Striped Bass Reproduction Facts
When river temperatures reach 55°F/13°C in the Spring, Striper bass begin to swim upstream from the ocean. However for those that are land locked spawning is successful in only a few places like Lake Texoma, which is a deep reservoir in Texas. Spawning doesn’t actually occur until the river temperature reaches about 60°F/16°C. Stripers don’t build nests. Instead several small males escort a larger female to an area where eggs and milt mix in a flurry of thrashing males. The floating fertilized eggs must be kept afloat by the river current for 30 to 70 hours.
River Temperature Matters
The eggs are semi-buoyant. But if the water temperatures are outside of the spawning range, the eggs will sink and die.
- If the river temperature is able to sustain 60°F/16°C, then the fry will hatch in about 65 hours
- If the water temperature in the river sustains a higher temperature of 70°F/21°C, then the fry will hatch much quicker. In about 36 hours
- Bass spawn in brackish water at the heads of estuaries or in fresh rivers.
- They don’t spawn in the open ocean or in saltwater like the European bass.
- Striper bass may enter rivers just above the head of the tide to spawn or travel much further upstream to deposit their eggs. No-one really knows why this is, but we do know that those bass that travel as far as 200+ miles actually stay the year round before heading back to the ocean.
- Striper bass require running water to prevent their eggs from settling on the river bed. Unlike lakes, rivers silt up quickly and would prevent the eggs from hatching.
- Spawning season varies from location to location with the season lasting from late April in North Carolina to July in the St. Lawrence.
A large female may release as many as 1.25 million eggs during her spawning run with each being roughly 1.2 mm in diameter.
After fertilization the eggs swell to about 4 mm. The eggs have a large oil globule that keeps them buoyant in flowing water but causes them sink in still water.
The fry hatch some 75 hours after fertilisation with ambient water temperature of 60°F/16°C. That time dramatically reduces to 30 hours if the water temperature is 71°F/22°C.
Striped Bass growth
After hatching, the fry grow much faster than other North American freshwater bass.
- at the end of the first year, they reach about 5 inches/10 cm
- by the end of the second, they are at 12 inches/30 cm
- by the third year, they usually reach 16 inches/41 cm
Only a small fraction of the 60 thousand to 5 million eggs produced by each mature female will survive.
Because of the specific water conditions required for successful spawning, most freshwater striper populations are the result of widespread stocking programs.
Natural striper bass populations are limited to the Santee-Cooper complex, the Colorado River below the Davis Dam (Lake Mohave), and portions of the Arkansas, Missouri, and Washita rivers and Lake Texoma in Texas.