A morphological re-examination of the frog genus Nannophrys (Anura: Ranidae) with comments on its biology, distribution and relationships

The morphology of Nannophrys Günther, 1869, a genus of ranid frogs endemic to Sri Lanka, is reexamined. The three species comprising the genus are redescribed, and a detailed account of the osteology of the type-species, N. ceylonensis Günther, is given for the first time. Adults of two species show heavy secondary cranial ossification, a feature known in only one other ranid genus, the Solomon Islands Ceratobatrachus. New information on the tapdole of N. ceylonensis is provided. N. marmorata Kirtisinghe, 1946, is accorded full species status. Reference is made to the ecological niches of N. ceylonensis and N. marmorata. The resemblance of Nannophrys to the myobatrachine leptodactylids is noted, both groups possessing a cartilaginous omosternum and dilated sacral diapophyses. On the basis of this resemblance and other data presented in the present paper, it is suggested that Nannophrys may be interpreted as a primitive ranid genus which has independently acquired a large number of derived features. Comparison is made with a selected group of related Indian ranid genera, and with Ceratobatrachus. Results indicate that Nannophrys show some affinity with the southern Indian genera Nannobatrachus and Nyctibatrachus , and also with Ceratobatrachus. Comment is made on the correlation of the zoogeographical subdivision of the southern Indian region and Nannophrys relationships.     

Effects of developmental and growth history on metamorphosis in the gray treefrog, Hyla versicolor (Amphibia, Anura)

In ecological models, the timing of amphibian metamorphosis is dependent upon rate of larval growth, e.g., tadpoles that experience a decrease in growth rate can initiate metamorphosis early. Recent authors have suggested that this plasticity may be lost at some point during the larval period. We tested this hypothesis by exposing groups of tadpoles of the gray treefrog, Hyla versicolor, to different growth schedules. In endocrine models, metamorphosis is dependent on thyroxine levels and thyroxine is antagonized by prolactin (amphibian larval growth hormone), consistent with the idea that a rapidly growing tadpole can delay metamorphosis. Thus, we also manipulated the rate of development by supplementing or maintaining natural thyroxine levels for half of the tadpoles in each growth treatment. All tadpoles that received thyroxine supplements metamorphosed at the same time regardless of growth history. They also metamorphosed earlier than tadpoles not treated with thyroxine. Tadpoles not given thyroxine supplements metamorphosed at different times: those growing rapidly during day 15-34 metamorphosed earlier than tadpoles growing slowly. Growth rate before day 15 and after day 34 had no effect on metamorphic timing. The difference in larval period between these rapidly growing tadpoles and their sisters given thyroxine treatments was less than the same comparison for tadpoles that grew slowly during the same period. This apparent prolactin/thyroxine antagonism did not exist after day 34. These results are consistent with the hypothesis of a loss of plasticity in metamorphic timing.     

Belonoperca pylei, a new species of seabass (Teleostei: Serranidae: Epinephelinae: Diploprionini) from the cook islands with comments on relationships among diploprionins

Belonoperca pylei is described from five specimens collected at depths of 68–122m from Rarotonga, Cook Islands. It differs from all other known diploprionin serranids in having IX, 10 dorsal-fin rays, III, 7 anal-fin rays, and a color pattern composed primarily of yellow and organge pigments. Cladistic analysis of epinepheline morphology supports monophyly of the diploprionin generaBelonoperca andDiploprion and suggests thatBelonoperca is the sister group ofDiploprion plus the monotypicAulacocephalus.     

Cladistic analysis and osteological descriptions of the frog species in the Leptodactylus fuscus species group (Anura, Leptodactylidae)

The genus Leptodactylus is predominantly Neotropical (a few species have colonized the southern Neartic region) and is distributed from Texas to Argentina and on certain Caribbean islands. Leptodactylus was divided into five groups of species: Leptodactylus melanonotus , Leptodactylus ocellatus, Leptodactylus fuscus , Leptodactylus pentadactylus and Leptodactylus marmoratus . Among these, the L. fuscus group is the one with most species, with 27 taxa. Characters unverified in most of the species are used to define the L. fuscus group. However, the monophyly of the group has never been tested rigorously in a quantitative phylogenetic context. Thus, the main goal of this study was to test such monophyly and to construct a phylogeny of the L. fuscus group. A matrix of 114 characters scored across 43 taxa was constructed, with 31 characters taken from external morphology, 58 from adult skeletons, 16 from larval chondrocranium, 5 from ethology and 4 from morphometric data were included. Out of all the species examined, 23 belonged to the ingroup and 20 to the outgroup. The data set was analysed with implied weights, by using TNT software. The monophyly of the group was strongly supported in the fittest cladogram obtained. The optimizations of some characters on this hypothesis support traditional evolutionary hypotheses. The optimizations also suggest the presence of paedomorphic character states in some species, which is also discussed.     

