Tiggin' It

Today I started four new colonies of our adorable copepods, Tigriopus californicus. I had originally started a batch from the first stock we ordered, using about 15 mating pairs, and since then that culture's gone crazy.

We're gonna need more tigs, so I started four more cultures, which I'm calling Tig Hauses (I don't know how plural forms work in Deutsch, apologies). Each one is a plastic food storage container with 0.75 L of filtered seawater. I mixed in some commercial microalgae filter feeder food so the tigs have something to go off of.

I had a fun afternoon sorting and counting tigs to be added to the Hauses. I started off collecting mating pairs of tigs (the male uses his antennae to grasp onto the female when they mate). I added 25 pairs to each, which helped to keep my sex ratio at 50:50. Because these were from a colony started with just 30 tigs, I wasn't sure I was getting a great genetic diversity if I just used that. To help, I got five male and five female tigs from the original stock (these weren't mating). I generally wanted to keep the sex ratio 50:50, since the guarding/amplexus behavior would suggest that monogamy must be higher than chance (totally assuming). To round off my numbers to a nice 75, I lastly added non-mating males and females from my colony (eight female and seven male).