| nematode parasites of puerto rican tree frogs, eleutherodactylus spp: two new species and a proposal of poekilostrongylus gen. nov. (trichostrongylidae). | poekilostrongylus puertoricensis gen.nov., sp.nov. is proposed for nematodes recovered from eleutherodactylus coqui, in puerto rico. the new genus is similar to oswaldocruzia travassos, 1917, but lacks longitudinal ridges on the cuticle. oswaldocruzia lenteixierai viqueras, 1938, is partially redescribed, and a key to the genera of the oswaldocruziinae is given. thelandros (parathelandros) garciai sp.nov. is described from e. antillensis and e. portoricensis. strongyloides sp. was found in e ... | 1975 | 1128929 |
| the lack of influence of exogenous testosterone on male parental behavior in a neotropical frog (eleutherodactylus): a field experiment. | males of the puerto rican frog eleutherodactylus coqui exhibit prolonged parental care (nest attendance and defense) of direct-developing eggs in nonaquatic nest sites. earlier work showed that plasma androgen levels are significantly lower in males caring for eggs than in noncaring, calling males. in this study, we investigated the effects of elevated plasma androgens on parental care behavior by implanting either testosterone (t) or placebo (p) pellets in parental males brooding eggs in the fi ... | 1991 | 1937425 |
| patterns of distal-less gene expression and inductive interactions in the head of the direct developing frog eleutherodactylus coqui. | the direct developing frog eleutherodactylus coqui exhibits radical changes in its embryogenesis. a frog-like head forms directly with no appearance of a cement gland or several jaw cartilages characteristic of tadpoles, and limbs appear early in development. the numerous differences in the embryogenesis of e. coqui provide an opportunity to examine developmental causes for the evolutionary shift from biphasic to direct development. we have cloned dna fragments corresponding to four e. coqui gen ... | 1996 | 8873761 |
| development of the retina is altered in the directly developing frog eleutherodactylus coqui (leptodactylidae). | the loss of a free-living larval stage during the evolution of directly developing frogs of the genus eleutherodactylus resulted in dramatic alterations in ontogeny. immunostaining for proliferating cell nuclear antigen reveals that in the directly developing frog eleutherodactylus coqui pervasive cell proliferation occurs throughout the retina even after the plexiform layers have formed. in striking contrast to biphasically developing frogs (e.g. discoglossus pictus or xenopus laevis), in e. co ... | 1997 | 9131659 |
| limb development and evolution: a frog embryo with no apical ectodermal ridge (aer). | the treefrog eleutherodactylus coqui is a direct developer--it has no tadpole stage. the limb buds develop earlier than in metamorphosing species (indirect developers, such as xenopus laevis). previous molecular studies suggest that at least some mechanisms of limb development in e. coqui are similar to those of other vertebrates and we wished to see how limb morphogenesis in this species compares with that in other vertebrates. we found that the hind limb buds are larger and more advanced than ... | 1998 | 9688504 |
| secondary coverage of the yolk by the body wall in the direct developing frog, eleutherodactylus coqui: an unusual process for amphibian embryos. | eleutherodactylus coqui develops directly from a large 3.5-mm egg to a froglet, without an intervening tadpole stage. we have examined the development of the body wall, a structure whose behavior has been altered in this derived development. in an event that is unusual for amphibian embryos, the yolk mass is secondarily surrounded by the body wall, which originates near the embryo's trunk. the epidermis of the body wall is marked by melanophores, and the rectus abdominis, which will form the ven ... | 1998 | 9799426 |
| evolutionary alteration in anterior patterning: otx2 expression in the direct developing frog eleutherodactylus coqui. | the homeobox gene otx2 is a key regulator for specifying the rostral part of the vertebrate head. in xenopus, otx2 directly controls the differentiation of the cement gland, the anterior-most organ formed in the tadpole. since embryos of a direct developing frog, eleutherodactylus coqui, lack a cement gland, we are interested in whether altered expression of the otx2 gene is involved in this evolutionary change. we have cloned the e. coqui homologue of otx2, ecotx2. the homeodomain of the ecotx2 ... | 1999 | 9917359 |
| loss of ectodermal competence for lateral line placode formation in the direct developing frog eleutherodactylus coqui. | in the direct-developing frog eleutherodactylus coqui neuromasts and ganglia of the lateral line system never develop. we show here that this absence of the lateral line system, which is evolutionarily derived in anurans, is due to very early changes in development. ectodermal thickenings, which are typical of lateral line placodes, and from which neuromasts and ganglion cells of the lateral line originate, never form in e. coqui, although other neurogenic placodes are present. moreover, althoug ... | 1999 | 10479453 |
| ectopic expression of xenopus noggin rna induces complete secondary body axes in embryos of the direct developing frog eleutherodactylus coqui. | we tested the effects of noggin rna from xenopus laevis on axis induction in embryos of a direct developing frog, eleutherodactylus coqui. we microinjected noggin rna into one blastomere of 4-cell embryos at the site close to the animal pole, and found that overexpression of noggin rna is not only sufficient to induce additional axes but also induces heads with eyes. we also injected noggin rna into 8-cell or 16-cell embryos in various sites, including the marginal zone, above the marginal zone, ... | 2000 | 10603083 |
| mesoderm formation in eleutherodactylus coqui: body patterning in a frog with a large egg. | the direct developing frog, eleutherodactylus coqui, develops from a large egg (diameter 3.5 mm). to investigate the effect of egg size on germ-layer formation, we studied mesoderm formation in e. coqui and compared it to that of xenopus laevis (diameter 1.3 mm). first, we identified the position of prospective mesoderm in the 16-cell e. coqui embryo by cell-lineage tracing. although the animal blastomeres are small, they form most of the blastocoel roof and make extensive contributions to some ... | 2001 | 11456448 |
| parallel microtubules and other conserved elements of dorsal axial specification in the direct developing frog, eleutherodactylus coqui. | specification of the dorsal axis in commonly studied frogs, such as xenopus laevis and rana pipiens, depends on a microtubule-mediated movement of cytoplasm in the fertilized egg. the puerto rican tree frog, eleutherodactylus coqui, has an egg that is twenty times the volume of that of x. laevis, raising the question as to whether the mechanism of dorsal axial specification is conserved in these large eggs. fertilized eggs of e. coqui develop a transient array of parallel microtubules, similar t ... | 2003 | 12590350 |
| mosaic evolution of neural development in anurans: acceleration of spinal cord development in the direct developing frog eleutherodactylus coqui. | previous studies have shown that spinal cord development in direct developing frogs of the genus eleutherodactylus, which have evolutionarily lost the tadpole stage, differs from that in biphasically developing anurans (with the larval and the adult stage separated by metamorphosis). the present study of spinal cord development in eleutherodactylus coqui provides additional information about neurogenesis, neuronal differentiation and growth analyzed by immunostaining for proliferating cell nucle ... | 2003 | 12592573 |
