Etymology

Percina = small perch (Latin); evides = comely

Other common names

gilted darter

Nomenclature and Authority

Alvordius evides Jordan and Copeland in Jordan 1877a:44

Ericosma evides Jordan 1877b:8-9

Hadropterus evides Forbes 1884:65

Percina evides Bailey and Gosline 1955:14

Prior to 1955 gilt darters were referred to in the Minnesota literature as Hadropterus evides. The Cannon River specimen referred to by Carlander (1941) and Eddy and Underhill (1974) is a misidentified P. maculata (Hubbs 1945).

Distribution (map) and Status

The distribution of the gilt darter has become markedly fragmented during this century. Formerly, this species occurred from the Allegheny River drainage of southwestern New York and Pennsylvania west to the St. Croix River drainage of Minnesota and the White River of Northern Arkansas, and south to the Tennessee River drainage of northern Alabama and Mississippi and the Hiwassee River drainage of northern Georgia. At present, the gilt darter is considered extirpated in Iowa, Illinois and Ohio (Roosa, 1977; Smith, 1979; Trautman, 1981) and has been accorded rare or endangered status in Kentucky, Indiana and Pennsylvania (Miller, 1972; Branson, 1977; Burr, 1980; Margulies et al., 1980).

In Minnesota, gilt darters are restricted to the St. Croix River proper and four of its major tributaries-the Sunrise, Snake, Kettle, and Upper Tamarack rivers (Hatch, 1986). Populations are common and well established in riffles and raceways of the Snake, the lower reaches of the Sunrise, and the St. Croix above the dalles. These populations have survived mainly because of the extremely low sediment loads and lack of impoundment in the Upper St. Croix basin. Gilt darters have been collected downstream of the St. Croix Dalles as recently as 1977, but at present we believe populations in this portion of the drainage are sporadic and uncommon (Hatch, 1986).

Description of Minnesota Specimens

The adult gilt darter is a robust darter with a stout, moderately compressed body; slightly blunted, short snout; and a terminal mouth. The body bears 7-9, rarely 10, quadrate lateral blotches that usually join with 6-9 dark, dorsal saddles forming a distintive series of bands across the back of the fish. The first dorsal fin has 10-13 (modally 12) spines, and the second has 11-14 (modally 12) soft rays. The anal fin has 2 spines and 8-11 (modally 9) soft rays, 12-16 (modally 14) pectoral rays, and 59-77 (modally 66) lateral line scales. Contrary to the statement of Eddy and Underhill (1974), both the cheeks and opercles of Minnesota specimens are scaled, although those of the cheek are few (4-8), poorly developed, often lack cteni and are embedded in the epidermis of the postocular stripe.

Gilt darters exhibit strong sexual dimorphism in size, coloration, and the presence of breeding tubercles. Male gilt darters are Minnesota's only brilliantly colored Percina species, and a male in full breeding colors is nearly as spectacular as the rainbow (Etheostoma caeruleum), Iowa (E. exile) or banded darters (E. zonale). The back of the fish and the lateral blotches become an intense, iridescent blue-green, while the ventral portions of the body and head, the spinous dorsal fin and the area between the blotches become brilliant yellow and orange, the latter sometimes punctuated with reddish dots. At the height of the breeding season, the orange body color is further punctuated by an intense blue-black pigment that accumulates in the breast, in the pelvic and spinous dorsal fins and at the base of the anal fin. Females show only slight hints of the seasonal color changes that are so striking in males. Only males develop tubercles

In preserved condition, gilt darters most closely resemble blackside darters (P. maculata ) and, to a lesser extent, river darters (P. shumardi ). The former lacks the gilt darter's dorsal banding pattern and instead exhibits a vermiform pattern of light and dark pigmentation. The latter possesses 4 distinctive black spots in the membrane of the spinous dorsal fin-one between the first and second spines and one following each of the last three spines.

Minnesota gilt darters most closely resemble populations from the Ohio River drainage with respect to general body shape and cheek squamation. However, our darters exhibit significantly higher lateral line, above the lateral line, anal to first dorsal diagonal, second dorsal to anal diagonal, and least caudal peduncle scale counts, as well as higher anal ray counts (Hatch 1982).

