TN00222 WHITE BASS MORONE CHRYSOPS
Physical description: This is a deep-bodied fish with faint to mod- erate, often broken lateral stripes; adults usually grow to be 230- 410 mm Total Length. The body is moderately compressed and deep; the back is prominently arched; head small or moderate; eye moderate; the mouth is moderate and terminal, with the lower jaw slightly protruding; the tongue has two narrow tooth patches on the anterolateral margin and a single median patch (which is occasionally weakly subdivided). Dorsal fins are not conjoined, and there is a slight gap or no gap be- tween them; the first dorsal fin is markedly convex; the caudal is forked and its lobes often pointed; anal is concave; pectoral pointed. The anal spines are moderately stout and somewhat graduated in length, with the longest spine around 50-75% of the height of the fin. Uro- genital differences between the adult sexes have been noted; most ob- vious of these are the swollen postanal papilla-like folds of the fe- male, while folds are absent or scarcely evident in males. The formula for the lateral line scales is (52)54-58(60); scales above lateral line (7)8-11; scales below lateral line (15)16(17) (Jenkins counts 13-14). First dorsal spines 9; second dorsal with 1 spine, (12)13(14) rays; anal spines 3; anal rays (11)12(13); pectoral rays (15)16(17). Color: The dorsum is bluish, dark green or gray; the side and venter are sil- ver; the body has a gold to blue iridescence; the lateral stripes are gray-olive to dark olive. The median fins have pale bases, and are dusky gray-blue distally; the paired fins are pale to milky white *4205*. Reproduction: sexual maturity relates to age and size, most males mature by age II and all males mature by age III, maturity in females extremely size dependent, can be mature at age II or III, and all mature by age IV (unless stunted) *3294,3295,3308*; spawning occurs in mixed groups in open water over firm bottom; adults home to shoals or stream pools to spawn; homing is an important spawning behavior; migrates to spawn in open water, sand, or gravel *3294,3297*; spawning occurs in spring (May-June); open water deposition of eggs; eggs are adhesive and stick to gravel and vegetation; eggs are not guarded *3297,3295,3306, 3309,3313*; females produce more ova than are brought to maturity (ap- proximately 50% mature, 50% never reach maturity), with fecundity rates from 61,700 ova/fish to 994,000 ova/fish; mature ova are effective fe- cundity with larger diameter ova than immature ova which are recruitment ova *3294,3247,3309*; mature ova range from 0.57-0.85 mm in diameter *3295,3309*; factors influencing reproduction and survival of eggs in- clude: (1) water level fluctuation, (2) wind and wave action, (3) water quality, (4) aquatic and terrestrial cover, (5) air and water tempera- ture, (6) invertebrate and fish predation, and (7) human activity *1272* Males migrate to spawning grounds when water temperatures reach 12-16 degrees C; spawning stops if temperatures fall below 12 degrees C. *CPC3*. White bass prefer to spawn over a firm substrate in water 0.5- 6.0 meters deep, most commonly at depths of 0.6-2.0 meters *CPC3*. Eggs have been hatched in 45 hours at 20.2 degrees C and in 41 hours at 21.5 degrees C *CPC3*. Behavior: After spawning, males and females abandon the area *3309*. Adult fish found in open water in small schools *1140,3295,2128,3296*. The young eat insects and larval fishes; adults are primarily pisci- vores, and they form predaceous schools whose peaks of feeding often occur at dawn and dusk; adults primarily take alewife, black crappie and crayfish in Claytor Lake; feeding centers on large mayflies during heavy hatches in this lake *4205*. Origin: Native *835,3247*; present range extended beyond historical na- tive range through introduction into reservoirs *1115,835*; historical range included the large lakes and rivers of the Great Lakes and Missis- sippi River drainages, with its center in the Lake Erie drainage; de- pletion of white bass in the Great Lakes and increased stocking in newly constructed resevoirs resulted in a southward shift in its center of abundance *CPC3*; Population parameters: Food is primary factor influencing growth in adults *3302,3306*; growth is rapid, and best growth correlates with abundance of forage fish or other food *3306,3310,3311*; time of annulus formation is dependent on age of fish, but annuli age formed every year; older fish are slower to form annuli *3309*; very old fish may not form annuli *3295,3315*; slight declines occur in growth after initial stock- ing *3311*; adult growth rates decline with decline of forage fish; diet of zooplankton sustains adult population, but growth is slow *3305,3309, 3313*; fry approximately 3 mm when hatched, and can reach 8 mm in 15 days *3309*; fingerling size selective in feeding habits, and select for larger prey items with increase in growth *3302,3305*; greater growth rates relate to the frequency of occurrence of fish in the diet *3302,3309*; elements to model a fish (bass) population in a reservoir include: (1) need minimum of 25 pounds/acre of predator (bass), (2) 75 pounds/acre of plankton feeders (e.g., shad), and (3) 100 pounds/acre bottom feeders (e.g., catfish)--production of these 3 factors is con- trolled by: fertility of water, climate, water level fluctuations, shape of basin and substrate composition *1271*; biological factors which influence early life stages include: (1) size of spawning popu- lation, (2) predation and cannibalism, (3) disease and fungi (important in hatcheries, not in wild), and (4) starvation (important in hatch- eries, not evident in wild populations) *1155*; factors needed to es- timate standing crop of bass include: (1) water depth and area of water- shed and area underwater, (2) fertility of water and watershed, (3) species composition of system, (4) population estimate, (5) average seasonal water temperature, and (6) length of growing season *1292*; Average life span is 4 years in southern areas; 7-10 years in northern waters; first year growth ranges from 10 cm in the north to 20 cm in the south *CPC3*. Most white bass mature by age 2; typical longevity is 4-6 years; Claytor Lake produced an 8-year-old fish; females are very fecund, bearing 140,000-994-000 total ova; the eggs are demersal and adhesive, attaching to the substrate *4205*. Limiting factors: Water temperature affects growth of young fish; growth increases with increasing temperature during summer; growth in fall relates to available food *3311*. Aquatic/terrestrial associations: In riverine habitats, associated Dorasoma cepedianum and Potomageton richardsoni *3296,3301*; in lake habitats, associated with Stizostedium vitreum and Scirpus acutus *3296, 3295,3301*.
| Life History |
References for Life History Codes
1140, 835, 3295, 2128, 3296, 3308, 3310, 3311, 3300, 3297, 3294, 3309, 3313, 3302, 3306, 3315, 3305, 3316, 3317, CPC3, 4205
Comments on Life History Codes
Life stages: (1) egg = stage from ova fertilization to hatching (em- bryo, fluids, and shell), (2) larva (fry) = hatching to dispersal from nest (yolk sac absorption and pigmentation formation), (3) fingerling (young of year) = dispersal from nest to adult (first season or first year of life), and (4) adult = post-fingerling stage (after first year, may or may not be reproductive) *1155*.