Cowmooflage

December is upon us! And this week on Weirdo Wednesday we have...

The Plainfin Midshipman - Porichthys notatus

They are a type of toadfish found along the West Coast of the United States. They are small and brown, but along their lateral line and along their ventral side they have photophores, meaning they are bioluminescent. However, the photophores only appears in a part of their population. Scientists in Puget sound recorded seeing plainfin midshipman without photophores, while population further south like in San Francisco do see photophores. They are considered deep sea fish, scientists don’t need an ROV to study them. Once a year, they make an incredible journey to the shallows.

A most extreme exodus

In the summer, the plainfin midshipman migrates from depths of about 400 meters to the intertidal zones for breeding. The intertidal is an extreme area full of fluctuations in tide, salinity, oxygen, and predators. The males excavate a nest spot and he will guard this nest for months until the eggs hatch. It takes a clutch about 2 months to hatch, but successful males guard more than one clutch a year. 

A serenade 

So first the male finds a nest, then in order to find each other, these weirdos sing! Yes I know what you’re thinking, fish don’t sing. Well, then what do you call the vocalization this weirdo makes? It sounds like a low pitched continuous hum, and can be so loud that people who life close to their breeding spots can hear them! Residents of Sausalito CA have said they can’t sleep at night during this time. The females are attracted to the singing and follow the sound to the nests, where they decide if they should lay her eggs there or not. Males will continue to sing, even if they already collected eggs. 

Shout out to Elkhorn Slough Reserve for the photos and for this amazing video on these weirdos!!