| induced ovulation and egg deposition in the direct developing anuran eleutherodactylus coqui. | this study investigates ovulation and egg deposition behaviors in the anuran eleutherodactylus coqui from puerto rico in response to stimulation with gonadotropin and gonadotropin releasing hormones. five hormones were tested by injection over a range of doses, including mammalian lhrh, avian lhrh, fish lhrh, d-ala6, des-gly10 ethylamide lhrh and hcg. we report a low level of ovulation and egg deposition in response to all hormones, with the most complete and consistent results from the non-natu ... | 2004 | 14748925 |
| cryopreservation of spermatozoa of the terrestrial puerto rican frog, eleutherodactylus coqui. | world-wide reports of amphibian population declines have led to increased interest in the reproductive biology of anurans. as a model system, here we present evidence for the effective cryoprotection of sperm from the puerto rican frog, eleutherodactylus coqui, using mixtures of fetal bovine serum (fbs) and dimethylsulfoxide (me(2)so), glycerol or sucrose extenders. using a fluorescent dye exclusion assay, we found that 53.9 and 50.4% of all sperm with intact membranes prior to freezing maintain ... | 2004 | 14969686 |
| localization of rnas in oocytes of eleutherodactylus coqui, a direct developing frog, differs from xenopus laevis. | eleutherodactylus coqui develops directly on land to a frog. the large 3.5-mm oocyte of e. coqui has enough yolk to allow development without a feeding tadpole. in the smaller xenopus laevis oocyte, 1.3 mm in diameter, mrnas involved in germ layer formation, such as vegt and vg1, are localized to the vegetal cortex of the oocyte. we hypothesized that an animal shift has occurred in the localization of the e. coqui orthologs of vegt and vg1 due to the large egg size. through a combination of dege ... | 2003 | 14984038 |
| status of rnas, localized in xenopus laevis oocytes, in the frogs rana pipiens and eleutherodactylus coqui. | early development in the frog model, xenopus laevis, is governed by rnas, localized to the vegetal cortex of the oocyte. these rnas include xdazl rna, which is involved in primordial germ cell formation, and vegt rna, which specifies the mesoderm and endoderm. in order to determine whether orthologues of these rnas are localized and have similar functions in other frogs, we cloned rpdazl and rpvegt from rana pipiens, a frog that is phylogenetically distant from x. laevis. rnas from both genes ar ... | 2005 | 15515051 |
| arginine vasotocin activates advertisement calling and movement in the territorial puerto rican frog, eleutherodactylus coqui. | arginine vasotocin (avt) is a neuropeptide that modulates social behavior in amphibians and activates calling in frogs. the puerto rican coqui frog, eleutherodactylus coqui, is a terrestrial anuran that exhibits complex social behaviors, including territoriality and paternal care. males have a distinctive social hierarchy and can be any of the following: satellite (non-calling), territorial (calling), or paternal (guards and broods embryos). field experiments were conducted to determine the effe ... | 2004 | 15664026 |
| protamines in the internally fertilizing neobatrachian frog eleutherodactylus coqui. | the internally fertilizing primitive frog ascaphus truei (family ascaphidae) from the pacific northwest is the only frog with an intromittent organ. the more advanced neobatrachian frog eleutherodactylus coqui (family leptodactylidae) from puerto rico has secondarily acquired internal fertilization but mates by cloacal apposition. nonetheless, both frogs have introsperm with an elongated head containing highly condensed chromatin. characterization of sperm nuclear basic proteins (snbps) in e. co ... | 2005 | 15696590 |
| development in frogs with large eggs and the origin of amniotes. | the origin of the amniote egg is one of the most significant events in the evolution of terrestrial vertebrates. this innovation was probably driven by increased egg size, and to find potential parallels, we can examine the derived development of extant amphibians with large eggs. the embryo of the puerto rican tree frog, eleutherodactylus coqui, exhibits an alteration of its fate map and a secondary coverage of its yolky cells, reflecting the large 3.5 mm egg. comparable changes may have occurr ... | 2002 | 16351861 |
| conservation of pitx1 expression during amphibian limb morphogenesis. | in contrast to the pattern of limb emergence in mammals, chicks, and the newt n. viridescens, embryos such as xenopus laevis and eleutherodactylus coqui initiate pelvic limb buds before they develop pectoral ones. we studied the expression of pitx1 in x. laevis and e. coqui to determine if this paired-like homeodomain transcription factor directs differentiation specifically of the hindlimb, or if it directs the second pair of limbs to form, namely the forelimbs. we also undertook to determine i ... | 2006 | 16609707 |
| nutritional endoderm in a direct developing frog: a potential parallel to the evolution of the amniote egg. | the egg of the direct-developing frog, eleutherodactylus coqui, has 20 x the volume as that of the model amphibian, xenopus laevis. increased egg size led to the origin of nutritional endoderm, a novel cell type that provides nutrition but does not differentiate into digestive tract tissues. as the e. coqui endoderm develops, a distinct boundary exists between differentiating intestinal cells and large yolky cells, which persists even when yolk platelets are depleted. the yolky cells do not beco ... | 2007 | 17436277 |
| a comparative analysis of frog early development. | the current understanding of xenopus laevis development provides a comparative background for the analysis of frog developmental modes. our analysis of development in various frogs reveals that the mode of gastrulation is associated with developmental rate and is unrelated to egg size. in the gastrula of the rapidly developing embryos of the foam-nesting frogs engystomops coloradorum and engystomops randi, archenteron and notochord elongation overlapped with involution at the blastopore lip, as ... | 2007 | 17606898 |
| phylogenetic study of eleutherodactylus coqui (anura: leptodactylidae) reveals deep genetic fragmentation in puerto rico and pinpoints origins of hawaiian populations. | | 2007 | 17765575 |
| unusual productivity of aedes aegypti in septic tanks and its implications for dengue control. | increased den-2 virus transmission in puerto rico during 2005 prompted the implementation of a rapid intervention programme to suppress aedes aegypti (l.) (diptera: culicidae) emergence, which in turn lead to the discovery of previously unknown breeding sites underground. initially, the following control measures were applied in playa/playita (pp), a town of 1,400 households, to all areas where the number of pupae per person exceeded the expected threshold for dengue transmission; all containers ... | 2008 | 18380655 |
| development of the retinotectal system in the direct-developing frog eleutherodactylus coqui in comparison with other anurans. | abstract: | 2008 | 18573199 |
| gene expression reveals unique skeletal patterning in the limb of the direct-developing frog, eleutherodactylus coqui. | the growing field of skeletal developmental biology provides new molecular markers for the cellular precursors of cartilage and bone. these markers enable resolution of early features of skeletal development that are otherwise undetectable through conventional staining techniques. this study investigates mrna distributions of skeletal regulators runx2 and sox9 along with the cartilage-dominant collagen 2(alpha)1 (col2a1) in embryonic limbs of the direct-developing anuran, eleutherodactylus coqui ... | 2008 | 18638321 |
