Hi Ardavan.

Do you want to look at activity in natural environment or in the lab?

If you are doing lab work you could, for instance, put a crayfish in a tank on a table and record with a webcam from the ceiling. Then you can analyze distance moved (and other parameters) using a tracking-software (there are some free ones, e.g. Ctrax). You can also draw lines to make squares on the tank floor and count number of lines they cross during a certain time period (alternatively you can make the lines on a transparent plastic sheet and put it on your computer screen when watching the video).

Dear Joacim thanks alot for u r advise

i want to do my study in lab! this is my thesis title Effect of photoperiod and stocking density on growth indices, feeding performance, physiological responses and body biochemical composition of juvenile narrow-clawed crayfish Astacus leptodactylus.

what is u r idea about feeding behavior and aggressive behavior, which parameters i can investigate for feeding behavior and aggressive behavior?

I have mostly worked with fish myself, so I have no good idea about how feeding behaviour in crayfish would be measured. Aggressive behaviour in crayfish can be indicated by dyads (fights between two individuals) - in that case it may be a good idea to size match two crayfish from different treatments and then see who attacks first and who wins. I guess you could also size match two individuals from the same treatment and see how long they fight compared to pairs of another treatment.

There are many papers about crayfish fighting that you can find on Google Scholar - I'm sure you can find a good experimental design from them.

Doing behaviour studies myself, I would suggest that you have as large sample sizes as possible - behaviour is often very variable, so to get good publishable data, aim for large samples. And keep in mind that one fight (two individuals) is only one sample unit.

Good luck!

Try contacting AQ1 Systems (http://www.aq1systems.com/farming/13510001)

AQ1 has developed acoustic technology to measure feeding intensity of farmed shrimp. It has been tested on a range of shrimp species and might also work with crayfish.

Dear Harry thank you very much. using AQ1 systems is good idea, but unfortunately we dont have this system in our country also maybe using this system is expensive. in addition i think this system can be used for one tank or one cage.... in this study i have 27 tanks so i need 27 sensors. it seems that providing 27 AQ1 systems is very expensive and is not feasible. any way thank you very much dear Harry you give a lat of information about AQ1 systems.

Hi Saeed

No, unfortunately. I did not use any software. I did not work on feeding behavior.