ETHEOSrOMA {OLIGOCEPHALUS) NUCHALE. A NEW DARTER 
FROM A LIMESTONE SPRING IN ALABAMA 
WILLIAM MIKE HOWELL 
and 
RICHARD DALE CALDWELL 
Department of Biology, University of ALibama 
University, Alabafua 
Abstract 
Etheosto»ia (Oligocephalns) vnchalc 
is described from 71 specimens collected 
from a limestone spring' in the Black 
Warrior River system near Bessemer, 
Jefferson County, Alabama. E. nuchaJc 
is known only from Glen Spring, the 
type locality, which is located above the 
Fall Line. It is compared tO' its nearest 
known relative, E. swaini (Jordan), 
from which it is geographically iso- 
lated. E. su-aini does not normally cross 
the Fall Line, and is a wide-ranging 
species found along the Gulf Coastal 
Plain from the Ochlockonee River in 
Florida to the Amite River system of 
southeastern Louisiana and southern 
Mississippi. The species differ in de- 
tails of body proportions, squamation, 
pigmentation, development of lateral 
line and cephalic sensory canals, cer- 
tain fin-ray counts and habits. 
On 21 March 1964, Dr. Ronald A. Bran- 
don and Ron Altig collected three specimens 
of an undescribed darter while dip-netting 
for salamanders in Glen Spring at Bessemer, 
Jefferson County, Alabama. On 24 March 
1964, we visited the spring and obtained 51 
additional specimens. This distinctive spe- 
cies differs consistently from its nearest 
known relative, Etheostonia swaini (Jordan), 
in details of body proportions, squamation, 
pigmentation, development of lateral line 
and cephalic sensory canals, certain fin-ray 
counts, and habits. 
Counts and measurements were obtained 
by methods defined by Hubbs and Lagler 
(1958: 19-26) unless otherwise noted. 
Techniques of Hubbs and Cannon (1935) 
were used in making measurements to the 
nearest 0.1 mm. Proportional measurements 
are expressed as thousandths of the standard 
length. 
We wish to thank the following individ- 
uals who have aided us in this study: Dr. 
Ronald A. Brandon and Ron Altig of the 
University of Southern Illinois first collected 
specimens of this handsome new species and 
made them available to us; Dr. Herbert T. 
Boschung, Jr., our major professor, con- 
tinually encouraged us and gave many help- 
ful suggestions; Dr. Ralph Chermock of the 
University of Alabama criticized our manu- 
script in its early stages; Dr. Ralph Yerger 
of Florida State University permitted us to 
examine his unpublished data on Etheostoma 
swaini and also made radiographs for us; 
Dr. Royal D. Suttkus and John S. Ramsey 
of Tulane University made available to us a 
collection of the species described herein; 
Dr. Reeve M. Bailey of the University of 
Michigan criticized the final draft of our 
manuscript and made many helpful sug- 
gestions. 
Etheostoma niichale, sp. n. 
Watercress Darter 
(Fig. 1) 
Material. — The holotype, University of 
Michigan Museum of Zoology, UMMZ 
187523, an adult male, 39.4 mm in standard 
length, was collected by us on 24 March 
1964 in Glen Spring at Bessemer, Jefferson 
County, Alabama (NEI4 SEl^ Sec 17, T 
19s, R 4W) along county highway 20. In 
Editorial Committee for this Paper: 
Reeve M. Bailey, Curator of Fishes, Museum of Zoology, University of Michigan, 
Ann Arbor, Michigan 
Royal D. Suttkus, Professor of Zoology, Tulane University, New Orleans, Louisiana 
Ralph W. Yerger, Professor of Zoology, Department of Biological Sciences, Florida 
State University, Tallahassee, Florida 
101 
102 
Tulane Stitdies in Zoology 
Vol. 12 
the same collection we obtained the follow- 
ing specimens: the allotype, UMMZ 187524, 
an adult female 39-8 mm in standard length; 
20 paratopotypes, UMMZ 187525; 20 para- 
topot}'pes, U. S. National Museum, USNM 
259800-Fl; and 9 paratopotypes. University 
of Alabama Ichthyological Collection, UAIC 
1227. Twenty paratopotypes, Tulane Uni- 
versity No. 34591, were collected on 9 Sep- 
tember 1964 by Dr. Royal D. Suttkus, John 
S. Ramsey, and Francis L. Rose. 
At present this species is known only 
from the type locality in the Black Warrior 
River system of Alabama. 
