Babies, babies, babies – Releasing juvenile Murray Crayfish into SA!
Have you ever seen a baby Murray Crayfish? One of the cutest (and feistiest) little animals around. With some great news for South Australia’s River Murray – for the first time ever, 250 baby Murray Crayfish have been released into the river, marking a huge milestone for conservation in SA. You may have read that this species of crayfish is the second largest in the world and had become extinct in the southern reaches of the Murray River, until we released adult crayfish back into the wild recently. We have been tracking their progress, and with two successful adult releases undertaken, we’ve now returned 250 juveniles back to the wild in SA.
These little guys have had quite the journey. They started their life in a hatchery facility (their own little nursery) at Nature Glenelg Trust in Victor Harbor. As eggs, they were carefully carried under their mums’ abdomens for about two months. Even after hatching, they weren’t quite ready to go solo, clinging to their mums’ swimmerets (kind of like built-in baby carriers) for a couple of months while she fanned them to provide oxygen. Eventually, she decided it was time to channel her inner Taylor Swift and ‘shake them off,’ sending them out into the world to survive on their own.
In the wild, baby Murray Crayfish don’t have it easy – many don’t make it past the early stages, mainly due to predators. That’s why the team at Nature Glenelg Trust and the Murraylands and Riverland Landscape Board stepped in to give them a better chance. Nature is all about survival of the fittest, especially for Murray Crayfish, who are competitive to the point of eating each other. To prevent this, this group of baby crayfish was raised in aquariums with habitat features where they could hide, preventing fighting. Thanks to this labour intensive and careful approach, the team successfully nurtured the baby crays to their five-month milestone – way beyond what most would achieve in the wild.
Raising 250 baby crays wasn’t an easy task – it really does take a village! These little ones needed care 7 days a week, with twice-daily feedings of protein balls, bloodworms, wood, plants, and organic vegetables. Their aquariums needed weekly water changes, probiotics to keep them healthy and regular measuring and grading to check their growth. They even had some music played to them because who doesn’t love a bit of background music?
To give them the best chance of survival, the team trialled different setups – some crays were raised in aquariums with high-density habitat, some in separate containers, and others in large outdoor tubs – all to determine the ideal conditions for the highest survival rate.
The good news? All methods worked well, and survival rates were high with all scenarios. So, it was finally time to send the babies off into the big wild world, marking a huge step in bringing Murray Crayfish back to SA’s waters. Hopefully, they will grow, thrive, and start a whole new generation of crayfish in the future.
This initiative is a partnership between Nature Glenelg Trust, and the Murraylands and Riverland Landscape Board through funding from the landscape levies and the Landscape Priorities Fund, with support from New South Wales Department of Primary Industries, and the River Murray and Mallee Aboriginal Corporation (RMMAC)
