Just prior to commencing the task of writing this article, I was reading some critical comments regarding the Endangered Species Act, active now for 25 years. The Crystal darter (Crystallaria asprella) is clearly (pun intended) a poignant case in point with a species, while not endangered nationally though often state listed, seems to be a residual beneficiary of laws enacted to clean up our rivers. Several populations of the Crystal darter appear to be on the rebound albeit not all things are rosy for this resident of higher quality fast flowing larger rivers. Crystal darters originally resided throughout the larger river basins of the Mississippi and Ohio Rivers but conspicuously absent from the vast Missouri River drainages aside from the Gasconade River of Missouri. Populations have become severely disaggregate due largely because of dam construction and secondarily from siltation and pollution contributing to their decline. Largely due to more efficient and diligent sampling methods and likely rebounds of several populations the Crystal darter appears to be in better shape then it was a 30 years ago. It can be argued but it appears likely that coinciding with the Endangered Species Act the rare Crystal darter appears to be on the rebound. One more reason the Endangered Species Act should be continued.

The Crystal darter is a member of the Perch family which includes the much more familiar Yellow Perch (Perca flavescens) and the Walleye (Stizostedion vitreum). Unlike many members of of the largest Perch group, the Darters, the Crystal darter is not exceedingly colorful but does possess handsome cryptic markings. The Crystal darter is a large, cigar shaped fish slightly flattened making it supremely adapted for the overbearing water currents they typically reside in. The body is generally bi-colored with the lower half being white or silvery. The upper body is variable with the most typical pattern (of Wisconsin/Minnesota specimens) being a tan or brownish mottled base with 4 black or chocolate brown distinctive dorsal saddles. Their fins are essentially colorless though the caudal fin dorsally may have darkened bands of pigment. This is the one color phase of the darter that is very distinctive and appealing. Another phase seen, often in juveniles and sometimes within the same individual of adults displaying the aforementioned pattern is a lighter phase which is much more plain and somewhat reminiscent of the typical related Sand darters (Ammocrypta). In this plain version the dorsal areas are much paler with the dorsal saddles barely visible. A mid-lateral series of spots and/or blotches are more visible in this form. Some literature reports state that the Crystal darter is translucent when alive (Page 1983) but except in one extremely small juvenile I had caught, their seems to be no transparency in any specimens I've seen. Some specimens, generally from the darker phase will display a yellow green cheek and opercle and a really exceptional fish will show yellow green dorsally between the dorsal blotches. These colors do seem more intense during presumed spawning activity. The dorsal pattern, when viewed above the Crystal darters proffered substrate blends them cryptically with their surroundings. For a darter, Crystals are relatively large reaching a size of just over six inches.

The systematics of the Crystal darter has become clearer in recent years. As previously mentioned they are a member of the Perch family (Percidae). Sharing no other species within their genus they are without question the most distinctive perch of North America. Long considered to be a member of the Sand darter genus (Ammocrypta). Simon (1991) based upon morphology hypothesized that subgenera Crystallaria and Ammocrypta are phylogenetically different. Even when a laymen observes both Sand darters and the Crystal darter they appear very different from one another. Typical Sand darters are small, very translucent and much more slender then the Crystals with a very different pigmentation pattern, when there is pigment. Both genus display an affinity for burying themselves within the sand substrate with only their eyes protruding. Here the Crystal darter habitat varies as they prefer a more gravelly sometimes small pebbled substrate though we have caught them over pure sand also. The burying habit is not exclusive to the Sand darters as other Darter species have displayed this practice also. The Snail darter, (Percina tanasi), the Glassy darter, (Etheostoma vireum) and the Rainbow darter (E. caeruleum) have been observed burying themselves within the substrate. Hobbyists and scientists are noticing more species engaging in this practice and it should be noted that Swamp darter species will commonly burrow in soft silty substrates. Obviously they can escape predation by this practice but it also conserves swimming energy and allows the ambush of prey items.

When collecting the Crystal darter the author would note an area which had flocculating substrate where my boots would literally sink into the bottom. The raging water currents would create flocculent pockets of gravel and pebbled substrates and the Crystal darters I collected would show a strong affinity to occupy such areas.

