A preliminary checklist of the fishes of Caddo Lake in northeast Texas.

Abstract. -- Based upon both historical records and recent collections, a total of 86 species of fish in 19 families are reported from Caddo Lake in northeast Texas. A large fraction of these are both native and essentially freshwater species; only four are introduced (Cyprinus carpio, Morone chrysops, M. saxatilis and Stizostedion vitreum) and only two migrate from estuaries (Alosa crysochloris and Anguilla rostrata). This diversity represents more than half of the native nonestuarine species known from Texas. Seventeen additional species which are expected to occur in Caddo Lake are also reported. The fish diversity of Caddo Lake is compared with other regions of North America.

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The extraordinary diversity of Caddo Lake freshwater fishes is undoubtedly related to its unique habitat diversity and minimal human disturbance. Many Texas streams have had substantial anthropogenic changes (Anderson et al. 1995; Hubbs et al. 1997). Additionally, among Texas waters it is close to the center of North American freshwater fish diversity that is greatest in the southern Appalachian region, and which tends to decrease with distance from that focal center (Hocutt & Wiley 1986). Nevertheless, Caddo Lake is unique for Texas as a relatively undisturbed and biologically diverse ecosystem.

This study is based upon both historical records as well as recent collections. Voucher specimens are deposited with the holdings of the Texas Cooperative Wildlife Collection (TCWC) of Texas A&M University, the Texas Natural History Collection (TNHC) of the University of Texas at Austin, the University of Louisiana at Monroe (NLU), the Strecker Museum (SM) of Baylor University and the Oklahoma State University Collection (OSUS). However, many of the species reported in this study were collected only by the late Robert J. Kemp who was the resident biologist in Marshall with the Texas Game and Fish Commission for more than 20 years. Both the presence and identification of specimens of these species was earlier verified by the author. Unfortunately, these reference collections were discarded by later workers. Those species noted with an asterisk (*) are those which were collected by Robert J. Kemp.

DOCUMENTED SPECIES

Family Petromyzontidae

Ichthyomyzon castaneus. -- The chestnut lamprey is a parasitic lamprey that is well known in the Austroriparian area.

Material examined. -- TCWC 38701.

Family Polyodontidae

* Polyodon spathula. -- This species is considered a species of concern by Texas Parks and Wildlife. Paddlefish have declined recently as a result of dams that are barriers to their migration.

Family Lepisosteidae

* Lepisosteus osseus. -- The longnose gar is abundant throughout Texas and is a major predator on all fish and competitor to largemouth bass. Like all gars, it has limited gill capacity and often has to breathe atmosphere air. Like all gars, it has a ganoid scale armor that provides protection against most predators.

Lepisosteus oculatus. -- The spotted gar is widely distributed in the Austroriporian. Like the longnose gar, it is a major fish predator and competitor with largemouth bass.

Material examined. -- TCWC 31902.

* Lepisosteus platostomus. -- The shortnose gar is widely distributed in the Austroriparian. Like all gars, it is a major fish predator and a competitor with largemouth bass.

* Lepisosteus spatula. -- The alligator gar is the largest gar and widely distributed in east Texas. As a large predator fish it eats many fish.

Family Amiidae

Amia calva. -- The bowfish is widely …