Diagnosis. — A species of Etheostoma of 
the subgenus Oligocepbalns (Bailey and 
Richards, 1963) distinguished by: lateral 
line incomplete, moderately straight; supra- 
temporal canal incomplete; infraorbital canal 
usually incomplete; nape naked mesially; 
top of head, breast, and prepectoral areas 
naked; cheek largely naked but always with 
few to several embedded or exposed scales 
along posteroventral margin of eye; opercle 
with large exposed or embedded, ctenoid 
scales; body scales large, with 35-42 scales 
in the lateral series; 12-24 pored scales in 
lateral line; branchiostegal membranes mod- 
erately to narrowly conjoined, sometimes 
overlapping anteriorly. Fin-rays: dorsal VIII 
to XI (usually IX or X), 10 to 12; anal II 
(rarely III), 6 to 8; pectoral 11 or 12. Nape 
distinctly humped, usually decurving sharply 
to occiput. Breeding adults with a sub- 
marginal red band in spinous dorsal fin. 
Description. — A moderately robust species 
with body slightly compressed; snout mod- 
erately pointed to somewhat rounded; pec- 
toral fin shorter than head length; 11 to 14 
branched caudal rays; 15 to 17 scale rows 
around caudal peduncle, of which 6 to 8 
( usually 7 ) are above the lateral series and 
6 to 8 (usually 7) are below; transverse 
scales are 10 to 12 (counted from origin of 
second dorsal fin posteroventrally to anal 
fin base); supratemporal canal incomplete, 
Figure 1. Top. Etheostoma nuchale, sp. n. Adult male holotype, 39.4 mm in standard 
length (UMMZ 187523). 
Bottom. Etheostoma nuchale. Female allotype, 39.8 mm in standard length (UMMZ 
187524). 
No. 4 
A New Darter 
103 
Table 1. 
Compariso)! of Proportional Measurements of Etheostoma nuchale and E. swaini^ 
(Expressed As Thousandths of Standard Length) 
Species 
Etheostoma nuchale 
Museum number 
Sex 
UMMZ UMMZ UMMZ UMMZ 
187523 187524 187525 187525 
Holotype Allotype Paratypes Paratypes 
M F 
Etheostoma swaini 
UAIC 929, UAIC 
1112,1113, 1060,1090, 
1150,1162 1162,1180 
and 1184 and 1192 
M 
F 
M 
F 
^ All specimens of E. sivaini from the Black Warrior River system 
104 
Ti/laue Studies in Zoology 
Vol. 12 
Table 2. 
Frequency DistribHtio)i of Fui-Ray Counts in Etheostonia nuchale and E. sivaini^ 
1 All E. swaini from Black Warrior River system 
* Atypical fin has count of III, 7 
Table 3. 
Frequency Distribution of Scale Roiv Counts in Etheostonta nuchale and E. swai)n'^ 
1 All E. swaini from Black Warrior River system 
Table 4. (Continued on opposite page) 
Development of Lateral Line iyi Etheostoma nuchale and E. swaini^ 
1 All E. swaini from Black Warrior River system 
No. 4 
A New Darter 
105 
with 2 pores on each side branch; lateral 
canal complete with 5 ( rarely 4 or 6) pores; 
postorbital, coronal, interorbital, posterior 
nasal, and anterior nasal pores present; pre- 
operculomandibular canal complete with 10 
pores; anterior portion of infraorbital canal 
separated from posterior portion in 85 per 
cent of specimens; infraorbital pores usually 
3 -|- 5 { posterior plus anterior pores ) but 
varies from 1 + 5 to 4 -j- 6 with several 
intermediate combinations. In two of 51 
specimens the infraorbital canal is inter- 
rupted twice with pore counts of 3 + 1+4 
and 2-(- 1 -|- 3; one specimen has the canal 
interrupted three times with pore counts 
of 1 -f- 2 -|- 2 -)- 3; infraorbital canal com- 
plete with 8 pores in 15 per cent of speci- 
mens. The upper lip is bound to the snout 
by a well developed frenum; branchiostegal 
rays 6; vertebrae 34 or 35 (mean = 34.4) 
in counts made from radiographs of 15 
specimens; holotype with 34 vertebrae; 
nuptial tubercles absent; genital papilla of 
breeding females is a short, blunt, somewhat 
conical tube; pored portions of lateral line 
conspicuous, being nearly devoid of pig- 
ment; humeral region beneath the semi- 
transparent opercular membrane is darkened; 
sexual dimorphism is pronounced; general 
body outlines are shown in Fig. 1. Body pro- 
portions are given in Table 1. In Tables 2-4, 
counts for the holotype appear in boldface. 
