Thursday, August 7, 2008

The Mysterious and Elusive Blackside Darter (Percina maculata)

And with that, Analyze Everything is back. Expect a weekly post on Thursday or Friday, focused initially on Kansas T&E and SINC species. Other posts will pop up sporadically. Hope you enjoy, and feel free to ask questions.

State and federal Threatened and Endangered Species lists are riddled with species who are so rare that they may easily be considered extirpated (or even extinct; see Eskimo Curlew). Although apparently facing no global threat of extinction (even in 1973 the darter was considered endangered in Kansas but not nationally), the Blackside Darter has become a whisper of a ghost in Kansas. According to the NatureServe distribution map (see it here), the existing (or recently existing) Kansas population is confined to the Mill Creek Watershed. This is interesting because the next closest population is in Missouri or Oklahoma, between 4-8 HUC8s away.

During the Summer of 2008, KDWP conducted a survey of the Mill Creek looking for Topeka Shiners (more on them elsewhere). There was some optimism that the Blackside Darter would be found at the same time, since unlike many darters, the Blackside is a common mid-column pool resident (Cross and Collins 1995). At this point, no Blacksides have been found (although some collected specimens may be identified as such later), and as far as I can tell, none have been found in Kansas since 1974! (Drenner and Cross 1981) Actually, now that I dig around the KDWP Stream Survey database I see a record of 3 Blackside Darters found on a site in 1994. A return visit in 2000 didn’t find any, however.

I wonder if the Blackside Darters are becoming extirpated in part due to their hybridization with logperch (P. caprodes). The two species have overlapping ranges, and have been observed to hybridize in Kansas (Drenner and Cross 1981), with hybrids having intermediate physical characteristics. Winn (1958) observed logperch males chasing female P. maculate (the latter being a small portion of the overall darter population even when relatively common). Hybridization may have some weird implications for conservation of rare species (c.f. Perry 2001). I did see a logperch in Mill Creek in July of 2008 that looked ‘funny.’ I wonder if that individual has a Blackside ancestor (might explain why we caught it in a pool).

The Blackside Darter is sexually mature in their second year (Becker 1983), and females may continue breeding until they are 4 years old (Bart and Page 1992). This darter consumes primarily benthic invertebrates (NatureServe 2008), although Cross and Collins (1995) also mentioned that the Blackside Darter “sometimes rises to the surface for food.” Among Kansas darters, the Blackside is unique for not clinging to the stream bottom. In general the species tends to prefer streams that one would consider good for mayfly and stonefly species (i.e., cool, clear streams with moderate currents and gravel substrates). Many Flint Hills streams fit this description, but despite fairly extensive sampling efforts in the Northern Flint Hills (mostly hunting the Topeka Shiner), the species is only known to occur in Mill Creek.

Bart, H. L., Jr., and L. M. Page. 1992. The influence of size and phylogeny on life history variation in North American percids. Pages 553-572 in R. L. Mayden, editor. Systematics, historical ecology, and North American freshwater fishes. Stanford Univ. Press, Stanford, Calfiornia. xxvi + 969 pp.

Becker, G. C. 1983. Fishes of Wisconsin. Univ. Wisconsin Press, Madison. 1052 pp.

Cross, F.B. and J.T. Collins. 1995. Fishes in Kansas. University Press of Kansas, Lawrence KS. p 238.

Drenner, R.W. and F.B. Cross. 1981. A natural hybrid fish, Percina maculate × P. caprodes, from Kansas. Transactions of the Kansas Academy of Sciences 84:61-62.

NatureServe. 2008. NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.0. NatureServe, Arlington, Virginia. Available (Accessed: July 21, 2008 ).

Perry, W.L., J.L. Feder, and D.M. Lodge. 2001. Hybridization and introgression between introduced and resident Orconectes crayfishes; implications for conservation. Conservation Biology.

Soil Conservation Commission (SCC). 1973. Rare, Endangered and Extirpated Species in Kansas. I. Fishes. Transactions of the Kansas Academy of Science 76:97-106.

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