Sperm morphology of five species of Colostethus (Anura, Dendrobatidae) from Brazil, with phylogenetic comments

We describe the sperm ultrastructure of five species of Colostethus from Brazil. The general structures of the spermatozoa (acrosomal complex and flagellar apparatus) were similar to species within the Bufonoidea. Colostethus brunneus, Colostethus sp. (aff. trilineatus), Colostethus nidicola and Colostethus sp. had biflagellated spermatozoa, whereas the spermatozoa of Colostethus stepheni had a single flagellum, a characteristic previously unknown for this genus. In addition, the spermatozoa of this species showed some mitochondria within the thick, undulating membrane. These characteristics are apparently common to dendrobatid species that have a single flagellum. Based on these findings, we tentatively consider biflagellarity to be an apomorphic condition in the Dendrobatidae. In addition, the results described here do not support the proposed regrouping of the ‘brunneus’ and ‘alagoanus’ groups in a monophyletic ‘trilineatus’ group.     

Morphology of the cranial skeleton and musculature in the obligate carnivorous tadpole of Lepidobatrachus laevis (Anura: Ceratophryidae)

Ziermann, J.M., Infante, C., Hanken, J. and Olsson, L. 2011. Morphology of the cranial skeleton and musculature in the obligate carnivorous tadpole of Lepidobatrachus laevis (Anura: Ceratophryidae). —Acta Zoologica (Stockholm) 00 :1–12. Lepidobatrachus laevis (Ceratophryidae: Ceratophryinae) is a bizarre frog endemic to the Chacoan desert of central South America. Its tadpole is an obligate carnivore that can catch and consume live prey nearly its own size. Morphological adaptations associated with this unique feeding mode, including the larval skull anatomy and associated cranial musculature, have only been partly described. We studied the head of Stages 26–27 larvae using gross dissection, immunohistochemistry, and standard histology. Derived features of this tadpole compared to the microphagous, herbivorous larvae of most other anurans include simplified chondrocranial cartilages and very robust jaw muscles. The mm. suspensorio‐ et quadratoangularis do not take their origin from the processus muscularis of the palatoquadrate, as in most other tadpoles, but instead originate from the corpus of the palatoquadrate caudal to this process. The jaw levators are unusually large. The tadpole of Ceratophrys, another member of the ceratophryine clade, also consumes large animal prey, but its morphology is very different. It probably has evolved independently from a generalized, mainly herbivorous tadpole similar to the larva of Chacophrys, the third ceratophryine genus. Most specialized features of the larval head of Lepidobatrachus laevis are adaptations for ‘megalophagy’—ingestion of whole, very large animal prey.     

Systematics of treefrogs of the Hypsiboas calcaratus and Hypsiboas fasciatus species complex (Anura,Hylidae) with the description of four new species

We review the systematics of the Hypsiboas calcaratus species complex, a group of widely distributed Amazonian hylid frogs. A comprehensive analysis of genetic, morphological, and bioacoustic datasets uncovered the existence of eleven candidate species, six of which are confirmed. Two of them correspond to Hypsiboas fasciatus and Hypsiboas calcaratus and the remaining four are new species that we describe here. Hypsiboas fasciatus sensu stricto has a geographic range restricted to the eastern Andean foothills of southern Ecuador while Hypsiboas calcaratus sensu stricto has a wide distribution in the Amazon basin. Hypsiboas almendarizae sp. n. occurs at elevations between 500 and 1950 m in central and northern Ecuador; the other new species (H. maculateralis sp. n., H. alfaroi sp. n., and H. tetete sp. n.) occur at elevations below 500 m in Amazonian Ecuador and Peru. The new species differ from H. calcaratus and H. fasciatus in morphology, advertisement calls, and mitochondrial and nuclear DNA sequences. Five candidate species from the Guianan region, Peru, and Bolivia are left as unconfirmed. Examination of the type material of Hyla steinbachi, from Bolivia, shows that it is not conspecific with H. fasciatus and thus is removed from its synonymy.     

