Say! What a Lot of Fish There Are.
Dr. Suess had it right. His famous children’s poem One Fish Two Fish Red Fish Blue Fish taught us life lessons about diversity and wonder and that no matter our size, shape, or color, all things are important. This certainly is true of the small, nongame fishes of Missouri, which can also be “black fish, blue fish, old fish, new fish.” About 225 fish species can be found in Missouri. They range in size from giant sturgeons, paddlefish, and catfishes, which may grow to more than 100 pounds in weight, to tiny species, some barely over an inch long (and given appropriately descriptive names like banded pygmy sunfish and least darter).
Most of Missouri’s fishes are rather small and inconspicuous, and they go unnoticed by the casual observer. This is unfortunate, because these are some of the most interesting examples of our fish fauna.
Some Families Have It All
Darters are arguably some of the most colorful and strikingly beautiful of Missouri’s fishes. They are the smaller members of the perch family, Percidae, which includes the more familiar and sought-after walleye, sauger, and yellow perch. Among the darters, one group in particular is both showy and of great interest to taxonomists (those who study the classification of organisms) and ecologists (those who study the relationship of the organism to its environment); this group is known as the orangethroat darter complex or species-group.
We call this group a “complex” because the populations are closely related, often looking quite similar to one another. Only through careful examination of individual characteristics (color, pigment patterns, scale counts, body proportions, etc.) and observation of habits (habitat selection, reproductive behavior, etc.) can scientists separate them into bona fide species.
Orangethroat darter and closely related relatives make up a few of the more than 40 darter species known to Missouri. Accurately identifying many of these darters requires some time, patience, and familiarity with fish taxonomic keys. But as the common name of this species-group implies, they all have bright orange gill membranes (the approximate “throat” region) and in some populations the orange color may extend onto the head.
In general, members of this group live in riffles in headwater streams where they are sometimes the only or the most abundant darter. They can be found in medium-sized streams too, usually near riffles or in shallow, gravelly shoals and may occur near populations of rainbow darters (E. caeruleum). These