Overview of the Darters of the Genus Etheostoma
Although there are four genera of darters in the family Percidae, the largest (and most colorful) are those in the genus Etheostoma. Small in size and mild in temperament, the Etheostoma darters are among some of the best suited native fish to small-to-moderate home aquariums. Though there are too many lovely fish in this genus to discuss in great detail, this article should give you an idea of how to take care of the “average” darter.
Species
Etheostoma is a very large genus of fish in the family Percidae, containing 156 known species in that family. All are native to North America, with 153 species being found in the US and 3 (E. lugoi, E. pottsi, and E. segrex) are found solely in Mexico. The pictured fish species for this article is the Slackwater Darter (E. boschungi).
None of these species are commonly available in the pet trade,
though do see their way into stores on occasion.
Conservation Status
According to the IUCN Redlist, there are 102 Least Concern, 15 Near Threatened, 23 Vulnerable, 11 Endangered, 3 Critically Endangered, and 1 Data Deficient species of darters. Always know the conservation status of any/all fish collected from the wild for home use. Of course, you’ll want to avoid those which are threatened with extinction and focus on those species which are of stable populations.
One species, the Maryland Darter (E. sellare), was declared Extinct in 1988.
Description
Darters are generally small fish, most reaching between 1 (Golden Darter, E. denoncourti) and 6.5
inches (Greenside Darter, E. blennioides). The vast majority of species reach a maximum of 2 to 3.5 inches. For many species, coloration is seasonal with brightest colors being shown around breeding time.
Darters act very “goby-ish” in that they spend the majority of their time on the substrate, save for swimming in short bursts to argue with tankmates or lunge at food. That said, they are typically pretty easy-going with other fish and (personality-wise) are compatible with a wide range of smaller fish such as the smaller minnow species. Darters aren’t the fastest feeders, though, and care should be taken not to place them with other species which will eat all the food before darters figure out that it’s dinner time. That said, I did have a darter that enjoyed swimming at the top of the tank when it came time for feeding so it may depend on individual fish.
Darters are retiring and will spend much of their time holed up in caves or hiding behind tank decor if the option is presented. They especially seem to prefer rockwork and will explore nooks and crannies in larger piles. These fish are escape artists and will find a way to exit uncovered tanks (or through holes in hoods). Floating plants like Anacharis can help prevent this from happening.
Feeding
Darters at first do best with live foods such as blackworms, but I’ve found they convert to frozen foods fairly quickly. Mine in particular prefers bloodworms most and only nibbles a bit at brine and mysis shrimp, but you should provide a variety of foods for best effect. It’s not very likely that they will make the switch to prepared foods.
Feeding can sometimes prove problematic with tankmates, given the slow nature of the darter’s feeding habits. Particularly active tankmates (like Chrosomus minnows) and stronger bottom feeders are especially likely to out-compete darters. Spot feeding may help solve this issue.
Water Quality
Darters are not particularly picky about water hardness and pH, provided that extremes are avoided. Most species should do well around 5-15 dH and pH 6.5-7.5, though some sources state that slightly alkaline conditions (dH 10-15, pH 7-7.5) are better. Darters prefer cool-to-cold water and do best at around 60-65 F, though should be fine up to 68 F. Although a few species do come from warmer areas, the majority of species will fail to thrive if not kept in lower temperature conditions.
As stream fish, they need high quantities of oxygen in the water to do well. High filtration (8-12 times tank turnover per hour) and/or powerheads are recommended.
Brackish Suitability
Of the documented species of darters, only one species (The Gulf Darter E. swaini) has been noted as tolerating low end brackish conditions and probably only around 1.003 at that. Most darters hail from freshwater streams in the wild and are not noted in brackish areas.
Tank Size
Given their relative inactivity, most darters (of up to 3.5 inches) could be kept in 20 gallon long tanks. For the species larger than this (4 to 6.5 inches), look into a 30 to 40 gallon tank for long term care.
Final Thoughts
Darters are colorful, peaceful fish that can make very good inhabitants in the native fish tank. If you can provide cooler conditions, high water flow, and a steady supply of live/frozen food, these might just be the fish for you.
Sources
Fish Identification, Fishbase
North American Fishes for the Home Aquarium, David M. Schlesser
Our Native Fishes, John R. Quinn
Darters: Aquarium Care and Design Guidelines, Ray Katula
Etheostoma zonale, The Aquarium Wiki
(Image Source: Me!)