Designing Fake Eggs and Sperm

30 10 2012

Recap: Black abalones are awesome, hardy creatures that survive in a hostile environment.  Although they were once incredibly abundant, their numbers have dwindled due primarily to disease.  A 30-year old study has documented small pockets of recovery around San Nicolas Island, leading to an onslaught of research questions: mainly, why isn’t the recovery spread evenly around the island?

Here’s where I describe my fantastic, yet fiscally responsible project.  Our main objective is to figure out how close two spawning abalone must be in order to successfully fertilize eggs and create offspring.  But first, I will outline some obstacles that might help explain the reason behind my decisions in the design.

Stacking black abalone, San Nicolas Island, CA (G. VanBlaricom)

In an ideal world, I would be able to place two black abalone in a tide pool, whip out my handy timer, say, “Ready…set… … SPAWN!” and collect water samples.  Not only are they not that accommodating, but it would be three kinds of illegal.  The black abalone is an endangered species, listed in January 2009, so you need a permit to do any sort of work with them.  Anyone who has ever tried to get a permit of any kind probably knows the timeline you’re faced with when going through that application process, so I can honestly say it’s not a document you get overnight.  Furthermore, we haven’t been able to spawn in the black abalone in laboratory settings.  They’re a little gun-shy and prefer to keep some things private, I guess.  I can’t say I blame them; that’s an awkward moment to have an audience.

Female Ezo abalone spawning (

Now that using actual black abalone is not an option, we had to find particles that were the size of black abalone gametes, and use them as surrogates for the real thing in simulated spawning events.  That brings us to obstacle number 2: if we haven’t been able to spawn black abalone in the lab, how do we know the size and amount of eggs and sperm?

I combed through literature, spent hours and days sifting through the dry material, and was unable to find all the information I need.  All I was able to find out was the size of the pre-spawn egg size.  Fortunately, I was able to find those details and more for different species of abalone.  I looked for abalone that were most similar to black abalone and had the same pre-spawn egg size, and blacklip abalone from Australia fit that profile.  They are a temperate species, like black abalone; they live in similar and deeper depths than black abalone; they are the same size; and (although this doesn’t really relate to spawning capabilities) they have a similar name!

Green microspheres from Cospheric (

Now that I had collected the requisite information, I was ready to design the particles that will be used in my experiments.  Cospheric is an amazing company that designs particles, which come in a variety of sizes and colors.  Heck, if I wanted, they could put smiley faces on each one.  Smiling fake sperm particles.  I crack myself up…

The particles I chose to represent eggs are green (like real abalone eggs), and between 212 to 250um (um=micrometer).  To give that a little perspective, a grain of salt is about 1,000um, so an abalone egg is about a quarter the size of a grain of salt.  Particles chosen to represent sperm are white (like real sperm), and between 10 to 45um.

Now that I have the particles, I’m about ready to design my experiment…



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