NSW Aquaculture Association Inc.

Serving the Aquaculture Industry Since 1994

by Rob McCormack

The Yabby is a freshwater crayfish native to Australia. Also known as a crawchie, crawdad, craybob or even lobbie, it’s all dependent on where you come from.

The Yabby Cherax destructor

Yabbies as a name can refer to any number of different crayfish species (small smooth shelled species) but as a rule it generally refers to Cherax destructor. This species is a native of the Murray Darling system (west of Great Divide) and has the broadest distribution of any species in Australia. In fact the yabby Cherax destructor is one of the few species other than man which is increasing its distribution across the planets surface. Unfortunately, it is an invasive species and is becoming established along the eastern drainage of Australia in streams that it is not endemic to. The repercussions of this and the effects to the native crayfish species and animals that live in these streams are unknown but could be devastating to many species.

Yabbies are also known as the western blue claw yabbies, basically because they mostly have blue claws. Yabbies can be any colour blue, black, white, brown, red, green or any combination, they will change colour to that which is most suitable for camouflage in the wild. Yabbies grow to a maximum size of 350 gram, however, the common large size is 120 – 150 gram. Yabbies have a life span of only 5 – 7 years under average conditions, in the wild their life expectancy is much shorter as they are towards the bottom of the food chain and a vast amount of animals consume them. Some of their main predators are insect larvae, fish, eels, turtles, birds and water rats. They are also cannibalistic so will eat each other, they are most susceptible to cannibalism when they moult leaving them soft and vulnerable.

Aquarium Pets – Yabbies make great aquarium pets, they are easy to fed and keep without any problems compared to fish. They eat any of the sinking fish food plus meat, fish, fruit and vegetables so just about anything. They have gills just like fish so breath oxygen from the water so must be kept in the water just like a fish. Fill the tank completely with water, they do not need to get out of the water unless the water goes bad. An aerator or filter in the tank will keep your water fresher longer and supply oxygen into the water for them to breath. Usually you don’t have to change the water until it becomes smelly. Water quality is directly related to the amount of food placed into the water, most people kill their yabbies with kindness, they place too much food in the water and it is not eaten so goes rotten, polluting the water. For further information check out the book “Keeping Pet Yabbies” or go to http://www.rbmaqua.com.au/bookshop.shtml to purchase.

  • If you would like to buy a pet yabby then try:

Aquablue Seafoods Pindimar NSW 2324 Neil Meyrick “yabbies available” www.aquablueseafoods.com.au

Mudgee Yabbies and Fish bait yabbies” “dam stockers” “eating yabbies” Marg & Peter Burns Phone: 02 63732236 Email: margaret@ipstarmail.com.au

12 Mile Creek Aqua Farm Pacific Highway, Karuah NSW. Yabbies for sale! bait, farm stock and restaurant grades available phone Nigel 0405 439 259 Email: amhtouristark@bigpond.com

Otway Yabbies Steve Chara 240-250 Portreath Road, Bellbrae Vic. Email: yabbies@charas.com.au

Farm Dams – Yabbies are great for farm dams as they don’t need anything except a good dam. Yabbies thrive in farm dams. Best dams are those without large numbers of predators in them, i.e., fish, eels, turtles, etc. Also, best results will be in very turbid (Muddy ) dams, yabbies don’t like clear water. Average farm dams produce 50 – 100 kgs of yabbies per year without any effort. To stock your dam use dam stock breeders 50 – 100mm head to tail, these are yabbies large enough to look after themselves, too large for most predators to eat and ready to breed. Minimum required to start a population is 100, maximum is 1,000. The more you put in the greater your chances of successfully starting a viable population. Technically you only need two to start a population, one male and on female, however the chances of something happening to one is high. Plus the chance of that boy finding that girl in the dam again is astronomical. Best results are achieved by stocking with a minimum of 100 yabbies. No feeding required, yabbies eat grass, leaves, seeds, whatever blows or washes into the dam plus whatever grows in the dam, weeds, algae, insects, worms, etc. No permit is required to grow them in your own dam for your own consumption. Note: You can only legally stock your farm dams, it is dangerous, irresponsible and illegal to stock your local creeks.

Yabbies can be captured via meat on a string or commercial yabby traps.

  • To buy yabby traps go to www.rbmaqua.com.au
  • If you would like to buy yabbies to stock your dam then try one of these members:

Aquablue Seafoods Pindimar NSW 2324 Neil Meyrick “yabbies available” www.aquablueseafoods.com.au

Mudgee Yabbies and Fish bait yabbies” “dam stockers” “eating yabbies” Marg & Peter Burns Phone: 02 63732236 Email: margaret@ipstarmail.com.au

12 Mile Creek Aqua Farm Pacific Highway, Karuah NSW. Yabbies for sale! bait, farm stock and restaurant grades available phone Nigel 0405 439 259 Email: amhtouristark@bigpond.com

Otway Yabbies Steve Chara 240-250 Portreath Road, Bellbrae Vic. Email: yabbies@charas.com.au

Commercial Aquaculture Farms – You do not need any permits to grow yabbies for your family and yourself, however, if you want to sell yabbies then you will need an aquaculture permit from your states Fisheries Department.

