Amphibian defence against predators and microorganisms is directly related to cutaneous glands that produce a huge number of different toxins. These glands are distributed throughout the body but can form accumulations in specific regions. When grouped in low numbers, poison glands form structures similar to warts, quite common in the dorsal skin of bufonids (toads). When accumulated in large numbers, the glands constitute protuberant structures known as macroglands, among which the parotoids are the most common ones. This work aimed at the morphological and biochemical characterization of the poison glands composing different glandular accumulations in four species of toads belonging to group Rhinella marina (R. icterica, R. marina, R. schneideri and R. jimi). These species constitute a good model since they possess other glandular accumulations together with the dorsal warts and the parotoids and inhabit environments with different degrees of water availability. We have observed that the toads skin has three types of poison glands that can be differentiated from each other through the morphology and the chemical content of their secretion product. The distribution of these different glands throughout the body is peculiar to each toad species, except for the parotoids and the other macroglands, which are composed of an exclusive gland type that is usually different from that composing the dorsal warts. Each type of poison gland presents histochemical and biochemical peculiarities, mainly regarding protein components. The distribution, morphology and chemical composition of the different types of poison glands, indicate that they may have different defensive functions in each toad species.

中文翻译：

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不同环境中蟾蜍（Rhinella marina 组）皮肤毒腺的形态和生化特征

两栖动物对捕食者和微生物的防御与产生大量不同毒素的皮肤腺体直接相关。这些腺体分布在全身，但可以在特定区域形成堆积。当数量较少时，毒腺会形成类似于疣的结构，在蟾蜍（蟾蜍）的背部皮肤中很常见。当大量积累时，腺体构成称为巨腺的突起结构，其中腮腺是最常见的。这项工作旨在研究属于 Rhinella marina 组 (R. icterica、R. marina、R. schneideri 和 R. jimi) 的四种蟾蜍中组成不同腺体积累的毒腺的形态和生化特征。这些物种构成了一个很好的模型，因为它们与背疣和腮腺炎一起拥有其他腺体积累，并且栖息在具有不同程度水可用性的环境中。我们观察到蟾蜍皮具有三种毒腺，可以通过其分泌产物的形态和化学成分相互区分。这些不同腺体在全身的分布是每种蟾蜍特有的，除了腮腺和其他大腺体，它们由一种独特的腺体类型组成，通常不同于构成背疣的腺体类型。每种毒腺都呈现出组织化学和生化特性，主要与蛋白质成分有关。分布，