Notropis topeka (Gilbert, 1884)
Mound Creek, Rock County, Minnesota 17 August 1988
Find out more about the Topeka shiner in Minnesota
Listed as Federally Endangered by US Fish and Wildlife Service, effective 14 January 1999 (http://www.fws.gov/r9endspp/endspp.html)
Listed in the state as Special Concern by Minnesota Department of Natural Resources (URL), effective November 1996 (http://www.dnr.state.mn.us/fish_and_wildlife/endangered_species/index.html)
Historically, the Topeka shiner occupied roughly 175 low-order, prairie streams in the central portion of the Great Plains (1). Today, it is absent from many of those streams and occurs at only 20% its historic sites (Tabor 1998). The species clearly is on the decline in Kansas, Missouri, Nebraska and Iowa, but it may be holding its own in South Dakota and Minnesota.
Recent studies by this author (Hatch 2001) and Dahle (2001) in Minnesota have shown that Topeka shiners are far more common than once was thought. Although the species is restricted to the Missouri River drainage of southwestern Minnesota, it has been found to date at 98 sites in 17 subwatersheds of the Rock River and Big Sioux River drainages (Dahle 2001).
Why Has the Topeka Shiner Declined?
Cross and Moss (1987) attribute the general decline of several prairie species to the "unstable water levels, loss of aquatic vegetation, and increasing temperatures and turbidity" resulting from agricultural development of the Great Plains. We know that accelerated erosion has added a larger and more continuous sediment load to most prairie streams than they experienced when bison were the chief contributor to sediment loading. We also know that small streams and creeks of the Great Plains frequently become intermittent during the low-flow period of late summer. In pre-agricultural times, pools in these streams were maintained by groundwater percolation and, presumably, Topeka shiners adapted to this type of flow regime (see Minckley and Cross 1959 and Habitat below). Many human activities now compete for both ground and surface waters in our prairie states, leaving many small streams nearly to completely dry in late summer. Because Topeka shiners prefer pool habitats, they may become trapped there during low flows and die from anoxia or exposure. Kerns (1983) noted "high mortality" of Topeka shiners in Kansas from just these conditions, despite this species' exceptional "drought resistance." In addition, we can also speculate that further habitat alteration from activities such as ditching, channelization, and impoundment may be contributing to the documented loss of Topeka shiner populations (Tabor 1998). We also know that in stream reaches where largemouth bass have been introduced, Topeka shiners are rare to non-existant. In Kansas, at least, the presence of largemouth bass in a reach and the number of ponds or impoundments in the area correlates highly with Topeka shiner absence (Schrank et al. 2001).
In Minnesota, we have few historical records that we can use to determine trends in population growth. However, our data suggest that our populations may be as robust now as they were in the middle 20th Century (Dahle 2001; Hatch 2001). The area in Minnesota where Topeka shiners occur suffers from the same kinds of agricultural chemical runoff and sediment loading as the southern Great Plains. What is different is the amount of ditching, channelization, and impoundment that has taken place. Most of the stream reaches in southwestern Minnesota still follow their natural meander, and the alluvial deposits of the stream corridors are largely intact. There are few impoundments and very little introduction of largemouth bass. In addition, groundwater draw-down so far has been minimal. We have not yet demonstrated that the differences in these conditions have caused the differences in population status, but they suggest plausible causal mechanisms, some of which are currently being tested.
