The Illustrated Guide to Making Squid Babies:
By Danna Shulman
The Gilly lab is studying the Humboldt squid, a.k.a. the jumbo flying squid, a.k.a. Dosidicus gigas. It is a principle prey item of virtually every large fish, bird, and mammal that can catch it—including humans. In fact, Dosidicus supports the largest cephalopod fishery in the world! These squid, in turn, are opportunistic predators of whatever they can find—usually crustaceans, fish, and fellow squid. Dosidicus must consume their prey in enormous quantities to fuel a truly remarkable growth rate. During a life span that is probably two years or less, Dosidicus can grow from hatchlings of one to two millimeters to fully grown adults of one to two meters.
My research focuses on these very small hatchlings, called paralarvae. However, wild paralarvae can't be found very reliably, so I've taken to making my own. All I need is one mature female, with some stored sperm from previous matings, and I can fill as many petri dishes as I could wish with artificially fertilized squid eggs.
Here's how it works:
Step 1: Catch squid. Not as easy as it sounds! As seasoned fishermen like to remind me, it's called “fishing” not “catching”. But then, on some evenings the squid are so thick in the water that you have to pull them up quickly, or they'll get ripped off the lure by their voracious fellows.
Step 2: Identify mature, mated female.
This is fairly straightforward. Ripe eggs are a bright orange color and can be easily separated from the yellow-brown unripe eggs (lower left inset). Spermatophores are embedded in the area around the mouth; this “buccal membrane” can be removed
and taken into the lab for easier spermatophore extraction (upper right inset).
Step 3: Extract gametes and perform artificial fertilization. This is “real science” involving gloves, petri dishes, pipettes, razor blades, etc.
 Step 4: Wait a few days, changing the embryos' water and monitoring their development. During the first day, you can observe the first cell divisions, which is very exciting. Then the individual cells become so small you can no longer see them dividing, and the embryos enter what I call the “boring stage”. After another day or two, however, organogenesis begins, and things get exciting again. Eyes appear! Now chromatophores! The embryo starts spinning slowly, then pulsing! Soon: squid babies!

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