| strong founder effects and low genetic diversity in introduced populations of coqui frogs. | the success of non-native species may depend on the genetic resources maintained through the invasion process. the coqui (eleutherodactylus coqui), a frog endemic to puerto rico, was introduced to hawaii in the late 1980s via the horticulture trade, and has become an aggressive invader. to explore whether genetic diversity and population structure changed with the introduction, we assessed individuals from 15 populations across the hawaiian islands and 13 populations across puerto rico using six ... | 2009 | 19674300 |
| frequency matching of vocalizations to inner-ear sensitivity along an altitudinal gradient in the coqui frog. | acoustic communication involves both the generation and the detection of a signal. in the coqui frog (eleutherodactylus coqui), it is known that the spectral contents of its calls systematically change with altitude above sea level. here, distortion product otoacoustic emissions are used to assess the frequency range over which the inner ear is sensitive. it is found that both the spectral contents of the calls and the inner-ear sensitivity change in a similar fashion along an altitudinal gradie ... | 2010 | 19939848 |
| lbx1 expression and frog limb development. | in order to identify prospective limb muscle cells in a frog, we cloned lbx1 from the direct developing frog eleutherodactylus coqui. like in embryos of the frog xenopus laevis but unlike in other vertebrates, eclbx1 is expressed in all trunk somites. like in embryos of chick, mouse, and zebrafish, cells expressing eclbx1 are then found in limb buds, consistent with migration of those cells from somites. eclbx1 is also expressed in the dorsal spinal cord as in other vertebrates. | 2010 | 20091319 |
| persistence with chytridiomycosis does not assure survival of direct-developing frogs. | the chytrid fungus, batrachochytrium dendrobatidis (bd) has been linked to extinction and decline of numerous amphibians. we studied the population-level effects of bd in two post-decline anuran species, eleutherodactylus coqui and e. portoricensis, at el yunque national forest, puerto rico. data on amphibian abundance was updated to report long-term population trends. mark-recapture data was used to monitor bd-infection status and estimate survival probabilities of infected versus uninfected ad ... | 2010 | 20585971 |
| early cranial patterning in the direct-developing frog eleutherodactylus coqui revealed through gene expression. | genetic and developmental alterations associated with the evolution of amphibian direct development remain largely unexplored. specifically, little is known of the underlying expression of skeletal regulatory genes, which may reveal early modifications to cranial ontogeny in direct-developing species. we describe expression patterns of three key skeletal regulators (runx2, sox9, and bmp4) along with the cartilage-dominant collagen 2alpha1 gene (col2a1) during cranial development in the direct-de ... | 2010 | 20618433 |
| novel regulation of yolk utilization by thyroid hormone in embryos of the direct developing frog eleutherodactylus coqui. | thyroid hormone (th) is required for metamorphosis of the long, coiled tadpole gut into the short frog gut. eleutherodactylus coqui, a direct developing frog, lacks a tadpole. its embryonic gut is a miniature adult form with a mass of yolky cells, called nutritional endoderm, attached to the small intestine. we tested the th requirement for gut development in e. coqui. inhibition of th synthesis with methimazole arrested gut development in its embryonic form. embryos treated with methimazole fai ... | 2010 | 20883213 |
| seasonality of batrachochytrium dendrobatidis infection in direct-developing frogs suggests a mechanism for persistence. | batrachochytrium dendrobatidis (bd), a disease-causing amphibian-specific fungus, is widely distributed in puerto rico, but is restricted to elevations above 600 m. the effect of this pathogen in the wild was studied by monitoring eleutherodactylus coqui and e. portoricensis in 2 upland forests at el yunque, a site characterized by historic population declines in the presence of chytridiomycosis. we tested a potential synergistic interaction between climate and bd by measuring prevalence of infe ... | 2010 | 21268989 |
| Germ plasm in Eleutherodactylus coqui, a direct developing frog with large eggs. | ABSTRACT: | 2011 | 21978790 |
| molecular anatomy of the developing limb in the coquí frog, eleutherodactylus coqui. | the vertebrate limb demonstrates remarkable similarity in basic organization across phylogenetically disparate groups. to gain further insight into how this morphological similarity is maintained in different developmental contexts, we explored the molecular anatomy of size-reduced embryos of the puerto rican coquí frog, eleutherodactylus coqui. this animal demonstrates direct development, a life-history strategy marked by rapid progression from egg to adult and absence of a free-living, aquatic ... | 2011 | 23016903 |
| [carlos coqui. in memoriam]. | | 2016 | 4931407 |
| environmental fluctuations and host skin bacteria shift survival advantage between frogs and their fungal pathogen. | fluctuating environments can modulate host-pathogen interactions by providing a temporary advantage to one of the interacting organisms. however, we know very little about how environmental conditions facilitate beneficial interactions between hosts and their microbial communities, resulting in individual persistence with a particular pathogen. here, we experimentally infected eleutherodactylus coqui frogs with the fungal pathogen batrachochytrium dendrobatidis (bd) under environmental condition ... | 2017 | 27935596 |
| seasonal and ontogenetic variation of skin microbial communities and relationships to natural disease dynamics in declining amphibians. | recently, microbiologists have focused on characterizing the probiotic role of skin bacteria for amphibians threatened by the fungal disease chytridiomycosis. however, the specific characteristics of microbial diversity required to maintain health or trigger disease are still not well understood in natural populations. we hypothesized that seasonal and developmental transitions affecting susceptibility to chytridiomycosis could also alter the stability of microbial assemblages. to test our hypot ... | 2015 | 26587253 |
| coqui frogs persist with the deadly chytrid fungus despite a lack of defensive antimicrobial peptides. | the amphibian skin fungus batrachochytrium dendrobatidis (bd) occurs widely in puerto rico and is thought to be responsible for the apparent extinction of 3 species of endemic frogs in the genus eleutherodactylus, known as coquis. to examine immune defenses which may protect surviving species, we induced secretion of skin peptides from adult common coqui frogs e. coqui collected from upland forests at el yunque. by matrix-assisted laser desorption/ionization time-of-flight (maldi-tof) mass spect ... | 2015 | 25667340 |
