Bufo calamita and Bufo bufo ) by means of the histological structure of the phalanges. Narrow, haematoxylinophilic lines were visible in these, and evidence from the examination of subadults and frog ( R. temporaria ) recaptures showed the lines to be annual. The validity of using the lines as age indicators was tested most extensively on natural frog populations and the effects of endosteal resorption were not found to be significant. The evidence for this conclusion was provided directly by recapture data and indirectly by an analysis of histological measurements made on the phalanges.     

Low Phylogeographic Structure in a Wide Spread Endangered Australian Frog <Emphasis Type="Italic">Litoria aurea</Emphasis> (Anura: Hylidae)

The green and golden bell frog (Litoria aurea) has a widespread distribution along the south-east coast of Australia. The species range, however, is highly fragmented and remaining populations are predominately isolated and restricted to the coastline. Previously, the range extended further inland and the species was considered common. Here we report a study designed to identify the phylogeographic and conservation genetic parameters of L. aurea. Mitochondrial DNA sequences were examined from 263 individuals sampled from 26 locations using both phylogenetic and population analyses. Despite a general consensus that amphibians are highly structured we found no phylogeographic divisions within the species, however, there was significant structure amongst extant populations (F _ST=0.385). Patterns of haplotype relatedness, high haplotypic diversity (mean h=0.547) relative to low nucleotide diversity (mean π=0.003) and mismatch distribution analysis supported a Pleistocene expansion hypothesis with continued restricted dispersal and gene flow. We conclude that the genetic structure of the species may permit ‘well managed’ intervention to mediate gene flow amongst isolated populations and provide some guidelines for the implementation of such conservation strategies.     

The ontogeny of the filter apparatus of anuran larvae (Amphibia,Anura)

