Fish Health and Genetics Laboratory

at A.E. Wood Fish Hatchery

Staff member working under hood
505 Staples Road
San Marcos, Texas 78666
Telephone (512) 353-7332


The Fish Health and Genetics Laboratory serves the Inland Fisheries Division of Texas Parks and Wildlife Department, providing timely support services to five freshwater fish hatcheries, the Heart of the Hills research station, and field offices across the state. With a diverse staff and up-to-date equipment, the lab is able to provide a wide array of services. Recent projects have helped Inland Fisheries understand the dispersion and prevalence of largemouth bass virus in Texas, control golden algae in hatchery ponds, and track the genetic makeup of various fish stocks.

The laboratory staff consists of a director, a water quality specialist, a fish health specialist, and a geneticist. These professionals, often assisted by student interns from Texas State University, provide support in three main topic areas:

Water Quality Analysis

In warmwater fish culture, hatchery biologists increase production by enhancing the natural productivity of the aquatic environment. This can be a delicate balancing act. Fertilizing a pond provides more nutrients for young fish, but over-fertilization can reduce dissolved oxygen to levels where growth and even survival may be impaired. By-products of fish growth must also be carefully managed, along with the pH or acidity level of the water. Each Texas state hatchery has a water quality laboratory to monitor culture ponds and ensure that the used water leaving the hatchery's treatment plant meets state and federal standards. The laboratory at A.E. Wood performs these services for its own hatchery and runs periodic quality checks on other hatcheries' testing procedures. More on water quality

Fish Health

Fish get diseases, just as other living organisms do. Outbreaks of largemouth bass virus (LMBV) and "golden algae" (Prymnesium parvum) have affected Texas fisheries in recent seasons. The A.E. Wood Laboratory tests fish found in the wild for viruses, bacteria, parasites, and other microbes capable of causing disease. The lab also tests fish grown in state hatcheries to avoid spreading potential pathogens to the natural environment. Standard protocols for detecting pathogens are adapted from accepted procedures published by the American Fisheries Society Fish Health Section and the U.S. Fish and Wildlife Service. More on fish health services

Molecular Genetics

In their continued quest to improve Texas fisheries, biologists need to track the progress of captive-bred stock released into lakes, rivers and streams. Tagging techniques have been used for this purpose, and are still appropriate for short-term studies of small numbers of fish. However, current advancements in the science of genetics have made it possible to use molecular markers to identify fish derived from captive-bred lines. This eliminates the need to tag each individual fish, and the markers are passed on to subsequent generations. Molecular genetics can also help biologists distinguish variants of the same fish species (for example, the Florida subspecies of largemouth bass) and evaluate which variants perform best under various conditions. More on molecular genetics