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RESUMO: Este estudo objetivou avaliar a biometria corporal e o perfil hematológico de Trachemys scripta elegans (N=28) e de Trachemys dorbignyi (N=22) criadas em cativeiro na região do submédio do Vale do São Francisco, semiárido nordestino brasileiro, visando estabelecer valores sanguíneos básicos de saúde e gerar dados úteis na fisiologia comparativa de Testudines. Após 120 dias de adaptação e jejum de 24 horas, 2,5 mL de sangue foram coletados do seio occipital dorsal e depositados em tubo com heparina sódica para a avaliação, na sequência, dos níveis hematologicos. A contagem total de eritrócitos (CTE) e global de leucócitos (CGL) foi realizada em câmara de Neubauer; a dosagem de hemoglobina (HGB) pelo método da método da cianometahemoglobina e o hematócrito (HCT) através da técnica do microhematócrito. A partir da CTE estabeleceram-se matematicamente os índices hematimétricos. A biometria corporal também foi avaliada: a) massa corporal (MC, g); b) dimensões máximas da carapaça [comprimento (CMC, cm) e largura (LMC, cm)];c) dimensões máximas do plastrão [comprimento (CMP, cm) e largura (LMP, cm)]; d) comprimento total da cauda (CTC, cm); e) comprimento linear da base da cauda ao orifício cloacal (CprC, cm); f) comprimento linear do orifício cloacal a extremidade da cauda(CpoC, cm). T. scripta elegans apresentaram valores maiores (P < 0,05) para a biometria corporal, enquanto que o CTC e CprC foram maiores (P0,05) entre as espécies. Os resultados demostram que a maior parte da variação observada entre T. scripta elegans e T. dorbignyi é explicada pelas variáveis biométricas e que algumas correlações hematológicas caracterizam diferenças interespecíficas. Conclui-se que os resultados lançam luz sobre valores de referência para estas espécies mantidas em cativeiro na região do semiárido e servem como um modelo para a fisiologia comparativa intra e interespécies.

ABSTRACT: Although Trachemys scripta elegans is an exotic species popular as a pet in Brazil, studies on reproductive biology and capacity are non-existent in the Brazilian Cerrado. This study analyzed ovarian and oviduct characteristics and the egg production capacity of T. scripta elegans grown in this biome. The findings will associate with the size of the specimens and the sexual maturity, aiming at comparisons with native and exotic populations, as well as interspecific and contributing to the understanding of its impact on the invaded ecosystems and the establishment of eradication programs. Thus, 39 females had evaluated the body biometry and the morphology and morphometry of the ovaries and oviducts. G2 (N=20): with Class I (>5-10mm) follicles, with Class I and Class II (>10-fold) follicles, 25mm) and G3 (N=9) with Class I, Class II and Class III (>25mm) follicles. Analysis of variance, Scott-Knott’s test, and Pearson’s correlation analysis showed that there was no significant difference between the groups in body biometry; in the mean gonadosomatic index and gonadal morphometry, only the width of the oviducts in the right antimer and the mass and width in the left antimer were higher in G3, the only one that presented eggs. There was positive and harmonic development between body mass, carapace, and plastron, and gonadal growth occurred concomitantly with body growth, indicating a higher reproductive potential and a positive relationship between the size of the litter and the female litter. The gonadosomatic index proved to be an excellent reproductive indicator, and the ovarian evaluation was a better indicator of sexual maturity than the maximum carapace length. Ovaries were irregular structures, without delimitation between the cortical and medullary regions and filled with vitelogenic follicles of different diameters, atresic follicles, and corpora lutea, which reflected the ovarian complexity of the species and the presence of follicular hierarchy. In the scarce stroma, two germinative beds were observed per ovary and the presence of gaps very close to the follicles and associated with the blood vessels. Analysis of gonadal tissue revealed three types of oocytes according to cytoplasmic characteristics: homogeneous, vesicular or vesicular in the cortex with apparent granules. Oviducts were functional and separated, joining only in the final portion to form the cloaca and subdivided into infundibulum, tuba, isthmus, uterus, and vagina. The structure of the uterine tube was composed of serosa, muscular and mucous, which was full of glands. The presence of eggs in the oviducts indicated that the specimens can reproduce in the Brazilian Cerrado. This study provides necessary and relevant information on the reproductive biology and capacity of T. scripta elegans in the Brazilian Cerrado and can contribute to the understanding of its impact on the invaded ecosystems and the establishment of eradication programs. The extraction of females with capacity can reduce the annual reproductive yield of the species and decrease its effect on local biodiversity.