Gross morphology and histology of the intestine of Aspidoras gabrieli, an endemic catfish of the lower Tocantins River basin


  • Karina Carvalho Fernandes Ferreira
  • Bruno Eleres Soares University of Toronto-Scarborough
  • Erika Cristina Ramos da Silva
  • Renata Bartolette
  • Thiago Henrique Alves Gomes Freire
  • Rafael de Oliveira Marques
  • Erica Pellerini Caramaschi
  • Marcelo Ribeiro de Britto



We describe morphological features of the digestive tract of the endemic callichthyid Aspidoras gabrieli in Serra dos Carajás, southeastern Amazon. The species displays a tubular digestive tract divided into the digestive and aerial gut, separated by a mild constriction. The aerial gut is longer, but with thinner walls than the digestive gut. Microscopically, the aerial gut exhibits several traits of respiratory tissues, such as pseudostratified cells in the mucosa and goblet cells. These traits may allow A. gabrieli to air-breath and thus inhabit hypoxic environments.


Armbruster, J.W. (1998) Modifications of the digestive tract for holding air in Loricariid and Scoloplacid catfishes. Copeia, 1998: 663-675.

Britto M.R. (2014) Callichthyidae (180-185). In: Queiroz L.J., Torrente-Vilara G., Ohara W.M., Pires T.H.S., Zuanon J., Doria C.R.C. (Orgs). Peixes do Rio Madeira – Volume II. São Paulo: Santo Antônio Energia. 354 p.

Ferreira K. C. F. & Britto M. 2019. Callichthyidae (Ostariophysi: Siluriformes) dissection protocol., doi:

Gee J.H. (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: 1030-1037.

Gee J.H. & Graham J.B. (1978) Respiratory and hydrostatic functions of the intestine of the catfishes Hoplosternum thoracatum and Brochis splendens (Callichthyidae). Journal of Experimental Biology, 74:1-16.

Graham J.B. (1997) Air-Breathing Fishes: Evolution, Diversity, and Adaptation. 1st edition. San Diego: Academic Press. 313p.

Nelson J.A. (2014) Breaking wind to survive: fishes that breathe air with their gut. Journal Fish Biology, 84: 554-576.

Lieschke G.J. & Trede N.S. (2009) Fish Immunology. Current Biology, 19: R678-682.

Lowe-McConnell R.H. (1999) Ecological studies in tropical fish communities. 1st edition. Cambridge: Cambridge University Press. 404p.

Persaud D.I. (2000) The functional morphology of the gut of the Callichthyid catfish Hoplosternum littorale (Hancock, 1828), Callichthys callichthys (Linnaeus, 1758) and Corydoras aeneus (Gill, 1858). Ph. D. Thesis, Agriculture and Natural Sciences Faculty. University of the West Indies, Saint Augustine, Trinidad and Tobago.

Plaul S.E., Barbeito C.G. & Díaz A.O. (2016) Histochemical differences along the intestine of Corydoras paleatus (Siluriformes: Callichthyidae). Revista de Biología Tropical, 64: 327-340.

Reis R.E. (1998) Anatomy and phylogenetic analysis of the neotropical callichthyid catfishes (Ostariophysi, Siluriformes). Zoological Journal of the Linnean Society, 124: 105-168.