Ontogeny of the Thyroid Glands During Larval Development of South American Horned Frogs (Anura, Ceratophryidae)

Fabrezi, Marissa; Cruz, Julio César

doi:10.1007/s11692-014-9292-5

Cited by 13 publications

(21 citation statements)

References 45 publications

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“…The high levels of TH in circulation inhibit the hypothalamic–pituitary–thyroid axis and in turn stop the endogenous TH production through a negative feedback mechanism (Denver, ; Huang, Cai, Remo, & Brown, ). Fabrezi and Cruz () described small thyroid follicles with low activity in the obligated carnivorous tadpoles of Lepidobatrachus and suggested the TH precursors for a rapid development may come from their diet. Unfortunately, few studies showing the effects of thyroid‐active substances on the gland—be they from diet (e.g.…”

Section: Discussionmentioning

confidence: 99%

“…Thyroid gland morphology as characterized by Etkin has subsequently been observed in a variety of other anuran species (Dodd & Dodd ; Fox, ; Grim et al, ; Jennings & Hanken, ; Michael & Adhami, ; Miranda & Pisanó, ). However, species having exceptional larval development (e.g., ceratophryids, Pseudis paradoxa ) may display distinctive thyroid gland histology (Cruz, ; Fabrezi & Cruz, ).…”

Section: Introductionmentioning

confidence: 99%

“…However, species having exceptional larval development (e.g., ceratophryids, Pseudis paradoxa) may display distinctive thyroid gland histology (Cruz, 2017;Fabrezi & Cruz, 2014).…”

Section: Introductionmentioning

confidence: 99%

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Differences in responsiveness and sensitivity to exogenous disruptors of the thyroid gland in three anuran species

2019

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Anuran larval development comprises tissues/organs/systems that are: exclusively of larvae, able to be remodelled, and those of postmetamorphic stages. Also, the anuran larval development is characterized by inter‐related parameters: time, size and shape forming part of growth and differentiation. The anuran metamorphosis starts when growth and differentiation achieve a threshold that differs among species since it is regulated by a number of external (environmental) and internal (hormonal) processes. Here we explore the consequences of exogenous disruptors on the thyroid gland (e.g., methimazole and thyroxine as T4) of three species by immersing premetamorphic tadpoles in predetermined concentrations of the disruptors for short periods (10 or 16 days). The species were Pleurodema borellii, Leptodactylus chaquensis, and Dermatonotus muelleri, which all breed in small temporary ponds during the summer, but differ in their ecomorphology. The experiments were conducted to evaluate the effects of these substances on larval development (based in Gosner larval stages), morphometric variation in body parameters (snout‐vent and total length by larval stages), and thyroid gland histopathology at the end of the assays. In P. borelli and L. chaquensis, methimazole produces significant increment of size measurements (nonparametric Kruskal–Wallis, p < .05) during stages of digit differentiation and induced thyroid gland hypertrophy. In the three species, T4 exposure accelerated limb development and caused atrophy of thyroid gland. Prolonged T4 exposure in L. chaquensis and D. muelleri triggered metamorphic transformation in the gut and skull cartilages. Discussion about interspecific differences in responsiveness and sensitivity elucidates the importance of hormonal signals to morphological evolution.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Differences in responsiveness and sensitivity to exogenous disruptors of the thyroid gland in three anuran species

2019

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“…The thyroid gland in carnivorous ceratophryid larvae is unique though in showing low activity throughout the larval period, even when development is accelerated (Fabrezi & Cruz, 2014). Fabrezi and Cruz (2014) suggested possible factors influencing larval development in the Ceratophryidae, such as THprecursors from their diets (e.g., crustaceans of the genera Hyalella and Daphnia, plus tadpoles) or as a maternal resource supplied to the larvae in the yolk of the eggs. Notably, maternal influences on anuran larval development have been documented for Rhinella marina and Xenopus laevis (Fini et al, 2012;Morvan-Dubois et al, 2006;Weber, Farrar, Tom, & Grau, 1994) and the direct developer Eleutherodactylus coqui (Laslo, Denver, & Hanken, 2019).…”

Section: Discussionmentioning

confidence: 99%

Histology and microscopic anatomy of the thyroid gland during the larval development of Pseudis platensis (Anura, Hylidae)

Cruz

Fabrezi

2019

Journal of Morphology

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Several hormones regulate anuran larval development, most notably thyroid hormones (THs). In anurans, metamorphosis fails when the thyroid gland is absent or inactivated, resulting in giant tadpoles. Larval gigantism occurs naturally in neotropical frogs of the genus Pseudis as a result of a prolonged larval period. Its thyroid function is poorly investigated and the focus of this study. We describe qualitative and quantitative variations in larval development for field‐captured specimens of Pseudis platensis and compare those to the development of two sympatric species, Phyllomedusa sauvagii and Pithecopus azureus, which have small tadpoles and a shorter larval period. We describe morphological changes in the thyroid glands of larval and adult specimens. In contrast to other species with similar ecological requirements, P. platensis exhibits distinct glandular activity. During premetamorphosis, there was little or no thyroid activity, a period in which the tadpole reached 70% of its maximum size. Development and degree of activity of the thyroid gland determine the duration of the early stages of the larval period. Thyroid gland histology in tadpoles appears to correlate with the TH activity, and in turn with the diversity in anuran life history transitions.

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“…An early activation of thyroid and interrenal axes under conditions of pond desiccation was shown experimentally in Spea hammondii (Denver, ). In ceratophryids, Fabrezi and Cruz () found low activity in the thyroid gland and suggested that the ability of these species to grow and develop rapidly could be explained by the accumulation of maternal T 3 and T 4 , an unusual proliferation of heterotopic follicles, and the acquisition of extra exogenous hormones from diet.…”

Section: Discussionmentioning

confidence: 99%

Embryonic ontogeny of three species of Horned Frogs, with a review of early development in Ceratophryidae

Grosso

Baldo

Costa

et al. 2019

Journal of Morphology

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Horned Frogs of the family Ceratophryidae are conspicuous anurans represented by three endemic South American genera. Most ceratophryids inhabit semiarid environments, but three species of Ceratophrys occupy tropical or temperate humid areas. Several morphological and behavioral characters of larvae and adults are conserved across the family. Based on examination of specimens and accounts in the literature, the embryonic development of C. ornata, C. cranwelli, and the monotypic genus Chacophrys are described and compared with that of species of Lepidobatrachus. Ceratophryid embryos share a suite of morphological features and heterochronic shifts during development. Most features, such as gill structure, ciliation, early hatching, and precocious differentiation of the gut and hind limbs, are shared by all the species regardless the differences in the habitats that occupy. This is consistent with previous observations of some adult characters, and likely supports the hypothesis of an early diversification of ceratophryids in semiarid environments. Other embryonic features, such as the morphology and ontogeny of the oral disc and digestive tract, are correlated with larval feeding habits and vary within the family. The evolutionary and ecological significance of some conserved characters (e.g., gastrulation pattern, Type‐A adhesive glands) and other taxon‐specific features (e.g., nasal appendix) remain to be explored in the group.

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Ontogeny of the Thyroid Glands During Larval Development of South American Horned Frogs (Anura, Ceratophryidae)

Cited by 13 publications

References 45 publications

Differences in responsiveness and sensitivity to exogenous disruptors of the thyroid gland in three anuran species

Differences in responsiveness and sensitivity to exogenous disruptors of the thyroid gland in three anuran species

Histology and microscopic anatomy of the thyroid gland during the larval development of Pseudis platensis (Anura, Hylidae)

Embryonic ontogeny of three species of Horned Frogs, with a review of early development in Ceratophryidae

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