Natural History in Minnesota

Gilt darters inhabit clear, moderate to large-sized streams (20-100 m wide) that exhibit strong flow all year. During the summer, gilt darters are found most frequently in rubble riffles and cobble or boulder raceways where currents are moderate to swift (0.5-1.2 m/sec); rarely do they occur in pools or in association with rooted, aquatic vegetation. Gilt darters typically exhibit a seasonal migration between habitats. In the fall, they move from shallow riffles and raceways to the deep chutes of rubble and boulder riffles, where they overwinter. Mature individuals return to shallower silt-free, cobble raceways in the late spring and early summer to spawn. Thoughout the summer, juveniles use these same cobble raceways as nursery areas. The benthic species that share the greatest habitat overlap with gilt darters are the slenderhead darter (P. phoxocephala ), the blackside darter (P. maculata ), the logperch (P. caprodes ), the longnose dace (Rhinichthys cataractae ), and the stonecat (Noturus flavus ).

In Minnesota, gilt darters reach maturity at about 50 mm SL (11-13 months for males and 22-23 months for most females), and typically spawn during June and early July, although spawning can commence as early as middle May and end in late July. Spawning time and duration are determined principally by the combined effects of temperature and flow conditions. Temperatures need to exceed 16°C and flow must be sufficient to keep spawning substrates clear of fine sediments to initiate spawning. Sustained temperatures over 23°C appear to terminate spawning events. Gilt darters are egg-buriers (Page 1985), and spawning takes place over gravel and sand in cobble and cobble-boulder raceways of moderate (0.2-0.8 m/sec) but persistant flow (Hatch 1982, 1986; Page et al. 1982).

The following description of reproductive behavior is based on observations made in aquaria and in the field by the author (Hatch 1982) and in the field by Page et al. (1982). During the breeding season only, male gilt darters establish fixed territories around cobble or boulder stones from which they exclude rival males through a combination of chasing and ritualized body posturing, tail beating, fin display and rapid color changes. Males may immediately pursue females who enter the territory or they may be inticed to pursue by body posturing and tactile stimulation of the female. When the female comes to rest on a suitable spawning site, the male mounts in a head-to-head position, and the two quiver intensely pushing down slightly into the substrate while releasing eggs and milt. Head-to-tail positioning, which was observed by Page et al., appears to be an attempt to turn the female, perhaps to reorient her to the current.

We do not know how many eggs are laid during each spawning event nor how many times a single individual may spawn. However, the counts of mature ova from 15 specimens taken just prior to spawning ranged from 132 to 397 with a mean of 247. Counts of all ova with yolk were 305-762 (Hatch in prep.). The counts were strongly correlated with size and age (Price and Hatch 1987). At this time the mass of the ovary typically exceeds 20% of the adjusted body mass. Mature, water hardened ova are 1.1-1.4 mm in diameter, yellow to orange in color with a single coelesced oil globule. Eggs hatch in about 8-10 days when water temperature is near 20 °C. Larval gilt darters hatch at 4.0-4.8 mm, and larval development lasts about one week. Males grow faster than females, and disparity in size between the sexes increases with age (Hatch in prep.). Maximum longevity is 4 years (1 out of 1240 specimens), but less than 10% of 1-year olds complete a third growing season. Lutterbie (1976) and, subsequently, Becker (1983) reported some specimens older than 4 years from the St. Croix River, but I found no specimens in their samples older than 3 years.

In the Sunrise River study, gilt darters were diurnal feeders, feeding most heavily in the afternoon hours. Seasonal feeding activity rose sharply in April, continued at a high level through August, and declined rapidly in September. Very little feeding took place from November through March. The diet consisted almost exclusively of immature mayflies (46%), diptera (43%), and caddisflies (10%), but the composition varied seasonally and with age. Juvenile (not larval) gilt darters ate proportionately more caddisfly larvae in the first 2 months of life than they did later, although the size of the larvae ingested increased. As caddisfly larvae decreased in relative importance in the diet, midge and black fly larvae increased. Mayfly naiads were most important in the diet of very young darters and in the diet of pre-spawning adults. Overall the diet patterns from this and a subsequent study (Hatch 1985) suggested opportunistic feeding according to the availability of accessable surface-dwelling insects. The latter study also showed that, at least in regard to late summer feeding, blackside darters have the greatest feeding niche overlap with gilt darters.