|One of the earliest descriptions of Topeka shiner habitat appears in Evermann and Cox (1896), where they report taking the species in "pond-like, isolated portions of streams which dry up in parts of their course during dry weather." They characterize the ponds as clear and cool with spring seeps, "an abundance of water vegetation", and "mostly soft mud" bottoms. There is no other detailed description until that of Minckley and Cross (1959), who studied the species in eastern Kansas. They found Topeka shiners "almost exclusively in quiet, open pools of small, clear streams that drain upland prairies." The streams typically were "a series of large pools . . . connected by short riffles and smaller pools; their flow [was] usually less than five cubic feet per second" and their bottoms "predominantly gravel, with some rubble and sand." They noted that "[i]n summer, the pools often develop plankton blooms, but rooted aquatic vegetation is uncommon." This species occupied "riffles only when . . . exceptionally abundant" and was "rarely found in streams that maintain a continuously strong flow" and was "not found in streams that are muddy and highly intermittent." However, "many of the streams . . . approach intermittency in summer" but the "pools are maintained at fairly stable levels by percolation through the gravel or by springs." Cross (1967) largely reiterated the above and added that "[p]robably many western streams provided this kind of habitat prior to plowing of the prairie sod."||
|Pflieger (1975) confirmed similar habitat characteristics for populations in Missouri, noting that extant populations were "largely restricted to direct tributaries of the Missouri River having sufficient gradient to prevent extensive deposition of silt." While such characteristics may be preferred by this species and apparently was typical of Kansas and Missouri populations, we now know that, in the northwestern portion of its range, Topeka shiners commonly occur in periodically turbid waters whose sand, gravel or rubble bottoms are covered by 5 cm or more of silt and detritus (Michl and Peters 1993; Elsen 1977). Further, we have discovered that Topeka shiners often are far more abundant (catches often greater than 100 individuals) in off-channel oxbows and excavated pools than they are in main channel pools and runs (Dahle 2001; Hatch 2001). Sampling in similar habitats in northwestern Iowa has produced similar results, which further have been linked to morainal deposits of the Des Moines Lobe (Clark 2000). Seasonal studies of these habitats in Minnesota have shown that Topeka shiners can complete their entire life cycle in these habitats (Dahle 2001).|
Spawning Period--Cross and Collins (1995) report that Topeka shiners spawn from late June to August in Kansas. Based on an analysis of seasonal changes in GSI, Kerns (1983) delimits the Butler Co., Kansas, breeding season as late May through July. Pflieger (1975) reports the same season for Missouri populations. Despite the more northern location of our populations, studies of seasonal ovarian development have shown spawning seasons of early June to mid-August in 1997 (Hatch 2001) and mid-May to early August in 1998 (Dahle 2001). In both years, spawning start-up corresponded to a water temperature of 22 degrees C, the same early spawning temperatures found by Kerns (1983). In 1997, spawning continued during a period when water temperatures reached 31 degrees C. Working with captive Topekas, Katula (1998) induced spawning by slowly increasing water temperatures from 21.1 to 24.4 degrees C in one instance and from 22.2 to 25.6 degrees C in another.
Spawning Habitat and Behavior--Observations by Kerns (1983) and Pflieger (1975) indicate that Topeka shiners spawn in pools over gravel and rubble substrates in association with green sunfish (Lepomis cyanellus ) and orangespotted sunfish (L. humilis) nests. Our observations suggest the use of rubble, boulder, and concrete rip-rap at the margins of pools and slow runs. In most but not all cases, breeding male orangespotted or green sunfish have been captured in the same locations. Both Kerns and Pflieger report breeding male Topeka shiners defending small territories (<0.25 m2) near the sunfish nests. We have observed this same behavior on 3 occasions at the one location where these fish could be clearly seen. Katula (1998) noted aggressive defense of territory in his captive shiners. A male would chase females as well as other males. Only persistent females elicited spawning behavior from the territorial male. Katula describes the spawning act as head to head, upright spawning in midwater. "Several eggs" were spawned during each of two to four brief sessions.
Embryonic and Larval Periods--Katula (1998) reports an incubation period of 5 days at 22.2 dgrees C. Four days later free-swimming larvae were observed. Feeding commenced soon afterward and included live brine shrimp nauplii after 16 days. We have not yet completed our meristic and morphometric studies of larvae set to us by Katula.
Age of Maturation and Fecundity--Most male and female Topeka shiners likely reach maturation at 12-14 months of age (Kerns 1983; Pflieger 1975; Cross 1967), but the determining factor is probably size rather than age (Kerns 1983). In his Kansas study, Kerns (1983) found that males smaller than 47 mm total length were never mature nor were females smaller than 37 mm total length. In our 1998 study (Dahle 2001), 20% of age-1 males captured between May 16 and August 6 were mature; 86% of age-2 males were mature. During the same period, 52% of age-1 and 93% of age-2 females were mature. The smallest mature female was 29.0 mm SL (standard length), and the smallest mature male was 41.2 mm SL.
Our examination of ovarian develop has shown that Topeka shiners are multiple-clutch spawners (Hatch 2001), i.e., they spawn more than one set of eggs during a spawning season (see Heins 1990). Multiple-clutch spawning allows a small fish with limited abdominal volume to produce a greater number of eggs during a season without having to substantially decrease the size of each egg. Kerns (1983) provided the only estimates of clutch size from southern populations. He reported an average of 356 mature ova from 1-year-olds and 819 from 2-year olds, with a range of 140-1712 (total N = 32). Our preliminary results from 1997 showed a much lower mean of 267 ± 43 (2SE) with all ages combined (N = 25) (Hatch 2001). However, our more detailed 1998 study gave a much higher mean of 453 ± 46 (2SE) with all ages combined (N = 66). The age breakdown was 351 ± 44 for age-1 (N = 32), 559 ± 71 for age-2 (N = 30), and 478 ± 93 for age-3 (N = 4)(Dahle 2001). It may be that Minnesota fish produce smaller clutch sizes, or it may be that our estimates are lower because we used the methods of Heins and Rabito (1986), which are more conservative in determining which ova are mature. As did Kerns (1983), we found that clutch size was significantly correlated to body size even more so than age.