Summary The pharynx ofBufo calamita, Rana temporaria andBombina variegata larvae (larval Types IV and III) changes considerably during the latter part of embryonic development. The entodermal regions between the visceral pockets flatten inward to form the anlagen of the filter plates. The ectoderm thrusts forward from the area of the persistent epidermal gills overlying the anlagen of the filter plates. The esophagus pushes dorsolaterally into the pharynx to give rise to the ciliary cushions. Comparison with the development ofXenopus laevis (larval Type I) reveals shared characters: (1) the filter plates are overlapped by the sensory layer of the epiderm and (2) the ciliary grooves are, like the ciliary cushions of larval Types III and IV, anteriorly directed dorsolateral extensions of the esophagus. In all the species studied an ectodermal-esophageal filter apparatus develops. The evolutionary origin of this filter apparatus is discussed. The epidermalization of gills is suggested as a common character with the sister group of Dipnoi, and is therefore a plesiomorphic character in all amphibians. The tendency of filter plate epidermalization is considered to be the end of a process which is also indicated in the epidermalization of the first visceral pouch in lung fish. The ciliary groove is unique in anuran larvae within the Lissamphibia, and is therefore seen as an autapomorphic character within amphibians. On the basis of the different structure of the ciliary cushion inX. laevis and in the other species of this study, two alternative levels of evolutionary ciliary groove origin are discussed. Derivation from the esophagus took place: (1) in a common anuran larval ancestor, or (2) at two independent levels; the first in the Pipidae (-Rhinophrynidae) ancestor and the second in the ancestor of all the other anuran families. Several larval characters and cladistic aspects make the first alternative more probable than the second. Larval Type II anatomy and Larval Type II truncation from the Larval Type IV of Ranoidea do not contradict these considerations. There is disproportionately early commencement of ingestion activity inR. temporaria (G Stage 23),B. calamita (G Stage 23), andB. bufo (G Stage 24) compared toXenopus. Feeding in the former three species precedes the differentiation of the filter plates, their mucus production, and the exhaustion of the yolk supply in the gut tissue. By contrast, the goblet cells and the ciliary cells of the ciliary cushions are already differentiated when feeding starts. This suggests that ingestion in these early stages requires mucus production by the ciliary cushions and transport by their ciliary cells. Presumably in fully formed larvae, the ciliary cushions are the mucus donors, whereas the filter plates are the mucus depositors. By contrast,X. laevis does not begin active food intake by suspension feeding until after the yolk supply has been used up from the entoderm of the buccal cavity to deep in the esophagus.Abbreviations AAC anlage of apical cell - AC apical cell - ACE anlage of cerebrum - ACG anlage of ciliary groove - AD aorta dorsalis - ADV anlage of dorsal velum - AG anlage of glottis - AFP anlage of filter plates - AFR anlage of filter rows - AFPC anlage of epidermal fold of peribranchial chamber (anlage of operculum) - ant. anterior - AMF anlage of middle fold - AO adhesive organ - APEG anlage of persistent epidermal gills - APOP anlage of postnarial papilla - APSF anlage of primary side fold - ASC1 anlage of Type 1 secretory cell - ATE anlage of tuba Eustachii - ATEG anlage of transient epidermal gills - AVV anlage of ventral velum - B branchial arch - BI-IV branchial arches I–IV - BFA buccal floor arena - BFT branchial food trap - BL basal lamina - BRA buccal roof arena - C cilium, cilia - CA cartilage of visceral arch - CC ciliary cushion - CE cerebrum, brain - CG ciliary groove - CH choana - CHY ceratohyale - CIC ciliary cell - CL capillary vessel - CN centriole, basal body - COC cuboidal cells - CT connective tissue - CTC connective tissue cell - d dorsal - DV dorsal velum - DVI–III dorsal vela I–III - E esophagus - e early - ED edge of filter plate - EN endothelium - ENC entodermal cell - EP epiderm - EPC epidermal cell - ER endoplasmatic reticulum - ET erythrocyte - ETZ ectodermal-entodermal transition zone - EV ear vesicle - EX merocrine extrusion - EY eye - EZ zone of extrusion - FP filter plate - FPII filter plate of the 2nd branchial arch - FPIV filter plate of the 4th branchial arch - FPC epidermal fold of peribranchial chamber (operculum) - FC filter cavity - FN filter niche - FR filter row - GL glottis - GS gill slit - 1. GS first gill slit - GZ glandular zone - H heart - HP hypobranchial plate - HY hyoid arch - IC intercellular space, enlarged by fixation and dehydration - L late - LJ lower jaw - LT larval type - LV lipid vacuole - M mitochondrion - MA mandibular arch - MF middle fold - med. median - MS microvillous stubs - MZ zone of microtubes - NAC nucleus of apical cell - NCIC nucleus of ciliary cell - NCL nucleus of capillary vessel - NCOC nucleus of cuboidal cells - NCT nucleus of connective tissue - NENC nucleus of entodermal cell - NEPC nucleus of epidermal cell - NO external nares - NPEC nucleus of periderm cell - NRC nucleus of random cell - NSC1 nucleus of Type 1 secretory cell - NSC3 nucleus of Type 3 secretory cell - NSLC nucleus of sensory layer cell - NSPC nucleus of supporting cell - NSQC nucleus of squamous epithelial cell - OC oral cavity - OS mouth - P papilla - PC peribranchial chamber - PCW peribranchial chamber wall - PE periderm - PEC periderm cell - PEG persistent epidermal gill - PG pigment granule - post. posterior - PS primary side fold - PH pharynx - RC random cell - RO rootlet - SC1 Type 1 secretory cell - SC2 Type 2 secretory cell, goblet cell - SC3 Type 3 secretory cell - SC4 Type 4 secretory cell - SG secretory groove - SL sensory layer - SLC sensory layer cell - SP secretory pit - SPC supporting cell - SQC squamous epithelial cell - SR secretory ridge - SRC secretory ridge cell - SS secondary side fold - ST. stage - STD stomodeum - SU spiculum of hypobranchial plate - T tentacle - TA anlage of tongue - TEG transient epidermal gill - TZ transitional zone of branchial food trap and ventral velum - UJ upper jaw - v ventral - VA visceral arch - VC vacuole - VPI–IV visceral pockets I–IV - VP visceral pocket - VV ventral velum - YV yolk vacuoles Supported by the Deutsche Forschungsgemeinschaft (DFG)     

