7870

• UCREFRP Catalog Number: 7870
• Author: Lentsch, L. D., et al.
• Title: Options For Selective Control Of Nonnative Fishes In The Upper Colorado River Basin - Final Report.
• USFW Year: 1996.
• USFW - Doc Type: \
• Copyright Material: NO

SPECIES ACCOUNTS
Clupeidae-Herrings
Threadfin Shad Dorosoma petenense .*
Native Distribution:
Gulf of Mexico from Florida south to Guatemala and Belize 8
and north into Oklahoma and Texas [Carlander 19691.
Distribution and Status in Upper Colorado River Basin:
Widely introduced as a forage fish in warmer climates [Lee et
al. 19801. The threadfin shad is an important forage fish
for piscivorous game species in freshwater lentic habitats
of the central and southern United States [Carlander 1969;
Griffith 1978] ; controversy over whether introducing threadfin
shad is beneficial or deleterious to game species [Guest et
al. 1990]. First introduced into Lake Powell in 1968, now
abundant throughout the lake and enters tributary inflow
areas; not reported elsewhere in the UCRB [Tyus et al. 19821.
General Habitat:
Inhabit lakes, ponds, reservoirs, large rivers, and
estuaries [Lee et al. 19801. Prefer pelagic zones of
reservoirs [Tyus et al. 1982] .
Examples of Environmental Factors Affecting Distribution or
Abundance:
¦ Primary limiting factor is temperature (need warm water);
other limiting factors are over-crowding and a lack of
plankton for food [Johnson 1970].
Temperature.-
¦ Critical thermal minimum is 4°C with extremely high
mortality occurring when temperatures drop suddenly,
especially below 12°C. Threadfin shad acclimated to
15°C experienced 50% mortality when exposed to 5°C for
1 h and 100% mortality when exposed to 4°C for 3 h
[source unknown].
Salinity.-
¦ Prefer brackish water with salinity concentrations
of 12-20 ppt [Carlander 1969].
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