Designed by Paul Smith 2006. This website is copyrighted by law.
Material contained herewith may not be used without the prior written permission of FAUNA Paraguay.
Photographs on this web-site were taken by Paul Smith, Hemme Batjes, Regis Nossent,
Alberto Esquivel, Arne Lesterhuis, José Luis Cartes, Rebecca Zarza and Hugo del Castillo and are used with their permission.
Material contained herewith may not be used without the prior written permission of FAUNA Paraguay.
Photographs on this web-site were taken by Paul Smith, Hemme Batjes, Regis Nossent,
Alberto Esquivel, Arne Lesterhuis, José Luis Cartes, Rebecca Zarza and Hugo del Castillo and are used with their permission.
BUFONIDAE - TOADS
Fourteen species recorded in Paraguay, belonging to two different genera. The toads of the genera Rhinella were formerly placed in a much larger, cosmopolitan genus Bufo - that now applying only to Old World forms so that no species of Bufo now occurs in Paraguay. The genus Melanophryniscus sometimes bear the common name of "Neotropical Red-belly" or "Fire-bellied Toads" on account of their brightly coloured ventral regions. The genus Rhinella can be split into three "groups".
Toads are immediately identifiable by their thick glandular skin, often with a warty appearance. They are terrestrial in behaviour, though require access to water for breeding. They exhibit 5 to 8 procoelous, holochordal presacral vertebrae, where there are less than 8 it is due to fusions. Ribs are absent. The urostyle is free with two condyles, though some have a single condyle or have them fused to the sacrum. The pectoral girdle is usually arciferal. The sternum is bony and the omosternum is absent. The clavicle does not overlie the scapular. Palatines are present in most. No teeth present on the maxilla or premaxilla. Astralagus and calcaneum are fused only at the ends. No intercalary phalanges. The sartorius is a separate and distinct muscle. Pupil is horizontal. Bidder´s Organ is present. The skull is highly ossified, usually co-ossified with the head skin. Fertilisation is external, with aquatic eggs and larvae, though in a few rare cases direct development and/or viviparity is shown. 2n=22. Sperm with two equal tail filaments and curved head.
REFERENCES
Cei JM 1980 - Amphibians of Argentina - Monitore Zoologico Italiano Monografia 2.
Fouquette MJ (undated) - Synopsis of Recent Amphibians to Genus - Arizona University.
Whitfield P Ed.1984 - Longman Illustrated Animal Encyclopedia - Guild Publishing, London.
KEY TO THE PARAGUAYAN SPECIES OF MELANOPHRYNISCUS
Size small (SVL<35mm). Dorsal and/or ventral surface spotted or blotched with well-defined areas of red and/or yellow.
1a Dorsal surface heavily spotted with conspicuous, well-defined markings - 2
1b Dorsal surface uniform, with pale scapular patches and/or with inconspicuous spotting or blotching - 3
2a Dorsal spots large, blotchy and dispersed. Complete interocular band, or trace of interocular band formed by broken blotches - klappenbachi
2b Dorsal spots small, regular and numerous. No trace of interocular band - fulvoguttatus
3a Dorsal colouration principally brownish. Ventral colouration orange or orange-red. Femoral patch orange-red, no conspicuous against ventral patternation. Skin granulose with small keratinised spines - 4
3b Dorsal colouration principally blackish. Ventral colouration yellow, white, orange or red. Contrasting red femoral patch on ventral side. Skin smooth or granulose, with or without small keratinised spines - 5
4a Frontal area of head swollen. Pale orange scapular patches frequently visible and indistinct traces of patternation on dorsal surfaces. Iris dark. Extensive orange patch covering femoral and belly area. - devincenzii
4b Frontal area of head not swollen. Dorsal surface uniformly brown with no pale scapular patches or traces of patternation. Iris yellow and pupil ringed with gold. Ventrally with irregular orange spots of variable extent. - krauczuki
5a Dorsal surface usually with some trace of irregular yellowish patternation, including more or less visible yellow scapular patches. Skin granulose but not spiny. Ventral spotting red. - paraguayensis
5b Dorsal surface uniformly blackish with no shoulder patches or trace of patternation. Skin granulose with small keratinised spines. Ventral spotting yellow or orange. - atroluteus
KEY TO THE PARAGUAYAN BUFONIDAE IN THE "granulosa" GROUP
Medium-sized (SVL 35-81mm). Parotid gland small. Skin densely granular. Well-developed cranial crests.
1a Cephalic crests continuous. Infraorbital crest long and extending well beyond postorbital crest. - 2
1b Cephalic crests made up of a series of small warts (granulose). Infraorbital crest may be long (extending well beyond postorbital crest) or short. - 3
2a Dorsal colouration typically brownish, marbled with darker spots. Longitudinal dorsal stripe usually present.
