Text and Photos by Stan Sung
We were submersed in a crystalline stream that flowed swiftly over a gravelly riffle. With a little patience and just the right technique, many little gem – like darters ended up in our small hand net. As Joshua Weigert has explained, we use a variety of means to collect the species we are after. We assess the terrain, natural conditions and fish habits to ascertain which capturing method would work best for each situation. It just so happen to be that using hand nets and snorkeling in the darter streams provided us with relief from the scorching, Alabama sun in July. Fighting the current and outsmarting the Rainbow Darters took a little practice – but we soon got the hang of it and our buckets began to fill.
A MEETING AT THE UNIVERSITY OF ALABAMA IN HUNTSVILLE
We went to the modern, sparkling clean campus of the University of Alabama in Huntsville to meet with professor Bruce Stallsmith. It was a fantastic opportunity to meet and go out collecting with a well respected, long standing member of the North American Native Fishes Association. Bruce has authored many articles in which a number of them can be found on the NANFA website www.nanfa.org. NANFA’s mission is admirable as the leading agendas for them are the appreciation, conservation and aquarium care of our native fish species. Bruce was the president of NANFA for eight years, from 2000 to 2008.
We drove across the bridge at the entrance to the university which spanned across a lake with majestic fountains. The road led us to the imposing, white facade of the Shelby Science Center. The long, air-conditioned hallways and modern, clean lined finishes took a little getting adjusted to for us “swamp monsters” that had just spent a week collecting in the deep, dank swamps of Southern Georgia! Bruce soon greeted us at the entrance to the Biological Science center. He had a big smile and an easygoing personality. He never once made us feel out of place, although we were a ragtag assemblage, similar to what the cat might have dragged in. He introduced us to two of his students, Daniel Kerstien and Sandi Kirkland who would be spending the afternoon in the field with us.
HYPER – DOMINANT, DEEP PURPLE AND CRIMSON SHINERS
Before grabbing his seines and waders, Bruce gave us a quick tour of his newly completed laboratory. Currently the lab maintains some aquariums that contain the stunningly colored Scarlet Shiner Lythrurus fasciolaris. He has selected to work with these red and purple beauties for they are a common, widespread species that would serve as a standard study animal for his body of work. His studies look at the cause and effect of pronounced sexual dimorphism in breeding adults. Bruce and his students examine the brain size, and the function of specific brain regions between males and females. A look at the potent male steroid, 11 – ketotestosterone in dominant males, subdominant males and females. Fascinatingly, 11 – KT is about 200 times more powerful than typical testosterone. 11 – KT is only found in bony fishes. The large, brilliantly colored breeding males have up to ten times more 11 – KT than their mates. Bruce and his students and colleagues are currently in the process of writing two papers on better understanding of what neuroendocrine factors influence the reproductive ecology of bony fishes.
As an aquarium fish the Scarlet Shiner makes an incredible show fish to grace the hobbyists tanks. The scintillating purple bands, crimson fins and heavily tubercled males are one of the most beautiful of our native shiners. Although they are easily captured with a seine net, Lythrurus fasciolaris can be a bit fragile to hold and transport. Placing specimens directly into a breather bag with as little trauma as possible may do the trick. Once acclimated L. fasciolaris make active, beautiful and durable aquarium subjects.
