Eat and be eaten: reciprocal predation between axolotls (Ambystoma mexicanum) and crayfish (Cambarellus montezumae) as they grow in size

Abstract

Information about predator–prey relationships in aquatic systems can be helpful to improve the conservation management of endangered species. Restoration efforts for the endangered axolotl (Ambystoma mexicanum) involve the creation of refuges to increase the occurrence of suitable conditions for native species. Little is known about the predator–prey interaction between the axolotl and the native crayfish (Cambarellus montezumae) that also inhabits the refuges. To understand this interaction, we designed a set of experimental arenas and investigated both species at various life stages. Our findings suggest a switch in the predator–prey relationship between crayfish and axolotls at lengths between 2.6 and 3.5 cm. Individuals of both species below this size-range serve as prey, whereas larger individuals become predators. The 66.7% of crayfish that were preyed upon by axolotls were of intermediate size, whereas adult crayfish primarily consumed newly hatched axolotls (70%). We discuss the implications of this native species interaction with respect to their habitat conservation.

Keywords:

• Xochimilco
• crayfish
• restoration
• feeding
• salamander