Ventral white heavily pigmented with small dark spots. Snout rounded in lateral profile and not particularly short. Interorbital region fleshy with a few large, rounded granules slightly aligned in two parallel rows. Upper lip sharp, not swollen. Variable pale stripe along upper lip, spotted darker in some individuals. Infraorbital crest long, extending beyond postorbital crest. SVL male 34.6-49.8mm, female 36-59.3mm. - Rhinella bergi
2b Dorsal colouration typically dark greyish or black. Longitudinal dorsal stripe usually absent. Ventral with scattered dark spots. Snout rounded in lateral profile and highly-elongated. Interorbital region fleshy with a few large, rounded granules slightly aligned in two parallel rows. Upper lip swollen. Variable pale stripe along upper lip. Infraorbital crest long, extending beyond postorbital crest. SVL male 34.7-50.6mm, female 40.7-58.2mm. - Rhinella azarai
3a Dorsal colouration typically consisting of green, brown and yellow. Longitudinal dorsal stripe present or absent, yellow when present. Ventral yellowish may be unpigmented or with small dark spots, especially on lower abdomen and posterior sides of femur. Snout very short and blunt in lateral profile. Interorbital area smooth occasionally with a few scattered granules. Upper lip sharp, not swollen. SVL male 38.2-67.3mm, female 40-76.4mm. - Rhinella fernandezae
3b Dorsal colouration typically consisting of green, brownish-grey and creamy-white. Longitudinal dorsal stripe usually absent. Ventral unpigmented creamy-white. Snout rounded in lateral profile and not particularly short. Interorbital area mostly smooth with a few scattered granules. Upper lip not swollen. Pale stripe along upper lip. Infraorbital crest short and granulose, not extending well beyond postorbital crest. SVL male 35.8-72.8mm, female 33.9-81.1mm. - Rhinella major
KEY TO THE PARAGUAYAN BUFONIDAE IN THE "marinus" GROUP
Very large (SVL120-220mm). Cephalic crests very well-developed. Snout rounded, not protruding. Pale longitudinal line present or absent, though when present its edges are not the only dark markings on the dorsum. Dorsum spotted, or uniformly pale.
1a Ventral whitish, densely spotted darker. Parietal crest concave and with smoothly rounded posterior edge. Large parotid gland narrows posteriorly and extends beyond axilla. Conspicuous tibial glands. Dorsal warts with single dark central spine. - Rhinella schneideri
1b Ventral whitish and unspotted, except for dark vermiculations on chest, belly and femur. Parietal crest with finger-like projections on posterior edge. Large parotid gland rounded and posterior edge reaches axilla. Tibial glands not conspicuous. Dorsal warts with numerous spines. - Rhinella icterica
Fourteen species recorded in Paraguay, belonging to two different genera. The toads of the genera Rhinella were formerly placed in a much larger, cosmopolitan genus Bufo - that now applying only to Old World forms so that no species of Bufo now occurs in Paraguay. The genus Melanophryniscus sometimes bear the common name of "Neotropical Red-belly" or "Fire-bellied Toads" on account of their brightly coloured ventral regions. The genus Rhinella can be split into three "groups".
Toads are immediately identifiable by their thick glandular skin, often with a warty appearance. They are terrestrial in behaviour, though require access to water for breeding. They exhibit 5 to 8 procoelous, holochordal presacral vertebrae, where there are less than 8 it is due to fusions. Ribs are absent. The urostyle is free with two condyles, though some have a single condyle or have them fused to the sacrum. The pectoral girdle is usually arciferal. The sternum is bony and the omosternum is absent. The clavicle does not overlie the scapular. Palatines are present in most. No teeth present on the maxilla or premaxilla. Astralagus and calcaneum are fused only at the ends. No intercalary phalanges. The sartorius is a separate and distinct muscle. Pupil is horizontal. Bidder´s Organ is present. The skull is highly ossified, usually co-ossified with the head skin. Fertilisation is external, with aquatic eggs and larvae, though in a few rare cases direct development and/or viviparity is shown. 2n=22. Sperm with two equal tail filaments and curved head.
REFERENCES
Cei JM 1980 - Amphibians of Argentina - Monitore Zoologico Italiano Monografia 2.
Fouquette MJ (undated) - Synopsis of Recent Amphibians to Genus - Arizona University.
Whitfield P Ed.1984 - Longman Illustrated Animal Encyclopedia - Guild Publishing, London.
KEY TO THE PARAGUAYAN SPECIES OF MELANOPHRYNISCUS
Size small (SVL<35mm). Dorsal and/or ventral surface spotted or blotched with well-defined areas of red and/or yellow.