Along with several other darter species, gilt darters could be important indicators of degraded water quality. They are especially sensitive to sediment loading and probably to organic loading from sewage effluents (Margulies et al. 1980). Although they may occassionally be consumed by piscivorous fishes, they are probably not an important forage for our game species (Hatch 1982).

Literature Cited

Bailey, R. M. and W. A. Gosline. 1955. Variation and systematic significance of vertebral counts in the American fishes of the family Percidae. Miscellaneous Publications of the Museum of Zoology, Univ. Mich. 93:1-44.

Becker, G. C. 1983. The Fishes of Wisconsin. University of Wisconsin Press, Madison.

Branson, B. A. 1977. Threatened fish of Daniel Boone National Forest, Kentucky. Transactions of the Kentucky Academy of Science 38:69-73.

Burr, B. M. 1980. A distributional checklist of the fishes of Kentucky. Brimleyana 3:53-84.

Carlander, K. D. 1941. The darters (Etheostominae) of Minnesota. Proceeding of the Minnesota Academy of Science 9:41-48.

Eddy, S. and J. C. Underhill. 1974. Northern Fishes. 3rd revised ed. Univ. Minn. Press, Minneapolis.

Forbes, S. A. 1884. A catalogue of the native fishes of Illinois. Report of the Illinois State Fish Commission (1884):60-69.

Hatch, J. T. 1982. Life history of the gilt darter, Percina evides (Jordan and Copeland), in the Sunrise River, Minnesota. Ph. D. Thesis. Univ. Minn., Minneapolis.

Hatch, J. T. 1985. Comparative growth, reproduction, habitat, and food utilization of darters of the upper St. Croix River drainage. Minnesota Nongame Program Technical Report (December, 1985).

Hatch, J. T. 1986. Distribution, habitat, and status of the gilt darter (Percina evides ) in Minnesota. Journal of the Minnesota Academy of Science 51:11-16.

Hatch, J. T. (in preparation) Life history of the gilt darter (Percina evides ) in the St. Croix River drainage.

Hubbs, C. L. 1945. Corrected distributional records for Minnesota fishes. Copeia 1945:13-22.

Jordan, D. S. 1877a. On the fishes of northern Indiana. Proceedings of the Academy Natural Scienes, Philadelphia. 1877:42-82.

Jordan, D. S. 1877b. Contributions to North American ichthyology, based primarily on the collections of the United States National Museum. 2.A.-Notes on Cottidae, Etheostomidae, Percidae, Centrarchidae, Aphredoderidae, Dorysomatidae, and Cyprinidae, with revisions of the genera and descriptions of new and little known species. Bulletin of the United State National Museum 10:5-68.

Lutterbie, G. W. 1976. The darters (Pisces: Percidae: Etheostomatinae) of Wisconsin. M. A. T. Thesis, Univ. Wisc.-Steven's Point.

Margulies, D., Burch, O. S., and B. F. Clark. 1980. Rediscovery of the gilt darter (Percina evides) in the White River, Indiana. American Midland Naturalist 104:207-208.

Miller, R. R. 1972. Threatened freshwater fishes of the United States. Transactions of the American Fisheries Society 101:239-252.

Page, L. M. 1985. Evolution of reproductive behaviors in percid fishes. Illinois Natural History Survey Bulletin 33:275-295.

Page, L. M., M. E. Retzer, and R. A. Stiles. 1982. Spawning behavior in seven species of darters (Pisces: Percidae). Brimleyana 8:135-142.

Price, A. and J. T. Hatch. 1987. Reproductive capacity and body size in darters (Percidae: Etheostomatini). Journal of the Minnesota Academy of Science 53:17.

Roosa, D. M. 1977. Endangered and threatened fish of Iowa. Special Report No. 1., Iowa State Preserves Advisory Board, Des Moines.

Smith, P. W. 1979. The Fishes of Illinois. University of Illinois Press, Urbana.

Trautman, M. B. 1981. The Fishes of Ohio. Revised edition Ohio State University Press, Columbus.