Grass carp reproduction in the lower Trinity River,Texas

Reports of grass carp (Ctenopharyngodon idella) from the lower Trinity River and Trinity-Galveston Bay of southeastern Texas prompted concerns that this introduced fish may be successfully spawning and recruiting in local waters. To examine these possibilities, Texas Parks and Wildlife Department (TPWD) personnel conducted iethyoplankton sampling from April through July 1992 and 1993 and electrofished during July and August 1993 in the lower Trinity River. Additionally, fish-kill records from the Trinity-Galveston Bay area were examined. Icthyoplanton samples taken in 1992 and 1993 contained 708 grass carp eggs, including many that were viable and developing at the time of collection. In 1993, samples also contained 1,500 recently hatched grass carp larvae. Additionally, 54 juvenile grass carp between 104 and 175 mm total length (TL) were recorded from a section of Bray's Bayou off the Houston Ship Channel in September 1993. These data indicate successful grass carp spawning, egg development, hatching, and possibly recruitment are occurring in the lower Trinity River, Texas.