Morfologia e biometria do timo em araras dos gêneros Ara e Anodorhynchus

Abstract

RESUMOForam utilizados 12 exemplares de Ara ararauna -seis fêmeas e seis machos -, cinco exemplares de Ara chloropterus (uma fêmea e quatro machos) e dois exemplares de Anodorhynchus hyacinthinus -uma fêmea e um macho -, todos adultos, doados por criadouro particular, após óbito natural. Os lobos foram dissecados e medidos com paquímetro -comprimento x largura x espessura -e analisados quanto ao peso, à topografia e à morfologia individual. Independentemente do gênero, foram identificados, em 17 casos (89,5%), lobos tímicos nos antímeros cervicais esquerdo e direito, e em oito casos (42,1%), lobos na cavidade celomática. Os lobos apresentaram formatos alongados -52,6% -, arredondados -21,1% -ou ovalados -15,8% -, posicionados preferencialmente ventromedialmente ao longo do plexo vasculoneural do pescoço, com número médio de cinco lobos por antímero, tamanho médio de 0,49cm de comprimento, 0,12cm de largura e 0,05cm de espessura e peso médio de 0,076g. Palavras-chave: araras, anatomia comparada, aves silvestres, morfologia do timo ABSTRACT

Morphology and biometry of the thymus in Gallus gallus domesticus (Linnaeus, 1758) from the isa brow lineage

“…We emphasize here the findings of Pereira et al (2016) stating that young ostriches have clearly individual thymic lobes. The number of lobes, which in this study ranged from 3 or 4 in the right antimere and 3 to 5 in the left, should be considered as a reduced number and similar to those reported by Birck et al (2008) in birds of the Cobb 500 strain, Resende et al (2012), in mussels, Lima et al (2013) in macaws, and Santana; Netto; Silva. (2004) in the curassow, in which the authors found 3 to 5 lobes, 2 to 5, 5, and 6 lobes per antimere, respectively.…”

“…However, it should be noted that the number of lobes found by Santana et al (2007) for Angolan hens reached 22; therefore, they have a larger number of smaller lobes whereas in the birds of the Isa Brow line, there are fewer lobes (from 3 to 5) with larger dimensions. Lima et al (2013) described the thymus of macaws and in terms of body mass, results from that study justify the reduced dimensions found. Pereira et al (2016) studied ostrich pups, and because of their large size, those results corroborate the similarities in measurements found between that study and birds in the current study, which were adults.…”

“…For animals that presented 5 lobes, the measurements were: 0.75 x 0.41 x 0.35 cm for the cranial lobe; 1.40 x 0.73 x 0.43 cm for the middle cranial lobe; 1.86 x 0.61 x 0.43 cm for the middle lobe; 2.32 x 0.65 x 0.55 cm for the middle caudal lobe; 3.74 x 1.29 x 1.03 cm for the caudal lobe. Schwarze;Schröder (1972), Nickel;Schummer;Seiferle (1977), Kendall (1980), Getty (1986), Baumel (1993), Santana et al (2000Santana et al ( , 2001Santana et al ( , 2004Santana et al ( , 2007Santana et al ( , 2008, Silva et al (2001), Lima et al (2004Lima et al ( , 2009Lima et al ( , 2013, Pereira et al (2008), Birck et al (2008), Miranda et al (2008), Arantes et al (2011), Resende et al (2012 and Vianna et al (2012) are unanimous in describing the chains of thymic lobes occupying the distal third of the ventrolateral region of the neck, forming a chain of lobes that are arranged in a linear and parallel fashion, corroborating the holotopia of the thymus of the animals analyzed in this study. Regarding the location of the thymus, Santana et al (2001) and Lima et al (2009;2013) reported the presence of thymic lobes within the thoracoabdominal cavity, which did not occur in this study.…”

“…Morphometric data for the thymus were described by Santana et al (2007), Lima et al (2013) and Pereira et al (2016). The former dealt only with length and width and the latter two, as in this research, took measurements of length, width and thickness.…”

“…Vianna et al (2012), investigating 28 Gallus gallus domesticus of the Red Bro Cou Nu line, described two to 11 thymic lobes in the right antimere, with eight lobes being most common, and one to eight thymic lobes in the left antimere with five lobes being most common. Lima et al (2013) analyzing 19 specimens of macaws of three different genera, 12 Ara arauna, 5 Ara chloropterus and 2 Anodorhynchus hyacinthinus, found no cervical lobes in two cases (10.5%) and no coelomic lobes in 11 (57.9%). In all specimens and irrespective of the location found, the lobes presented elongated (52.6% of cases), rounded (21.1%) and oval (15.8%) forms.…”