The female reproductive data presented here and in previous work [ 52] document an approximately six month shift in spawning time between upstream Tarawera (spawning in summer) compared to downstream Tarawera and Rangitaiki rivers (spawning in winter).
One laboratory study suggested, for example, that antidepressants like Prozac could trigger spawning in some shellfish.
No one has ever witnessed adult eels spawning in the wild.
The fish, obviously, is not swimming or spawning in Pocantico Hills.
But escapees have since been found thriving and spawning in the same streams as wild salmon.
The presence of the sperm in the water initiates spawning in the female.
But they have escaped in large numbers, competing for habitat and spawning in the same streams as wild salmon.
The number of shad spawning in the river has declined by 90percentt over the last 20 years, he said.
Most fish can smell, and researchers hope that at least some species would have avoided spawning in oil.
Such fishes, spawning in fresh water and living most of their lives in the ocean, are called anadromous.
So after spawning in late September, the trout head downstream, about 60 miles to the Miramichi estuary, where they pig out all winter on shrimp.
