Análisis multivariado de los cambios hemáticos y morfométricos de Caiman latirostris y Caiman yacare según especie, sexo y estación del año

Abstract

To optimize breeding systems of captive caymans it is necessary to find diets able to accelerate their growth. The increases of weight, corporal dimensions and blood nutritional indicators are useful to evaluate the efficiency of a diet. The objective of this assay was to obtain reference values and physiological variations of these parameters in Caiman latirostris and Caiman yacare juvenile specimens. In a hatchery from Northeast Argentine, 207 caymans (50% each species and sex), fed ad libitum with meat flour and balanced pellets (47 and 37% of protein respectively), were studied. Weighing and determination of five corporal dimensions and thirty nine blood analytes were carried out in each season, during one year. Results were processed by means of multivariate analysis of the variance (MANOVA). Significant differences between species and seasons were found (p<0.05), but not between sexes. On average, albumin, glucose, calcium, magnesium, potassium, hemoglobin, MCH, MCHC, MCV, GGT, total longitude, muzzle-tail longitude, head wide, thoracic perimeter and liveweight were higher in C. latirostris. On the other hand, total proteins, globulins, uric acid, total cholesterol, triglycerides, LDL-C, sodium, copper, hematocrit, erythrocytes, leukocytes, CPK, ALP, AST, CHE, LDH and head longitude were higher in C. yacare. Nutritional indicators revealed higher values in summer, circumstance that may be attributed to the cease of feeding during the caiman winter lethargy. The absence of intersexual variations should be interpreted considering that studied animals were young specimens with no manifestation of reproductive behavior. In conclusion, reference values for sub-adult category specimens of captive C. latirostris and C. yacare, are reported. Liveweight, morphometrical sizes, and biochemical values varied according to species and season of the year. Data gathered in this assay may be used to improve breeding systems of autochthonous caimans).