| susceptibility to the amphibian chytrid fungus varies with ontogeny in the direct-developing frog, eleutherodactylus coqui. | age-related differences in susceptibility to infectious disease are known from a wide variety of plant and animal taxonomic groups. for example, the immature immune systems of young vertebrates, along with limited prior exposure to pathogens and behavioral factors, can place juveniles at greater risk of acquiring and succumbing to a pathogen. we studied the ontogenetic susceptibility of terrestrial direct-developing frogs (eleutherodactylus coqui) to the fungal pathogen, batrachochytrium dendrob ... | 2014 | 24807186 |
| a fungal pathogen of amphibians, batrachochytrium dendrobatidis, attenuates in pathogenicity with in vitro passages. | laboratory investigations into the amphibian chytrid fungus, batrachochytrium dendrobatidis (bd), have accelerated recently, given the pathogen's role in causing the global decline and extinction of amphibians. studies in which host animals were exposed to bd have largely assumed that lab-maintained pathogen cultures retained the infective and pathogenic properties of wild isolates. attenuated pathogenicity is common in artificially maintained cultures of other pathogenic fungi, but to date, it ... | 2013 | 24130895 |
| lability in host defenses: terrestrial frogs die from chytridiomycosis under enzootic conditions. | chytridiomycosis-induced mortalities often occur upon the emergence of batrachochytrium dendrobatidis (bd) in naïve amphibian populations. we report chytridiomycosis-associated mortalities in the wild of the coqui (eleutherodactylus coqui), a declining direct-developing frog with persistent bd infections. these findings provide additional evidence of decreased host defenses during cool-dry seasons in puerto rico. | 2013 | 23307390 |
| development of the nasal chemosensory organs in two terrestrial anurans: the directly developing frog, eleutherodactylus coqui (anura: leptodactylidae), and the metamorphosing toad, bufo americanus (anura: bufonidae). | nearly all vertebrates possess an olfactory organ but the vomeronasal organ is a synapomorphy for tetrapods. nevertheless, it has been lost in several groups of tetrapods, including aquatic and marine animals. the present study examines the development of the olfactory and vomeronasal organs in two terrestrial anurans that exhibit different developmental modes. this study compares the development of the olfactory and vomeronasal organs in metamorphic anurans that exhibit an aquatic larva (bufo a ... | 2004 | 15216526 |
| a simplified table for staging embryos of the pipid frog pipa arrabali. | pipa is a neotropical genus of frogs that dwell in freshwater environments. it includes four species that lack free-swimming larvae (p. aspera, p. arrabali, p. pipa, and p. snethlageae) and three with tadpoles (p. carvalhoi, p. myersi, and p. parva). developmental tables such as the one proposed by nieuwkoop and faber might be useful for pipa species with tadpoles. however, for the other pipa species, to determine stages by this table or by any of the tables already prepared for frogs without ta ... | 2016 | 27683762 |
| temperature variation, bacterial diversity and fungal infection dynamics in the amphibian skin. | host-associated bacterial communities on the skin act as the first line of defence against invading pathogens. yet, for most natural systems, we lack a clear understanding of how temperature variability affects structure and composition of skin bacterial communities and, in turn, promotes or limits the colonization of opportunistic pathogens. here, we examine how natural temperature fluctuations might be related to changes in skin bacterial diversity over time in three amphibian populations infe ... | 2017 | 28664981 |
| development of fore- and hindlimb muscles in frogs: morphogenesis, homeotic transformations, digit reduction, and the forelimb-hindlimb enigma. | here we provide the first detailed description, based on immunohistochemistry and dissections, of the limb muscle development in the direct developing frog eleutherodactylus coqui. we compare e. coqui with other tetrapods and discuss our results in a broad evolutionary and developmental context to address some major questions concerning the origin, evolution, and ontogeny of the tetrapod limbs. our observations and comparisons: (1) support the "in-out" developmental mechanism of the appendicular ... | 2014 | 24254979 |
| the extraordinary biology and development of marsupial frogs (hemiphractidae) in comparison with fish, mammals, birds, amphibians and other animals. | the study of oogenesis and early development of frogs belonging to the family hemiphractidae provide important comparison to the aquatic development of other frogs, such as xenopus laevis, because reproduction on land characterizes the hemiphractidae. in this review, the multinucleated oogenesis of the marsupial frog flectonotus pygmaeus (hemiphractidae) is analyzed and interpreted. in addition, the adaptations associated with the incubation of embryos in the pouch of the female marsupial frog g ... | 0 | 29305906 |
| frequency and time domain comparison of low-frequency auditory fiber responses in two anuran amphibians. | a comparative study of the phase-locked response of auditory nerve fibers was performed in two frog species, eleutherodactylus coqui and bombina orientalis. from the tuning characteristics and phase response of single auditory nerve fibers to low frequency tones (0.08-1.0 khz) we attempt to deduce the mechanics of the auditory organ responsible for low-frequency hearing in the frog, the amphibian papilla (a.p.). the phase-locked responses of auditory nerve fibers in b. orientalis were essentiall ... | 1987 | 3558132 |
| analysis of cell size in the gastrula of ten frog species reveals a correlation of egg with cell sizes, and a conserved pattern of small cells in the marginal zone. | we investigated the relationship between egg and cell sizes in the early gastrula of ten species of frogs with eggs of 1,100-3,500 μm diameters. we asked whether differences in cell size of the vegetal region, blastocoel roof, and marginal zone of the early gastrula were associated with egg size. alternatively, we proposed that cell size differences may associate with gastrulation characteristics. the analyzed species were as follows: xenopus laevis, engystomops randi, engystomops coloradorum, e ... | 2017 | 27381278 |
| using heterochrony plots to detect the dissociated coevolution of characters. | the comparison of developmental sequences among species is notoriously difficult. here, heterochrony plots are introduced as a new graphic method to detect temporal shifts in the development of characters in pair-wise species comparisons. plotting the timing of character development in one species against the timing of character development in another species allows us to compare a principally unlimited number of characters simultaneously and can detect whether suites of characters are dissociat ... | 2001 | 11598916 |
| evolution of nerve development in frogs. ii. modified development of the peripheral nervous system in the direct-developing frog eleutherodactylus coqui (leptodactylidae). | we use whole-mount immunohistochemistry to describe the pattern of development of cranial nerves and muscles in the direct-developing leptodactylid frog eleutherodactylus coqui. comparison with nerve development in the biphasically developing frogs physalaemus pustulosus (leptodactylidae) and discoglossus pictus (discoglossidae; described in a companion paper) allows us to infer the ancestral leptodactylid ontogenetic pattern and the extent to which it has been modified during the evolution of d ... | 1997 | 9261555 |