The functional significance of the pterygomaxillary ligament in Xenopus Iaevis (Amphibia: Anura)

A pterygomaxillary ligament, which runs postero-inferiorly from the posterior end of the maxilla to the pterygoid, is described macroscopically and microscopically in the aquatic anuran amphibian Xenopus laevis (Daudin). The quadratojugal is absent in this species, and consequently the short maxilla has no posterior articulation and is potentially mobile. However, the pterygomaxillary ligament limits upward and lateral displacement of the maxilla when pressure is applied upwards during closure of the lower jaw. The ligament absorbs forces applied to the posterior end of the maxilla and permits their dissipation via the pterygoid to the neurocranium.     

Phylogeny and genus-level classification of mantellid frogs (Amphibia, Anura)

We propose a novel classification of frogs in the family Mantellidae, based on published phylogenetic information and on a new analysis of molecular data. Our molecular tree for 53 mantellid species is based on 2419 base pairs of the mitochondrial 12S rRNA, 16S rRNA, tRNAVal and cytochrome b genes, and of the nuclear rhodopsin gene. Because the genus Mantidactylus Boulenger sensu lato is confirmed to be paraphyletic with respect to Mantella Boulenger, and is highly diverse in morphology and reproductive biology, we propose to partition Mantidactylus into seven genera by elevating four subgenera to genus rank (Blommersia Dubois, Guibemantis Dubois, Spinomantis Dubois, and Gephyromantis Methuen) and creating two new genera (Boehmantis gen. n. and Wakea gen. n.). In addition, we create the new subgenera Boophis (Sahona) subgen. n., Gephyromantis (Duboimantis) subgen. n., G. (Vatomantis) subgen. n., and Mantidactylus (Maitsomantis) subgen. n. The following species are transferred to Spinomantis, based on their phylogenetic relationships: S. elegans (Guibé) comb. n. (formerly in Mantidactylus subgenus Guibemantis); S. bertini (Guibé) comb. n. and S. guibei (Blommers-Schlösser) comb. n. (both formerly in Mantidactylus subgenus Blommersia); S. microtis (Guibé) comb. n. (formerly in Boophis Tschudi). Within Boophis, the new B. mandraka species group and B. albipunctatus species group are established. Boophis rhodoscelis (Boulenger) is transferred to the B. microtympanum group. The following five species are revalidated: Mantidactylus bellyi Mocquard and M. bourgati Guibé (not junior synonyms of M. curtus (Boulenger)); M. cowanii (Boulenger) (not syn. M. lugubris (Duméril)); M. delormei Angel (not syn. M. brevipalmatus Ahl); Mantella ebenaui (Boettger) (not syn. M. betsileo (Grandidier)). The new classification accounts for recent progress in the understanding of the phylogeny and natural history of these frogs, but it is still tentative for a number of species. Future modifications may be necessary, especially as concerns species now included in Gephyromantis and Spinomantis.Full article published online at: http://www.senckenberg.de/odes/06-11.htm     

The tadpole of Scinax skuki (Anura: Hylidae) from the type locality,with a description of its larval skeleton

Herein, we provide external and internal morphological data of Scinax skuki tadpoles from its type locality. The benthic tadpole of S. skuki has eyes and nostrils positioned dorsally, vent tube dextral and reaching the free margin of the ventral fin, oral disk ventral with posterior margin concave when partially closed, labial tooth row formula 2/3, and the presence of nonpigmented spurs behind the lower jaw. These characters, together with the absence of a tectum parietale, and the shapes of the pars articularis quadrati and suprarostral, are useful for species identification and may be informative for systematic purposes.