Comparative analysis of the integument of different tree frog species from Ololygon and Scinax genera (Anura: Hylidae)

Abstract

ABSTRACT. The integuments of ten treefrog species of two genera from Scinaxnae -O. angrensis (Lutz, 1973), O. flavoguttata (Lutz & Lutz, 1939), O. humilis (Lutz & Lutz, 1954), O. perpusilla (Lutz & Lutz, 1939), O. v-signata (Lutz, 1968, Scinax hayii (Barbour, 1909), S. similis (Cochran, 1952), O. trapicheroi (Lutz & Lutz, 1954) and S. x-signatus (Spix, 1824) -were investigated using conventional and histochemical techniques of light microscopy, and polarized light microscopy. All integuments showed the basic structure of the anuran integument. Moreover, the secretory portions of exocrine glands, such as serous merocrine and apocrine glands, were found to be restricted to the spongious dermis. Lipid content occurred together with the heterogeneous secretory material of the glands with an apocrine secretion mechanism. In addition, clusters of these apocrine glands were present in the ventrolateral integument of some species. Melanophores were also visualized in all examined hylids. However, the occurrence of iridophores, detected through polarized light microscopy, varied according to the species. The Eberth-Katschenko layer occurred in the dorsal integument from both genera, but it was only present in the ventral integument of O. albicans, O. angrensis, O. flavoguttata, O. perpusilla and O. v-signata. Although the integument of all treefrogs showed the same basic structure, some characteristics were genus-specific; however, these features alone may not be used to distinguish both genera.

Do host habitat use and cospeciation matter in the evolution ofOswaldocruzia(Nematoda, Molineidae) from neotropical amphibians?

“…Euclydes et al (2021) studied the nematode diversity of parasite communities of Atlantic species of anurans and found a positive correlation of habitat use with the variability in the parasite species composition and their functional diversity. They suggested that the higher functional diversity of parasite communities in terrestrial hosts may be related to the fact that nematodes are the main components of helminth diversity in amphibians and they are transmitted directly through contact with the soil, as pointed out by several studies (Campião et al , 2014; Hamann & González, 2015; da Silva et al , 2017; Gómez et al , 2020). Additionally, although the life cycle of most species of Oswaldocruzia remains unstudied, some works have demonstrated that the life cycles of some species are direct and well known (Anderson et al , 2000), and the greater vagility of terrestrial amphibians compared to arboreal species increases the possibility of contact with a higher diversity of parasites, as pointed out by Poulin (2007).…”

The sexual dimorphic inguinal glands of the frog species Ololygon centralis (Anura: Hylidae) at light and transmission electron microscopy

“…Sacale bars: 14, 15 = 1 μm, 12, 13 = 3 μm, 11 = 5 μm. 16 17 Felsemburgh et al 2007, 2009, Rigolo et al 2008, Gonçalves and Brito-Gitirana 2008, Jared et al 2009, Silva et al 2017). An exception is Odontophrynus americanus Duméril & Bibron, 1841, which has typical mucous and granular glands, but also a third tubule-alveolar gland with the same morphological and histochemical characteristics as observed in O. centralis (Felsemburgh et al 2007).…”

“…These glands, however, are spread throughout the body instead of being concentrated in a specific region (Felsemburgh et al 2007). One species of Scinax (S. hayii) and two species of Ololygon (O. agrensis, O. flavoguttata) have serous skin glands with cell fragments interspaced by colloidal material in the "lumen" (Silva et al 2017). These glands, however, are also not organized as macroglands.…”

“…The skin glands of at least 12 species of the related genera Scinax Wagler, 1830 and Ololygon Fitzinger, 1843 were investigated (Terreni et al 2002, Silva et al 2017. All these species have both mucous and granular glands distributed in their skin.…”

“…All these species have both mucous and granular glands distributed in their skin. Only four of these species have clusters of granular glands: O. angrensis Lutz, 1973, O. flavoguttata Lutz & Lutz, 1939, O. albicans Bokermann, 1967and S. hayii Barbour, 1909(Silva et al 2017) -but with no skin protuberances typical of macroglands.…”