Pterygoplichthys disjunctivus

vermiculated sailfin catfish





Type Locality



Etymology/Derivation of Scientific Name







Maximum size: 70 cm (Fuller et al. 1999).




Pharyngeal teeth count:




Body shape:


Mouth position: The mouth is inferior and the lips surrounding it form a 'sucking disk' (Hoover et al 2004).


External morphology: Adipose fin has a spine; pectoral fins have thick, toothed spines which are used in male-to-male combat and locomotion (Walker 1968). Body covering of bony plates (Nico and Martin 2001).


Distribution (Native and Introduced)

U.S. distribution: Florida and Texas (Fuller et al., 1999).


Texas distribution: Reproducing populations exist in the San Antonio River (Hoover et al. 2004) and in the Buffalo Bayou system in Houston since at least 1996 (Nico and Martin 2001).


Abundance/Conservation status (Federal, State, NGO)



Habitat Associations

Macrohabitat: Occur in lotic fresh and brackish waters (Sterba 1983; Sakuri et al. 1992) with wide temperature ranges (Sterba 1983).





Spawning season: Continuous in the San Antonio River, Texas, based on lack of seasonal variability in length frequency distributions (Hubbs et al. 1978).


Spawning Habitat: Like the armadillo del rio, they construct burrows to lay like young and are guarded by males until larvae leave (Hoover et al 2004). Sometimes forming a large group of nesting burrows on the bank, or a "spawning colony" in which several dozen occur in very close proximity (which can cause soil and bank erosion (Nikolsky 1963).


Spawning Behavior:




Age at maturation:




Growth and Population Structure: Growth is rapid during the first two years of life, more than 35 cm (Devick 1988, 1989).


Longevity: environmental


Food habits: Benthic feeder, adhering to streambeds and rocks; feeding is done by plowing along the substrate and using the thick-lipped, toothy mouth to scrape plant materials (filamentous algae, diatoms) from hard surfaces or to suck up fine sediments (Hoover et al 2004).


Phylogeny and morphologically similar fishes

Other sailfin catfishes have been found in the San Antonio River, including P. anisisti and P. multiradiatus, with pigmentation highly variable within and among species (Hoover et al 2004). They can be distinguished from other suckermouth catfish, Hypostomus sp., by their comparatively wider dorsal fin, with more than 10 rays, their snout with a granular margin, and an articulated interopercular bone with avertable spines (Burgess 1989).


Host Records:



Commercial or Environmental Importance

Most populations were probably started by aquarium releases when the fishes became too big for the tank (Hoover et al 2004). Fish can survive in the moist microhabitat of their nesting burrows even when the water levels fall far below the opening of the chambers. They have been found with eyes sunken into the sockets and surface dry to the touch, indicating prolonged aerial exposure. When returned to water, they recovered after several minutes and swam to deeper water (Hoover et al 2004). These traits enable sailfin catfishes to survive in natural and unnatural habitats (Burgess 1989, Sanford and Crow 1991). Grazing on benthic algae and detritus disrupts the food sources of most North American stream fishes (Hoover et al 2004). Mud and silt feeding (Walker 1968) could result in resuspension of sediments and/or changes in substrate size (Hoover et al 2004). Because they are bottom-feeders they may incidentally ingest eggs of native fishes, which are possibly less productive and have shorter life-spans (Hoover et al 2004)



Burgess, W. E. 1989. An atlas of freshwater and marine catfishes: A preliminary survey of the Siluriformes. Tropical Fish Hobbyist Publications, Inc., Neptune City, NJ.

Devick, W. S. 1988. Disturbances and fluctuations in the Wahiawa Reservoir ecosystem. Division of Aquatic Resources, Hawaii Department of Land and Natural Resources, Report Project F-14-R-12, Job 4, Study I, Hawaii

Devick, W. S. 1989. Disturbances and fluctuations in the Wahiawa Reservoir ecosystem. Division of Aquatic Resources, Hawaii Department of Land and Natural Resources, Report Project F-14-R-13, job 4, study I, Hawaii.

Hoover, J.J., K.J. Killgore and A.F. Confrancesco. 2004. Suckermouth Catfishes: Threats to Aquatic Ecosystems of the United States? Aquatic Nuisance Species Research Program Bulletin. Vol.04-1 (Feb 2004)

Hubbs, C., T. Lucier, G. P. Garrett, R. J. Edwards, S. M. Dewan, E. Marsh, and D. Belk. 1978. Survival and abundance of introduced fishes near San Antonio, Texas. Texas Journal of Science 30:369-376

Nico, L. G. and R. T. Martin. 2001. A population of the South American armored catfish Pterygoplichthys anisitsi (Pisces: Loricariidae) in Texas, with comments on foreign fish introductions in the American southwest. Southwestern Naturalist 46(1), in press.

Nikolsky, G. V. 1963. The ecology of fishes. Translation by I. Birkett. Academic Press, London. Neptune City, Jew Jersey.

Sakurai, A., Y. Sakmoto, and F. Mori editors. 1992. Aquarium fish of the world. Loiselle, V edition. 1992, Chronicle Books, San Francisco

Sandford, G., and Crow, R. 1991. The manual of tank busters. Tetra Press, Morris Plains, NJ.

Sterba, G. 1983. Pages 605 in The Aquarium Encyclopedia. The MIT Press, Cambridge, Massachusetts

Walker, B. 1968. The fish with the folded mouth. The Aquarium Series II. 1(10) 4-5 36-43.