The LDH isozymes of 494 specimens of 68 species 
ere examined. Patterns of 67 species are illustrated in 
g.1: Ammocrypta (Ammocrypta) beani: Leaf River, 
mes Co., Miss.; A. (A.) pellucida: Middle Fork, Ver- 
lion Co., Ill.; Etheostoma (Allohistium) cinereum: 
g South Fork, Scott Co., Tenn.; E. (Boleosoma) longi- 
anum: trib., James River, Botetourt Co., Va.; E. (B.) 
grum: trib., Gasconade River, Maries Co., Mo.; E. 
.) olmstedi: Tar River, Franklin Co., N. C.; E. 
atonotus) barbourt: Brushy Fork, Casey Co., Kye 
/.) flabellare: Maries River, Osage Co., Mo.; E. (Cy 
nnicotit: Big Creek, Hardin Co., Ill.; E. (C.) obeyense: 
rguson Creek, Livingston Co., Ky.; E. (C.) squami- 
bs: Sugar Creek, Livingston Co., Ky.; E. (C.) virgat- 
2: Harpeth River, Williamson Co., Tenn.; E. (C.) 
cies: Cypress Creek, Wayne Co., Tenn.; E. (Doration ) 
gmaeum: Little River, Blount Co., Tenn.; Clarks 
rk, Marshall Co., Ky.; E. (Etheostoma) blennioides: 
ibarras River, Cumberland Co., Ill.; E. (E.) histrio: 
af River, Jones Co., Miss.; E. (E.) rupestre: Cahaba 
ver, Bibb Co., Ala.; E. (E.) tetrazonum: Gasconade 
yer, Maries Co., Mo.; E. (E.) thalassinum: trib., 
uda River, Pickens Co., S. C.; E. (E.) zonale: Gas- 
made River, Maries Co., Mo.; E. (Hololepis) gracile: 
ar Creek, Union Co., Ill.; E. (H.) serriferum: Collie 
amp, Martin Co., N.C.; E. (Ioa) vitreum: Tar River, 
inklin Co., N. C.; E. (Litocara) nianguae: Big Tavern 
ek, Miller Co., Mo.; E. (Microperca) microperca: 
on Creek, Kane Co., Ill.; E. (M.) proeliare: Alcorn 
ek, Pope Co., Ill.; E. (Nothonotus) bellum: Brushy 
k, Casey Co., Ky.; E. (N.) camurum: Middle Fork, 
rmilion Co., Ill.; E. (N.) jordani: Conasauga River, 
ley Co., Tenn.; E. (N.) maculatum: Big South Fork, 
tt Co., Tenn.; E. (N.) rufilineatum: Little River, 
unt Co., Tenn.; E. (N.) tippecanoe: Big South Fork, 
tt Co., Tenn.; E. (Oligocephalus) asprigene: Clear 
ek, Union Co., Ill.; E. (O.) caeruleum: Embarras 
er, Cumberland Co., Ill.; James River, Webster Co., 
.; £. (O.) ditrema: Sugar Creek, Bradley Co., Tenn.; 
(O.) exile: Otter Creek, Winnebago Co., Ill.; E. (O.) 
ae: James River, Webster Co., Mo.; E. (O.) specta- 
: Stony Creek, Vermilion Co., Ill.; £. (O.) swaini: 
f River, Jones Co., Miss.; E. (Psychromaster) trisella: 
lasauga River, Bradley Co., Tenn.; E. (Ulocentra) 
sae: Sugar Creek, Bradley Co., Tenn.; E. (U.) duryi: 
ress Creek, Wayne Co., Tenn.; E. (U.) simoterum: 
le River, Blount Co., Tenn.; E. (U.) species A: Flat 
ek, Maury Co., Tenn.; E. (U.) species B: trib., Per- 
) River, Escambia Co., Ala.; E. (U.) species C: Clarks 
k, Marshall Co., Ky.; E. (Vaillantia) chlorosomum: 
ar Creek, Union Co., Ill.; E. (Villora) edwini: trib., 
lido River, Escambia Co., Ala.; Percina (Alvordius )! 
