by Joseph Parish
It seems like every week another alien species invades America’s waters usually with some very detrimental effects upon the native species. As a result of these unwanted additions to our waters every state has been forced to adopt illegal fish laws to combat these dangerous creatures; however they still somehow manage to invade our territorial waterways. Perhaps they were at one time part of someone’s fish collection and simply got too large for them to contain properly within their fish tank or they may have accidentally escaped their confines. Either way these species of fish generally kill off the natural fish in the area and unfortunately encounter no natural predators within their new found home.
The state of Delaware, like its neighboring states have enacted laws intended to prevent these invasive species from being released in the states waters. Several of these undesirable creatures include the walking catfish, the white amur, live Northern snakehead or the blotched snakehead fish.
The snakehead is a vicious creature who became established in the Potomac with drastic impacts upon the native fish. This species is long and cylindrical with a long dorsal and ventral fin. It possesses a large mouth with an abundance of sharp, jagged teeth. They can often be found in weedy ponds or streams. We have been lucky here in Delaware that none of these fish have been discovered however they have already invaded the waterways of neighboring Maryland. For us it is probably merely a matter of time.
The flathead catfish has previously been reported in the Pennsylvania area from the Schuylkill River to the stem of the Delaware River. These fish can be recognized by their very flat head profiles. Their coloration borders upon a blotchy black with portions of brown and they possess a lower jaw which protrudes well beyond their upper one. These fish often grow very large and frequently prey upon a variety of our native species.
The Zebra & Quagga Mussels are closely related freshwater creatures which can survive out of water for as much as a period of 5 days and are unknowingly transported from one place to another by human activities. These mussels can attach themselves to just about anything found in the water even another animal such as the crayfish. When inspecting for these marine vagabonds look for light and dark bands which appear on the shell. So far none of these ocean life creatures have been discovered in Delaware.
The last invader we are going to talk about is the Chinese Mitton crab. This creature was first discovered in 2006 within the area of the Chesapeake Bay. Unfortunately, there have been a number of these crabs discovered in Delaware waters. Their characteristic appearance is easy to identify since they display fuzzy claws with a notch between their eyes. They may grow to a length of up to 4 inches across.
Copyright @2010 Joseph Parish