Organism care

Water (as needed):

We keep a bucket of treated water available at room temperature.  This water is treated with Proline chloramine remover to make it safe for use with aquatic organisms.  At no time should other sources of water be used for live aquatic organisms!  When refilling this bucket, add ½ capful of Proline water treatment to tap water.  Treatment is immediate but it is always best to use water that is at the same temperature as the organism’s environment.

Algae (set-up new one every 3 weeks):

Cultures of Raphidocelis subcapitata (unicellular green algae) are kept under grow lamps or near a window.  These are to be used to feed zooplankton and thus need to be maintained on a continuous basis.  Cultures may be started in uncapped 1L Erlenmeyer flasks (or other suitable glass container) containing 300-750 mL of 100% COMBO nutrient media (located in refrigerator) by inoculating with ½ capful of concentrated algae (also in fridge).  Algae cultures should be swirled daily to re-suspend the cells.

Zooplankton (continuous feeding; 50% water changes every 3-weeks)

New culture set-up:

I typically purchase a 1L starter culture of Daphnia magna from Aquatic Biosystems and make sure I have a large (3-5 gallon) bucket of dechlorinated water at room temperature for making larger cultures upon their arrival.  I also make a 500 mL of baker’s yeast suspension with this water in a bottle and put it in the refrigerator.

Immediately upon arrival, I uncap the D. magna starter culture bottle and add a ¼ capful of R. subcapitata concentrate for an immediate small feed.  I then allow the culture bottle to warm to room temperature before creating cultures.

For growing the D. magna cultures, I assemble 3-4 2 L clear containers (anything clean with a large opening will work, even 2-L soda bottles with the top cut off).  Add ~1.5 L of dechlorinated room temp water to each container.  Alliquot the D. magna in roughly equal volumes to each container by pouring.  Start daily feeding regimen.

Daily feeding of zooplankton:Cultures of Daphnia magna (waterfleas) are maintained with daily feedings of R. subcapitata and aged yeast suspension (in fridge).  Feeding amounts will largely depend on how many Daphnia there are at the time and thus this feeding regime is not fixed.  Algae should be added to the water in the culture tanks until the water appears light green (not yellow or clear) in color.  If culture water appears without any hint of green from algae after 24 hours, increase the volume of algae fed daily by 25%.  One-half capful of aged yeast suspension should be added to each tank weekly.

Water changes should be done every three weeks to ensure water quality for the zooplankton.  This can be done as follows:

·         Select a culture for a water change.  Bring it, a clean empty tank, and a fine-mesh aquarium net to a sink.

·         Pour one-half of the contents of the culture into the empty tank.  Pour carefully so as not to re-suspend the dead plankton and fecal matter from the bottom of the tank into the water column.

·         Pour the remaining water and live Daphnia through the aquarium net and allow the water to drain into the sink.

·         Invert the net into the clean culture to release the captured animals.

·         Bring the clean culture to the culturing area and add clean treated, room-temperature water from the water bucket to the tank to re-establish the full volume.

·         Feed.

·         Scrub out the used and empty tank with tap water and sponge, then rinse repeated with deionized water.

·         Repeat these steps as necessary for additional cultures.

Damselfly larvae

Once collected from the field or received from a supplier, damselfly larvae are sorted by size and held individual containers (to prevent cannibalism): portions of an ice cube tray (small individuals) or 50 mL centrifuge tubes with a drinking straw perch (large individuals).  Feeding regime is dependent on organism size: small individuals should always have small Daphnia present with them (ad libitum feeding); large individuals should be fed ~3 Daphnia weekly.

Damselfly larvae should be moved into a clean container with fresh treated water every 3 weeks.