One of the interesting things about fish who build nests to spawn is that it is often the male who does the hard work. He first builds the nest by choosing a good site and then swimming in circles, fanning out the sandy bottom with his tail and fins. When the nest is ready, a female deposits her eggs, which the male then fertilizes. After that, the female takes off, leaving the male to guard the nest until the hatchlings emerge. It's surprising how many instances of male-heavy parenting take place in the natural world!
P.S. We're not entirely sure what kind of fish is pictured above - if you know, please do drop us a line in the comments.
