User:Cullen328/sandbox/Crangon franciscorum

This shrimp species is "an important part of the estuarine food web" in the greater San Francisco Bay. It feeds on bivalves, amphipods and foraminiferins,and is prey for various fish. Its diet is "heavily influenced by predator size, temperature-salinity preferences, and prey availability."

Life cycle
The shrimp are short-lived, with a lifespan ranging up to 18 months for males and 30 months for females. The males spawn once while longer lived females spawn twice. There is some evidence that the species may be protandrous hermaphrodites, which means that surviving males are transformed into females after one year of life. This may account for the longer lifespan of females.

The two most important natural environmental factors affecting the health of the shrimp population are water temperature and salinity. The shrimp thrive in brackish water, with a preferred salinity of 14 parts per thousand when young to 24 parts per thousand when ready to spawn. In contrast, open ocean waters have a salinity of about 35 parts per thousand. The species prefers a water temperature of about 18 degrees centigrade, or 65 degrees Fahrenheit. Because these factors vary within the bay, based on the seasons each year, and the variations in the inflow of fresh water in heavy rainfall years as opposed to drought years, the shrimp migrate around the bay, seeking optimal conditions. When heavy flows of fresh water enter the bay, mature females migrate to the saltier parts of the central bay, or out the Golden Gate to the Gulf of the Farallones. There, they mate with males who prefer a slightly saltier environment. The females then incubate from 2,000 to 8,000 eggs and when hatched, the young shrimp migrate back to the shallower and less salty estuaries around the bay. As the newly hatched shrimp develop and mature, they gradually migrate to "deeper, cooler and more saline water".