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About Vernonia's voice. (Vernonia, OR) 2007-current | View Entire Issue (March 5, 2020)
8 in other words march5 2020 A Word From the Watershed: The Weird and Wonderful Pacific Lamprey By Corrie Aiuto Pacific Lamprey are amazing animals. An eel-like, boneless, parasitic fish, they are resilient, older than the dinosaurs, and have a fascinating life cycle. They also live in our watershed. In January the Upper Nehalem Water- shed Council (UNWC) was happy to host Christina Wang of the U.S. Fish and Wildlife Service at the Vernonia Public Library to speak about Pacific Lamprey. We at the UNWC can’t stop talking about her presentation or these crazy fish. There are approxi- mately 40 species of lamprey around the world. Four species are native to our watershed: Pa- cific Lamprey, Western River Lamprey, Western Brook Lam- prey, and Pacific Brook Lamprey. Some species are anadromous, meaning they return to fresh water to spawn like salm- on, and some spend their whole lives in fresh water. The Western Brook and Pa- cific Brook are an example of resident fresh water lamprey. The infamously invasive sea lamprey, which decimated trout populations in the Great Lakes, is thankfully not found in our rivers. Lamprey, though they look like eels, are actually fish. They have no scales, and are boneless, having carti- lage instead. They have no paired fins on their sides (as goldfish do), only dorsal fins and a caudal fin. They have holes for gills, blue eyes, and depending on spe- cies they can be 4-33 inches in length. of their tail. Lamprey biology is ancient. Fossils dating 360 million years old show a recognizable lamprey, its body and form essentially unchanged, and they are estimated to have emerged 450 million years ago. That makes lamprey hundreds of millions of years older than the dinosaurs, sturgeon, salmon, and hu- mans. Their survival strategies are so They are also jawless, having a power- ful suction cup mouth with teeth used for feeding, anchoring, and climbing. Lamprey cannot jump and have no swim bladder, so they must constantly swim or use their mouths to anchor themselves. They also use their mouths to climb over waterfalls, attaching to a rock, and then propelling forward with a quick stroke successful that they lived through at least four mass extinction events on Earth. The life cycle of Pacific Lam- prey is one of many transformations and long journeys. Their range spans the up- per Pacific Rim from Mexico to Japan. When it is time to spawn, adult lamprey migrate upstream to build nests, or redds, in habitat similar to what salm- on prefer, with gravel bottoms and slower currents. However, rather than returning to native streams to spawn as salmon do, lamprey follow the pheromone signals of live baby lamprey in the larva stage, called ammocoetes. Because of this, an Oregon lamprey can eventually spawn in Russian freshwater, following the Mariolino’s Pizza & Grill Open for breakfast, lunch & dinner Daily Specials We have ice cream! 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They look and behave much like earthworms; sightless, tooth- less, they grow to be 8 inches long. They filter feed, pushing their mouths up above the silt to catch passing par- ticles and help mix oxygen and nutrients into the silt. There they stay, hiding in the streambed, for anywhere from 2-10 years. Juvenile lamprey, also called macropthalmia, stop feeding, grow eyes and teeth, develop their suction mouths, and the ability to swim freely. They turn silver and, between July and November, begin their outward migration to the ocean. During this journey they can feed parasitically, preying on larger fish. When they reach the sea, lam- prey quickly swim away from shore, and have been found at depths over 4,800 feet where they feed and survive as para- sites. They prey on pollock, hake, salm- on, flatfish, rockfish, and many others. Much of their life and behavior during this time is unknown. Some adults return to fresh water to spawn as quickly as 6 months, while others stay at sea for over 10 years. Adult lamprey are preyed upon by sharks, sea lions, birds, and many other marine mammals. They are calo- rie dense, which means they are an im- portant food source for many predators and their presence brings some relief to salmon and other fish listed under the Endangered Species Act. When lamprey at sea begin their migration to freshwater, they un- dergo one final transformation. 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