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Does anyone know if there is a formula for sorting out how much feed a cray should get?

I can eyeball the smaller ones with a bit of trial and error, but the new fellow (25cm blue marron) is substantially larger and has a different activity level to the other species I've kept. Jumping in at this stage of his life is a bit trickier than starting with a youngster.

Is there a rule of thumb? maybe a ratio based on body weight?

For animals, the entire universe has been neatly divided into things to (a) mate with, (b) eat, (c) run away from, and (d) rocks. - Terry Pratchett

Hi Calla,

Do you have any idea how much your new fellow weighs?

Most references I have found in my old aquaculture textbooks refer to feeding regimes for redclaw in large scale production ponds as a percentage of biomass. I'm making an assumption that marron would have similar requirements to redclaw, and that the difference between pond and tank grow out is just a matter of scale.

At first stocking of a growout pond redclaw are fed at a maximum of 12% biomass, three times a week (Jones, 1994) This equates to around 5% biomass per day.

The percentage of food fed gradually decreases as the animal grows until they are receiving 5% biomass, three times per week, or around 2% per day. (Jones, 1994)

Generally speaking, comercial-scale redclaw aquaculture operations use pellet type food with less than 20% crude protein which are usually low in fibre, high in starch and often include calcium supplements to assist in shell growth / hardening. These pellets are used for simple convenience.

As with most things though, it's probably a matter of trial and error with your particular animal... find a level that works for you and then vary it as you feel is necessary. Usually on farms the method for monitoring food consumption is to feed in the evening, placing some food in the shallows, if all food is eaten by morning the feed levels are increased marginally. If uneaten food remains levels are reduced accordingly.

I have seen references to commercial aquaculture operations using nothing but hay / chaff / legume material within the pond as a food source, on the theory that redclaw are detrital feeders that can obtain all their protein requirements from the bacteria and fungi involved in decomposing organic material. IMO you'd need to be really careful using this method in a tank environment as I can see water parameters being compromised fairly quickly as the material decays if you are not completely vigilant in your monitoring of parameters and your water change regime.

Hope this helps

G_T


Never be afraid to try something new. Remember that a lone amateur built the Ark. A large group of professionals built the Titanic.