Not an Oxymoron
There are some concepts that fit the definition of an oxymoron, but unbeknownst to the majority of the non-ichthyologically educated public, the phrase “Big Minnow” does not qualify for that concept. When most of us think of minnows we think of very small fish, but often the fish species that come to mind don’t fit the proper definition either. Fishermen frequently speak of “minnies” as any small fish that is used for bait, but let me take an opportunity to tell you some of what I’ve learned about minnows. First of all, the scientific definition of minnows limits the group to the fish family Cyprinidae, so all those little bass, darters and sticklebacks may be used for bait, but they are not minnows.
Next, allow me to elaborate on the idea that not all minnows are small: Did you know that the minnow family includes common carp? Oh, and there’s a subject that needs some correction as well! You see, carp are not only the bottom feeding scavengers that the term conjures up in our minds, but instead include a diverse assemblage of fish species such as Koi, Goldfish and “Asian Carp”, a term that begs for explanation in of itself. We’ll return to that area of controversy later in this post.
Pikeminnows are the largest native North American minnow species, reaching six feet in length with a maximum recorded weight of about 40 pounds. The biggest minnow species at up to 10 feet long and almost 140 pounds is the Giant Barb Catlocarpio siamensis, found in southeast Asia where it is sometimes kept in ponds for food.
OSUM 74564 Ptychocheilus umpquae Umpqua pikeminnow
Catlocarpio siamensis Giant barb (photo from National Geographic)
Speaking of Asia, let me take a few sentences to flesh out the term “Asian Carp”. Recently, sensational news reports revealed invasive fish species now found in several tributaries to the Mississippi River that are included under the umbrella term “Asian Carp”. It is a fact that all carp originally came from Asia and parts of Europe, but the carp that are currently most notorious are actually two species, the Bighead Carp and the Silver Carp. Two other species, Grass Carp and Black Carp, are also relatively recent invaders, but the Common Carp has been here since the mid-1800’s when they were imported by entrepreneurial European farmers in an effort to continue their husbandry of the fish that they had raised in ponds back in their homelands. Unfortunately the U.S. Department of Conservation decided that a little bit of a good thing would only be better if it were increased, so they transported Common Carp in rail cars across the United States. Common Carp in the wild are bottom feeders and require removal of the “mud vein” to make them palatable, so the invasive fish became a nuisance since they actually muck up the waters and decrease aquatic habitat quality. Fast forward to the past 50 years when another well-intentioned effort resulted in disaster: Overflowing Bighead and Silver Carp hatcheries in Missouri introduced those species to the Missouri River from where they proliferated and now represent a substantial portion of the fish fauna in much of the Mississippi River mainstem and watershed.
Hypophthalmichthys molitrix, Silver carp (photo by Brian Zimmerman)
Now, most minnows are indeed small, and the smallest minnow, by the bye, is also the smallest known fish species in the world (Paeodocypris progenetica) for which there is no common name that I could find. Found only in Sumatra, the species matures at about 10mm long. For comparison the smallest minnow in North America is relatively a whopper at 38mm. Minnows are a very well researched group of animals and there is a lot more to talk about; for example going into more depth I could tell you that the only true minnows are the fishes placed in the subfamily Leuciscinae, or that true minnows only have teeth in their throats…but we’ll leave those tidbits for another blog.