Wednesday, October 19, 2016

The Erratic Crappie Leaves Many Anglers Happy, by Don Orth

Crappies are a great American sport fish that provide food and sport for millions of recreational anglers each year.   There are only two species and they widely distributed;  any recreational angler can locate and catch crappies.   Reservoir construction in the Midwest and Southeastern USA greatly increased habitat for both species.  Crappie remain very popular among anglers, many of whom prefer to catch and eat their catch.     Crappie can be captured by a variety of fishing methods and use of affordable sonar allows for better targeting of deep structures that hold more crappie.   Although many impoundments still suffer from “small crappie syndrome,” management of prey and angler harvest can enhance crappie fisheries.  The International Game Fish Association all tackle records  are 2.35 kg (5 pounds, 3 oz) for White Crappie Pomoxis annularis and 2.26 kg (5 pounds) for Black Crappie Pomoxis nigromaculatus.  Tournament fishing for crappies has emerged with a large following in Crappie Masters.    If you are itching to catch more crappie, view this video.

Illustrations of the White Crappie (left) and Black Crappie (right)
The White Crappie was described in Ichthyologia Ohiensis (1818) by Constantine Samuel Rafinesque during his expedition to the Ohio River valley.   Both species are deep bodied and strongly compressed laterally. This explains their association with the term, panfish, as they are suited for being fried in a pan. The French word, crapet, refers to sunfish, and is the root for the common name, crappie (also spelled croppie or crappé).  Therefore, the crapet vert is French for Green Sunfish.  Some pronounce Crappie so it rhymes with hoppy (ˈkrä-pē) , others say it so it rhymes with happy (ˈkra-pē)Only a linguist can explain why.     No matter how you pronounce ‘crappie, you will be impressed with the gape of this sunfish relative.  The jaws are large with the upper jaw extending well past the middle of the eye.  The spiny and soft dorsal fins are broadly connected.  The principal difference is the coloration pattern.  White crappie is silver with 5-10 often faint, dark vertical bars. The dorsal fin has 6 spines.   In contrast, Black crappie have irregularly arranged speckles and blotches instead of faint vertical bars as the color pattern. They also have 7 or 8 dorsal fin spines instead of 6.  
Development of White Crappie 
Drawings from Tabor (1969), not to scale.  Juvenile is 25.5mm.
Crappie are nest spawners and females are very fecund.   Males begin to defend territories and chase intruders by biting, butting or flaring opercles. Males sweep sediments out of the nest depression with fin and body movements; however, the crappie nests are not as well defined as nests built by sunfish Lepomis species. Larval development is fast.  Compared to other centrarchids, crappie have a longer spawning season, large clutch size, and shorter hatching time and time to disperse from the brood.  They often nest in colonies and have less specific habitat requirements for nesting.  Their strategy works well and,  in small ponds, crappie often overpopulate, leaving the pond owner with “small crappie syndrome.” Elsewhere, the duration and magnitude of water-level fluctuations and the development time of early life stages are critical to determining reproductive success.  Recruitment of crappie is highly variable, even erratic (Mitzner 1991; Guy and Willis 1995; Allen and Miranda 1998; Clark et al. 2008).  Bad recruitment years lead to bad years of fishing and unsatisfied crappie anglers.   Many states do supplemental stocking of crappie with variable success, creating many unhappy crappie anglers.  
 