Crystal darters are so rarely caught that several debates have surfaced as to what collecting method is most advantageous in capturing specimens. Because of the Crystals habits of burying themselves under the substrate, most nets pass right over them. When disturbed Crystals have displayed incredible speed, no doubt an adaptation to their living in swift currents. Because of the river current's speed it is not practical to pull a seine net upstream which is the most typical of seine pulls. Using a one man seine, 4 feet x 4 feet in size the author has captured 4 specimens of the Crystal darter after considerable effort. One theory is that Crystal are nocturnal and therefore more easily captured at night. Elsewhere it has been suggested that the downstream areas of islands prove fruitful and Glenn Clemmer (Mississippi State University) has stated that evening collecting in slackening current at the foot of large riffles may produce success when day collecting has proved fruitless. Konrad Schmidt, editor of the Native Fish Conservancy and fish surveyor for the stare of Minnesota has published a study on collecting Crystals and has determined that using large seines is the best way to sample Crystals with boom shocking the second best method. Crystal darters are often caught in deep water and this presents more problems for the collector as most minnow seines contain floats and these effectively raise the bottom of the seine off the substrate. Most seines that are over 4 feet deep generally possess a mesh too large to allow the capture of small fishes. Andy Bartels of the Wisconsin D-N-R has captured a Crystal in 30 feet of water with a deep water trawl. Konrad and Jay Hatch had caught a fair number of Crystals below wingdams which help expedite water flow and help scour the bottom. This is one man made structure that has apparently helped a rare species. In a habitat where feasible (not too deep) it appears that the most successful method is to take a large seine with two men pulling on it and proceeding downstream at break neck speed. After running ten to twenty yards lift the bottom out of the water and then checking the contents of the seine. In this manner Konrad Schmidt and I captured three specimens in one day, by far our most productive day. Boom shocking is productive in some situations but has it tangible problems as well. In deeper water or turbid water it's difficult to sight specimens after they have been shocked in order to net them. As a Darter, Crystals have no swim bladder and therefore cling to the bottom after being shocked. Obviously, even with the best collection methods we can develop and optimal conditions, it is a difficult species to collect. About half my time was spent collecting at dusk or at night yet did not appear to be any more productive then daytime collecting. Konrad Schmidt and myself did collect below several islands but this yielded no specimens. It appeared that for about every two hours worth of collecting yielded one specimen.

All of my collection attempts were made in the Red Cedar basin of Wisconsin. Konrad Schmidt had made much more extensive collections throughout the upper Mississippi River basin. While I have no true basis of comparison, the next day following a day of Crystal darter collecting feels as if I had been hit by a train. After Konrad's 30 years of collecting natives and my own 30 years of experience we both agree that collecting Crystals is by far the most strenuous of any collection attempts we had made. Running full speed down a fast flowing river with chest waders, dodging boulders, logs, and net entanglements is not for the meek, or for that matter, the sensible minded individual. Because of the aforementioned difficulties it could be that the Crystal darter is not as rare as they appear to be. Populations may never have been all that large and unless specifically targeted in fish surveys, they are not likely to turn up in your average fish collecting activity. Konrad Schmidt has recently caught a Crystal darter in the lower Root River in Houston County of Minnesota, a first. Thirty years ago they were not known to have occurred in the Chippewa, Red Cedar, and Trempealeau Rivers but are now known to occur in these river basins. With the Root River discovery it would seem that the Crystal darter will ultimately turn up in more river systems, particularly if targeted in collection efforts. The lower Black River appears to a prime candidate river for it contains extensive sandy shoals and fast currents not to mention many sympatric species. Other potential Crystal darter locales in Wisconsin could be the lower Buffalo river and the lower Kinnickinnic river.