OUT IN THE FIELD: THE WONDERS OF LIMESTONE CREEK
Let’s get out in the field now and get back to collecting the magnificent Rainbow Darters Etheostoma caeruleum. Once at Limestone Creek, our group fanned out in different directions. Tom and I dragged the large seine downstream, over treacherously slippery, algae covered limestone slabs. Bruce, Daniel and Sandi worked the smaller, two – man seine over the rock rubble. I could tell by watching them that they have worked together in the field many times. Bruce and Sandi held each end of the seine as Daniel expertly thrashed and kicked the substrate and water to scare out any shiners or darters toward the awaiting net. John, Jim, Ken and Mark collected with small, hand- held dipnets along a submersed embankment of small stones. The seine that Tom and I were pulling was large, and quite difficult to manage in the rather strong current at this site. We managed to capture a few Redhorse Moxostoma sp and some open – water shiners. Common shiners such as the large Striped Shiner Luxilus chrysocephalus, many silvery Cyprinella shiners, Bluntnose minnows Pimephales notatus, and some of the desirable Scarlet Shiners L. fasciolaris were found within the folds of the seine. The handsome Fundulus olivaceus killie fish were easily spotted at the surface, hugging the shoreline and were easily captured. We even scared a water moccasin into the thickets of root tangles along the shore. After some time we decided to see what the guys upstream had discovered. John and Ken proudly showed off a bucket with many pairs of Rainbow Darters in it. John showed me how he collected them by taking one hand and guiding the fish into an awaiting handnet. It seems that the darters concentrate on the moving hand and do not give the awaiting net much attention. Despite the blazing colors of Rainbow Darters, they can be difficult to spot while in their rocky habitats. When viewed from above they are quite mottled, couple that with the rippling surface from the riffles and the glare of the sunlight and it did take a few minutes of practice before getting the hang of it. This deliberate technique yielded us a number of this most eye – poppingly colorful of US fish.
THE RAINBOW OF THE SOUTHERN STREAMS
The rainbow darter Etheostoma caeruleum is one of the most widespread and instantly recognizable beauties of this resplendent genus of fishes. Its range encompasses many tributaries of the vast Mississippi River drainage of the middle United States. They occur in both the east and west sides of the Mississippi River. This species, along with their close cousin ( and equally beautiful Orange Throat Darter Etheostoma spectabile ) may be part of a complex of similarly patterned, yet distinct species.
In nature, Darters in general feed constantly on many invertebrates continuosly, all day long. Darters are “pickers” that eat throughout the day, and when in captivity they should be fed at least twice a day when possible. These little fishes maintain high activity levels and their need for nourishment remains constant. Foods offered should be of the sinking variety, although most will learn to swim to the upper water strata to retrieve food.
In the wild, Rainbow Darters share their environment with numerous other darter species. Their preferred habitat is characterized by a mix of rocks and gravel, creating many caves and hiding places. Most of the darters, including the Rainbows, are less than three – inches long. These small fish are found along the creek and river edges and shallow areas where there may be abundant plant and algae growth on the rocks. This type of habitat provides plenty of hiding places to elude predators. Their arch nemesis is the Mottled Sculpin that infiltrates the darter habitats and preys upon them. Darters are social and gregarious and can often be abundant in the correct habitats.
KEEPING RAINBOWS IN CAPTIVITY
A community of mixed darter species can make an interesting aquarium. Provide river rocks, slate and driftwood and if there is access to Willow Moss these bushy plants should be added. Keeping in mind their habitat of cool, flowing and pristine environments, any aquarium housing darters should have good water quality and high amounts of dissolved oxygen. When aquatic conditions degrade, the health of the fishes will too. Darters will quickly decline in poorly maintained aquariums. These fish inhabit the bottom of the tank where the aquarist should be vigilant about keeping the lower parts of the tank clean and free of detritus. Hardwater with a PH above 7 should be implemented. Although darters generally like cooler temperatures, Rainbow Darters can tolerate warmer conditions than many other species of etheostoma. They are best when maintained in the mid – seventies and lower. These and many other darters can be challenging to keep in aquariums. Rainbow Darters have been bred numerous times in captivity. Fish that have been “over wintered” naturally will breed in the warmer conditions of the home aquarium. Many of the native fishes can be and will appreciate a wintering period in aquaria as well. A few weeks in cold conditions where they are fed sparingly will serve as winter conditions. Increased temperatures and photo periods sometimes stimulate spawning.
