The Nonindigenous Occurrences section of the NAS species profiles has a new structure. The section is now dynamically updated from the NAS database to ensure that it contains the most current and accurate information. Occurrences are summarized in Table 1, alphabetically by state, with years of earliest and most recent observations, and the tally and names of drainages where the species was observed. The table contains hyperlinks to collections tables of specimens based on the states, years, and drainages selected. References to specimens that were not obtained through sighting reports and personal communications are found through the hyperlink in the Table 1 caption or through the individual specimens linked in the collections tables.

Ancistrus sp.
Ancistrus sp.
(bristlenosed catfish)

Copyright Info
Ancistrus sp. Kner, 1854

Common name: bristlenosed catfish

Synonyms and Other Names: antenna armored catfish

Taxonomy: available through www.itis.govITIS logo

Identification: The genus Ancistrus contains ~50 described species (Burgess 1989; Armbruster 1997). Members of this genus exhibit marked sexual dimorphism (Ferraris 1991) and are primarily identified by the presence of fleshy tentacles on and around the snout (Burgess 1989). Burgess (1989) and Armbruster (1997) gave distinguishing characteristics of the genus and a key to loricariid genera; Burgess (1989) also provided key to selected species. Photographs were given in Burgess (1989) and Ferraris (1991).

Size: 15 cm (Burgess 1989)

Native Range: Tropical America. Central and South America (Armbruster 1997).

Hydrologic Unit Codes (HUCs) Explained
Interactive maps: Point Distribution Maps

Nonindigenous Occurrences:

Table 1. States with nonindigenous occurrences, the earliest and latest observations in each state, and the tally and names of HUCs with observations†. Names and dates are hyperlinked to their relevant specimen records. The list of references for all nonindigenous occurrences of Ancistrus sp. are found here.

StateFirst ObservedLast ObservedTotal HUCs with observations†HUCs with observations†
FL200120062Everglades; Florida Southeast Coast
UT202020232Hamlin-Snake Valleys; Lower Sevier

Table last updated 7/15/2024

† Populations may not be currently present.

Ecology: Bristlenosed catfish, like many other loricariid catfishes, are benthic fishes that primarily consume algae and detritus (Burgess 1989).

Species in this genus are found throughout rivers and floodplain areas. Ancistrus cf. cirrhosus inhabits streams ranging from still, turbid water with clay substrate to free-flowing, clear water with gravel substrate (Froese and Pauly, 2012).  The unique tentacles are thought to be used in sensing speed and direction of stream currents and perhaps in detecting odors (Burgess, 1989). Another hypothesis is that they resemble juvenile fish and are used to attract females (Sabaj et al. 1999). Only the males develop the bull, bushy tentacles (Sabaj et al. 1999).

Ancistrus species have the capability of obtaining oxygen by breathing air their modified stomach. This allows them to survive in conditions with low oxygen levels (Gee 1976; Sabaj et al. 1999).

Breeding takes place in hollows, caves, and mud holes in banks. The female may lay 20–200 adhesive eggs, usually to the ceiling of the cavity. The male takes care of the young. During this time, a male usually will not leave the cavity to feed, or will leave occasionally and quickly return. The eggs hatch in 4–10 days; the male guards the eggs for 7–10 days after hatching. The fry remain in the cave and become free swimming in 2–4 days (Sabaj et al. 1999).

Means of Introduction: Aquarium release; bristlenosed catfish (along with many other species of the armored catfish family Loricariidae) are highly popular in the aquarium trade.

Status: Unknown. Shafland et al. (2008) listed this species as 'possibly established', citing the collection of a small (122 mm TL) individual as evidence of reproduction. However, individuals of this size are common in the aquarium trade, and no further specimens have been reported.

Impact of Introduction: The impacts of this species are currently unknown, as no studies have been done to determine how it has affected ecosystems in the invaded range. The absence of data does not equate to lack of effects. It does, however, mean that research is required to evaluate effects before conclusions can be made.

Remarks: No known voucher specimens exist.

According to aquarium information, it appears that the species found is most likely A. cf. cirrhosus.  This is the most common species in the trade; however, no one really knows the origin of the stock or even if they are still pure. They may be a hybrid. This species so commonly is raised in captivity that it is called Ancistrus sp. 3 (SeriouslyFish, 2012c).

References: (click for full references)

Armbruster, J.W. 1997. Phylogenetic relationships of the sucker-mouth armored catfishes (Loricariidae) with particular emphasis on the Ancistrinae, Hypostominae, and Neoplecostominae. Unpublished Ph.D. dissertation, University of Illinois, Champaign-Urbana, IL.

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.

Ferraris, C. J., Jr. 1991. Catfish in the aquarium. Tetra Press, Morris Plains, NJ.

Froese, R. and D. Pauly (eds). 2012. FishBase. World Wide Web electronic publication. Available from: http://www.fishbase.org.  Version (08/2012).

Gee, J. 1976. Buoyancy and aerial respiration: factors influencing the evolution of reduced swim-bladder volume of some Central American catfishes (Trichomycteridae, Callichthyidae, Loricariidae, Astroblepidae). Canadian Journal of Zoology 54(7):1030-1037.

Sabaj, M.H. and R.A. Englund. 1999. Preliminary identification and current distribution of two suckermouth armored catfishes (Loricariidae) introduced to Oahu streams. Bishop Museum Occasional Papers 59:50-55.

SeriouslyFish. 2012c. Ancistrus cf. cirrhosus Common Bristlenose Catfish. Available from: http://www.seriouslyfish.com/species/ancistrus-sp-3/ Accessed 3/26/2013.

Shafland, P.L., K.B. Gestring, and M.S. Stanford. 2008a. Categorizing introduced fishes collected from public waters. Southeastern Naturalist 7(4):627-636.

Shafland, P.L., K.B. Gestring, and M.S. Stanford. 2008b. Florida's Exotic Freshwater Fishes - 2007. Florida Scientist 71(3):220-245.

Other Resources:
FishBase Summary

Author: Leo Nico, Pam Fuller, and Matt Neilson

Revision Date: 5/9/2019

Peer Review Date: 8/7/2013

Citation Information:
Leo Nico, Pam Fuller, and Matt Neilson, 2024, Ancistrus sp. Kner, 1854: U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/FactSheet.aspx?SpeciesID=2598, Revision Date: 5/9/2019, Peer Review Date: 8/7/2013, Access Date: 7/16/2024

This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.


The data represented on this site vary in accuracy, scale, completeness, extent of coverage and origin. It is the user's responsibility to use these data consistent with their intended purpose and within stated limitations. We highly recommend reviewing metadata files prior to interpreting these data.

Citation information: U.S. Geological Survey. [2024]. Nonindigenous Aquatic Species Database. Gainesville, Florida. Accessed [7/16/2024].

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