Coloration. — Sexual dichromatism is pro- 
nounced. Breeding males are brilliantly col- 
ored, breeding females are plain. The fol- 
lowing description is of the holotype, a 
breeding male. Notes were made immedi- 
ately after preservation. Five dark orbital 
bars are present on the head. A black bar 
which originates behind and just below the 
center of the eye extends backward and 
slightly upward almost to the origin of the 
lateral line. This postorbital bar is broken 
immediately anterior to the upper portion 
oi the preopercular margin. A preorbital 
dark bar which originates in line with the 
center of the eye extends abruptly down- 
ward and forward, passing just below the 
anterior naris; it then continues along the 
outer edge of the premaxillary frenum and 
ends on the upper border of the premaxilla. 
The lower lip is densely punctated with 
melanophores near its midline. A dark sub- 
orbital bar subequal in width to the pupil 
extends downward and slightly forward and 
ends on the interopercular margin. In the 
interorbital area is a very short supraorbital 
bar which begins on the iris slightly posterior 
to the mid-dorsal edge of the orbit and ex- 
tends about one-third the distance to the 
mid-dorsum. Halfway between the supra- 
orbital and postorbital bars is a dark bar 
which extends obliquely backward to the 
supratemporal canal at a 45 degree angle 
to the postorbital bar. The cheek and breast 
are light gray with distinct, evenly scattered, 
stellate melanophores. The isthmus and 
branchiostegal membranes are darker than 
the breast. There is no prepectoral spot; 
the melanophores at the pectoral fin base 
are widely and evenly distributed. The 
humeral region beneath the semitransparent 
opercular membrane is dark. The lateral 
line is without dark pigment, and forms a 
conspicuous light line. The pupil is blue- 
gray. Tlie iris is metallic gold. Each body 
scale is margined with melanophores. A 
large dark spot is present in the center of 
most body scales giving an appearance of 
horizontal lines along the body ( Fig. 1 ) . 
The genital papilla and the region immedi- 
ately surrounding the anus is white. The 
Table 4. (Continued) 
Development of Lateral Line in Etheostom-a nuchale and E. swaini^ 
^ All E. swaini from Black Warrior River system 
106 
Tulane Studies in Zoology 
Vol. 12 
belly is bright red-orange ventrolaterally. 
On the mid-venter the red-orange is broken 
by a narrow light stripe which extends from 
the anal area to the interpelvic region. The 
bright red-orange of the belly fades abruptly 
into light yellowish-white at the fourth scale 
row below the lateral line. There are six, 
poorly defined vertical bars best developed 
on their lower halves on the posterior half 
of the body. The bars are two to three scale 
rows wide, bluish-brown in color, and are 
separated by poorly defined orange bars. 
Ventrally the red-orange of the belly extends 
posteriorly uninterrupted to the middle of 
the anal fin base where it is broken by the 
first complete vertical bar. The nape has 
an irregular-edged, light yellow stripe which 
extends uninterrupted along the mid-dorsum 
from the base of the first dorsal spine to 
the occiput. There are seven highly irregu- 
lar dorsal saddles which are two to four 
times wider than the interspaces. There 
are three indistinct, black spots in a vertical 
series at the caudal fin base. Immediately 
behind the basicaudal spots are two large, 
round orange spots, one above the other. 
The orange spots extend a short distance 
onto the caudal fin. Except for the orange 
spots, the basal third of the caudal fin is 
blue; remainder of fin is clear. Melano- 
phores on the caudal fin are confined chiefly 
to the rays while chromatophores are on 
rays and membranes. The anal fin is bright 
blue. The pelvic fins are blue basally be- 
coming lighter toward the tips. The pectoral 
fins are largely clear, becoming light blue 
basally. Pectoral rays are evenly outlined 
with melanophores. Listed in sequence from 
fin margin to fin base, the first dorsal fin 
has the following color bands: (1) a mar- 
ginal blue band, ( 2 ) a submarginal red- 
orange band, ( 3 ) another blue band, and 
(4) a basal red band. Listed in like order, 
the second dorsal fin has the following color 
bands: (1) a wide marginal blue band, 
(2) a submarginal light orange band, (3) 
an intense red band, (4) a blue band, and 
(5) a basal red band. 
In breeding male paratypes the coloration 
of the cheeks, breast, and prepectoral region 
varies from immaculate white to dark gray. 
The belly is light orange, red-orange, or 
bright red. Prepectoral spots are present or 
absent. Larger specimens usually have the 
nape mottled while most smaller specimens 
possess a conspicuous light stripe extending 
along the mid-dorsum from the base of the 
first dorsal spine to the occiput. A few 
specimens have a vertical red bar near the 
middle of the caudal fin. Patches of red 
pigment are sometimes present on the anal 
fin. Dorsal saddles are highly irregular, vary- 
ing in number from 4 to 9. 
