I was curious about the difference(s) between spotfin shiner and satinfin shiner. It sounds like except for minor variation in the number of rays in the anal fin and color changes at the time of spawning, they are almost the same creature.

I found this and thought it interesting reading about these cool shiners. Heppy, if you save some for an aquarium, they should be in spawning colors soon (mid June if I recall right once temps are right in the waters)

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Fishes Of The Lower Susquehanna And Northern Chesapeake Tributaries, Part IV (Minnows)
By William Estes and Bruce Gebhardt
reprinted from American Currents, March-June 1988
Earlier Installments of this series appeared in the Oct 86, Mar-Apr 87, and Jan 88 issues.



Satinfin Shiner (Notropis analostanus) and Spotfin Shiner (Notropis spilopterus)

Since these two species are said by ichthyologists to be virtually indistinguishable in the field while alive, they are treated together here. Vague methods of distinguishing will be suggested.

Both species are members of the subgenus Cyprinella. They have usual Cyprinella attributes; streamlined shape; great speed and swimming ability; prominent diamond-shaped scales. They can also be identified by feel: it's as though they were made of metal. Males of the two species have several things particularly in common during breeding season: whitish or yellowish fins, pearlescent bodies, and rough tubercles on the snout. Females axe similar to each other, lacking high color.

The anal-fin ray count differs--satinfin 9, spotfin 8. C.L. Smith in Inland Fishes of New York State says the spotfin has 37-39 lateral-line scales, the satinfin 35-37. The most definite distinction Smith asserts, which the authors have not yet tested, is that satinfins have pigment scattered throughout the dorsal-fin membranes, while in the spotfins it is confined to the black dashes between posterior dorsal rays.

The authors of this summary have their own method of telling the species apart--blind instinct. But between them they usually agree, so there might be something to their guesswork. First, a major habitat clue: adult spotfins are more likely to inhabit small creeks, such as Kelly Run, Lancaster County, Pa.; adult satinfins, large ones. The habitat distinction is not 100-percent, however. Second, we have found satinfins only in the eastern part of this area--adjacent to the Delaware drainage, where we have never found spotfins (though both species are said to be there, too).

Now their looks: First, It appears that most fresh-caught spotfins are slightly trimmer than satinfins, possibly because they sometimes occur in great density; after a while in aquaria, spotfins fatten and the distinction blurs. Second, one is more conscious of greenish overtones to the bodily iridescence of spotfins, yellowish with satinfins. Both may develop yellowish fins. Aside from looks, in aquaria one author (BG) has found satinfins (males) slightly more assertive than spotfins.

In breeding time, the male satinfin's beauty magnetizes--especially that dorsal fin with its silver-white iridescence, lit kaleidoscopically with iridescent hues--blue, blue-green, green, gold, bronze. Is there another fish in the world with this type and brilliance of color? The other fins are silvery-white at their tips. The diamond-scaled pearl-gray body also flashes other colors.

A fantastic display is afforded by putting some male satinfins in an aquarium with a dark background, then having them only dimly lit by distant room light behind the viewer. He sees only the brilliant iridescent fins slashing the black, tracing incredible acrobatics. Satinfins and spotfins are two of the very best swimmers among native fishes. They make impossible moves at high speed, males sometimes chasing each other in tight circles, inseparable by human vision.

Frankly, we're not sure if we've ever seen a spotfin male in prime breeding condition. There have been occasional males with yellow-white fins which were quite attractive, but we've never seen any as spectacular as satinfins. The authors would be interested in reading good descriptions of breeding colors of male spotfins.

Satinfins occur usually above the Fall Line from upper New York State to North Carolina. Spotfins are found over a much more extensive mideast/midwest range. One of the authors (BG) has had several occasions to observe satinfins in nature during spawning season (May-June +) in the Wissahickon Creek, Philadelphia (Delaware drainage). John Eccleston and John Clairmont have also witnessed this. Satinfins dominate the shallows, males everywhere taking up stations, sortieing from them to attract females. Their fin displays are something to behold, as the silver-white is visible at some distance. Peak condition is attained in late May in the Wissahickon, which is at about the same latitude as the Lower Susquehanna in Pennsylvania.

It's compulsory to have a couple pairs of these fish in aquaria during breeding season despite the minor inconveniences--i.e., males unmercifully pursue any fish that can't swim out of the way; mighty few can. That tendency is not restricted to breeding season, though it becomes more intense then. After a while, in fact, it may become wearing to watch them!

There's no problem feeding these fish, They need lots of fuel to maintain their high-energy life-style, One doesn't buy a Ferrari for fuel economy, does one? They love flake food, freeze-dried food, live food, frozen food--you serve it, they'll eat it. At the start of aquarium life, they need lots of oxygen. They may be hard to transport home for that reason, so ice or some means of cooling is advisable. They soon adjust to reduced oxygen, however.

--BG

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