I appreciate the chance to look up information about animals other than salmon from time to time. And I also appreciate an obvious idea for a "Drops of Water" article. So I was happy to receive a call last month from someone curious about the blobs growing in the Black River. In past articles we've covered the salmon and trout, as well as the "other" fishes of the Chehalis. Now here's information about the blobs and some of the "other" creatures that one may find in local waters.
The Blobs - These turned out to be freshwater bryozoans. "Bryozoan" literally means "moss animal." The way science classifies animals, bryozoans are in a group all to themselves - the phylum Bryozoa. Most bryozoans are marine, but a few species inhabit freshwater environments. Common freshwater bryozoans are often jelly-like masses as large as a human head. They are actually a colony of smaller animals, and, like colonies of bees and ants, individuals in the mass can have different jobs to do. If you're brave enough to approach one under water, you may be able to see the "tentacles" of feeding individuals.
Some species of freshwater bryozoans have been introduced into lakes and rivers where they do not naturally occur. I haven't been able to find out if the Black River bryozoans are native or introduced. In any event, they are there and they are blobs, however some other blob-like things are out there too. Frog and salamander egg masses can be similar looking. I don't know if there are freshwater sponges in the Chehalis system, but they can resemble bryozoans. There may be blobs out there that we really don't want to know so intimately. My advice is to examine blobs carefully.
Giant Water Bug - This insect is named appropriately; it is quite giant, it lives in the water, and it is a true bug. (So-called "true bugs" are those in the order Hemiptera.) I have also heard them called "toe biters" and "electric light bugs." Scientific types call them "Bellostomatids." Their front pair of legs is sharply tipped for grabbing prey, and they have piercing mouth parts, hence their toe biting reputation. And they are known to fly around lights.
Giant water bugs lurk awaiting something like a small fish or tadpole to swim by. They have even been known to take adult frogs larger than themselves. They are good swimmers and can chase things down over a short distance. Their piercing mouth parts are like a sucking probe contained in a sheath. I once put one in an aquarium where it quickly sucked the life out of four goldfish and a crayfish. I could see the mouth parts probing around under the skin. This is one of those animals that we should be really happy isn't as big as us.
Crayfish - The common crayfish of the Chehalis Basin is the American Signal Crayfish (Pacificastus leniusculus). They are native to Oregon, Washington and British Columbia, but have been introduced all over the world due to their large size and popularity on the dinner plate. They are responsible for the demise of native crayfish species in California and Europe. They are one of the biggest crayfish in the world, and I have seen individuals in the Chehalis that were longer than my hand. Be careful around their claws; I happen to know that even small ones can break skin.
Freshwater Mussel - The large dark-brown-on-the-outside and purple-on-the-inside native mussel commonly found in western Washington rivers and streams is the Western Pearlshell. Its specific name is Margaritifera falcata. Have respect for your elders; western pearlshells can live 100 years! The shells you may find on bars in the river often show teeth marks from otters and other predators. Western Pearlshell larvae, called "glochidia," are released from the females in the spring and must quickly find fish whose gills they can attach to. It forms a cyst on the gill filament and grows into a tiny mussel before dropping off in a few weeks. Trout and salmon are the most common hosts for the glochidia. They are not normally damaging to the fish unless they become extremely numerous.
You may also find the Asian Clam (Corbicula fluminea) in the Chehalis. It has been brought in from Asia as a food item and released into waters in at least 38 states. It looks like a typical clam, and reaches about an inch wide. It can cause fouling of water intake systems and other facilities, and competes with native species for food and space.
Amphibians - If you find a native frog in the Chehalis Basin, chances are that it's either a Pacific Tree Frog (Pseudacris regilla) or a Red-Legged Frog (Rana aurora). The Pacific Tree Frog is usually less than two inches in body length (not including legs), has a distinct dark mask that runs through the eye, and is often bright green, but may be brown or gray or a mix of colors. They have pads on their toes that allow them to be good climbers, and they can be found clinging to walls while hunting at porch lights. For such a little frog they have a strong voice, which they exercise often.
The Red-Legged Frog is up to 4 inches in body length, usually marked with numerous small spots, and are red/orange on the underside. Red-Legged Frogs don't make much noise. Their hatched-out egg masses may be covered in algae and become the most likely blob to be mistaken for a bryozoan.
The Oregon Spotted Frog (Rana pretiosa) is perhaps the rarest native frog in western Washington. One of the last known remaining populations on the west side of the Cascades is located in the Black River drainage. They are similar in size and appearance to Red-Legged Frogs, but usually have larger rosette-like spots, upward oriented eyes, no patches of color on the groin, and rougher skin.
If you go hiking in the southern Olympics, you may find Tailed-Frogs (Ascaphus truei). They get up to about two inches in body length, and adult males have a short "tail." They can be a variety of reddish, brownish, grayish or yellowish colors with mottling. They have a vertical pupil, rather than round, and their tadpoles have a distinctive sucker-like mouth. I've read that there are Cascades Frogs (Rana cascadae) in the Olympic Mountains extending into the Chehalis Basin, but I don't know that I have seen one. They are similar in size and appearance to Red-Legged and Spotted Frogs, but can be recognized by having sharp-edged spots compared to the fuzzy edges of the other two.
There are also Bullfrogs in the Chehalis, but they don't belong here, they eat everything in sight, and I refuse to say anything more about them.
Western Toads (Bufo boreas) are our only local toads. They are warty, dry and robust, like you would expect a toad to be, and they have a whitish line that runs down the middle of their back. Their eggs are laid in distinctive long strings along the water's edge. Like other toads they crawl rather than hop, and can be found far from water. When they're hassled by predators and kids and the like they can secrete a mild poison from glands in their skin. This toad is becoming rare in lowlands, and some populations have rapidly disappeared.
There are a number of salamanders that may be encountered in ponds, streams and forests of the Chehalis Basin. One of the most dramatic is the Northwestern Salamander (Ambystoma gracile). Adults can reach almost 10 inches in total length and have distinct "ribs." They are dark brown with lighter colored swollen areas on the head, tail and sides from which they can secrete a poison. They are secretive, and like to hide in and under cover and in burrows. Their egg masses are more conspicuous, being visible as compact masses of clear jelly with developing larvae clearly visible. Look for egg masses in late winter and early spring.
I can't end this without saying something about Rough-Skinned Newts (Taricha granulosa). If you haven't come across these guys, you must be watching way too much TV. They are brown above and bright orange below. In the winter/spring breeding season you can observe their "wrestling matches" in almost any ditch, rut, puddle or pond in forested areas. They are a good example of why it's a bad idea to go around tasting brightly colored animals. The book that I'm getting some of this information from (Amphibians of Washington and Oregon by William Leonard, et al. Published by the Seattle Audubon Society Trailside Series) says that there is enough poison in a Rough-Skinned Newt to kill 25,000 mice. They say that there is little harm in handling one, but you should wash your hands thoroughly if you do.
There are plenty of other creatures swimming, lurking, flying, creeping, crawling and hanging around out there in our Chehalis River Basin. If you have questions about any of them, or ideas for future articles, please call me and I'll see what I can find out. Mike Kelly, U.S. Fish and Wildlife Service, at 360-753-9560.
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