| similarities and differences in the cytoarchitecture of the tectum of frogs and salamanders. | frogs exhibit a morphologically complex (multiply laminated) optic tectum, while salamanders have one of the morphologically simplest tecta among vertebrates. in a comparative approach, the morphology of tectal projection neurons is investigated in three salamander species, hydromantes italicus, h. genei and plethodon jordani, and two frog species, discoglossus pictus and eleutherodactylus coqui, by means of retrograde biocytin labeling complemented by intracellular biocytin staining of cells. d ... | 1996 | 9124009 |
| behavioural tuning in a tropical amphibian along an altitudinal gradient. | males of the coqui treefrog, eleutherodactylus coqui, produce a distinct two-note 'co-qui' advertisement call from sunset to midnight throughout most of the year. previous work established that both the spectrotemporal aspects of the call and the frequency of highest inner-ear sensitivity change with altitude above sea level. these variations are such that the frequency of the emitted co-note closely matches the frequency to which the inner ear is most sensitive. given this parallel variation, w ... | 2017 | 29237810 |
| skin bacterial microbiome of a generalist puerto rican frog varies along elevation and land use gradients. | host-associated microbial communities are ubiquitous among animals, and serve important functions. for example, the bacterial skin microbiome of amphibians can play a role in preventing or reducing infection by the amphibian chytrid fungus, batrachochytrium dendrobatidis. evidence suggests that environmental bacteria likely serve as a source pool for at least some of the members of the amphibian skin bacterial community, underscoring the potential for local environmental changes to disrupt micro ... | 2017 | 28875068 |
| mammalian nonapeptides activate territorial behavior in an amphibian. | arginine vasopressin (vp) and oxytocin (ot) are two nonapeptides present in mammals and execute a wide array of physiological and behavioral functions. in amphibians arginine vasotocin (vt) is hypothesized as a homologous nonapeptide for vp and also performs physiological and behavioral tasks. studies have demonstrated that the structural and functional relationships between vp, ot, and vt receptor families are similar; however, little behavioral data has complimented these studies. the objectiv ... | 2017 | 28668618 |
| origins and genetic diversity of introduced populations of the puerto rican red-eyed coquí, eleutherodactylus antillensis, in saint croix (u.s. virgin islands) and panamá. | the red-eyed coquí, eleutherodactylus antillensis, is a terrestrial frog endemic to the puerto rican bank (puerto rico and numerous islands and cays off its eastern coast), in the eastern caribbean sea. the species was likely introduced in saint croix, an island c. 100 km southeast of puerto rico, in the late 1930s, and in panamá city, panamá, in the late 1950s or early 1960s, but the source(s) of these introductions are unknown. we analyzed sequence data from one mtdna locus and four nudna intr ... | 2017 | 28649148 |
| transcription factors mix1 and vegt, relocalization of vegt mrna, and conserved endoderm and dorsal specification in frogs. | protein expression of the transcription factor genes mix1 and vegt characterized the presumptive endoderm in embryos of the frogs engystomops randi, epipedobates machalilla, gastrotheca riobambae, and eleutherodactylus coqui, as in xenopus laevis embryos. protein vegt was detected in the animal hemisphere of the early blastula in all frogs, and only the animal pole was vegt-negative. this finding stimulated a vegt mrna analysis in x. laevis eggs and embryos. vegt mrna was detected in the animal ... | 2016 | 27140624 |
| tongue and taste organ development in the ontogeny of direct-developing salamander plethodon cinereus (lissamphibia: plethodontidae). | the latest research on direct developing caecilian and anuran species indicate presence of only one generation of taste organs during their ontogeny. this is distinct from indirect developing batrachians studied thus far, which possess taste buds in larvae and anatomically distinct taste discs in metamorphs. this study is a description of the tongue and taste organ morphology and development in direct developing salamander plethodon cinereus (plethodontidae) using histology and electron microsco ... | 2016 | 27087010 |
| frogs as integrative models for understanding digestive organ development and evolution. | the digestive system comprises numerous cells, tissues and organs that are essential for the proper assimilation of nutrients and energy. many aspects of digestive organ function are highly conserved among vertebrates, yet the final anatomical configuration of the gut varies widely between species, especially those with different diets. improved understanding of the complex molecular and cellular events that orchestrate digestive organ development is pertinent to many areas of biology and medici ... | 2016 | 26851628 |
| climate as a driver of tropical insular diversity: comparative phylogeography of two ecologically distinctive frogs in puerto rico. | the effects of late quaternary climate on distributions and evolutionary dynamics of insular species are poorly understood in most tropical archipelagoes. we used ecological niche models under past and current climate to derive hypotheses regarding how stable climatic conditions shaped genetic diversity in two ecologically distinctive frogs in puerto rico. whereas the mountain coquí, eleutherodactylus portoricensis, is restricted to montane forest in the cayey and luquillo mountains, the red-eye ... | 2015 | 26508809 |
| future u.s. supply of mo-99 production through fission based leu/leu technology. | coquí radiopharmaceuticals corp. (coquí) has the goal of establishing a medical isotope production facility for securing a continuous domestic supply of the radioisotope molybdenum-99 for u.s. citizens. coquí will use an leu/leu proven and implemented open pool, light-water, 10 mw, reactor design. the facility is being designed with twin reactors for reliability an on-site hot lab chemical processing and a waste conditioning area and a possible generator producing radio-chemistry lab. coquí iden ... | 2015 | 26224990 |
| development of neuroendocrine components of the thyroid axis in the direct-developing frog eleutherodactylus coqui: formation of the median eminence and onset of pituitary tsh production. | direct-developing frogs lack, wholly or in part, a wide range of larval features found in metamorphosing species and form adult-specific features precociously, during embryogenesis. most information on thyroid regulation of direct development relies on hormone manipulations; the ontogeny of many thyroid axis components has not been fully described. this analysis examines differentiation of the median eminence of the hypothalamus and production of thyroid-stimulating hormone (tsh) by the pituitar ... | 2015 | 25745815 |
| a novel whole-embryo culture model for pharmaceutical and developmental studies. | this report introduces a new vertebrate whole-embryo culture model for the direct application of pharmaceuticals and/or toxins into developing embryos. this method uses a terrestrial amphibian system and therefore has eliminated the problem of mammalian placental and uterine concerns. to test the utility and effectiveness of this method, we investigated the effect of fluoxetine on craniofacial development. fluoxetine is one of the most commonly prescribed selective serotonin reuptake inhibitor ( ... | 2015 | 25724095 |