sa: Tar River, Franklin Co., N. G.; P. (A.) macu- 
: Clarks Fork, Marshall Co., Ky.; P. (A.) peltata: 
River, Franklin Co., N. C.; P. (A.) notogramma: 
» James River, Botetourt Co., Va.; P. (A.)* roanoka: 
noke River, Montgomery Co., Va.; P. (A.) species: 
asauga River, Bradley Co., Tenn.; P. (Cottogaster) 
landi: Big South Fork, Scott Co., Tenn.; Shoal 
*k, Cherokee Co., Kan.: P. (Ericosma) evides: Gas- 
conade River, Maries Co., Mo.; P. (E.) palmaris: Cona- 
sauga River, Bradley Co., Tenn.; P. (Hadropterus) len- 
ticula: Leaf, River, Jones Co., Miss.; P. (H.) nigrofas- 
ciata: Leaf River, Jones Co., Miss.: P. (H.) sciera (eight 
specimens) : Embarras River, Cumberland Cog lle: 2: 
(Hypohomus) aurantiaca: Little Pigeon River, Sevier 
Co., Tenn.; P. (Imostoma) shumardi: Main Ditch, New 
Madrid Co., Mo.; P. (I.) uranidea: Main Ditch, Missis- 
sippi Co., Mo.; P. (I.) species: Conasauga River, Bradley 
Co., Tenn.; P. (Percina) caprodes carbonaria: Big Tav- 
ern Creek, Miller Co., Mo.; P. (P.) c. caprodes x semi: 
fasciata: Embarras River, Cumberland Comal lem: 
(Swainia) phoxocephala: Embarras River, Cumberland 
Co., Ill.; P. (?)* cymatotaenia: Gasconade River, Pulas- 
ki Co., Mo. 
Fig. 2: E. caeruleum: Embarras River, Coles Co., 
Ill.; E. flabellare: Gasconade River, Pulaski Co., Mo.; 
E. gracile: Clear Creek, Union Co., Ill.; E. nigrum: Em- 
barras River, Cumberland Co., IIl.; P. caprodes: Embar- 
ras River, Cumberland Co., Ill.; P. cymatotaenia: Gas- 
conade River, Pulaski Co., Mo.; P. maculata: Gibbons 
Creek, Pope Co., Ill.; P. phoxocephala: Embarras River, 
Cumberland Co., Ill.; P. sciera: Embarras River, Cum- 
berland Co., Ill.; P. uranidea: Main Ditch, Mississippi 
Co., Mo. 
Fig. 4: E. cinereum: Little River, Blount Co., Tenn.: 
E. duryi: Cypress Creek, Wayne Co., Tenn.: E. edwini: 
trib., Perdido River, Escambia Co., Ala.; E. flabellare: 
Cypress Creek, Wayne Co., Tenn.; E. microperca: Coon 
Creek, Kane Co., Ill.; E. proeliare: Alcorn Creek, Pope 
Co., Ill.; E. trisella: Conasauga River, Bradley Co., 
Tenn.; P. caprodes: Maries River, Osage Co., Mo.; P. 
sciera: Leaf River, Jones Co., Miss. 
RESULTS AND DISCUSSION 
The suitability of electrophoretic data for assessment 
of evolutionary relationships among fishes has been dem- 
onstrated by Tsuyuki et al. (1965), Ohno et al. (1968), 
Markert & Holmes (1969), Lush et al. (1969), Koehn 
(1969) , and Whitt & Horowitz (1970). As specific gene 
products, isozymes (multiple molecular forms of an en- 
zyme, Markert & Moller 1959) are useful as taxonomic 
characters. The LDH isozymes of fishes have proven to 
be excellent gene markers (Markert & Faulhaber 1965, 
Goldberg 1966, Morrison & Wright 1966, Odense et al. 
1969, and Whitt 1970). The following analysis includes 
only those isozymes formed by the assembly of LDH sub- 
units encoded in the LDH A and B loci (Markert & 
Faulhaber 1965). The activity of the LDH E locus was 
too low to employ the retinal-specific E, isozyme (Whitt 
et al. 1971, Horowitz & Whitt 1972) as a genetic marker. 
LDH patterns tended to be highly conservative. For 
the 494 specimens (68 species) examined, intra- 
specific variation was limited to infrequent poly- 
morphism, occasional low activities of  indi- 
vidual bands, slight geographic variation in a few 
species, and marked geographic variation in Percina 
copelandi (Page & Whitt 1973). 
1 Subgeneric reassignments in Percina are based on conclusion by the 
senior author (Page 1974). 
s 