Growth and Mortality--Like many of our native minnows, Topeka shiners are short-lived, living for a maximum of 3 years (Dahle 2001; Kerns 1983; Pflieger 1975; Cross 1967). Age composition of a random subsample of specimens collected by Minckley and Cross (1959) in October 1956 was 75.8% age class 0 (1956 cohort), 19.7% age class I (1955 cohort), and 4.5% age class II (1954 cohort). Age composition for a set of 3 quantitative samples taken by Kerns (1983) in winter, spring and fall 1980 was 90.0%, 9.8% and 0.2% for age classes 0, I, and II, respectively. Our analysis of 1998 and 1999 catches showed similar steep mortality rates between age classes (Dahle 2001). We aged 544 females and 383 males. The oldest females were 36 months old and the oldest males were 37 months old.
Minckley and Cross (1959) report average total lengths of 28, 48, 58 mm for class 0, I and II fish captured in October 1956, but they did differentiate between sexes. Kerns (1983) reports mean standard lengths of 34.6, 42.5, 53.2 mm for 12-month old, 24-month old, and 36-month old fish taken in May 1981. Fish taken in October 1980 showed first- and second-year lengths of 35.5 and 51.2 mm, respectively, considerably longer fish at age than those collected by Minckley and Cross. Kerns reports a variety of other growth measurements, some of which differentiate between sexes. These measurements suggested that males grew more rapidly than females, a finding noted also by Pflieger (1975). We found that size at age-1 varied considerably among our study sites and the sexual difference for this age was not significant. Beyond age-1, males were significantly larger than same-age females regardless of site. On average males and females were about 30 mm total length (TL) after one year's growth (class I). Class II males were about 47 mm TL; class II females were 42 mm TL; class III males were 69 mm TL, while females were on 47 mm TL (Dahle 2001).
Until recently, there were no published food studies of this species, and the categorization of the Topeka shiner as an insectivore was based largely on anecdotal accounts (Churchill and Over 1933, Pflieger 1975, Cross and Collins 1995). Kerns (1983) and Cross and Collins (1995) indicated that Topeka shiners function as benthic insectivores but added that they also utilized microcrustaceans, while Pflieger (as cited in Tabor 1998) regarded this species as a "nektonic insectivore." Churchill and Over (1933) noted the consumption of vegetation in their brief anecdote.
In a preliminary study of Minnesota populations, we examined the total gut contents of 65 Topeka shiners collected from four sites in the Rock River drainage (Hatch and Besaw 2001). Our results indicated a highly omnivorous diet that included several kinds of microcrustaceans, other invertebrates, larval fish, algal and vascular plant matter (including seed capsules), and detritus in addition to a variety of immature aquatic insects. Our more recent quantitative study based on 343 stomachs corroborated the preliminary study (Dahle 2001).
(1) Number of streams estimated from dot maps, tables and text found in the following sources: South Dakota (Owen et al. 1981; Elsen 1977; Nickum and Sinning 1971; Bailey and Allum 1962), Minnesota (Hatch unpub.; Anderson et al. 1977; Eddy and Underhill 1974), Nebraska (Michl and Peter 1993; Bailey and Allum 1962), Iowa (Harlan et al. 1987), Kansas (Kerns and Leon 1982; Cross 1967; Minckley and Cross 1959), and Missouri (Hrabik, 1996; Gelwick and Bruenderman 1996; Pflieger 1971).
Anderson, C. P., J. E. Erickson, J. Ross, and J. C. Underhill. 1977. Revised distribution records of some Minnesota fishes. Journal of the Minnesota Academy of Science 43: 3-6.
Bailey, R. M. and M. O. Allum. 1962. Fishes of South Dakota. Miscellaneous Publications of the Museum of Zoology, University of Michigan 119:1-131.
Churchill, E. P. and W. H. Over. 1933. Fishes of South Dakota. The South Dakota Department of Fish and Game. 87 pp.
Clark, S.J. 2000. Relationship of Topeka shiner distribution to geographic features of the Des Moines Lobe in Iowa.Ê M.S. Thesis, Iowa State University, Ames.