Morphology of the nasal capsule of Heloderma suspectum with comments on the systematic position of helodermatids (Squamata: Helodermatidae)

A serially sectioned embryonic head of Heloderma suspectum formed the basis for a three-dimensional reconstruction of the cartilaginous nasal capsule and its membrane bones. Further, the soft parts of the nasal capsule were analysed microscopically. The embryonic nasal capsule is described and compared to the morphological conditions in other lizards, especially the varanids, which many recent authors believe to be their closest relatives.
The results support the close affinities between the helodermatids and the varanids. Both groups have a well developed recessus lateralis in a cartilaginous capsule, entered by the nasal concha. Further, in both groups a fragmentation of the cartilago paraseptalis occurs in a comparable location and form. Heloderma has no double lacrimal duct, in contrast to previous accounts, but the two canaliculi at the origin of the duct fuse noteworthy far ahead (in other squamates they fuse in front of the bulbus oculi). In the varanids the two branches of the lacrimal duct remain separate and open separately.
Some unique features of Heloderma are presented as well, above all the presence of a second concha.     

Comparing bivariate reaction norms among species: time and size at metamorphosis in three species of Hyla (Anura: Hylidae)

Summary Univariate and bivariate methods for comparing norms of reaction among species are discussed and illustrated with an example using North American hylid treefrogs. Norms of reaction for size at metamorphosis (SM) and length of larval period (LP) were compared among treefrog species raised at different food levels (Hyla cinerea vs H. gratiosa) and at different temperatures (H. cinerea vs H. gratiosa vs H. squirella). Hyla cinerea and Hyla gratiosa show parallel norms of reaction across food levels and temperatures. Across temperatures, H. squirella shows a much smaller change in SM relative to change in LP than do H. cinerea and H. gratiosa. This difference in shape of reaction norms may reflect different histories of selection resulting from these species' use of different larval habitats.     

Phylogenetic relationships of subgenera of the genus Exorista Meigen,with a revision of the Japanese species (Diptera: Tachinidae)

Phylogenetic relationships of the subgenera of Exorista Meigen (Diptera: Tachinidae) are inferred from morphological data. Our results show that the genus Exorista is not monophyletic and that members of the subgenus Spixomyia Crosskey are divided into two clades. Each subgenus is redefined based on male and female morphological features. The Japanese species of Exorista are revised and classified into five subgenera: Adenia Robineau‐Desvoidy, Exorista Meigen, Podotachina Brauer and Bergenstamm, Ptilotachina Brauer and Bergenstamm, and Spixomyia Crosskey. Thirteen species are recognized, including two newly recorded species, Exorista (Adenia) cuneata Herting and Exorista (Spixomyia) lepis Chao. Exorista cantans Mesnil is transferred to the subgenus Podotachina from Spixomyia.     

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.     

A new species of Dicranocentrus (Collembola,Entomobryidae) from China with comments on the systematic position of the genus

Dicranocentrus liuae sp. n. is described from the northern subtropical region of China. The new species is most similar to D. wangi Ma & Chen, 2007, but differs from it in the relatively shorter Ant. V, the 1+1 central macrochaetae on Abd. III, the number of chaetae on tenaculum, and the absence of dental spines. The systematic position of Dicranocentrus is also discussed. Present evidence, particularly S-chaetotaxy, indicates that the genus is closer to Heteromurus than to the unscaled species of Orchesella and Orchesellides.     

