Engaeus affinis is known from central north-eastern Victoria. (VIC)Features:
As with other burrowing crayfish, the cephalothorax (head/middle section) is large in comparison to the abdomen (tail section). The claws are large, and the movable finger moves up and down in the vertical plane. The body is smooth and orange-brown in colour. The large claws are orange with black-brown fingers.Ecology/Way of Life:
Engaeus affinis feed mostly on plant roots and other plant matter. The reproductive cycle is not known, but they probably mate in spring or summer. Females carry eggs beneath the abdomen until they hatch. The juveniles remain in the burrow with the adults and may not disperse very far. Crayfish burrow in habitats ranging from the margins of rocky creeks to flood plains or clayey hillsides. Burrows in flood-plains reach down to the water table and generally do not have large chambers or additional burrow openings for juveniles. The burrow descends to between 0.5 and 1 m, turns horizontally and then descends again. In contrast, burrows in hillsides do not reach the water table, and any water in the burrow comes from rain and runoff. In such burrows, several openings for juveniles are usually present. The tunnels from each of the surface burrow openings converge underground and lead to a single large chamber which may be up to 0.5 m in diameter.Interaction with Humans/Threats:
Engaeus fossor lives in a variety of habitats over a relatively large geographic area, therefore is not presently considered under threat. The major threat to Engaeus fossor is habitat loss or reduction, such as forest clearing, and land reclamation.Other Comments:
Engaeus affinis was named by Smith & Schuster in 1913.Further Reading:
Horwitz, P. (1990). A taxonomic revision of species in the freshwater crayfish genus Engaeus Erichson (Decapoda: Parastacidae). Invertebrate Taxonomy 4(3): 427–614.
Jones, D. S. & G. J. Morgan. (1994). A Field Guide to Crustaceans of Australian Waters. Reed Books, Sydney.
Text and map by Shane Ahyong. Photograph by Patrick JohnsonSponsorship welcomed:
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