Morphology of the syrinx of three species of birds from Brazilian cerrado (Psittacara leucophthalmus, Rhynchotus rufescens and Cariama cristata): Gross anatomy and light microscopy study.

The aim of this study was to describe the morphology of the trachea and syrinx at macroscopic and light microscopy levels of three species of birds from different orders that inhabit the Brazilian cerrado. For that, five adult specimens (three males and two females of each species) of white-eyed parakeet (Psittacara leucophthalmus), red-winged tinamou (Rhynchotus rufescens) and red-legged seriema (Cariama cristata) were used. The trachea and syrinx of the birds were collected and destined for anatomical and histological studies. The trachea of the studied birds presented an elongated path and originated in the larynx and extended caudally to the syrinx. No sexual dimorphism was observed in the syrinx of the studied species, probably because it is associated with their song, which is very similar between males and females of these species. The findings of this study allowed us to classify the syrinx as tracheal in the white-eyed parakeet and tracheobronchial in the red-winged tinamou and red-legged seriema. In general, the morphological features of the trachea and syrinx were similar to those described for other species of birds, such as the presence of intrinsic and extrinsic syringeal muscles, and the lateral and medial tympaniform membranes, which would represent important anatomical structures in sound production through vibration during expiration and eventual inspiration. The morphological structure of the syrinx in the three avian species of the Brazilian cerrado is consistent with the ability of these avian species to perform a potential vocalization, especially the red-legged seriema that emits characteristic sounds very loud and can carry several kilometres.

Cytometric blood phenotyping in free-living white-eyed parakeet (Psittacara leucophthalmus)

ABSTRACT: This study aimed at performing cytometric phenotyping of the blood samples from free-living, young white-eyed parakeets (Psittacara leucophthalmus), stained with 3,3-dihexyloxacarbocyanine [DiOC6(3)]. DiOC6(3)-stained whole blood samples from 19 free-living, young white-eyed parakeets were analyzed by flow cytometry and cell types were distinguished by their typical fluorescence in blue laser channel (FL-1) and SSC (side scatter). It was possible to differentiate erythrocytes (58.3±13.6) from leukocytes (32.4±13.1) and some of the leucocyte subpopulations: lymphocytes/thrombocytes (29.7±7.7), monocytes (30.6±8.5), and granulocytes (5.9-26). However, lymphocytes and thrombocytes could not be sorted in the plots. Our study determined that the predominant population in white-eyed parakeet (P. leucophthalmus) was lymphocytes, thrombocytes, and monocytes in the leucocytes gates in comparison to the granulocyte population. The cytometry method and use of DiOC6(3) stain was available for parakeets blood samples and can be studied and applied to other species of parrots.

RESUMO: Este estudo teve como objetivo realizar a fenotipagem citométrica com 3,3-di-hexiloxacarbocianina [DiOC6 (3)] de amostras de sangue de maritacas jovens de vida-livre (Psittacara leucophthalmus). As amostras de sangue total, coradas com DiOC6(3) de 19 maritacas de vida livre, foram analisadas por citometria de fluxo e os tipos de células foram distinguidos por sua fluorescência típica no canal laser azul (FL-1) e SSC (dispersão lateral). Foi possível diferenciar eritrócitos (58,3±13,6) de leucócitos (32,4±13,1) e algumas subpopulações de leucócitos: linfócitos/trombócitos (29,7±7,7), monócitos (30,6±8,5) e granulócitos (5,9-26), entretanto, linfócitos e trombócitos não puderam ser diferenciados em duas populações distintas. Nosso estudo determinou que a população predominante P. leucophthalmus foi mononuclear agranulocítica em comparação com a taxa de aquisição da população granulocítica. A metodologia de citometria de fluxo com uso da coloração de DiOC6(3) foi aplicável a amostras sanguíneas das maritacas e pode ser estudado e aplicado para outras espécies de psitacídeos.

Cytometric blood phenotyping in free-living white-eyed parakeet (Psittacara leucophthalmus) / Fenotipagem citométrica do sangue de maritacas jovens de vida-livre (Psittacara leucophthalmus)

This study aimed at performing cytometric phenotyping of the blood samples from free-living, young white-eyed parakeets (Psittacara leucophthalmus), stained with 3,3-dihexyloxacarbocyanine [DiOC6(3)]. DiOC6(3)-stained whole blood samples from 19 free-living, young white-eyed parakeets were analyzed by flow cytometry and cell types were distinguished by their typical fluorescence in blue laser channel (FL-1) and SSC (side scatter). It was possible to differentiate erythrocytes (58.3±13.6) from leukocytes (32.4±13.1) and some of the leucocyte subpopulations: lymphocytes/thrombocytes (29.7±7.7), monocytes (30.6±8.5), and granulocytes (5.9-26). However, lymphocytes and thrombocytes could not be sorted in the plots. Our study determined that the predominant population in white-eyed parakeet (P. leucophthalmus) was lymphocytes, thrombocytes, and monocytes in the leucocytes gates in comparison to the granulocyte population. The cytometry method and use of DiOC6(3) stain was available for parakeets blood samples and can be studied and applied to other species of parrots.(AU)

Este estudo teve como objetivo realizar a fenotipagem citométrica com 3,3-di-hexiloxacarbocianina [DiOC6 (3)] de amostras de sangue de maritacas jovens de vida-livre (Psittacara leucophthalmus). As amostras de sangue total, coradas com DiOC6(3) de 19 maritacas de vida livre, foram analisadas por citometria de fluxo e os tipos de células foram distinguidos por sua fluorescência típica no canal laser azul (FL-1) e SSC (dispersão lateral). Foi possível diferenciar eritrócitos (58,3±13,6) de leucócitos (32,4±13,1) e algumas subpopulações de leucócitos: linfócitos/trombócitos (29,7±7,7), monócitos (30,6±8,5) e granulócitos (5,9-26), entretanto, linfócitos e trombócitos não puderam ser diferenciados em duas populações distintas. Nosso estudo determinou que a população predominante P. leucophthalmus foi mononuclear agranulocítica em comparação com a taxa de aquisição da população granulocítica. A metodologia de citometria de fluxo com uso da coloração de DiOC6(3) foi aplicável a amostras sanguíneas das maritacas e pode ser estudado e aplicado para outras espécies de psitacídeos.(AU)

Complete mitochondrial genome of white-eyed parakeet (Psittacara leucophthalmus): the basal species to other Psittacara.

Recently resurrected Psittacara genus is one of the 19 recognized in parrot tribe Arini. The status of taxa within Psittacara remains controversial because some forms are treated as species or subspecies depending on authorities. Evolutionary history of Psittacara is also unclear because related phylogenetic clades contain taxa from distant and non-overlapping regions. However, the basal placement of Psittacara leucophthalmus with wide South American distribution suggests that other taxa with restricted range could emerge by a local split of larger population. We sequenced P. leucophthalmus mitogenome to increase the set of sequences required to determine taxonomic level and phylogeny of Psittacara taxa.