Hematological and biochemical blood values in wild populations of black howler monkeys (Alouatta pigra) of Campeche, México.

BACKGROUND: The clinical analyses of free-ranging New World primates are extremely limited. The aim of this study was to obtain baseline data of blood chemistry and hematological values of free-ranging Alouatta pigra. METHOD: 17 males and 17 females were captured. We collected blood from the caudal tail vein; conventional techniques were used to analyze the samples RESULTS: Hemoglobin, hematocrit, and erythrocytes were significantly higher in males than in females. In relation to biochemical blood values, albumin/globulin ratio, cholesterol, triglycerides, calcium, phosphorus, magnesium, and iron were significantly higher in males than in females, while creatinine was significantly higher in females than in males. CONCLUSIONS: In general, measured parameters are similar to those of other primates and will be used as reference values for futures studies.

Variation in the Extraction Efficiency of Estradiol and Progesterone in Moist and Lyophilized Feces of the Black Howler Monkey (Alouatta pigra): Alternative Methods.

Several fecal steroid extraction techniques have been developed to measure the ovary function in different species of mammals. However, regardless of the method of extraction and the sample type chosen, it has been observed that they can yield results with different percentages of recuperation. The objective of this study was to determine whether the type of substratum, solvent and extraction method used have any influence on the extraction efficiency in the feces of Alouatta pigra (black howler monkey). For this purpose we used two methods: agitation and ebullition. With each method, we utilized moist and lyophilized feces. The validation of radioimmunoassay method was accurate and precise for quantify estradiol and progesterone in lyophilized feces of A. pigra. To both of which ethanol and methanol, absolute and at 80%, were added, besides the hormones (125)I-Estradiol and (125)I-Progesterone. The extraction efficiency for (125)I-Estradiol was from 87.72 ± 3.97 to 41.24 ± 2.67%, and for (125)I-Progesterone from 71.15 ± 4.24 to 42.30 ± 1.19% when we used the agitation method. Whereas with the ebullition method, the extraction efficiency for (125)I-Estradiol ranged from 86.89 ± 2.66 to 71.68 ± 3.02% and for (125)I-Progesterone from 98.31 ± 1.26 to 85.40 ± 1.98%. Due to the differences found in these assays, which depend on the method used, the type of feces employed and the type of solvent added to them, we recommend the ebullition method and the lyophilized feces of A. pigra for extracting the hormones, since in moist feces there may exist variables which might interfere in the quantification of (125)I-Estradiol and (125)I-Progesterone.

Blood parameters are little affected by time of sampling after the application of ketamine in black howler monkeys (Alouatta pigra).

BACKGROUND: Ketamine hydrochloride is an anesthetic commonly utilized to obtain biological samples in various non-human primates. Its application alters individual hematologic and biochemical values. The aim of this study was to analyze its effect on blood parameters of Alouatta pigra. METHOD: We collected blood samples at 10 and 40 minutes after the application of ketamine in 12 adult female A. pigra living in free-ranging conditions. RESULTS: The analysis showed that 40 minutes after application of ketamine, the number of platelets, lymphocytes and concentration of phosphorus decreased; however, creatinine, cholesterol, triglycerides, and potassium values increased. CONCLUSIONS: Our results suggest that ketamine appears to have little effect on the hematology and blood biochemistry of Alouatta pigra females with respect to those reported for other non-human primates. It is also important to consider the elapsed time after their application when taking blood samples for proper interpretation of the hemogram of Alouatta pigra females.

The karyotype of Alouattapigra (Primates: Platyrrhini): mitotic and meiotic analyses.

We describe for the first time the karyotype of the black howler monkey, Alouatta pigra. Conventional staining, G- and C-banding, and fluorescence in situ hybridization (FISH) with a peptide nucleic acid (PNA) pantelomeric probe were performed. Eight free ranging adult individuals, four males and four females, within the natural distribution of the species presented a diploid karyotype with 2n = 58. Mitotic analyses showed an autosomal complement composed of 6 submetacentric, 3 metacentric, and 19 acrocentric chromosome pairs for females, and 6 submetacentric, 3 metacentric, and 18 acrocentric pairs for males. Meiotic analyses in males revealed 27 autosomal bivalents and a quadrivalent composed of a submetacentric X(1) and acrocentric X(2), Y(1), and Y(2). The G-banded karyotype allowed us to identify pair #17 as the autosomal pair involved in the rearrangement and the morphology of the quadrivalent components. C-banding technique in metaphase I corroborated the structure of the quadrivalent showing four C+ centromeres. FISH analysis showed telomeric signals at the terminal regions of all chromosomes. No interstitial signals were detected. DNA sequence data were in accordance with those previously published for this species.