The wide – ranging, and highly variable Redbreast Sunfish Lepomis auritus was also captured from Limestone Creek. This species is native to most of the eastern and southeastern United States and has been widely transplanted outside its native range. All varieties, whether they are yellow – orange, forest green, seafoam – green or robin egg blue are beautifully colored and suitable fish for the home aquarium. Adults posses very long, solid black ear flaps and males will exhibit brilliant red, orange or even yellow breasts. This species is usually associated with clear, rocky streams and rivers, but may also inhabit lakes and reservoirs. These are medium – sized sunfish with large adults averaging under eight inches long. Tom has caught enormous, plate size Redbreasts in southwestern Georgia that were over ten – inches long and several inches tall.
Redbreast Sunfish adapt well to aquarium conditions. Lepomis auritus posses a moderate – sized mouth and can take larger prey items than many sunfish of a similar size. Live meaty foods are best but they will quickly learn to take prepared foods. Although most Lepomis species are hardy and adaptable, we have found that the Redbreasts tend to be more sensitive to poor water conditions and easily break down if good water quality is not maintained. L. auritus also seem to have a stronger need for more dissolved oxygen in their water than most other Lepomis species. Good aeration from a powerful air pump or powerhead should be utilized. These are one of the larger Sunfishes, yet despite their large dimensions and sizeable mouth, this Lepomis species is not nearly as aggressive as its cousins – the longear L. megalotis, Green L. cyanellus or Pumpkinseeds L. gibbosus. Male redbreasts grow much larger than females so the hulking, dominant males can be rough on them. A large aquarium with plenty of hiding places will usually solve this problem.
Green Sunfish were also captured in the clear waters of Limestone Creek. The Green Sunfish Lepomis cyanellus has an even wider range than the previously mentioned species. Second only to the Bluegill Lepomis macrochirus in introduced range, the Green Sunfishes natural range of the central and southeastern United States has been enlarged widely through introductions to the north and far west. This is an undemanding species that can be encountered in many types of water conditions. They will even inhabit polluted, turbid environments not likely to contain other species. This is a hefty, rugged, bass – like centrarchid. L. cyanellus has a more elongated shape and big, bass – like mouth than most taller – bodied sunfish. These brutish fish are quite attractive with a dark shade of green on the back, transitioning to a light green or yellow color on its flanks. The chest can be yellow or orange. Blue and purple highlights adorn their military green bodies and their heads have iridescent striations. Most noticeable on this species is the unique, opaque white, yellow and / or orange trim they posses on the edges of their fins. This trait is similar to the Green Terror Cichlids Aequidens rivulatus. Like the Green Terrors, this sunny is for the hobbyists who like their fish a little bit larger and more aggressive.
The Green Sunfish makes an excellent aquarium fish. They acclimate to aquarium life quickly and learn to take prepared foods without a fuss. These are bullet – proof charges that rarely succumb to infection or disease. In temperament L. cyanellus is similar to many cichlids of Central America. Males can be territorial and large specimens can become hyper – dominant in the confines of an aquarium. A pecking order will usually be established when a colony is placed into the same enclosure. Sometimes however, the dominant male Green Sunfish will become too brutal and additional means of maintenance must be used. Tom introduces us to two ways of keeping groups of aggressive sunfish. He either keeps a group with one, very dominant male and several females – and sometimes a few smaller males, or he will keep them crowded like Malawi Cichlids in the aquarium. Keeping several males among females, and many other fish will help diffuse the aggression. In these crowded conditions, hyper- dominant males will have a difficult time maintaining territories which in turn, diminishes the fighting. Large, male sunfish do like to stake out the most desirable spot in the aquarium. They like an area with cover, however they also like to be closest to where the food gets dropped in. These fish often put on a show for their keepers. They will flare, spread their fins and beg for food, in the front and center of their aquarium.
These predators are not at all difficult to feed in captivity. They will quickly accept pellets, krill, frozen fish and all other meaty foods offered. Live foods such as fish, crayfish, earthworms, tadpoles, insect nymphs and terrestrial insects can also be fed. Because of the nutritious diet these fish are usually offered in captivity, Greenies will sometimes grow much larger than their wild counterparts. An adult Green Sunfish larger than six inches long in nature can be considered rare. In well cared for aquariums this species can double that size.
