Lungless lampreys link air-breathers to their ancestors

A fish-like creature coughed and unveiled a key secret about breathing.

Today, University of Alaska Fairbanks researchers escaped the new snow and ice to head to New Orleans for the annual Society of Neuroscience meeting. Their research today centers around a cough about 9 seconds into this video

That shows a lamprey larva ventilate normally through its gills, then coughing. You see, lampreys don’t breathe like we do. They don’t breathe air, and they don’t have lungs. But they are sensitive to carbon dioxide in a way that reminds UAF researchers Michael Harris and Barbara Taylor of amphibian breathing patterns. The nervous system responds similarly in both lamprey coughs and a part of breathing called a rhythm generator. This rhythm generator makes many animals sensitive to carbon dioxide and, Harris and Taylor say, evolved before lungs.

Lampreys don’t have lungs, but they are on the same path vertebrates took to start breathing. Eventually, vertebrates learned how to take in oxygen and expelling carbon dioxide. When lampreys encounter carbon dioxide, they cough.

Lampreys in Alaska can grow up two different ways — some are like salmon, living in salt water until spawning in fresh water, and some hang around fresh water their entire lives. Like salmon, they bring nutrients from the sea to land ecosystems. They start out as little ammocoetes — that larva in the video. These ammocoetes filter muddy water through their bodies and store the bits of food they come across. As adults they grow a nasty set of teeth that, if parasitic, they can use to suck blood from a host like a leech. The fresh water lampreys usually aren’t parasitic, and they don’t eat — they rely on the resources they gathered as youth.

I just arrived in Juneau to intern for KTOO. More on that later this week.

Also, speaking of UAF science: congratulations, R/V Sikuliaq, on your successful launch! I created a Storify of social and news media reactions to the launch. What do you want to know about the Sikuliaq?

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