Historic ranges of the White Crappie (left) and Black Crappie (right).  source Lee et al. (1980)
The distribution of the two crappie species violates the notion that closely related species should not overlap in distribution.   The two sister species show broad overlap throughout the native range.  The problem when examining speciation of these two species is that we don’t know what the distributions were when the species diverged in the Miocene.   The overlap means that Black and White Crappie produce natural hybrids in the zone of overlap, in one case as high as 17% (Travnichek et al. 1996; Spier and Heidinger 2003). This may raise the question ‘how rare does hybridization have to be to accept these as distinct species?’   Hybridization appears to be higher in zones where the two species are allopatric.  I could find no research into the olfactory, acoustic, or visual cues that may serve as pre-mating barriers to hybridization in the two crappie species.   There must be species recognition by one or more senses in breeding individuals for speciation to occur.   In the rare cases of hybridization, these premating barriers must break down.   The hybrids are viable and approximately 50% male; therefore, post-mating isolating mechanisms are not important.   Like other hybrid sport fishes, hybrid crappie demonstrate hybrid vigor and accelerated growth.  Naturally produced hybrids in Weiss Reservoir, Alabama, were less vulnerable to angling even though they grew faster (Travnichek et al. 1997). Most hybrid crappie are sold to the sportfish market for stocking ponds and small impoundments (Kelly and Baumhoer 2014).   Hybrids may not solve the “small crappie syndrome,” but a sterile triploid crappie might. 
White Crappie (top), Hybrid crappie (middle), and Black Crappie (bottom). Photo from Tennessee Wildlife Resources Agency.
An orange crappie is a rare find. This is a condition called xanthism or xanthochroism or xanthochromism.   It is a rare condition where all pigments other than yellow and orange are either absent or minimally expressed. It is hard to imagine the xanthic crappie pictured below successfully feeding and avoiding predators to become a full-size adult; however they are rarely encountered in the wild.  The xanthic pigment anomaly has been observed in other vertebrates as either partial or fully xanthic.
Xanthic crappie.  photo by Donnie Lornson
Another variation of the crappie is the “black-striped” variation of the Black Crappie.  This fish has a dark line along the dorsal margin from its nose to its tail.  This black stripe is a recessive trait and fish culturists quickly learned that it breeds true.  In an attempt to solve “small crappie syndrome” Mississippi Department of Wildlife, Fish and Park created a triploid Magnolia Crappie. It’s a cross between a white Crappie female and a black-striped Black Crappie male in which the embryo is pressure treated to create three sets of chromosomes.  The triploid is sterile and will direct energy to growth instead of reproduction (Parsons and Meals 1997). 
 
Black-striped variant of the Black Crappie.  Photo by Jim Negus.
If you are confused about crappie, don’t feel alone.   Just remember it rhymes with ‘hoppy’ -- unless you’re in the south.  No matter where you catch them, eating crappie makes you happy.

References
Allen, M.S., and L.E. Miranda. 1998.  An age-structured model for erratic crappie fisheries.  Ecological Modeling 107:289-303.
Clark, M.E., K.A. Rose, J. A. Chandler, T.J. Richter, D.J. Orth, and W. VanWinkle. 2008. Water-level fluctuation effects on centrarchid reproductive success in reservoirs: a modeling analysis.  North American Journal of Fisheries Management 28:1138-1156. 
Guy, C.S., and D.W. Willis.  1995.  Population characteristics of black crappie in South Dakota waters: a case for ecosystem-specific management.  North American Journal of Fisheries Management 15:754-765.
Kelly, A.M. and B. Baumhoer.  2014.  Species profile: hybrid crappie.  Southern Regional Aquaculture Center Publication No. 7212. 5 pp.  
Lee, D.S., C.R. Gilbert, C.H. Hocutt, R.E. Jenkins, D.E. McAllister, J.R Stauffer, Jr. 1980.  Atlas of North American freshwater fishes.  Publication #1980-12 of the North Carolina Biological Survey.  854 pp.
Mitzner, L. 1991.  Effect of environmental variablesupon crappie young, year-class strength, and the sport fishery.  North American Journal of Fisheries Management 11:534-542. 
Parsons, G.R., and K. Meals. 1997.  Comparison of triploid hybrid crappie and diploid white crappie in experimental ponds.  North American Journal of Fisheries Management 17:803-806.
Spier, T.W., and R.C. Heidinger. 2003.  Hybridization between black crappie and white crappie in southern Illinois.  Transactions of the Illinois State Academy of Science 96:119-133.
Tabor, C.A. 1969.  The distribution and identification of larval fishes in the Buncombe Creek arm of Lake Texoma with observations on spawning habits and relative abundance.   Doctoral dissertation, University of Oklahoma.  120 pp. 
Travnichek, V. H., M. J. Maceina, S. M. Smith, and R. A. Dunham. 1996. Natural Hybridization Between Black and White Crappies (Pomoxis) in 10 Alabama Reservoirs. American Midland Naturalist 135: 310-316.
Travnichek, V. H., M. J. Maceina, and R. A. Dunham. 1997.  Angling vulnerability of black crappies, white crappies, and their naturally produced hybrid in Weiss Reservoir, Alabama Fisheries Research 29:185-191. 

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