Ceratophrys Ornata Research Articles

Histology and lectin-binding patterns in the skin of the terrestrial horned frog Ceratophrys ornata

The terrestrial horned frog, Ceratophrys ornata, lives on a wet substratum and absorbs water through the ventral epidermis; water is lost by evaporation from the dorsal skin. Thus, this species may be useful as a model for determining whether or not skin histology and lectin-binding patterns, indicative of glycoconjugates, are related to skin functions such as osmoregulation and water balance. With this in mind, a histological and lectin-histochemical study was carried out on dorsal and ventral skin of aquatic tadpoles and of a young terrestrial frog of C. ornata. Sections of skin were stained with various dyes to demonstrate general histological features and with two horseradish peroxidase (HRP)-conjugated lectins, Ulex europaeus agglutinin (UEA 1) and soybean agglutinin (SBA) which bind to specific terminal sugar residues of glycoconjugates, namely L-fucose and N-acetyl-D-galactosamine or D-galactose, respectively. In early stage tadpoles both lectin-binding patterns were similar in the bilaminar epidermis of dorsal and ventral skin (i.e., each lectin stained the apical cell layer). However, metamorphic changes resulted in a young frog with typical adult-type skin composed of a stratified squamous epidermis and three distinct types of glands containing glycoconjugates in their secretions. Strikingly different lectin-binding patterns were evident in the epidermis from dorsal and ventral regions of the body. The epidermis from the dorsal region was stained by both lectins; in contrast, that from the ventral region, although stained strongly by HRP-SBA, did not react with HRP-UEA 1, indicating that few, if any, fucose residues were present in the ventral epidermis.(ABSTRACT TRUNCATED AT 250 WORDS)

A different type of amphibian mesoderm morphogenesis in Ceratophrys ornata.

Ceratophrys ornata, the Argentinean horned frog, has a significantly different pattern of early morphogenesis than does the most studied amphibian, Xenopus laevis. Time-lapse videomicroscopy, scanning electron microscopy, histological sections and lineage tracers have shown that, in C. ornata, some prospective notochord, somite and tailbud mesoderm cells leave the surface epithelium of the archenteron by ingression. After gastrulation, SEM reveals cells with constricted apices and a bottle shape in three zones on the archenteron roof and in a fourth zone around the blastopore. Prospective somitic tissue ingresses first from two lateral zones, followed by ingression of prospective notochord from the medial zone and tailbud mesoderm from the circumblastoporal zone. This is unlike X. laevis, in which no cells with constricted apices are present on the dorsal surface of the archenteron, nor do any cells ingress into the deep mesodermal layers from the surface layer.

Relationships of the Frogs of the Genus Ceratophrys (Leptodactylidae) and their Bearing on Hypotheses of Pleistocene Forest Refugia in South America and Punctuated Equilibria

Lynch,J. D. (School of Life Sciences, The University of Nebraska, Lincoln, Nebraska 68588) 1982. Relationships of thefrogs of the genus Ceratophrys (Leptodactylidae) and their bearing on hypotheses of Pleistocene forest refugia in South America and punctuated equilibria. Syst. Zool., 31:166-179.-Of the eight currently recognized species of Ceratophrys (aurita, calcarata, cornuta, cranwelli, ornata, pierottii, stolzmanni, and testudo) six are considered to be species. Ceratophrys testudo is considered a synonym of C. cornuta. The subfamily Ceratophryinae is argued to be monophyletic and is defined on the basis of two synapomorphies. The genus Ceratophrys (excluding C. pierottii) is monophyletic and is defined on the basis of three synapomorphies. Two subgenera are recognized within Ceratophrys. The subgenus Ceratophrys (one synapomorphy) includes C. aurita, C. cranwelli, and C. ornata where C. aurita and C. ornata are more closely interrelated. The subgenus Stombus (three synapomorphies) includes C. calcarata, C. cornuta, and C. stolzmanni where C. calcarata and C. cornuta are nearest relatives. Ceratophrys pierottii is hypothesized to be an intergeneric hybrid between Ceratophrys cranwelli and Lepidobatrachus llanensis. The least refuted hypothesis of relationships is inconsistent with the hypothesis that speciation amongst forest-dwelling species was mediated by Pleistocene contractions of forest into refugia. The northern species of Ceratophrys form a group fragmented in part by the Andes and the southern (and eastern) species form a second group fragmented ecologically but not physically. The widespread Amazonian species, C. cornuta, shows little evidence of having had its distribution fragmented by forest contractions. Ceratophrys cornuta is the most widely distributed species, is centrally distributed, and is by far the most apomorphous (measured in terms of autapomorphies). Such a combination is contrary to the expectations under the macroevolutionary hypothesis termed punctuated equilibria. [Cladistics; Ceratophrys; South America; Pleistocene forest refugia; punctuated equilibria; systematic relationship; hypothesis testing.] The biota of South America is remarkably diverse reflecting the antiquity of the continent's isolation as well as its ecogeographic diversity. The Neotropics contain a very diverse anuran fauna. Some elements of that fauna are wholely restricted to rainforests, others are endemic to non-forest units, and yet others have species in both rainforests and non-forest environments (Lynch, 1979). An example of the latter is the leptodactylid frog genus Ceratophrys with three rainforest species (C. aurita in the Atlantic forests of Brazil and C. cornuta and C. testudo in the forests of the Amazon Basin) and five species in non-forest areas (C. calcarata in northern Colombia and Venezuela, C. cranwelli and C. pierottii in the Chaco, C. ornata in the grasslands of Argentina, and C. stolzmanni in the arid terrain around the Gulf of Guayaquil (Fig. 1). Ceratophrys and the Chacoan genus Lepidobatrachus make up the subfamily Ceratophryinae (Lynch, 1971). Two of the rainforest species (C. aurita and C. cornuta) have been considered closely related (Cochran and Goin, 1970; Lynch, 1979) and as such provide support for the refugia hypothesis of Haffer (1969, 1974, 1979) and indirectly for a relatively recent speciation event. The purposes of this study are two-fold: firstly, to discover the pattern of relationships within Ceratophrys and, secondly, to use these data