| population declines of mountain coqui (eleutherodactylus portoricensis) in the cordillera central of puerto rico. | the mountain coqui (eleutherodactylus portoricensis) is a frog endemic to montane rainforests in the cordillera central and luquillo mountains of puerto rico. classified as endangered by the iucn red list and as vulnerable by the department of natural and environmental resources of puerto rico, this species has undergone considerable decline in the luquillo mountains. to evaluate the population status of e. portoricensis across its entire range, we conducted ~87 hours of surveys at 18 historical ... | 2014 | 25685250 |
| chronic fluoxetine treatment promotes submissive behavior in the territorial frog, eleutherodactylus coqui. | serotonin (5-ht) is an essential neurotransmitter for many physiological and behavioral processes. clinically and experimentally 5-ht metabolism can be altered using a class of drugs known as selective serotonin reuptake inhibitors (ssris). ssris such as fluoxetine have proven effective tools for elevating 5-ht activity and are routinely utilized to study the role of 5-ht in aggressive behavior. the puerto rican coquí frog, eleutherodactylus coqui, is a terrestrial amphibian that exhibits territ ... | 2014 | 24887449 |
| cranial muscle development in frogs with different developmental modes: direct development versus biphasic development. | normal development in anurans includes a free swimming larva that goes through metamorphosis to develop into the adult frog. we have investigated cranial muscle development and adult cranial muscle morphology in three different anuran species. xenopus laevis is obligate aquatic throughout lifetime, rana(lithobates) pipiens has an aquatic larvae and a terrestrial adult form, and eleutherodactylus coqui has direct developing juveniles that hatch from eggs deposited on leaves (terrestrial). the adu ... | 2014 | 24877162 |
| climate change and frog calls: long-term correlations along a tropical altitudinal gradient. | temperature affects nearly all biological processes, including acoustic signal production and reception. here, we report on advertisement calls of the puerto rican coqui frog (eleutherodactylus coqui) that were recorded along an altitudinal gradient and compared these with similar recordings along the same altitudinal gradient obtained 23 years earlier. we found that over this period, at any given elevation, calls exhibited both significant increases in pitch and shortening of their duration. al ... | 2014 | 24718765 |
| commitment to nutritional endoderm in eleutherodactylus coqui involves altered nodal signaling and global transcriptional repression. | the vegetal cells of a xenopus laevis embryo commit to mesendoderm via the nodal-signaling pathway. in the direct developing frog eleutherodactylus coqui, mesendoderm is specified at the marginal zone of the early gastrula, and vegetal core cells transform into nutritional endoderm. nutritional endoderm, a novel tissue, consists of transient, yolky cells that provide nutrition but remain undifferentiated. we report a dual regulation for the generation of nutritional endoderm. first, differential ... | 2014 | 24323742 |
| characterization of the nutritional endoderm in the direct developing frog eleutherodactylus coqui. | unlike xenopus laevis, eleutherodactylus coqui develops without a tadpole. the yolk-rich vegetal region of the embryo forms a transient nutritive tissue, the nutritional endoderm (ne). the definitive endoderm (de) in e. coqui comes from cells closer to the animal pole in contrast to its vegetal origin in x. laevis. rna important for initiating the endoderm specification network is absent in presumptive ne cells, raising the question whether signaling occurs in them. we explored the nature of ne ... | 2013 | 24043604 |
| expression of cyclin d1, cyclin d2, and n-myc in embryos of the direct developing frog eleutherodactylus coqui, with a focus on limbs. | species of frogs that develop directly have removed the tadpole from their ontogeny and form adult structures precociously. to see whether cell cycle regulators could be involved in this altered embryogenesis, we examined the expression of ccnd1, ccnd2, and mycn in embryos of the direct developing frog, eleutherodactylus coqui. notable differences compared to embryos of xenopus laevis, a species with a tadpole, included prominent expression of ccnd2 in the midbrain and ccnd1 in the mandibular ne ... | 2017 | 23473789 |
| metamorphosis in a frog that does not have a tadpole. | the evolutionary removal of the tadpole from the frog life history is a very successful strategy, particularly in the tropics. these direct developers form limbs and a frog-like head early in embryogenesis, and they have reduced or lost tadpole-specific structures, like gills, a long, coiled intestine, and tadpole teeth and jaws. despite the apparently continuous development to the frog morphology, the direct developer, eleutherodactylus coqui, undergoes a cryptic metamorphosis requiring thyroid ... | 2013 | 23347522 |
| sea level, topography and island diversity: phylogeography of the puerto rican red-eyed coquí, eleutherodactylus antillensis. | quaternary climatic oscillations caused changes in sea level that altered the size, number and degree of isolation of islands, particularly in land-bridge archipelagoes. elucidating the demographic effects of these oscillations increases our understanding of the role of climate change in shaping evolutionary processes in archipelagoes. the puerto rican bank (prb) (puerto rico and the eastern islands, which comprise vieques, culebra, the virgin islands and associated islets) in the eastern caribb ... | 2012 | 23163292 |
| expression of a cardiac myosin gene in non-heart tissues of developing frogs. | direct developing frogs, like eleutherodactylus coqui, provide opportunities to investigate limb early development in anuran amphibians that are less available in species with tadpoles. we have found that myosin heavy chain 6 (myh6), a myosin gene usually considered heart-specific in xenopus and other animals, is expressed in limbs of e. coqui embryos. the gene for microrna(mir)-208 is contained in an intron of the e. coqui myh6 gene as in mammals, and mir -208 was detected as a microrna, more h ... | 2013 | 23076351 |
| arginine vasotocin activates aggressive calls during paternal care in the puerto rican coquí frog, eleutherodactylus coqui. | the puerto rican coquí frog, eleutherodactylus coqui, is a directly developing frog that exhibits male territoriality and paternal behaviors. male frogs also produce advertisement and aggressive vocalizations or calls. territorial males emit advertisement calls to delineate territories and attract mates. paternal males guard and brood the directly developing embryos during embryogenesis and up to five days after hatching; advertisement calling is normally absent or infrequent during paternal car ... | 2012 | 22884614 |
| cast adrift on an island: introduced populations experience an altered balance between selection and drift. | a long-standing question in evolutionary biology is what becomes of adaptive traits when a species expands its range into novel environments. here, we report the results of a study on an adaptive colour pattern polymorphism (stripes) of the coqui frog, eleutherodactylus coqui, following its introduction to hawaii from puerto rico. we compared population differentiation (φ st and f st ) for the stripes locus--which underlies this colour pattern polymorphism--with neutral microsatellite loci to te ... | 2012 | 22718957 |