Females, in contrast to the brilliant nup- 
tial colors of males, are plain. Dominant 
colors in females are brown and black which 
contrast sharply with the white of the belly, 
breast, cheeks, and other light areas. Melano- 
phores are concentrated in the center of 
many body scales but do not produce hori- 
zontal lines as in males. The dorsum and 
sides of most females have interspersed 
black, brown and white spots which form 
no definite pattern ( Fig. 1 ) . Head colora- 
tion is similar to that of males. Five orbital 
bars are present. The nape is irregularly 
mottled in some specimens while most pos- 
sess a prominent predorsal light stripe. The 
prepectoral spot is present or absent. Dorsal 
saddles are usually highly irregular, varying 
in number from 3 to 9. The median fins 
have rows of discrete black spots on the rays. 
The black spots are boldly contrasted against 
the clear interradial membranes. The pec- 
toral fin rays are usually margined with 
melanophores while the interradial mem- 
branes are clear. The pelvic fins have me- 
lanophores on rays and membranes. The 
spinous dorsal is the only fin with bright 
color in breeding females, being similar to 
males but much subdued. 
Habitat and habits. — The type locality, 
Glen Spring, is a limestone spring which is- 
sues from the base of Glen Hill and forms a 
small, clear creek 2-9 feet wide and 2-18 
inches deep. The creek flows into a man- 
made lake approximately 200 yards north 
of the spring basin. The estimated discharge 
of the spring at the date of collection was 
500 gallons per minute. This flow is par- 
tially dependent upon recharge from local 
precipitation. The flow was greatly reduced 
during a long dry period in November 1964 
but was restored December 1964, after the 
drought ended. The temperature of the 
spring varies narrowly between 16 and 18 
degrees Centigrade. The elevation at the 
spring is 480-500 feet above sea level. Glen 
Spring is located within the small portion 
of the Valley and Ridge Physiographic Prov- 
ince which extends into the eastern part of 
the Black Warrier River Basin. 
No. 4 
A New Darter 
107 
The outflow creek is choked with dense 
growths of watercress, Nasturtium officinale. 
The stream bottom consists of angular gravel 
in riffle areas and silt and mud in areas of 
reduced flow and heavy watercress growth. 
EtheostoDia nuchale is very habitat specific; 
it is found only among the watercress. Wc 
have observed nuchale as it perched upon 
the leaves and roots of watercress at mid- 
water depths. There it feeds upon the 
abundant snails, crustaceans, and insect lar- 
vae which inhabit the spring and outflow 
creek. In aquaria, nuchale moves about 
freely, perching here and there upon roots 
and leaves of aquatic plants. It does not 
normally inhabit the bottom as do most 
darters. E. nuchale can be collected almost 
anywhere along the stream course above the 
lake. It is absent below the lake where the 
stream becomes heavily polluted. The stream 
below the lake runs into Halls Creek which 
flows through a residential section of Besse- 
mer, Alabama. 
We have collected in other springs in tne 
Birmingham-Bessemer area but have not 
taken nuchale. Most of the springs have 
either been exploited for public or industrial 
water supplies or have otherwise been al- 
tered. Glen Spring is located approximately 
twenty yards off the present Jefferson 
County Hwy. 20. The outflow creek closely 
parallels the highway. E. nuchale is in dan- 
ger of extinction on the basis of its limited 
habitat alone. At present we are contem- 
plating the transplantation of nuchale to 
other suitable springs in the area. 
E. nuchale is abundant and very success- 
ful in the spring basin and outflow creek. 
Associates of nuchale are, in order of de- 
creasing abundance, Semotilus atromaculatus 
( Mitchill ) , Leponiis cyanellus Raf inesque, 
Etheostoma whipplei artesiae ( Hay ) , and 
Ca?ftpostoma anomalum ( Rafinesque ) . 
Relationship. — Etheostoma nuchale is ap- 
parently a highly sf>ecialized derivative of 
E. sivaini (Jordan), from which it is geo- 
graphically isolated. E. nuchale is known 
only from the type locality which is above 
the Fall Line in the Black Warrior River 
system of Alabama. /:. siraini normally does 
not cross the Fall Line and is a wide-ranging 
species found along the Gulf Coastal Plain 
from the Ochlockonee River in Florida to 
the Amite River system of Southeastern 
Louisiana and southern Mississippi (R. W. 
