Researchers in Sweden have discovered that traces of many medicines can be found in fish that have been swimming in treated waste water. One such medicine, the hormone levonorgestrel, was found in ...

WASHINGTON — An all-female freshwater fish species called the Amazon molly that inhabits rivers and creeks along the Texas-Mexico border is living proof that sexual reproduction may be vastly ...

Every year in September and October, fisheries biologists for the North Dakota Game and Fish Department conduct fall fish reproduction surveys on lakes and rivers in North Dakota. Game and Fish ...

BISMARCK — North Dakota Game and Fish fisheries biologists spend a lot of time in fall surveying district lakes and the Missouri River System in North Dakota looking for natural fish reproduction, ...

Select an option below to continue reading this premium story. Already a Honolulu Star-Advertiser subscriber? Log in now to continue reading. The queen of egg production is the ocean sunfish ...

Several U.S. research teams report reproductive problems in Gulf Coast fish that periodically encounter oxygen at concentrations as low as those in so-called dead zones (SN: 6/5/04, p. 360: Dead ...

Seasonal hypoxia, when dissolved oxygen concentrations in water drop below 2 milligrams per liter, is a normal summer occurrence in estuaries. Over the past 20 years, however, pollution has increased ...

A DNA probing technique clarifies the mechanism behind clonal reproduction of female dojo loach fish, also providing insight into the ancestral origin of the clonal population. A DNA probing technique ...

FRENCH RIVER, Minn. - The St. Louis River has a healthy population of adult lake sturgeon, but those fish are not producing the numbers of young fish that biologists had hoped to see. Few adult ...

In this segment of “North Dakota Outdoors,” host Mike Anderson takes us to Lake Sakakawea during this year’s fall fish reproduction survey. Fisheries supervisor Russ Kinzler says this year’s fall fish ...

The process of vitellogenesis is fundamental to fish reproduction, involving the synthesis of vitellogenin (VTG) in the liver, its release into circulation and the subsequent uptake by developing ...