live food

This page provides information on preparing live food to feed stickleback.

Brine Shrimp culture

These instructions are from the SOP for brine shrimp (by Monica Yau)

Here are the materials you need:

  • Hatching cone
  • Brine shrimp eggs
  • Clean, dechlorinated saltwater
  • Air pump and tubing
  • Warm water bath, such as a 3/4-filled aquarium, containing water heated to 27-29 degrees C OR environment chamber heated to 25-29 degrees C
  • Aquarium heaters for water bath
  • A lamp giving off bright light, day and night
  • Scrub pad to clean hatching cone

Here’s the procedure for hatching brine shrimp eggs.

  1. Scrub the hatching cone to remove any bacterial slime from the sides.
  2. Fill the cone with salt water, between 10-12 ppt (Note: this low salinity is ideal for hatching brine shrimp, but a higher concentration, 28-32 ppt, is necessary to keep the shrimp alive over 24h, as they will die at lower concentrations). Use a higher salt concentration when rotating cultures. Adjust salinity by adding salt or water, as necessary.
  3. Insert the air line tubing into the cone and make sure the straw at the end of the air line is inserted into the hole at the bottom of the cone. The water should be bubbling vigorously.
  4. Place the bright light above the jar and keep on always.
  5. Eggs should hatch within 24 hr.

Finally, you need to separate the brine shrimp from the eggs.

  1. When hatching is complete remove the air line from the cone and leave alone for about 15 minutes. The empty shells, if present, will float to the top. Unhatched eggs will sink to the bottom. The live brine shrimp (bright orange) will be hovering in the middle.
  2. You may have to repeat the egg separation step a few times. It is important that we separate as many eggs as possible as they will block the digestive systems of the baby fish, which will cause mortality.

Microworm culture

The following method was provided by Joey Courchesne.

Materials needed:

  • microworm starter culture
  • a predetermined number of small Ziploc-style plastic containers (anything with a smooth inner surface)
  • white bread (continual supply)
  • Fleishman’s dry bakers yeast (continual supply)
  • a wooden chopstick, toothpick or other suitable feeding utensil

Procedure:

  1. Poke minute holes (up to eight) in each of the Ziploc container lids
  2. Take a small handful of white bread and moisten it thoroughly. It is important not to soak the bread, nor to leave it too dry. The end consistency should be similar to store-bought hummus dip
  3. Add a portion of the microworm starter culture
  4. Mix both the bread and culture well adding water or more bread as needed to maintain an optimal consistency. The mixture should only take up 1/8th to 1/4th of the total volume of the container
  5. Add enough yeast to just cover half of the surface of the mixture. Do not concentrate the yeast in a single area, but spread it out over the surface
  6. Adjust consistency of mixture if needed
  7. Place the lid on and the culture in a warm area that is not too dry (see figure 1 below)

Feeding:

  1. Allow microworms to build up a layer around the inside surface of the container (figure 2 above)
  2. Scrape along the inside surface with the chopstick or toothpick in order to pick up the equivalent of 2 rice grains worth of microworms (figure 3 above)
  3. Dip chopstick/worm combo into the tank containing the fish to be fed
  4. Dry off chopstick and repeat as necessary

Paramecium culture

Start one right away. The easy but less reliable method is to place a pile of hay in a spare aquarium and keep it warmer than room temperature. After a couple of weeks, stir the contents and scoop some of the liquid into a petri dish. With a microscope you should see Paramecium swimming around.

A more reliable but slightly more labor-intensive method, provided by Joey Courchesne, is as follows. It makes 1L of paramecium culture.

Materials needed: 2L flask, 2.5g cerophyl powder (wheat grass powder), 3/4 g of dibase sodium phosphate powder, klebsiella starter culture, large jar (<2L), and a hotplate.

  1. Fill flask with 1L of distilled water
  2. Measure out 2.5g of wheat grass powder and 3/4 of a gram of sodium phosphate (Sigma Aldrich cat# S-0876) and add to water
  3. Bring mixture to a boil
  4. Allow mixture to cool to room temperature
  5. [optional step] Filter cooled mixture through cotton or nitex to filter out wheat grass particles
  6. [optional step] Autoclave cooled and filtered mixture
  7. Inoculate mixture with klebsiella medium (cut off a chunk of the bacteria rich agar and add straight to the mixture; the piece of agar should be about the size of your thumbnail)
  8. Incubate inoculated mixture overnight (8-12 hours) @ 37 degrees. The high temperature is necessary for proper bacterial bloom
  9. Pour mix into the large jar and add paramecium culture; or add mix directly to existing paramecium culture for continued rapid growth
  10. Allow paramecium population to expand for 1-3 days
  11. Ripe culture should have a paramecium population visible as a “cloud” in the jar. Sufficient population size can be confirmed with a dissection microscope where paramecium presence should be very strongly evident.
  12. Replenish culture with new food (steps 1-8) every 1-4 weeks as needed