| corticotropin-releasing factor regulates the development in the direct developing frog, eleutherodactylus coqui. | direct developing frogs lack a free-living larval phase, such that miniature adults hatch directly from the eggs. even under such extreme reorganization of the ancestral biphasic developmental pattern, direct developers still undergo thyroid hormone (th)-dependent post-embryonic development. hypothalamic regulation of th synthesis and release plays a central role in controlling the timing of metamorphosis in biphasic developers. in particular, the neuropeptide corticotropin-releasing factor (crf ... | 2010 | 20850439 |
| genetic basis of a color pattern polymorphism in the coqui frog eleutherodactylus coqui. | many species of frog exhibit striking color and pattern polymorphisms, but the genetic bases of these traits are not known for most species. the coqui frog, eleutherodactylus coqui, a species endemic to the island of puerto rico, exhibits a wide variety of color and pattern polymorphisms including 4 discrete stripe patterns on its dorsal surface and an unstriped morph. we conducted breeding experiments to determine the mode of inheritance for these 5 dorsal color patterns in e. coqui. we analyze ... | 2010 | 20643755 |
| raldh expression in embryos of the direct developing frog eleutherodactylus coqui and the conserved retinoic acid requirement for forelimb initiation. | embryos of the direct developing frog, eleutherodactylus coqui, provide opportunities to examine frog early limb development that are not available in species with tadpoles. we cloned two retinaldehyde dehydrogenase genes, ecraldh1 and ecraldh2, to see which enzyme likely supplies retinoic acid for limb development. ecraldh1 is expressed in the dorsal retina, otic vesicle, pronephros, and pronephric duct, but not in the limb. ecraldh2 is expressed early at the blastoporal lip and then in the mes ... | 2008 | 18668545 |
| serotonin modulates vocalizations and territorial behavior in an amphibian. | it is well established that the serotonergic system modulates social and aggressive behaviors. this study employed field experiments to examine the effects of serotonin on male social structure and behavior in the puerto rican coquí frog, eleutherodactylus coqui. this frog displays three types of male behavioral phenotypes: territorial, satellite, and paternal males. territorial males produce advertisement calls that delineate territories and actively defend these areas. satellite males typicall ... | 2008 | 18554729 |
| the contribution of habitat loss to changes in body size, allometry, and bilateral asymmetry in two eleutherodactylus frogs from puerto rico. | amphibian populations have been declining worldwide and the exact mechanisms underlying these changes are not well understood. we examined environmentally induced phenotypic changes that may reflect ongoing stresses on individuals and therefore their ability to persist in increasingly changing landscapes. specifically, we evaluated the contribution of habitat loss on the size, allometry, and levels of fluctuating asymmetry of eleutherodactylus antillensis and e. coqui, 2 common species that are ... | 2008 | 18477027 |
| isolation of microsatellite loci from the coqui frog, eleutherodactylus coqui. | thirteen microsatellite loci were isolated from the coqui frog (eleutherodactylus coqui) and optimized for future research. the loci were screened across 37 individuals from two puerto rican populations. loci were variable with the number of alleles per locus ranging from three to 38. polymorphic information content ranged from 0.453 to 0.963 and observed heterozygosity for each population ranged from 0.320 to 0.920. | 2008 | 21585738 |
| cranial ontogeny in philautus silus (anura: ranidae: rhacophorinae) reveals few similarities with other direct-developing anurans. | direct development has evolved in rhacophorine frogs independently from other anuran lineages, thereby offering an opportunity to assess features associated with this derived life history. using a developmental series of the direct-developing philautus silus (ranidae: rhacophorinae) from sri lanka, we examine features of cranial morphology that are part of a suite of adaptations that facilitate feeding in free-living tadpoles, but have been changed or lost in other direct-developing lineages. la ... | 2007 | 17538972 |
| cranial neural crest-cell migration in the direct-developing frog, eleutherodactylus coqui: molecular heterogeneity within and among migratory streams. | direct development is a specialized reproductive mode that has evolved repeatedly in many different lineages of amphibians, especially anurans. a fully formed, albeit miniature adult hatches directly from the egg; there is no free-living larva. in many groups, the evolution of direct development has had profound consequences for cranial development and morphology, including many components that are derived from the embryonic neural crest. yet, the developmental bases of these effects remain poor ... | 2002 | 16351851 |
| ontogeny of central serotonergic neurons in the directly developing frog, eleutherodactylus coqui. | embryonic development of the central serotonergic neurons in the directly developing frog, eleutherodactylus coqui, was determined by using immunocytochemistry. the majority of anuran amphibians (frogs) possess a larval stage (tadpole) that undergoes metamorphosis, a dramatic post-embryonic event, whereby the tadpole transforms into the adult phenotype. directly developing frogs have evolved a derived life-history mode where the tadpole stage has been deleted and embryos develop directly into th ... | 2005 | 16151854 |
| serotonin metabolism in directly developing frog embryos during paternal care. | central serotonin (5-ht) metabolism during embryogenesis and a 3-day post-hatching period was analyzed using high performance liquid chromatography in the directly developing frog, eleutherodactylus coqui. this anuran bypasses the free-swimming larval stage and embryos hatch as miniature frogs in the adult phenotype. during embryogenesis and for a short time immediately after hatching, male e. coqui provide paternal care by brooding and guarding eggs/embryos to prevent desiccation and predation. ... | 2005 | 16039059 |
| in vitro fertilization and artificial activation of eggs of the direct-developing anuran eleutherodactylus coqui. | although much is known about the reproductive biology of pond-breeding frogs, there is comparatively little information about terrestrial-breeding anurans, a highly successful and diverse group. this study investigates the activation and in vitro fertilization of eggs of the puerto rican coqui frog obtained by hormonally induced ovulation. we report that spontaneous activation occurs in 34% of eggs, probably in response to mechanical stress during oviposition. artificial activation, as evidenced ... | 2004 | 15296510 |
| clutch effects explain heart rate variation in embryonic frogs (cave coqui, eleutherodactylus cooki). | few physiological studies to date have focused on whether variation among sibling groups during development can account for often large, intraspecific physiological variation. in this study, we measured heart rate in the direct-developing frog eleutherodactylus cooki throughout its embryonic development and examined heart rate variation among egg clutches comprising from 10 to 40 eggs. clutches were collected in the wild in yubucoa, puerto rico, and individual eggs were maintained under equivale ... | 2006 | 14671715 |
| top-down effects of a terrestrial frog on forest nutrient dynamics. | many studies have found top-down effects of predators on prey, but few studies have linked top-down effects of vertebrate predators to nutrient cycling rates in terrestrial systems. in this study, large and significant effects of a terrestrial frog, eleutherodactylus coqui (coquí), were recorded on nutrient concentrations and fluxes in a subtropical wet forest. in a manipulative experiment, coquís at natural densities were contained in or excluded from 1 m3 enclosures for 4 months. chemistry of ... | 2002 | 28466166 |
