Riek’s Crayfish Euastacus rieki (first breeding record)

Berried Euastacus reiki from Namadgi National Park, ACT
Berried Euastacus rieki from Namadgi National Park, ACT

The ACT Aquatic Team  from the ACT Government’s Conservation Planning and Research Unit sent me this photo of a berried Euastacus rieki and I just had to share it with you all. It’s the first female with eggs recorded and a tremendous leap towards filling the huge knowledge gaps on this cryptic species.

The Aquatic Team from the ACT Government’s Conservation Planning and Research Unit have been surveying subalpine bogs as well as creeks and rivers in the ACT to determine potential methods for a broader distribution survey of two species of spiny crayfish.

The current project is stage 1 to test methods for a program to determine the distribution and relative abundance of Euastacus crassus and Euastacus rieki. Despite being the type location for Euastacus rieki, very little is known on the distribution or habits of these two species in the ACT or elsewhere.

Among the more than 50 crayfish collected the team discovered two berried E. rieki (42 & 53mm OCL) with 100, 3.5mm orange eggs. Both crays were collected in a subalpine bog (approximately 1600m a.s.l) in Namadgi National Park.

This is the first breeding information regarding E. rieki and indicates that berried females remain active and are likely to hold their eggs over winter, despite the frequent snow cover and sub zero temperatures. Improved monitoring of alpine areas will be important in understanding potential impacts from climate change

The project was directed by ecologists from the Environment and Sustainable Development Directorate of the ACT Government. The work has been supported through ACT Government climate change funding.

Euastacus rieki from Yarrangobilly, NSW
Euastacus rieki from Yarrangobilly, NSW