Brook Lamprey
Riverdave’s Journal
This essay appeared in the Durham Herald-Sun on 3/5/97

Often the protection of endangered species is understood by the general public as concern for the megafauna of exotic places like East Africa or Amazonia. The African elephant and the Amazonian giant river otter are good examples. These two creatures have several things in common. They are large and have highly conspicuous behavior, they are beautiful to behold, they possess body parts that are of high economic value (tusks and skins) and their habitats are vanishing because of competition for space with humans.

But increasingly, endangered species protection is being understood in a broader way. What if there were endangered species that were small and inconspicuous, were ugly to us in human terms, had body parts that had no economic value to us and were even loathsome, but whose habitats were also threatened by human encroachment? Would we love and cherish these forms of life as well?

In fact, the latter types of wildlife are far more common than the former and are right here in our midst. They provide links in the web of life that are as important as those provided by the megafauna. If studied up close, these less popular animals are as exotic and interesting to our imaginations as the most bizarre Serengeti or Amazonian creature.

So where are the hidden recesses in the Triangle area that harbor these endangered species? An expedition last week with the State Museum of Natural Sciences up a muddy creek in southern Wake County turned up one such creature - the least brook lamprey, Lampetra aepytera.

I had requested help from the museum staff to locate this fish along the Eno River in Durham and Orange counties. There exist only five records for this fish in the Neuse River basin east of the Eno in Wake and Jones counties. But the museum staff had encouraged me to look for the brook lamprey upstream on the Eno as well. To help me understand its habitat and see what it actually looked like, they took me to a site in Wake County where the fish was last seen five years ago. We found it, but in much fewer numbers than were recorded previously.

What is this strange denizen of our local rivers? The brook lamprey belongs to a class of fishes that are both separate from and more primitive than the true fishes. It is related to the scavenging and blind hagfish of the ocean depths that enters the carcasses of dead animals that fall to the floor of the ocean and then consumes them from the inside out! Unless this mode of recycling appeals to you, be careful not to drown at sea!

However, the lampreys are somewhat different in that some species feed on live fish by means of an oral sucking disc. The best known species is the sea lamprey, a migratory fish that entered the great lakes of the northern United States a number of years ago and decimated the whitefish and trout fisheries.

But most of the nineteen species of lampreys found in North America have evolved as freshwater, non parasitic fish. They still retain a vestigial sucking disc, but don't even feed as adults. They are the brook lampreys. This primitive, eel-like fish lacks jaws, scales, paired fins and bones, but does possess a line of seven small gill openings behind its eyes.

Why is this fish so inconspicuous? For one thing, the least brook lamprey is a pencil-thin, six inch long, silver-gray fish that will never end up at the end of your fishing line. In its larval stage it lives in the muddy detritus along the edge of rivers only as a filter feeder of microorganisms.

The larva is known as an ammocoete and will continue in this form for three to eight years. At the time of its metamorphosis into an adult, its dorsal fins enlarge and in late February or early March, it does a short migration up small feeder streams to spawn in clean, clear, gravel-bottomed stream riffles.

The male builds a nest by moving small stream pebbles with its sucking disc to create a cup-shaped pit and fans out the fine sand with gyrations from its body. He then waits for a female to come and lay her eggs in it, whereupon he promptly fertilizes them. Both sexes, having completed only a brief adult stage where they don't even feed, will then die, leaving their limp bodies to litter the stream and be consumed by other animals.

We are currently in the brief spawning season when the adult least brook lamprey finally emerges from its multiple years of larval hiding. If it is indeed present here in the headwaters of the upper Neuse River Basin, it will be entering feeder streams along the Eno, Little and Flat Rivers during the next couple of weeks. We need your help to locate them.

Look for small feeder streams to our larger rivers that may be only three or four feet wide with only a few inches of water. Locate a gravel bed on the feeder stream within its first one hundred feet. Search carefully for the grayish fish swimming over gravel or for its pit-like nest of rocks. Carefully lifting up nearby larger rocks, check for hiding fish. If you find the lamprey, be careful not to disturb the fish or its nesting site since it is protected by our state. You may call my office at West Point Park at 471-3802 and I'll come out to confirm the siting with you.

If you live near streams in the Neuse River basin of northern Durham and Orange counties, you may want to set out on your own expedition to locate and confirm the presence of this unusual animal. Maintaining its specialized habitat by ensuring a high level of water quality in our local streams will then continue to be one of our community's great challenges.

Photo by Robert Rice and the Native Fish Conservancy: least brook lamprey