Demography, Habitat, Reproduction, and Sexual Dimorphism of the Crystal Darter, Crystallaria asprella (Jordan), from South-Central Arkansas
Habitat and demography of the crystal darter, Crystallaria asprella, from the Saline River, Arkansas, were studied utilizing field samples (March 1992 to Feb. 1993) and museum collections (1968-1991). Crystallaria were typically collected at depths of 114-148 cm and velocities of 46-90 cm/sec. Predominant substrata were grael, small cobble, and patches of sand. Cystallaria were not colelcted from habitats containing mud, clay, or submerged aquatic vegetation. The reproductive season was from late Jan. through mid-April with a 1:1 sex ratio during the season. Clutch sizes were 106-576 mature oocytes/female and were positively correlated with SL (r9 = 0.97, P < 0.01). Diameters of mature of ripening oocyes were 1.0-1.2 mm. Long term changes in GSI and ooctye diameter were not apparent for the 25-year span represented by museum colelctions. Both sexes attained sexual maturity before Age I, when females were 50 mm and males 61 mm SL. Sexual dimorphism was pronounced immediately prior to and during the reproductive season. Mature males possessed longer soft dorsal and anal fins than females. Males were usually larger than females, although maximum sizes were not appreciably different. Life expectancy of Crystallaria was at least two years.
George, S. G.,
Slack, W. T.,
Douglas, N. H.
(1996). Demography, Habitat, Reproduction, and Sexual Dimorphism of the Crystal Darter, Crystallaria asprella (Jordan), from South-Central Arkansas. Copeia, 1996(1), 68-78.
Available at: https://aquila.usm.edu/fac_pubs/8720