The aim of this study was to estimate the allometric parameters of different parts of pirapitinga (Piaractus brachypomus), as well as to establish if the growth of these components is allometric or isometric. In total, 60 specimens collected at random from a farm in Arauca (Colombia) were used. Live weights, carcass weights and weights of scales, viscera and gills were determined. Three algorithms were tested to quantify the relationships between live body weight and each of the components: Ordinary Least Squares, Reduced Major Axis, and Major Axis. The data were logarithmically transformed in order to fit the equations to the allometric function y=10bxa, where y represents the body component in question and x is the independent associated variable. The three methods provided regression coefficients that are, from a theoretical point of view, different, thus providing different estimates...

The objective of the study was to describe and analyze the growth pattern of the domestic cat. A total of 68 cats (37 males and 31 females, with an age range of 1.4-84 and 1.5-84 months, respectively), of undefined racial composition, from the urban area of the municipality of Arauca, Colombia were studied. Age, body length, pelvic girth, skull perimeter, and fore and hind right limb lengths were recorded. Growth was determined for each sex with the logistic equation y=a/(1+be-cx). Results showed a similar growth pattern between sexes, except for hind limb length (p=0.033), which presented an initial accelerated growth with an ulterior asymptotic growth in females, but there were few changes in males. Final size was similar for both sexes. This study constitutes a first contribution to growth models in domestic cats.

El objetivo del estudio fue describir y analizar el patrón de crecimiento del gato doméstico. Se trabajó con 68 gatos (37 machos y 31 hembras, con rango de edades de 1.4-84 y 1.5-84 meses, respectivamente), de composición racial indefinida, del área urbana del municipio de Arauca, Colombia. Se registró la edad, longitud corporal, circunferencia pelviana, circunferencia del cráneo, longitud del miembro posterior y longitud del miembro anterior derecho. Se determinó el crecimiento para cada sexo con la expresión logística y=a/(1+be-cx). Los resultados mostraron un patrón de crecimiento similar en ambos sexos, excepto la del miembro posterior (p=0.033), que presentó un crecimiento acelerado inicial y un posterior crecimiento asintótico en las hembras, pero con poco cambio etario en los machos. La talla final fue similar para ambos sexos. Este trabajo proporciona una primera apr...

Geometric morphometry of 42 equine skulls from different domestic breeds was used. A digital photograph of the dorsal plane of each skull was obtained, on which were placed seven craniometric landmarks, involving both the neuro and the splanchnocranium. It is verified that the ontogenic process of domestic equids conforms to the CREA rule (Cranial Evolutionary Allometric), by which there is a common allometric pattern among taxa of mammals, by which the smaller species would have shorter faces and skulls wider than larger species. A dolichoprosopy correlated with dolichocephaly is accepted, or in other words, a facial hypermorphosis (since the facial width also has a behavior similar to that of the length of the face) parallel to the increase in the size of the head for domestic equids.

Se recurrió al estudio por morfometría geométrica de 42 cráneos de equinos de diversas razas domésticas. Se obtuvo una fotografía digital del plano dorsal de cada cráneo, sobre la que se situaron siete hitos craneométricos, que incluían puntos, tanto del neuro como del viscerocráneo. Se comprueba que el proceso ontogénico de los équidos domésticos se ajusta a la regla del CREA (“Cranial Evolutionary Allometric”), por la que existe un patrón alométrico común entre taxones de mamíferos, por el cual las especies más pequeñas presentarían caras más cortas y cráneos más anchos que las especies de mayor tamaño. Se acepta una dolicoprosopia correlacionada con la dolicocefalia, o dicho de otro modo, una hipermorfo¬sis facial (puesto que la anchura facial también tiene un comportamiento similar al de la longitud de la cara) paralela al aumento del tamaño de la cabez...