Saving the Longeared Sunfish

By Fred Hamilton
First published in Fincinnati, the official newsletter of the Greater Cincinnati Aquarium Society
Aquarticles

Sunfish are members of the family Centrarchidae - the ecological equivalent of the cichlids, which belong to the family Cichlidae. The most familiar of all game fish, the bluegill, Lepomis macrochirus, is a sunfish. Locally, we are fortunate to have one of the most beautiful representatives of the family, the longeared sunfish, Lepomis megalotis (Fig. 1). This article relates my experiences in keeping and breeding this beautiful fish, and how I came to make an effort to conserve this species (and the pumpkinseed sunfish, Lepomis gibbosus ) (Fig. 2) with the help of the Cleveland Metropark Zoo.

Fig. 1. Longeared sunfish, Lepomis megalotis

Fig. 2. Pumpkinseed sunfish, Lepomis gibbosus

Unfortunately, the longeared sunfish is an endangered species over much of its former range. It is officially listed as "threatened" in Wisconsin, Pennsylvania, and New York, and as a "Species of Concern" in North Carolina. Illinois populations have been recognized as being in decline since 1979, and the species is become extinct in Iowa. The Ohio Department of Natural Resources website notes significant threats to the species caused by habitat destruction in western Ohio. As a result of these and similar pressures, the longeared sunfish is now absent from all of southwestern Ohio, except for two populations in Clermont County, one at scattered points in the Little Miami River, and another in a tributary of the Ohio near the Moscow, Ohio Zimmer power plant. I have collected young fish from each of these populations, and around Christmas, 1997, a pair finally spawned.

Longears are typical of members of the genus Lepomis, and breed in nests formed by the males, which fan a depression in gravel by standing upright, using their tails as a "broom." Groups of transparent adhesive eggs (typically 100-300 in captivity) are expelled by the female who is literally pressed to the substrate by the amorous male. After spawning, the female is driven away: after the fry become free-swimming, the male also loses interest. Fig. 3 shows the male enticing a female into a nest created in a terra-cotta flowerpot base. Fig. 4 shows the young at about three years. The size variation between young male and female longeared sunfish is dramatic: Fig. 4 shows a young adult male of about four inches TL, surrounded by smaller females ranging in size from 1" to 2.5".

Fig. 3: Romance in longeared sunfish

Fig. 4: Three-year-old fry

Raising newborn sunfish is difficult -- but only for the first month or so. Fry must be fed newly-hatched brine shrimp during this period, but thereafter will eat virtually anything you care to feed them, including flake food, trout chow, worms, mosquito larvae, and especially frozen brine shrimp. My first spawn was raised in a 55-gallon, then a 125 gallon, and finally, in a 1,000 gallon concrete tank (an article about the 1,000 gallon tanks appears elsewhere at this site). Below (Fig.5) is a photo of the "grow-out" tank containing about 200 longears which survived to three years of age.

Fig. 5: Thousand gallon grow-out tank

Word of these fish spread around the internet, and with the help of the North American Native Fishes Association's mailing list, I was able to share about 50 fry with collectors in Idaho, Florida, and Ohio. In September, 2000, I received an e-mail from Nick Zarlinga, an Aquarium Biologist at the Cleveland Metropark Zoo, inquiring about the possibility of obtaining longears and pumpkinseed sunfish for a 65,000 gallon outdoor display (with underwater viewing window). Needless to say, I was thrilled (and relieved -- note that 200 longears eat a lot of frozen brine shrimp!). So, one Saturday, a van from the Zoo, with the Zoo's Curator Don Kuenzer, arrived at the door of my fishroom in Kennedy Heights (Fig. 6-7).

Fig. 6. Don Kuenzer (left) and me (in Volunteer uniform)

Fig. 7. Zoo logo on "Fishmobile"

The prior day, I had removed one ton of creekstone from the 1,000 gallon tank (Fig. 8). This simplified the capture of 75 longears of a suitable size for display and their transfer into the van, which was equipped with two transport tanks of about 200 gallon capacity, and electrically-powered air pumps (Fig. 9).

Fig. 8. One ton of Cincinnati rock from grow-out tank

Fig. 9. Sump pump transferring shipping water

After a brief cooperative effort by me and Don, the first batch of three-year-old longears were ready for shipment (Fig. 10). A second effort netted eight assorted-size pumpkinseed sunfish obtained from an Idaho breeder -- also destined for the Zoo's display (Fig. 11).

Fig. 10: 3 year olds - ready to ship, Lepomis megalotis

Fig. 11: Yearling pumpkinseed, Lepomis gibbosus

I have worked with many species of fish, but the longeared sunfish is probably one of the easiest -- and certainly one of the most beautiful -- species which I've had the pleasure to know. More importantly, it is one of many native species which need our our attention and our help in order to survive in the new millenium. Hopefully, thanks to efforts of Nick, Don and the staff of the Cleveland Zoo, the public will become more aware of this endangered "hidden gem" which graces our local waterways.

Interested in educational efforts aimed at safeguarding our aquatic resources? The Wave Foundation at the Newport Aquarium is accepting applications for volunteer educators. Call Jenny Yee, Volunteer Coordinator, at (606) 815-1441