A beach walk leads down a rabbit hole.
Walking on the beach, we notice clusters of small yellow eggs. Maybe ten to a cluster. What are they? I take a photograph and then search, for local fauna in Bellingham.
The eggs belong to the plainfin midshipman, or Porichthys notatus. I am charmed by the name. They mostly live in the ocean, except when reproducing. The male finds a nest site under a rock in the intertidal zone. The female lays eggs then the male spawns and stays with the eggs. The female leaves. The male may have more than one female lay eggs in his nest. The male tends them. He fans them, keeps the nest clean, and hydrates them if they begin to desiccate at low tide. These are good dads! The males hang with the larvae until they leave the nest, about 45 days.
We keep finding eggs and then occasionally find a dead plainfin midshipman on the beach.
The plainfin midshipmen are also bioluminescent, but only during courtship. They light up, baby. Each fish has over 700 photophores on its head and body. They live all the way from Sitka, Alaska down to Magdalena Bay in Baja, California. The southern ones light up but not the northern ones. The northern ones and especially the Salish Sea ones, have lost their luciferin. How devilish.
These fish also make noises during courtship. The males use their swim bladder to make grunting sounds, music to the ears of gravid females. They are so noisy that they keep people awake in Sausilito, California, who respond by having a Humming Toadfish Festival. Plainfin midshipmen are a species of batrachoid toadfish. That is a whole other rabbit hole.
Doesn't this sound unlikely? Is it made up for SciFiQuest? Maybe. Glowing fish where the men guard the young for a month and a half. No way!
There are 253 known species of fish in the Salish Sea and that's just one. A walk on the beach leads down a fascinating rabbit hole.