Non-Native Suckermouth Armored Catfishes in Florida: Description of Nest Borrows and Burrow Colonies with Assessment of Shoreline Conditions

Non-native populations of the Neotropical family Loricariidae, the suckermouth armored catfishes, have been introduced and become established in many warm-climate regions of the world, including parts of the United States (e.g., Florida and Texas). In Florida, the most common loricariid catfishes are members of the genus Pterygoplichthys. Over the past 20 years these catfishes have invaded most inland drainages in the central and southern parts of the Florida peninsula. In certain rivers, canals, and lakes, they are widespread and abundant, accounting for a large proportion of the total fish biomass. Adult Pterygoplichthys attain sizes well over 40 cm long. In both their native and introduced ranges, Pterygoplichthys and certain other loricariid catfishes excavate and maintain burrows in shoreline slopes for use as spawning and nesting sites. The burrows are reportedly excavated and maintained by adult males. In larger reaches of some waterways, burrows created by Pterygoplichthys number in the hundreds or even thousands. The burrows are thought to cause or exacerbate bank erosion. However, there are no quantitative data available to adequately evaluate possible associations between presence and abundance of burrows and bank instability. The goal of the present study was to obtain baseline information on the burrows of Pterygoplichthys in Florida and to provide a preliminary assessment of shoreline conditions, including factors associated with bank stability and erosion. Specific objectives: 1) survey portions of selected rivers and canals in peninsular Florida to determine the number and location of loricariid catfish nest burrows; 2) measure and characterize burrow structures and surrounding habitats; 3) identify shoreline features correlated with the presence of burrows; and 4) categorize bank condition and erosion. Published in Aquatic Nuisance Species Research Program Bulletin, v09-01 p1-30, March 2009. The original document contains color images. All DTIC reproductions will be in black and white.