LABORATORY SPAWNING AND REARING OF THE ENDANGERED FOUNTAIN DARTER

Survival of the fountain darter (Etheostoma fonticola), a U.S. federal ly listed endangered species, may depend on captive propagation. Studi es were conducted to determine the effect of temperature on spawning a nd to develop methods for culture. The fountain darter spawned and pro duced viable offspring in aquaria at 27, 24, 21, 18, 15, 12, 9, and 6- degrees-C. The fish also spawned at 3 and 30-degrees-C but did not pro duce viable eggs. Daily egg production of individual fish held at 27, 21, 15, and 9-degrees-C was variable. The mean critical thermal maximu m for the fountain darter was 34.8-degrees-C. Early life stages, 4-14 mm long, were offered a variety of live protozoans, rotifers, and micr ocrustaceans. Food selection varied with fish size and food size. Foun tain darters reached sexual maturity in about 180 d when maintained at 21-degrees-C. Three-year-old darters produced viable offspring, and s everal lived longer than 4 years. Tricaine methanesulfonate was an eff ective anesthetic at 60 mg/L but was fatal to subadults at 100 mg/L.