Identification and Ecology of the Toad Bufo regularis

some Chacoan features (Fig. 1). There were many temporary pools alongside the national road to Mendoza during this exceptionally rainy summer. The following forms were taken: Leptodactylus bufonius, Physalaemus fuscomaculatus, Physalaemus sp., Ceratophrys ornata, Odontophrynus americanus, Bufo arenarum. I observed many subterranean nests of Leptodactylus bufonius in the clayey soil, and floating froth nests of Physalaemus fuscomaculatus in the pools. There were many social burrows of Lagidium (vizcacheras) in the vicinity, perhaps the shelters of Leptodactylus bufonius and Ceratophrys, as in the true Chacoan biocenosis. The invertebrate fauna of the pools was very abundant at this period, especially entomostracans (Apus and related forms) and dipteran larvae. Only three species of batrachians were recorded by Freiberg (1942) for the province of San Luis: Bufo arenarum, Hyla raddiana, Leptodactylus ocellatus. My report shows that the fauna of this territory is a transitional one. ome Chacoan features (Fig. 1). There were any temporary pools al ngside the national oad to Mendoza during this exceptionally ainy sum er. The following forms were taken: eptodactylus bufonius, Physalaemu fuscomacuatus, Physalaemus sp., Ceratoph ys ornata, dontophrynus americanus, Bufo arenarum. I bserved many subterran an nests of Leptoactylus bufonius in the clayey soil, and floating roth nests of Physalaemus fuscomaculatus in e pools. There were many social burrows of agidium (vizcacheras) in the vicinity, peraps the shelters of Leptodactylus bufonius and eratophrys, a in the true Chacoan bio enosis. he invertebrate fauna of the pools was very bundant at this period, especially ntomostraans (Apus and related forms) and dipteran arvae. nly three species of batrachians were ecorded by Freiberg (1942) for the province of It is composed of the more ancient Chacoan subtropical elements (ecological relicts in the clayey soil station nearJarilla) and the peculiar Andean fauna of the nearby Mendoza province2. It was imp ssible during the wet summer of 1951 to find the bove mentioned forms anywhere between the canfons of the Desaguadero River and the w stern arid zone of Mendoza.

Habits of the Horned Toad

THE arrival at the Gardens of the Zoological Society of London of a horned toad (Ceratophrys ornata) is an event worth recording. This creature, a native of northern Argentina and Paraguay, where it is known as the ‘Escuerzo’, is one of ten species noted for their singular coloration and habits. All share the peculiarity of a bony shield underlying the skin of the back. The coloration of C. ornata is protective in character and of considerable beauty. The greenish-yellow background is relieved by large dark green patches on the back, decreasing in size on the flanks. Each of these isolated patches is surrounded by a narrow line of white and yellow dots, interspersed with lines of rusty brown or red, producing a carpet-like pattern perfectly concealing the half-buried body. If there is not sufficient green vegetation it throws earth upon its back by the aid of the hind feet, and at the same time the skin wrinkles, and assumes a duller coloration. Extremely sluggish, it lies in wait for its victims, which include smaller members of its own species, as well as frogs, which are said to form its staple diet. Horned toads are said to inflate the body when angry, and to hop backwards and forwards uttering a succession of loud cries, hence they are also known as ‘crying frogs’. As the cause of their excitement is removed, they slowly deflate the body and relapse into the stony silence enjoined by the need of fresh victims. During the dry season, like many other batrachians living in hot countries, they ¦stivate.