How do you collect hemolymph from crab?

Answer 1

There are two ways that I know of.

First, pin the roach down on its back. lift the hind lag and make a small incision in the soft tussiue that will be exposed upon lifting the leg. You should get a few drops that can be collected by pipettor. The stuff is really sticky tho, and tough to homogenize in solution.

Another method I have been experiementing with is this:

Seal the mouth and anus with super glue, or ticky wax. Take a 50 mL eppendorf tube, and place a 10 mL eppendorf within. You will have to cut the 10 ml tube to fit in the 50 ml tube, and drill holes into the bottom of the 10 ml tube. Make an incision , being very careful not to nick any internal organ, and place the roach in the 10mL tube, then the 10 ml tube into the 50 ml tube. Centrifuge at ~1000g for as long as it takes to get the required volume.

Others have also inkected saline first into the insect, to ease the clotting action of the hemolymph, but that method won't work for me, since I need undiluted hemolymph for my study.

Answer 2

In my experience, I have used a 23-gauge needle with a 5-mL syringe. The larger the syringe...the larger the suction. I personally go through the back side of the crab. I sterilize the area between the carapace and the abdomen. I then press the needle through the soft membrane between the carapace and the abdomen in order to go straight to the heart. Be careful not to move the needle too much once inside the heart (this may kill the animal). Survival rates were 100 percent with this method. Be sure to insert the needle directly in the middle from the back. The heart is usually between the third and fourth walking legs. Careful not to draw the hemolymph too fast and remember you only need a drop!!! I have also read you can go through the arthrodial membrane and the hemal sinus (mainly on portunids).

Answer 3

Hemolymph from crabs can be collected by inserting a needle into a small joint or soft area of the exoskeleton and allowing the hemolymph to flow out. The collected hemolymph can then be transferred to a collection vial for further analysis or experimentation. It's important to work quickly to minimize stress on the crab and to ensure the hemolymph remains viable for testing.