Lowland Burrowing Crayfish Engaeus quadrimanus
Also known as “The Mernda Land Yabby” Engaeus quadrimanus (Clark 1936) is a relatively widespread and locally abundant species. It’s a lowland species generally found under 250 m a.s.l. from just north of Melbourne, east along the Victorian coast to just before the NSW border. Engaeus quadrimanus has been assessed as Least Concern on the IUCN Red List.
This specimen is from the west of the range. Collected from the bank of Fish Creek a tributary of the Tarwin River crossing Meeniyan-Promontory Rd, Fish Creek, Victoria.
A very robust and adaptable species that usually has large colonies with the area being riddled with burrows. Typically, burrows are round to oval in shape and open with excavated material at the entrance (see photo). In some areas they can create a pelleted chimney but for many areas it’s just an open hole in the ground as the excavated material has been washed away with flood waters. Burrows are type 2 and relatively basic with only 2-3 surface entrances descending to a horizontal corridor then a deeper burrow to water table. Typically most of the burrow system is flooded and typically they are individual burrows with both males and females having their own burrows. One of the keys to the species is that they are intersexed so hard to determine which are males and which females. Breeding season is autumn and they can be found sharing burrows together then. The species is extremely active during flood events and uses the creeks to migrate and find mates, etc.
For a similar article on this species and images from populations further east, go to: http://www.austcray.com/2015/09/engaeus-quadrimanus-from-cann-river-victoria/