A Kids’ Table for Squid

What am I looking at?

This is a composite image of five individual embryos of Loligo pealei squid, with their yolk sacs aligned in the center. Each squid displays a different combination of fluorescent markers. The nuclei of all the cells are blue dots (1). F-actin, a fibrous protein in the embryos’ neural structures, is green (2). Acetylated tubulin, in the cilia on the surface of the embryos, is red/pink (3). And beta-catenin, a molecule that aids in developmental signaling, is yellow (4).

Click on the right arrow to see a close-up of a single embryo (here, the acetylated tubulin is green, the F-actin is red, and the nuclei are blue).

Biology in the background

A squid egg contains a single embryo and a relatively large yolk sac. As the embryo develops, it feeds on the yolk sac to fuel its growth. When the squid gets close to hatching, it absorbs the yolk sac, which becomes part of its gut. Once a squid hatches, it looks like a miniature version of an adult squid and feeds on tiny animals (zooplankton) that come within the reach of its tentacles. As squid grow, they become active predators, feeding on larger animals like fish and other squid.

These squid embryos are about 1 millimeter long, or roughly 13 times larger than the width of a human hair.

Technique

This image was created using confocal microscopy.