1a Dorsal surface heavily spotted with conspicuous, well-defined markings - 2
1b Dorsal surface uniform, with pale scapular patches and/or with inconspicuous spotting or blotching - 3
2a Dorsal spots large, blotchy and dispersed. Complete interocular band, or trace of interocular band formed by broken blotches - klappenbachi
2b Dorsal spots small, regular and numerous. No trace of interocular band - fulvoguttatus
3a Dorsal colouration principally brownish. Ventral colouration orange or orange-red. Femoral patch orange-red, no conspicuous against ventral patternation. Skin granulose with small keratinised spines - 4
3b Dorsal colouration principally blackish. Ventral colouration yellow, white, orange or red. Contrasting red femoral patch on ventral side. Skin smooth or granulose, with or without small keratinised spines - 5
4a Frontal area of head swollen. Pale orange scapular patches frequently visible and indistinct traces of patternation on dorsal surfaces. Iris dark. Extensive orange patch covering femoral and belly area. - devincenzii
4b Frontal area of head not swollen. Dorsal surface uniformly brown with no pale scapular patches or traces of patternation. Iris yellow and pupil ringed with gold. Ventrally with irregular orange spots of variable extent. - krauczuki
5a Dorsal surface usually with some trace of irregular yellowish patternation, including more or less visible yellow scapular patches. Skin granulose but not spiny. Ventral spotting red. - paraguayensis
5b Dorsal surface uniformly blackish with no shoulder patches or trace of patternation. Skin granulose with small keratinised spines. Ventral spotting yellow or orange. - atroluteus
KEY TO THE PARAGUAYAN BUFONIDAE IN THE "granulosa" GROUP
Medium-sized (SVL 35-81mm). Parotid gland small. Skin densely granular. Well-developed cranial crests.
1a Cephalic crests continuous. Infraorbital crest long and extending well beyond postorbital crest. - 2
1b Cephalic crests made up of a series of small warts (granulose). Infraorbital crest may be long (extending well beyond postorbital crest) or short. - 3
2a Dorsal colouration typically brownish, marbled with darker spots. Longitudinal dorsal stripe usually present.
Ventral white heavily pigmented with small dark spots. Snout rounded in lateral profile and not particularly short. Interorbital region fleshy with a few large, rounded granules slightly aligned in two parallel rows. Upper lip sharp, not swollen. Variable pale stripe along upper lip, spotted darker in some individuals. Infraorbital crest long, extending beyond postorbital crest. SVL male 34.6-49.8mm, female 36-59.3mm. - Rhinella bergi
2b Dorsal colouration typically dark greyish or black. Longitudinal dorsal stripe usually absent. Ventral with scattered dark spots. Snout rounded in lateral profile and highly-elongated. Interorbital region fleshy with a few large, rounded granules slightly aligned in two parallel rows. Upper lip swollen. Variable pale stripe along upper lip. Infraorbital crest long, extending beyond postorbital crest. SVL male 34.7-50.6mm, female 40.7-58.2mm. - Rhinella azarai
3a Dorsal colouration typically consisting of green, brown and yellow. Longitudinal dorsal stripe present or absent, yellow when present. Ventral yellowish may be unpigmented or with small dark spots, especially on lower abdomen and posterior sides of femur. Snout very short and blunt in lateral profile. Interorbital area smooth occasionally with a few scattered granules. Upper lip sharp, not swollen. SVL male 38.2-67.3mm, female 40-76.4mm. - Rhinella fernandezae
3b Dorsal colouration typically consisting of green, brownish-grey and creamy-white. Longitudinal dorsal stripe usually absent. Ventral unpigmented creamy-white. Snout rounded in lateral profile and not particularly short. Interorbital area mostly smooth with a few scattered granules. Upper lip not swollen. Pale stripe along upper lip. Infraorbital crest short and granulose, not extending well beyond postorbital crest. SVL male 35.8-72.8mm, female 33.9-81.1mm. - Rhinella major
KEY TO THE PARAGUAYAN BUFONIDAE IN THE "marinus" GROUP
Very large (SVL120-220mm). Cephalic crests very well-developed. Snout rounded, not protruding. Pale longitudinal line present or absent, though when present its edges are not the only dark markings on the dorsum. Dorsum spotted, or uniformly pale.
1a Ventral whitish, densely spotted darker. Parietal crest concave and with smoothly rounded posterior edge. Large parotid gland narrows posteriorly and extends beyond axilla. Conspicuous tibial glands. Dorsal warts with single dark central spine. - Rhinella schneideri
1b Ventral whitish and unspotted, except for dark vermiculations on chest, belly and femur. Parietal crest with finger-like projections on posterior edge. Large parotid gland rounded and posterior edge reaches axilla. Tibial glands not conspicuous. Dorsal warts with numerous spines. - Rhinella icterica
