Paddlin' Madeline Home

Phantom Midge¹ gave me a few good suggestions recently, but alas, neither the Yeti Crab nor the Zombie Worm are listed, whether or not they are actually in danger of becoming extinct. There are gobs of disgusting-looking deep-sea critters, but since so little is known about their populations and habits, there is not enough information for them to be placed on an endangered species list. There is, however, an aquatic animal that I had known about for a while, but about which I have neglected to write.

Image from Texas Parks and Wildlife

This is the American Paddlefish (Polyodon spathula), which I have seen for years at the Columbus Zoo, and was sure it was on the Ohio Endangered Species List. It wasn’t which slightly upset me, since I was planning on writing about it for most of the week. Turns out it’s listed as vulnerable on the IUCN redlist, so I get to write about it anyway. It lives in large rivers of the Mississippi River basin, growing up to a size of seven feet, and living up to about twenty or thirty years.

The protruding…thingy (actually called a rostrum) from which the Paddlefish gets its name is covered with electroreceptors to help it find groups of zooplankton on which it feeds. The minute prey are swept unceremoniously from the water by the gaping maw of the Paddlefish, and then filtered from the water by raking protrusions on the gills. The fish’s mouth is specifically designed to open to an immense size to filter the largest amount of water possible. Wikipedia suggests that the rostrum also acts as a hydrofoil to help keep the head level in the water as filter feeding occurs, but I don’t really like to cite them as a source.

The American Paddlefish live in rivers, so of course dams affect their populations by impeding their moving patterns. Much like the sturgeon, they have been harvested for meat, and their eggs have been harvested for caviar. Agricultural runoff causes the streams to silt up, making filter feeding a difficult prospect. To help relieve some of these threats, farm-raised Paddlefish are released into the wild. Stricter regulations on Paddlefish harvesting have also been put into effect.

¹Still no blog, so here’s her sister’s link again.