Cross, F. B. 1967. Handbook of fishes of Kansas. Miscellaneous Publications of the Museum of Natural History, University of Kansas 45:1-357.
Cross, F. B. and J. T. Collins. 1995. Fishes in Kansas. University of Kansas Natural History Museum, Educational Series No. 3, 315 pp.
Dahle, S. P. 2001. Studies of Topeka shiner (Notropis topeka) life history and distribution in Minnesota. M.S. Thesis, University of Minnesota, St. Paul.
Eddy, S. and J. C. Underhill. 1974. Northern Fishes with special reference to the upper Mississippi Valley. 2nd Edition. University of Minnesota Press, Minneapolis. 404 pp.
Elsen, D. S. 1977. Distribution of fishes in the James River in North Dakota and South Dakota prior to Garrision and Oahe Diversion Projects. M. S. Thesis, University of North Dakota, Grand Forks. 86 pp.
Evermann, B. W. and U. O. Cox. 1896. A report upon the fishes of the Missouri River basin. Report of United States Commission of Fish and Fisheries 1894: 325-429.
Gelwicks, G. and S. A. Bruenderman. 1996. Status survey for the Topeka shiner in Missouri. Final Report. Missouri Department of Conservation, Fish and Wildlife Research Center, Columbia.
Harlan, J. R., E. B. Speaker, and J. Mayhew. 1987. Iowa fish and fishing. Iowa Department of Natural Resources. 323 pp.
Hatch, J. T. 2001. What we know about Minnesota's first endangered fish species: the Topeka shiner. Journal of the Minnesota Academy of Science 65(1):39-46.
Hatch, J. T. and S. Besaw. 2001. Food use in Minnesota populations of the Topeka shiner (Notropis topeka). Journal of Freshwater Ecology 16(2):229-233.
Heins, D. C. 1990. Field evidence for multiple clutches in the longnose shiner. Copeia. 1990:579-582.
Heins, D. C. and F. G. Rabito, Jr. 1986. Spawning performance in North American minnows: direct evidence of the occurrence of multiple clutch in the genus Notropis. Journal of Fish Biology 28:343-357.
Hrabik, R. A. 1996. A new distributional record of Notropis topeka (Teleostei: Cypriniformes) from the Mississippi River drainage in Missouri. Transactions, Missouri Academy of Science 30:1-5.
Katula, R. 1998. Eureka Topeka! (Shiners, that is). Tropical Fish Hobbyist. December, 1998.
Kerns, H. A. 1983. Aspects of the life history of the Topeka shiner, Notropis topeka (Gilbert), in Kansas. unpublished manuscript.
Kerns, H. A. and S. C. Leon. 1982. The occurrence of the Topeka shiner, Notropis topeka (Gilbert), in Buck Creek, Jefferson County, Kansas. Transactions of the Kansas Academy of Sciences 85:57-58.
Michl, G.T. and E. J. Peters. 1993. New distribution record of the Topeka shiner in Loup Drainage basin in Nebraska. Prairie Naturalist 25: 51-54.
Minckley, W. L. and F. B. Cross. 1959. Distribution, habitat, and abundance of the Topeka shiner Notropis topeka (Gilbert) in Kansas. American Midland Naturalist 61:210-217.
Nickum, J. G. and J. A. Sinning. 1971. Fishes of the Big Souix River: an annotated list. Proceedings of the South Dakota Academy of Science 50: 143-154.
Owen, J. B., D. S. Elsen, and G. W. Russell. 1981. Distribution of fishes in North and South Dakota basins affected by the Garrison Diversion Unit. Fisheries Research Unit, University of North Dakota, Grand Forks. 209 pp.
Pflieger, W. L. 1971. A distributional study of Missouri fishes. Museum of Natural History, University of Kansas Publications 20:225-570.
Schrank, S. J.,ÊC. S. Guy, M. R. Whiles, and B. L. Brock. 2001. Influence of instream and landscape-level factors on the distribution of topeka shiners Notropis topeka in Kansas streams.Ê Copeia 2001(2):413-421.
Starrett, W. 1950 Food relationships of the minnows and darters of the Des Moines, Iowa. Ecology 31: 216-233.
Tabor, V. M. 1998. Final rule to list the Topeka shiner as endangered. Federal Register 63(240):69008-69021.
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Text by Jay T. Hatch, Photographs by Konrad
General College and James Ford Bell Museum of Natural History
University of Minnesota, Minneapolis/St. Paul.
Last updated 29 October 2002