| one hundred million years of skin feeding? extended parental care in a neotropical caecilian (amphibia: gymnophiona). | maternal dermatophagy, the eating of maternal skin by offspring, is an unusual form of parental investment involving co-evolved specializations of both maternal skin and offspring dentition, which has been recently discovered in an african caecilian amphibian. here we report the discovery of this form of parental care in a second, distantly related neotropical species siphonops annulatus, where it is characterized by the same syndrome of maternal and offspring specializations. the detailed simil ... | 2008 | 18547909 |
| antileishmanial and antitrypanosomal activity of the cutaneous secretion of siphonops annulatus. | among the tropical parasitic diseases, those caused by protozoans are considered a challenge to public health, being represented by leishmaniasis and chagas disease. in view of the low effectiveness and toxicity of the current therapy, animal venoms such as amphibian secretions have been used as a promising source of new drug prototypes. the present work aimed to achieve bioguided fractionation of metabolites present in a cutaneous secretion of the caecilian siphonops annulatus (amphibia: gymnop ... | 2014 | 25873939 |
| metabolic and endocrine changes during the reproductive cycle of dermatophagic caecilians in captivity. | the amphibian order gymnophiona is poorly known, and studies about their reproduction are mainly comparative and descriptive, focusing on the structure of testes, ovaries and oviducts. however, to understand the reproductive processes, including those of the oviparous dermatophagic species, it is important to know the dynamics of storage and mobilization of energetic substrates to gonads and skin during the reproductive cycle of males and females, as well as the endocrine control associated. for ... | 2013 | 24001948 |
| caecilian jaw-closing mechanics: integrating two muscle systems. | caecilians (lissamphibia: gymnophiona) are unique among vertebrates in having two sets of jaw-closing muscles, one on either side of the jaw joint. using data from high-resolution x-ray radiation computed tomography scans, we modelled the effect of these two muscle groups (mm. levatores mandibulae and m. interhyoideus posterior) on bite force over a range of gape angles, employing a simplified lever arm mechanism that takes into account muscle cross-sectional area and fibre angle. measurements o ... | 2008 | 18482905 |
| skin gland concentrations adapted to different evolutionary pressures in the head and posterior regions of the caecilian siphonops annulatus. | amphibian skin is rich in mucous glands and poison glands, secreting substances important for gas exchange and playing a fundamental role in chemical defense against predators and microorganisms. in the caecilian siphonops annulatus (mikan, 1920) we observed a concentration of enlarged mucous glands in the head region. in the posterior region of the body a similar concentration is made up of enlarged poison glands. these accumulations of glands structurally resemble the macroglands previously re ... | 2018 | 29476100 |
| melanomacrophage functions in the liver of the caecilian siphonops annulatus. | melanomacrophages are phagocytes that synthesize melanin. they are found in the liver and spleen of ectothermic vertebrates, and in the kidney of fish. in agnathan and elasmobranch fish, melanomacrophages are seen as isolated cells, and forming clusters in all the other vertebrates. the natural phagocytic activity of melanomacrophages is poorly characterized, as most of the research works have focused on induced phagocytic activity only. furthermore, little is known about amphibian melanomacroph ... | 2018 | 29205335 |
| histology of the trachea and lung of siphonops annulatus (amphibia, gymnophiona). | the structure of the trachea and lung of siphonops annulatus was studied in ten specimens of routinely fed animals. the trachea is constituted mainly by incomplete cartilage rings lined by a respiratory epithelium (ciliated and mucous cells) with variable morphology according to the region observed. a rich vascularization of this organ suggests its participation in blood-air gas exchange. the right lung in this species is developed and the left one is atrophied. this organ is constituted mainly ... | 2000 | 10838935 |
| histology of the kidney and urinary bladder of siphonops annulatus (amphibia-gymnophiona). | the histology of the kidney and urinary bladder of siphonops annulatus was studied by light microscopy in semithin sections of tissue embedded in hydrophilic resin. the kidney's nephron comprises the renal corpuscle, neck segment, proximal tubule, intermediate segment, distal tubule and collecting tubule. nephrostomes are present. this structure, the neck segment, and intermediate tubules present long cilia, and probably play important roles in the propulsion of the peritoneal fluid and glomerul ... | 1999 | 10223741 |
| [observations on the teeth and the dental laminae of the upper jaw and the palate in siphonops annulatus (mikan) (amphibia: gymnophiona) (author's transl)]. | siphonops annulatus possesses a single line ("zahnzeile") of teeth in the upper jaw as well as in the palate paralleling the curvature of the jaws. an undivided continuous dental lamina provides the 2 nasopremaxillas and both maxillaries of the maxillopalatines with teeth, whereas each vomer and each (maxillo)-palatine is toothed by a separate dental lamina. the teeth are monocuspid, pedicellate and ancylosed to the bones in an extremely pleural condition. the results are compared to the conditi ... | 1980 | 7416496 |