Phylogenetic relationships within the Eurasian cattish family Siluridae (Pisces: Siluriformes), with comments on generic validities and biogeography

A numerical cladistic analysis, based on 23 terminal groups and 63 morphological characters, was done to infer phylogenetic relationships within the Eurasian catfish family Siluridae. Nine hundred and forty-five equally most parsimonious trees (134 steps, consistency index 0.634) were found that differ in their resolutions of four polychotomies. Strict consensus of these trees includes ten internal nodes, does not support monophyly of Silurus, Ompok and Kryptopterus , as usually defined, and offers ambiguous support for monophyly of Wallago. Silurus and Kryptopterus are each composed of two non-sister group clades, and Ompok is composed of at least two such clades. Heuristic searches constrained by monophyly of Silurus, Ompok or Kryptopterus yielded trees five or six steps longer than the shortest trees free of constraints. The strict consensus also infers a basal dichotomy that separates the Siluridae into a temperate Eurasian clade with about 20 nominal species and a subtropical/tropical south and southeast Asian clade with about 75 nominal species. The distributions of these clades overlap in a relatively narrow region of east Asia. A heuristic search for trees 1 step longer than the shortest trees yielded 253890 trees. A strict consensus of these trees also infers a basal dichotomy between the above-mentioned clades. This analysis revealed four additional putative synapomorphies of the Siluridae, pending further resolution of the family's outgroup relationships.     

Cytogenetic analysis of four species of the genus Alsodes (Anura: Leptodactylidae) with comments about the karyological evolution of the genus

A comparative cytogenetic analysis of Alsodes pehuenche, A. vanzolinii, A. verrucosus and A. aff. vittatus show that all four species share the same diploid number 2n = 26; the fundamental number is 50 in A. vanzolinii and 52 in A. aff. vittatus, A. pehuenche and A. verrucosus. The karyotypes of A. pehuenche and A. aff. vittatus are described for the first time; the C-band patterns, the NOR locations and Q-band patterns are also described for the first time for the four species. C-band patterns are species specific and useful to identify the taxa. The usefulness of the chromosomal data in taxonomy and systematics of Alsodes species is discussed. Transformation of euchromatin into heterochromatin and centric fissions and translocations are proposed as the main mechanisms that govern the chromosomal evolution of the frog genus Alsodes.     

The sperm of Hylodinae species (Anura, Leptodactylidae): Ultrastructural characteristics and their relevance to interspecific taxonomic relationships

Aaabstract Hylodinae leptodactylids(sensu Lynch 1971) form a group of diurnal frogs, which is hypothesized on the basis of morphological traits to be the closest relatives of the dendrobatid frogs. Our study describes ultrastructural characteristics of sperm from three hylodine species(Hylodes phyllodes, Crossodactylus sp. n. andMegaelosia massarti) to reassess the intergeneric relationships within the Hylodinae, as well as the supposed relationship between the Hylodinae and Dendrobatidae. The ultrastructure of the sperm is very similar among the three species and is indicative of its conserved nature within the Hylodinae. The structure of the acrosomal complex was very similar to that of other leptodactylid species, to most of the remaining species included in the Bufonoidea lineage, and also to that observed in the dendrobatid species examined so far. Since such a structure has been considered a plesiomorphic trait, it contributes little to our understanding of the relationships between the Hylodinae and Dendrobatidae. The flagellar apparatus ofCrossodactylus sp. n. is very similar to that of most leptodactylids. The sperm ofMegaelosia massarti andHylodes phyllodes display a distinctive condition in their axial and juxtaxonemal fibers. This distinctive flagellar condition expands the already known variability in sperm structure within the Leptodactylidae.     

Embryology ofMalaxis saprophyta,with comments on the systematic position ofMalaxis (Orchidaceae)

InMalaxis saprophyta, anther wall development corresponds to the Monocotyledonous type. The uninucleate tapetum is of secretory type and the endothecium develops U- and V-shaped thickenings on the inner tangential and radial walls. Cytokinesis is simultaneous; tetrahedral, isobilateral and T-shaped tetrads are formed which are compactly aggregated in pollinia. At anthesis the microspore tetrads are 2-celled. The ovule is anatropous, bitegmic and both integuments are dermal in origin. A single hypodermal cell develops directly into a megaspore mother cell. Embryo sac development is predominantly monosporic and less often bisporic. Irrespective of the type of development, the mature embryo sac is 6-nucleate. Although double fertilization occurs, the primary endosperm nucleus degenerates. Embryogeny is of the Onagrad type. The mature embryo lacks differentiation into cotyledon, plumule and radicle. The reticulate seed coat is formed entirely by the outer layer of outer integument. There are three sterile and three fertile valves in the ovary. Although initially parenchymatous, the entire three sterile valves in the ovary and the upper half of the three fertile valves become sclerified after fertilization. The embryological characters support the disputed systematic position ofMalaxis within subtribeMalaxidinae ofEpidendreae.