TOPEKA SHINER } Notropis girardi
DESCRIPTION: The Topeka shiner is a small minnow averaging about 1.5 to two inches in length, with an olive-yellow back, dark-edged scales, and a dark stripe running along its silvery sides. It has numerous bumps on its snout, head, body, and the rays of some of its fins, as well as a triangular black spot at the base of its tail fin. Breeding males have orange-red fins and an orange tint on their heads and bodies.
HABITAT: The Topeka shiner lives in small, low-order prairie streams with good water quality and cool temperatures. These streams generally exhibit perennial flow, but some approach intermittency during summer. The predominant substrate types within these streams are clean gravel, cobble, and sand, although not uncommon is a bedrock and clay hardpan overlain by a thin layer of silt. Topeka shiners are seldom found in choppy water and usually occur in mid-water and surface areas.
RANGE: Historically, the Topeka shiner was widespread throughout low-order tributary streams of the central prairie regions of the United States and was found in portions of Iowa, Kansas, Minnesota, Missouri, Nebraska, and South Dakota. It has been eliminated from the Smoky Hill and Solomon rivers in the Kansas River basin; the Wakarusa River, Big Blue River, Cedar, and Shell Rock watersheds; the Arkansas River basin; most of the Boone, Iowa, and Des Moines drainages, and numerous tributaries to the Missouri River. The Topeka shiner is now restricted primarily to a few tributaries within the Mississippi and Missouri river basins; it has been nearly extirpated from Nebraska.
MIGRATION: Topeka shiner populations generally swim downstream in times of drought to find suitable habitat, migrating back upstream when conditions allow. Impoundments and dams can block this migration.
BREEDING: The Topeka shiner is reported to spawn from late May through July in Missouri and Kansas, primarily over green and orange-spotted sunfish nests, near which male Topeka shiners establish small territories. Some biologists claims that the shiner is an obligate spawner on silt-free sunfish nests, while others state that the species also uses other silt-free substrates as spawning sites. Exact spawning behavior is unknown.
LIFE CYCLE: Topeka shiners are known to live for a maximum of three years, but only a small percentage of fish reach their third summer. Data concerning exact larval stages and subsequent development is lacking.
FEEDING: The Topeka shiner is reported to be a daytime feeder, primarily eating insects like midges, other true flies, and mayflies. Zooplanktons also contribute to this fish’s diet.
THREATS: This shiner has declined because of habitat destruction, degradation, and fragmentation from siltation, reduced water quality, tributary impoundment, stream channelization, and stream dewatering. It is also threatened by nonnative fish predation.
POPULATION TREND: The number of known Topeka shiner populations has been reduced by approximately 80 percent, with approximately 50 percent of this decline occurring within the last 25 years. The species now primarily exists as isolated and fragmented populations.
|Photo by Konrad Schmidt, Minnesota Department Of Natural Resources||HOME / DONATE NOW / SIGN UP FOR E-NETWORK / CONTACT US / PHOTO USE /|