TN00010 ALEWIFE ALOSA PSEUDOHARENGUS
ORIGIN: exotic *1361,1362,1365,1306,1360*; native *1360,1361,1362,1365,1306*; REPRODUCTION: breeding season: spring (return to coastal stream from the sea); landlocked breed from May to early August, peaking in mid to late May; gestation/incubation period: hatch in 6 days at 15.5 deg. C; average number of offspring/reproductive period: highly variable, fecundity rates may exceed 100,000 eggs/female--landlocked specimens average 17,000-38,000 eggs/female; avg.no. of reproductive periods/year: 1; age at sexual maturity: reached at about 20 mm and 3 or 4 yrs of age--landlocked specimens mature faster with majority of alewives at age 1 (86%) sexually mature with no evidence of sexual differences in age or size of first maturity; breeding behavior: strongly anadromous, ascending freshwater streams in the spring to spawn in ponds; pairs aggregate and produce millions of eggs that float to bottom in quiet waters; minimum and maximum breeding ages: year class 3 and 4 compose the majority of anadromous alewives; landlocked specimens will breed from age class 1-4, with ages 1 & 2 composing the majority of the reproduction *1310,1370,1371,2637*; BEHAVIOR: a) territoriality: none; b) home range size: never studied, but some specimens have been shown to return to natal streams to spawn; c) daily and seasonal periodicity: enter fresh water in the spring to spawn; when young reach a size of 1/2 inch in length, soon after hatching, they return to the sea; landlocked specimens will remain in open water pelagic area during the day and will move to littoral zone at night to feed (spring-winter); during winter they remain offshore entirely; d) dispersion/range: common from Nova Scotia to North Carolina, but known from Labrador to Florida; became landlocked in northeastern waters (Great Lakes, New York's Finger Lakes, ets.); in VA landlocked alewives found in Claytor Lake, Flannagan Reservoir, Philpott Reservoir, Smith Mtn. Lake, and Lake Chesdin *1370,1371*; e) migration and dispersal: found no documentation on movements of ocean stocks except for their return to fresh water streams to spawn; movements throughout the year were not found; landlocked specimens emigrate readily as seen in their rapid expansion in the Great Lakes and downstream of Claytor Lake; f) foraging strategy/sites: pelagic feeders; in the ocean alewives feed mainly on plankton including small shrimp, and crab-like forms and small fish; landlocked specimens fed in both the littoral and limnetic zones; their diet's bulk consists of zooplankton (principal taxa: cyclopoid copepod, Cyclops bicuspidatus; the calanoid copepod, Diaptomen reizhardi, and the cladocerans Diaphanosoma leuchtenbergianum, Daphnia retrocurva, Leptodora kindtii and Bosmina longirostris) with smaller amounts of aquatic insects, largely mayfly, chaoborid, and chironomid larvae, and fish larvae; the insect larvae were probably consumed while migrating through the water column, since alewives have difficulty feeding at or near the bottom *1310,1371*; g) spawning site: for anadromous specimens, slower water with a sand or gravel bottom is best (note: eggs are strongly adherent; they float to the bottom and stick to the substrate); studies of landlocked alewives have shown that these fish will indiscriminately spawn in littoral (< 5m) areas with little attached vegetation with a sand or gravel bottom; h) development of young: eggs hatch in about 6 days; food habits of young of year alewives are similar to that of the adults except fish were absent (see foraging strategy/sites above); in streams, when young reach 1/2 inch they move to the ocean; parental care of young is absent *1310,1370,1371*; SPECIES ORIGIN: a) native in salt water and associated spawning streams; b) stocked in Claytor Lake, Flannagan Reservoir, Philpott Reservoir, Smith Mountain Lake, and Lake Chesdin *1370*; POPULATION PARAMETERS: a) relative trend: in landlocked populations, great fluctuations occur; because they are extremely prolific they can withstand heavy predation; b) mortality rates are variable; c) survival rates are variable for landlocked specimens, high summer temperatures can cause massive die-offs; d) sex ratio is approximately 1:1; e) rate of increase is variable; f) turnover rates are variable; year class range from 1-5 in ocean environments and 1-4 in landlocked system *1310,1370,1371*; PHYSICAL DESCRIPTION: back dark gray-green; sides, belly light silver grayish green with faint horizontal stripes; a dark spot is usually present directly behind the gills, in line with the eyes; reaches a length of 15 inches (commonly less than 12 inches) and a weight of 14 ounces; landlocked specimens tend to be more slender and larger headed and have an emaciated look; range from 100-190 mm *1310,1370,1371,2637*
| Life History |
References for Life History Codes
1360, 1361, 1362, 1365, 1306, 1246, 1310, 1370, 1371, 2637, 1373
Comments on Life History Codes
Eggs are adhesive, stick to the bottom or on debris *1367*; spawn in quiet stretches of stream or in lakes; no preferred type of bottom *1336,1366,1367,1359*