Tuesday, April 28, 2009

Sea Lamprey circus! Video of lamprey heading up the Ipswich River to spawn

I recorded this minute long video of sea lamprey (Petromyzon marinus) trying to get over the last hurdle of the Ipswich River fish ladder and into the Mass. Division of Marine Fisheries trap:

To watch the video in high quality click here and click on the HQ button on YouTube.

Sea lamprey are anadromous, much like a salmon. The young hatch out in rivers and live in the mud filter-feeding, blind and toothless for 3 to 17 years.

Then they metamorphose into their parasitic form with that lovely mouth right out of a sci-fi film.

After about 12 to 20 months they metamorphose again in to their adult form at which point they migrate back into their native river to spawn and die. But don't worry! The lamprey writhing around in fishway traps all over the east coast aren't eating precious herring trying to be reintroduced. They're aestivating, or not eating.

Last year the DMF trap caught 1021 sea lamprey. They have a habit of all rushing up the river at once when the water hits about 20 degrees C. A few days ago there were only a few and this morning there were at least 15 lamprey all trying to get in the trap at once. It was the slimiest log jam I've ever seen.

As of yesterday DMF had caught a mere 37, I can't wait for the numbers from this week. I'm betting that will shoot up to at least 400 if not more!


  1. OMG! I never knew we had these so close to home! Is it wrong that I'm a tiny bit grossed out by them? They seem like something out of a medieval book of fish drawings. Ew.

    Cool post!

  2. they are kinda gross! you should go down to the ladder sometime and see it in person, it's unreal.


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