Once home, specimens had difficulty adjusting to life within the aquarium. Their shy nature made them jittery when a person would approach the aquarium. Were it not for an aquarium cover I'm sure many fish would become jettisoned and I would be picking up their dried remains from the fish room floor. Several specimens were lost due to injuries occurring around the head regions. Apparently they were bumping into the aquarium glass (I provided a 55 gallon aquarium) when disturbed. Another possibility was their substrate burrowing activity however some specimens survived for long periods and constantly buried themselves with no ill affects. Two Crystals were caught in early 1994 and did survive for a year and a half and gave up some clues as to their fecundity period and spawning methods. One specimen caught on March 23, 1994 appeared to be swollen, evidently carrying eggs. She survived and consumed a diet of whiteworms, glassworms and later was weaned onto a diet of frozen brine shrimp and frozen bloodworms. In April another specimen was added but sex was not definitely ascertained as the specimen was not visibly filled with eggs. When fed a captive diet though it's abdomen did distend and quite possibly was another female. When caught in March the aquarium temperature was at 55 F and gradually raised to 62 F by May 1st when eggs were first discovered. They were found buried within the substrate 1" to 2" deep. The eggs were relatively large, 1.8 mm by my best estimate using a small ruler. They were strongly adhesive and while most were found singly an occasional clump of 2 to 3 eggs attached to each other were also discovered. The eggs were a light straw color. Upon their discovery I siphoned the substrate gravel and found about 18 eggs which were placed into another bare aquarium to determine and monitor egg development- Unfortunately they never eyed up and had to conclude unless something went awry in my simulated setup, I possessed two females. On May 15th another effort to locate eggs proceeded with 25 more eggs found. They were separated and once again did not develop. Despite several more efforts no more eggs were found. Both these specimens lived throughout the next year and the following spring displayed distended abdomens from the middle of March through mid-May, likely their time of natural breeding activity in Wisconsin. The Crystals were kept in the basement of my home which simulated an overwintering period since it was not heated. Temperatures would dip down to the mid forties in mid-January and then subsequently rise thereafter. Other specimens caught, particularly in mid-summer, were very vulnerable to fungal infections and generally did not survive much longer then several weeks. As in collecting any coldwater fishes it appears the cooler the water collected in the better. Overall Crystals display very little activity within the aquarium. They do spend a considerable time buried within the substrate, buried so well sometimes I pondered if they indeed still inhabited the aquarium. This inactivity as aforementioned conserves valuable energy with the Crystal darters metabolism.

The Crystal darter appears to possess relatively healthy populations within the Upper Mississippi River and larger tributaries. While the two large impoundments caused by the Corp of Engineers dams creating pools 8 and 9 might impede the movement of Crystal darters into Iowa boundary waters, I would venture a guess that recent flood years has washed specimens and particularly larval fry into Iowa waters where they may reside in suitable habitats such as the tailwaters of wingdams. Dredging has been cited as a possible cause of habitat destruction however, Jay Hatch and Konrad Schmidt captured a specimen at a designated and active dredge spoil disposal site. They concluded that possibly the unconsolidated material gradually eroding back into the river might be providing a soft and suitable substrate for the Crystals burrowing activity. Siltation is likely a negative factor for Crystal darters since any deposition of silt is likely the result of lacking currents and any further impoundments on existing Crystal darter habitats should be curtailed not just to protect the immediate, inundated habitat but to also allow migration up and down the major rivers they prefer as habitat. Other populations of existing Crystal darters are severely fragmented and in many states they have become extirpated. They are still found in the Gasconade River of Missouri, Mississippi, Arkansas, Louisiana, Alabama all appear to possess some stable populations and a remote small population is present in West Virginia. The Crystal darter has become extirpated throughout most of it's eastern range including Illinois, Ohio, Kentucky and Tennessee and as previously mentioned, may or may not exist in Iowa boundary waters. Likely due to a variety of factors such as pollution and siltation the Crystal darter has virtually become eliminated from the vast Ohio River drainages.

With funding from the Native Fish Conservancy the author hopes to commence another captive breeding attempt not only to simply reproduce the species but also to observe the larval swimming characteristics since through captive breeding observations the author has noted a considerable number of Darter species are pelagic swimmers for 6 to 8 weeks. If this is indeed the case for Crystal darter fry, then there would seem to considerable promise that they might follow the whim of river currents and during high flood years, washed into downstream areas where they could repopulate historical range. This of course if suitable habitats exist for them. While it may not seem critical for the Crystal darters continued existence, they do represent a unique genus in the family of Perches, as Darters they do feed upon a considerable number of insects and they are often found sympatrically with Walleye, (Stizostedion vitreum) which likely feed upon the Crystals. They also serve as indicator species of our large rivers where there occurrence represents a healthy stream. They are not a species that will likely become a popular aquarium species but for the native fish enthusiast that loves a challenge, this is it. Anyone interested in learning more about our interesting North American native fishes should contact the Native Fish Conservancy, 1663 Iowa Ave. Ave. E., St. Paul, MN 55106 or contact at website: http:\\www.nativefish.org and the North American Native Fishes Association, Shireen Gonzaga, 125-C Dumbarton Rd., Baltimore, MD 21212 and website shireen~clark.net.

A special thanks goes out to Konrad Schmidt for helping provide information and most of all for sacrificing his body for numerous hours of collecting time on the Red Cedar.