Australian Aquatic Biological

Australian aquatic biodiversity research and consultancy

Central Highlands Burrowing Cray Engaeus affinis (Smith & Schuster 1913)

Engaeus affinis from a communal burrow, Healesville, Vic

Engaeus affinis from a communal burrow, Healesville, Vic

This species is endemic to Victoria with a relatively small distribution known at this time (estimated extent of occurrence of approximately 200 km2). Found in the upper Yarra, Acheron, Yea and Big Rivers. An area roughly from Kinglake to Eildon to Jamieson to Noojee to Hoddles Creek. Central Highlands Burrowing Cray Engaeus affinis has been assessed on the IUCN Red List as Data Deficient. 

Engaeus affinis, Healesville, Vic

Engaeus affinis, Healesville, Vic

It’s a robust species and at many sites relatively abundant. Typically, it’s a communal burrower, both type 2 & 3 burrows with multiple surface entrances (20 or so) over a square metre. Both fans shaped entrances and chimneys. Surface openings descend into large central burrows. Central burrows are relatively large in diameter (150 to 200 mm), typically water filled and tending horizontal and descending and converging into a larger chamber.

Engaeus affinis, Badger Creek, Vic

Engaeus affinis, Badger Creek, Vic

Typically, the easiest way to capture is to excavate down to the water level, usually from 200 to 600 mm deep. Once water is found, wait, (patience required), larger males will come to investigate the disturbance and you can grab them, otherwise, every 5 minutes or so, shove your hand down the burrow and feel around in the water. If you are lucky and have good feeling in your fingers you should be able to grab one every 5-10 minutes. That’s the way we collected the specimens for this article.

Burrow entrance, Badger Creek, Vic

Burrow entrance, Badger Creek, Vic

Those from Healesville were in a yellow clay on the slope beside a creek approximately 1.2 metres above the creek water height (7 metres from creek bank) but had water at 650 mm in the burrow system. Those from Badger Creek were in a fine silty material in a seepage area in the tree fern forest with water only 100 mm below ground level and over 100 m from Badger Creek.

Engaeus affinis, Badger Creek, Vic

Engaeus affinis, Badger Creek, Vic

Happy Yabbying

Cheers

Rob

Robert McCormack is the Research and Aquaculture Director for Australian Aquatic Biological P/L. He is a Research Associate with the Carnegie Museum in Pittsburgh, USA, is Secretary of the NSW Aquaculture Association Inc. and the team leader of the privately funded Australian Crayfish Project, which conducts biological studies of every creek and stream in Australia, collecting and identifying crustaceans. Robert has a passion for freshwater crayfish traveling across Australia to find and photograph them.

LinkedIn 

You can follow any responses to this entry through the RSS feed. You can leave a response, or trackback from your own site.

Tagged , ,

Leave a reply

Your email address will not be published. Required fields are marked *

*

13 + one =