Captive breeding of Crocodylus intermedius (Graves, 1819) under different stocking densities

Abstract

Crocodylus intermedius is restricted to the Orinoco River basins in Colombia and Venezuela. It is also one of the most endangered New World crocodilians. To determine the optimal density of individuals and the number of refuges to improve the rearing conditions of C. intermedius this study used 228 captive-reared crocodiles that were split in three individual densities and housed in concrete tanks. They were fed five days per week and measured at one, six, and eleven months of age. These data were used to calculate body condition index (BCI), weight, and length gain of each individual. Our results indicated that animals of groups group B (1.82 m2/individuals) were longer than animals of groups A (0.71 m2/individuals) and C (0.54 m2/individuals). While animals of groups A and C were less heavy than animals of group B, indicating that the density of C. intermedius is inversely correlated with their growth like in other crocodilian species. Whit respect to the BCI, group B had greater BCI than group A and C. This confirms the Orinoco crocodiles have a better development at relatively low densities. Through to the BCI we can be conclude that adding a second refuge only beneficial at “low” densities (associated with higher food conversion rates), whereas at “high” densities adverse effects on weight and length gain. To C. intermedius use of a second refuge and select a density that let rearing a major number of individuals and promoting a fast growth rate is beneficial for both conservation and commercial perspectives.