Yabbies grow well in farm dams and some commercial aquaculture operations are extensive farm dam harvest operations where yabbies are just trapped from farmer’s dams. If you have a group of farmers with lots of farm dams full of yabbies then this is a viable option. This type of aquaculture requires a Class E permit from NSW Fisheries.

Generally most commercial farms are located on rural properties in specially designed yabby ponds. Commercial yabby farms consist of large numbers of shallow ponds designed specifically for the yabbies. This maximizes the growth and numbers of yabbies that the pond produces. It also allows for easy management and less costs in construction and ongoing maintenance. For all you need to know on commercial yabby farming purchase “The Commercial Yabby Farmer” a 250 page book. http://www.rbmaqua.com.au/bookshop.shtml

Commercial farming is generally conducted either as extensive, semi intensive or intensive farming.

Extensive

Extensive is where the yabbies basically fend for themselves with little in the way of management or food added. The yabbies just live and breed in the pond and the farmer just catches them out with traps. Production is low to medium and all production is based on pond surface area. A hectare is 10,000 square metres in size and it is hectares that commercial farmers use to talk production. For example a pond that is 20m x 50m is 1000m² so is one tenth of a hectare. Good production by extensive methods is 800kgs of yabbies per hectare. Therefore our 20m x 50m pond can produce 80kgs of yabbies per year. There are less rules and regulations involved with extensive farming as it involves natural populations and natural food. This type of aquaculture requires a Class C aquaculture permit from NSW Fisheries.

Semi Intensive

Intensive yabby farming is where a greater level of management is used to produce larger numbers of yabbies. This involves stocking ponds at optimal levels, feeding and protecting the crop and using good genetic stock. This type farming will produce higher levels of crayfish at up to 2500kgs per hectare per year but at a lot higher cost in food and labour, etc. Yabby farming is something that you can do at your pace and at your level of input so very attractive to most people. To increase the production to semi intensive levels requires daily feeding of your crop. This means that you are adding nutrients to water and growing your yabbies at higher densities than would occur naturally. This means that more rules and regulations will apply to this type of farming. This type of farming requires a Class D aquaculture permit from NSW Fisheries.

Intensive

Intensive yabby farming is generally in the experimental stage. This is where very high numbers or yabbies are grown in small spaces. There are various methods for intensive yabby farming and all require intensive management with regular feeding and water quality management. This type of farming also requires a Class D aquaculture permit from NSW Fisheries.

In the eastern states the environmental rules and regulations that apply to aquaculture can be overwhelming to the average farmer.

  • For professional aquaculture consultants go to

Australian Aquatic Biological Pty Ltd. Web:  www.aabio.com.au   Email: info@aabio.com.au  Farm and aquaculture facility design. Preliminary site inspections, Statements of Environmental Effects, Environmental Impact Statements, Full farm design and licencing service, Freshwater and Marine aquaculture

RBM Aquaculture. Web: www.rbmaqua.com.au   Email: info@rbmaqua.com.au Preliminary inspections, concept plans, full farm design and licencing service integrating all species and all products, all species, Yabbies, Trout, Silver Perch, Cod, Eels, Shrimp, Crayfish, Snapper, Bream, Bass, etc.

Markets – Yabbies are used for a mass of different purposes and this is great for commercial farmers as they have a market for every size, shape and colour yabby they can produce. In NSW the demand for yabbies is phenomenal and all commercial farmers have more markets and far greater demand then they can possibly supply. All the members of the NSWAA work together to help each other out and attempt to keep their customers supplied.

Aquarium Trade – This is the smallest market available and is for the brighter prettier yabbies. It is a big market but there are some large farms specifically supplying this market so generally for most farmers it is only a small sideline. Additionally, is the aquarium bait market, this is where yabbies are used as food for aquarium species. Small feeder yabbies are generally in huge demand and something that most commercial farmers supply regularly.

Bait Yabbies – This is one of the largest demands in NSW, yabbies for recreational fishermen to go fishing with. Demand is phenomenal and most commercial farms in NSW supply huge amounts to this industry but demand far outstrips supply. Some of the larger yabby farms in NSW only produce bait yabbies as you get a huge price per kilo and it’s a very short growth time for small bait yabbies so you get a return very quickly.

Restaurants – Eating yabbies is another huge demand area. Large yabbies direct to the public or restaurants is the main reason most people start a yabby farm. Live yabbies are in huge demand and any restaurant that has a tourist trade and especially international tourists, wants something that is typically Australian and yabbies are perfect.

Others – The list is endless, dam stock, zoo food, soft shelled and fish outs are just a few.

For further information on Commercial Yabby Farming power point presentation or go to www.rbmaqua.com.au

 Sexing Yabbies

Determining the sex of your yabbies is easy. You need to check the underside of the yabby. Male yabbies have small projections on the inside base of the last walking pair of walking legs. The female yabbies are smooth on the back legs without any projections but have 2 round openings on the inside base of the third pair of legs, they are hard to discern but these are the openings from which the females will lay her eggs under her tail.

Sexing your yabbies