We have found that Lepomis cyanellus breed readily in the home aquarium. The male will usually dig a series of pits in the substrate and try to entice the much smaller females with flared gills and body wagging. The adhesive eggs are small and numerous. They are laid in the nest pits dug into the substrate. The male guards the eggs and fry. The eggs hatch in about two or three days and the fry become free – swimming after about a week post – hatching. The fry will consume baby brineshrimp as an initial food.
The Green Sunfish is an excellent addition to a large North American native fish display tank. They retain a “wildness” in captivity and look great among submersed wood and stones. Although they are not as gaudily colorful as some of our sunfish, they are still attractive fish that are roguish, brutish, wild, intelligent and entertaining fish to maintain.
THE NORTHERN STUDFISH
The Northern Studfish Fundulus catenatus is a killifish species not for the faint of heart! This is a big, powerful and aggressive denizen of the crisp flowing streams. I liken this fish as a killiefish who thinks they are a trout. We collected these seven – inch killies from various sites in the Paint Rock river system. Their favorite haunts are areas of moderate current that is flowing over either gravel or limestone slabs. Although they have a reputation for being rather fragile in captivity, we have found this studfish to be particularly durable in aquaria. These fish can be fearless. Jumbo males held in a photo tank will display with fins erect and gills flared. What Fundulus catenatus prefer in captivity is a large aquarium containing well – oxygenated, hard and alkaline water. Considering the massive size and dominant personality of the studfish, an aquarium of no less that forty gallons should be employed to adequately house them. Studfish love to roam. I keep them in an eight foot long aquarium where they utilize every square inch of it. The most dominant males are territorial and will display and battle one another at all stratas of the aquarium. These killies will get along well with medium size sunfish Lepomis sp. However they are far too rambunctious to be placed with small sunfish and most other types of killifish when they are mature.
Due to their highly active lifestyle, these fish love to eat – a lot and frequently! Frozen bloodworms and chopped earthworms being their favorite. Most frozen and live foods are taken. Chopped nightcrawlers put on weight and bulk – and are particularly helpful in filling the females with roe. This is a bottom – spawning killiefish that will lay their eggs in the sand or gravel substrate in nature. The well – armored head of the male studfish may be used to drive the breeding pairs deep into the substrate. Breeding males are beautifully colored with a metallic, light blue body, red spots and yellow fins. The constantly flared out gill membranes are also a lovely shade of yellow. The crowning touch in nuptial males are the fluorescent, limegreen streaks that run on top of their heads, just above each eye. These vibrant, slashes of color, combined with big, glowing gills make dominant males look formidable, with large, oversized heads.
In aquariums several techniques are used to spawn the Northern Studfish. One can use sand or gravel as a substrate – and periodically collect them by swirling the very large, light yellow eggs out from the bottom. In bare bottomed aquaria eggs can be netted off the bottom. The breeders will eat their eggs, so I like to put some sinking mops into their aquaria to provide the eggs some shelter. The eggs can also be picked out of these bottom mops as they are slightly adhesive and can gather on the yarn fibers. A delicate touch is not necessary as the eggs have very hard shells that are not easily damaged. Place collected eggs in a small, aerated container and change the water and pick out any fungused eggs frequently. The eggs will hatch in ten to twelve days. The fry are easily fed with newly hatched brineshrimp and pulverized flake foods. The young are strong swimmers – built for the riverine currents from which they hail. Rearing the fry is straight – forward and do not present any difficulties.
Most hobbyist could never imagine fishes of such glorious colors, whether it is the chromatic brilliance of Rainbow Darters or red and blues on a beautiful studfish swimming in our own watercourses. These true aquatic jewels can be found in the verdant, clear – running streams of the Alabama forests. A large display aquarium housing our native sunfish and bass – the centrarchids beholds the essence of wild frontiers, in deep pools of vast, tree – lined lakes. I would like to thank Dr. Bruce Stallsmith for his assistance and great wealth of knowledge regarding the ecology and biology of our own, wonderful fishes of the U.S.A.