TN00225 STRIPED BASS MORONE SAXATILIS
Physical description: This is a streamlined bass with bold dark stripes. The adults are usually from 300-900 mm TL. The body is terete, the profile moderate and the back is little elevated. The head length is moderate and the mouth is somewhat large and terminal. The tongue has two narrow tooth patches on the anerolateral margin, and two distinct medial patches. The eye is moderate. The dorsal fins are slightly seperate and the caudal is moderately or weakly forked with the lobes pointed. The anal is concave and the pectoral is subacute. The anal spines are of moderate stoutness and graduated in length with the longest spine ca 40-60 percent of the fin height. The lateral line scales number (53)57-63(65) with 9-11(13) scales above the lateral line and (13)14-16 scales below the lateral line. There are 25-30 circumpeduncle scales, (8)9-10(11) first dorsal spines and one anterior spine on the second dorsal with (10)11-12(14) rays. There are 3 anal spines (9)10- 11(12) anal rays and (13)14-16(17) pectoral rays. The dorsum is dark olive to steel-blue and the side and venter are silver with brassy sheens. The lateral stripes are dark olive to black and the pelvic is white to dusky. The pectoral is greenish *4205*. Reproduction: The females reach maturity at 4-5 years and the males are mature at 2 years *4205*. The larval stage will last 35-50 days and the larvae begin active feeding at 8 days (6-7 days). The juvenile stage lasts from 35-50 days to maturity. Spawning begins in April to early June in water from 10.5-23.6 degrees C in Chesapeake populations *4205*. Females produce between 15,000- 4,000,000 eggs *4205*. Spawning activity may slow from 1 to 3 peaks. These peaks are apparently associated with increases in water temperature *2545*. The eggs are spherical, semi-buoyant, nonadhesive, and approximately 1.3 mm in diameter at fertilization at 22 C or about 80 hours after fertilization at 11 degrees C. The larval stage is divided into 3 phases, yolk sac (3-9 days; 5-8 mm TL), finfold (metamorphosing stage)(11 days; 12 mm TL), and post fin- fold (20-30 days; 20 mm TL) *2545*. Factors influencing reproduction and survival of the eggs include: (1) water level fluctuations, (2) wind and wave action, (3) water quality, (4) aquatic and terrestrial cover, (5) air and water temperature, (6) invertebrate and fish predation and, (7) human activity *1272*. The eggs take 2-3 days to hatch and 4-10 days for the larvae to become free-swimming and feed *4205*. This species spawns in roving surface and near-surface schools. The eggs are broadcast in a moderate to strong current *4205*. Behavior: This species is a predaceous generalist and usualy piscivorous after the early juvenile stage. The young feed on a variety of worms, small crust- aceans, insects and fishes. The adults take fishes, squids, clams, lobsters, crabs, shrimps and other invertebrates. Striped bass feed during the spawning migration and fast only just prior to and during spawning. They spawn in the lower 40-120 km of tidal and nontidalsections of large rivers. The males ascend rivers before the females. Migration and spawning may be triggered by increased river flows. Limiting factors: Limiting factors on larval survival include predation and water and quality factors *795*. Population parameters: Growth is inversely related to population density, and curvilinearly related to forage crop. They are food dependent at low food availability, and food independent at high food availability. Elements to model a bass population in a reservoir: (1) need minimum of 25 lbs. per acre of predator (bass), (2) they need a minimum of 75 pounds/acre of plankton feeders (i.e., shad), (3) they need a minimum of 100 pounds/acre of bottom feeders (i.e., catfish). Production of these three factors is controlled by the fertility of water, climate, water level fluctuations, the shape of the basin and substrate composition *1292*. Biological factors which influence early life stages are: (1) size of spawning population, (2) predation and cannibalism, (3) disease and fungi--important in hatcheries, not important in wild populations, (4) starvation--important in hatcheries, not evident in wild populations *1155*. Factors used to estimate sthe tanding crop of bass are: (1) water depth and the area of watershed and area underwater, (2) fertil- ity of the water and watershed, (3) species composition of the system, (4) pop- ulation estimate, (5) average seasonal water temperature, (6) length of the growing season *2643*. Life stages include: (1) egg: stage from ova fertil- ization to hatching (includes embryo, fluids, and chorion--shell), (2) larva (fry): hatching to dispersal from nest (includes yolk sac absorption and pigmentation formation), (3) fingerling (young-of-year): dispersal from nest to adult (first season or first year of life), (4) adult: post-fingerling stage, after the first year they may or may not be reproductive *1155*. Aquatic/terrestrial associations: Predators of larvae include aquatic insects, bluegill, green sunfish, crappie, flathead minnow and mosquitofish *795*.
| Life History |
References for Life History Codes
2545, 795, 4205
Comments on Life History Codes