The cardiorespiratory system of miniature frogs.

Autor:	Carrasco-Medina AS; Departamento de Biologia Animal, Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Instituto de Biologia, Unicamp, Campinas, São Paulo, Brazil.; Pós-Graduação em Biologia Animal, Unicamp, Campinas, São Paulo, Brasil., Salla RF; Departamento de Biologia, Universidade Federal de São Carlos, Sorocaba, São Paulo, Brazil., Sebben A; Departamento de Ciências Fisiológicas, Instituto de Ciências Biológicas, Universidade de Brasília, Brasília, Federal District, Brazil., da Silva HR; Instituto de Ciências Biológicas e da Saúde, Universidade Federal Rural do Rio de Janeiro, Seropédica, Rio de Janeiro, Brazil., Passos FD; Pós-Graduação em Biologia Animal, Unicamp, Campinas, São Paulo, Brasil., Toledo LF; Departamento de Biologia Animal, Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Instituto de Biologia, Unicamp, Campinas, São Paulo, Brazil., Rebouças R; Departamento de Biologia Animal, Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Instituto de Biologia, Unicamp, Campinas, São Paulo, Brazil.; Pós-Graduação em Biologia Animal, Unicamp, Campinas, São Paulo, Brasil.
Jazyk:	angličtina
Zdroj:	Journal of anatomy [J Anat] 2024 Feb; Vol. 244 (2), pp. 232-248. Date of Electronic Publication: 2023 Oct 28.
DOI:	10.1111/joa.13965
Abstrakt:	Anurans of the genus Brachycephalus are among the smallest vertebrates in the world, due to an extreme process of miniaturization. As an example of this process, Brachycephalus species show loss of fingers, loss of the eardrum and middle ear, bone fusions, and the presence of paravertebral plates and parotic plaque. However, no studies addressing the consequences of miniaturization on internal organs, such as the lungs and heart, are currently available. Thus, this study aimed to investigate if overall small body size has affected the cardiorespiratory system. We investigated, via dissections, individuals of four Brachycephaloidea species: Brachycephalus rotenbergae, B. pitanga, Eleutherodactylus johnstonei, and Ischnocnema parva. We observed that B. rotenbergae and B. pitanga present a reduction of the atrial septum and absence of the carotid body. On the other hand, despite being a member of the sister genus to Brachycephalus (both genera belong to the Brachycephalidae), individuals of Ischnocnema present a heart with a complete septum and carotid body; this is also observed in E. johnstonei (Eleutherodactylidae). We observed that B. rotenbergae and B. pitanga have thin skin with a one to two cell thick germ layer, and their lungs likely exhibit lower blood supply when compared to individuals of the E. johnstonei and I. parva species. Based on the observed structures, we suggest that in species of Brachycephalus, respiration is performed mainly through the skin, and their lungs may have a reduced respiratory function. (© 2023 Anatomical Society.)
Databáze:	MEDLINE
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