Yerger, personal communication). We have 
made no attempt to study variation of E. 
swaini throughout its range as this problem 
is currently being investigated by Dr. Ralph 
W. Yerger of Florida State University. Since 
E. nuchale is such a distinctive species, it 
has been compared only with specimens of 
sivaini from the Black Warrior River system 
(Tables 1-5). All specimens of swaini are 
deposited in the University of Alabama 
Ichthyological Collection and have the fol- 
lowing accession numbers: UAIC 677, 679, 
929, 1060, 1112, 1113, 1150, 1161, 1162, 
1180, 1192, 1225, 1582, all from Tuscaloosa 
Co., Ala.; UAIC 1184 and 1190 from Fayette 
Co., Ala. 
Breeding males of nuchale and sivaini 
have the same basic color pattern with the 
colors being more intense in nuchale. Fe- 
males of nuchale and sivaini differ markedly 
in color pattern: in sivaini there are dark 
spots in the center of most body scales 
which usually produce definite horizontal 
lines along the body ( Fig. 2 ) ; in nuchale 
there are many darkened scales but horizon- 
tal lines are not usually developed ( Fig. 1 ) . 
Other color differences are also apparent. 
Sevenry-three per cent of 51 specimens 
of sivaini had either embedded or exposed 
scales on the nape. In nuchale the nape is 
always naked mesially. 
Table 5. 
Conipari.son of Etheostoma nuchale and E. sic aini^ 
Character 
E. nuchale 
E. swaini 
Supratemporal canal 
Infraorbital canal 
Pored lateral-line scales 
Unpored lateral-line scales 
Dors-^l spines 
Total pectoral rays 
Scales in transverse series 
Scales around caudal peduncle 
Widely interrupted 
Usually interrupted 
12-24 
15-27 
VIII-XI (x = 9.12) 
22-24 (x = 23.29) 
Usually 10 or 11 
15-17 (x = 15.86) 
Complete 
Complete 
28-38 
3-11 
X-XII (X = 10.70) 
24-29 (x = 25.61) 
Usually 11 or 12 
16-19 (x = 17.18) 
^ All E. swaini from Black Warrior River system 
108 
T/dane Studies in Zoology 
Vol. 12 
Fignire 2, Top. Etheostoma sivaini. Adult male, 41.8 mm in standard length, from 
Black Warrior River system (UAIC 1184). 
Bottom. Etheostoma sxvaini. Adult female, 44.7 mm in standard length, from Black 
Warrior River system (UAIC 1090). 
Body proportions ( Table 1 ) as well as 
visual comparisons (Figs. 1-2) show that 
nuchale is much more robust than the 
slender, stream-dwelling swaini. Since nuch- 
ale lives among dense growths of water- 
cress where water movement is very slow, 
the deep, robust body is probably a habitat 
adaptation. A distinctive feature of nuchale 
is the humped nape which decurves sharply 
to the occiput. The humped nape does not 
seem to be associated with breeding activities 
since it is well-developed, even in juveniles 
of nuchale. It is absent in stvaini. It is in- 
teresting to note that a few gravid females 
of nuchale were present in collections made 
from March through July. Under relatively 
constant environmental conditions of the 
spring, the breeding season of nuchale may 
be extended. We suspect that swaini of the 
Black Warrior River system breeds in early 
spring. 
The following characters of nuchale 
probably represent increased specialization 
over those of swaini: (1) reduced number 
of pored lateral-line scales, (2) incomplete 
supratemporal canal, (3) incomplete infra- 
orbital canal, (4) reduced number of pec- 
toral rays and dorsal spines, (5) increased 
sexual dimorphism and dichromatism, and 
(6) highly specific habitat. E. nuchale has 
probably evolved, as an isolated population, 
in response to relatively constant conditions 
encountered in the spring environment. 
Name. — The specific name, nuchale, "per- 
taining to the nape", calls attention to the 
light predorsal area and to the humped nape. 
The vernacular name, "watercress darter," 
is suggested in reference to its habitat. 
Literature Cited 
Bailey, R. M., and W. J. Richards. 1963. 
Status of Poccilichthys hopkinsi Fowler 
and Etheostoma trisella, new species, Per- 
cid fishes from Alabama, Georgia, and 
South Carolina. Occ. Papers Mus. Zool. 
Univ. Mich., 680: 1-21. 
HuBBs, C. L., and M. D. Cannon. 1935. 
The darters of the genera Hololepis and 
Villora. Misc. P7ibl. Mtis. Zool. Univ. 
Mich., 30: 1-93. 
, and K. F. Lagler. 1958. 
Fishes of the Great Lakes region. Cran- 
brook Inst. Sci. Bull. 26: xiii + 213 p. 
October 11, 1965