| limb development in a "nonmodel" vertebrate, the direct-developing frog eleutherodactylus coqui. | mechanisms that mediate limb development are regarded as highly conserved among vertebrates, especially tetrapods. yet, this assumption is based on the study of relatively few species, and virtually none of those that display any of a large number of specialized life-history or reproductive modes, which might be expected to affect developmental pattern or process. direct development is an alternative life history found in many anuran amphibians. many adult features that form after hatching in me ... | 2001 | 11754016 |
| the energetics of endotrophic development in the frog geocrinia vitellina (anura: myobatrachinae). | the energetics of endotrophic development, where the nutrition required to complete metamorphosis is provided solely by yolk, has seldom been quantified. the energy cost of development to metamorphosis of the endotrophic australian frog geocrinia vitellina was measured using bomb calorimetry and closed-system respirometry. dry yolk had an energy density of 26.4 j x mg(-1), and an average 2.8-mm-diameter ovum contained 144 j. incubation at 15 degrees c produced a froglet of 5.8 mm snout-vent leng ... | 2006 | 11731974 |
| frogs without polliwogs: evolution of anuran direct development. | direct development is the assumption of the adult morphology without progression through an intervening, morphologically distinct, free-living larval phase. we discuss the ecological factors contributing to the evolution of this derived life-history strategy in frogs, and the developmental modifications that facilitate such an unusual mode of embryogenesis. studies on the puerto rican tree frog, eleutherodactylus coqui, have identified several such modifications, including developmental adaptati ... | 2001 | 11223880 |
| opercular development and ontogenetic re-organization in a direct-developing frog. | the direct-developing frog, eleutherodactylus coqui, has eliminated the tadpole stage from its ontogeny, and lacks many larval characters. we demonstrate that the dermal folds of e. coqui are homologous with the opercular folds of metamorphosing frogs. in both e. coqui and its metamorphic counterparts the opercular folds grow over the developing forelimb before perforating to free the entrapped limb. opercular perforation in e. coqui occurs even in the absence of the forelimb but shows no signs ... | 2000 | 11180844 |
| thyroid hormone-dependent metamorphosis in a direct developing frog. | the direct developing anuran, eleutherodactylus coqui, lacks a tadpole, hatching as a tiny frog. we investigated the role of the metamorphic trigger, thyroid hormone (th), in this unusual ontogeny. expression patterns of the thyroid hormone receptors, tralpha and trbeta, were similar to those of indirect developers. trbeta mrna levels increased dramatically around the time of thyroid maturation, when remodeling events reminiscent of metamorphosis occur. treatment with the goitrogen methimazole i ... | 2000 | 10706622 |
| mechanistic basis of life history evolution in anuran amphibians: thyroid gland development in the direct-developing frog, eleutherodactylus coqui. | direct development is a widespread, alternative life history in recent amphibians. there is no free-living, aquatic larva; adult features form in the embryo and are present at hatching. the mechanistic bases of direct development remain relatively unexplored. the current study describes the embryonic ontogeny of the thyroid gland in the direct-developing frog eleutherodactylus coqui (leptodactylidae) and quantifies histological changes that occur in the gland after its initial appearance. the th ... | 1998 | 9679094 |
| jaw muscle development as evidence for embryonic repatterning in direct-developing frogs. | the puerto rican direct-developing frog eleutherodactylus coqui (leptodactylidae) displays a novel mode of jaw muscle development for anuran amphibians. unlike metamorphosing species, several larval-specific features never form in e. coqui; embryonic muscle primordia initially assume an abbreviated, mid-metamorphic configuration that is soon remodelled to form the adult morphology before hatching. also lacking are both the distinct population of larval myofibres and the conspicuous, larval-to-ad ... | 1997 | 9332017 |
| developmental regulation of the urea-cycle enzyme arginase in the direct developing frog eleutherodactylus coqui. | direct developing organisms obviate the larval intermediary from their ontogeny, hatching as miniature adults. to investigate this phenomenon, we have examined the developmental expression of arginase in the direct developing frog eleutherodactylus coqui. an enzyme in the ornithine-urea cycle, the activation of liver arginase is necessary for the switch from ammonotelism to ureotelism which occurs when many frogs metamorphose and assume a terrestrial existence. arginase enzyme activity is detect ... | 1996 | 8708631 |
| early cranial neural crest migration in the direct-developing frog, eleutherodactylus coqui. | direct development is a common reproductive mode in living amphibians characterized by absence of the free-living, aquatic larval stage. in eleutherodactylus, a species-rich genus of new world frogs, evolution of direct development from the ancestral biphasic ontogeny is correlated with a comprehensive modification in embryonic cranial patterning, including the loss of many larval-specific components and the precocious formation of many adult (postmetamorphic) structures. we use scanning electro ... | 1995 | 8659248 |
| leg development in a frog without a tadpole (eleutherodactylus coqui). | direct developing frogs, like eleutherodactylus coqui, have deleted the tadpole from their life history. limb buds appear early and develop continuously through embryonic life. the capacity for autonomous development of e. coqui limb buds was tested by explanation and transplantation. when limb buds were explanted to in vitro culture, they progressed for a few stages and then arrested. when limb buds were transplanted to embryos of a typical tadpole species (rana pipiens), the buds formed legs w ... | 1994 | 7964555 |
| reduction of tympanic membrane displacement during vocalization of the arboreal frog, eleutherodactylus coqui. | tympanic membrane (tm) velocities of vocalizing male frogs, eleutherodactylus coqui, were measured in the field using laser vibrometry. the animal's call produced levels of 114-120 db spl measured at distances of 12-20 mm from the eardrum and mean tm displacements in response to the two notes of the male's own advertisement call were 1.84 and 2.08 nm, respectively. these values are close to the tm displacements obtained in response to playback of the two-note call at much lower sound levels. thu ... | 1992 | 1619130 |
| cranial ontogeny in the direct-developing frog, eleutherodactylus coqui (anura: leptodactylidae), analyzed using whole-mount immunohistochemistry. | direct development in amphibians is an evolutionarily derived life-history mode that involves the loss of the free-living, aquatic larval stage. we examined embryos of the direct-developing anuran eleutherodactylus coqui (leptodactylidae) to evaluate how the biphasic pattern of cranial ontogeny of metamorphosing species has been modified in the evolution of direct development in this lineage. we employed whole-mount immunohistochemistry using a monoclonal antibody against the extracellular matri ... | 1992 | 1371162 |