Rhamdiopsis krugi

Bockmann and Castro 2010



Rhamdiopsis krugi appears to be one of the most troglomorphic fishes known.



It was 19 years (1991 - 2010) between the discovery of this fish and its formal description. In this large period of time close to 150 different publications referred to this fish using a very wide variety of different latin (Imparfinis, Rhamdella, and Rhamdiposis) and common names. The authors of the eventual formal description, Bockmann and Castro (2010), made an attempt to bring together as many of these names as possible into a comprehensive synonymy which runs to three pages. It is not repeated here but can be found in an open accesss journal at




Holotype. LIRP 5929, 37.1 mm SL.

Paratypes. LIRP 5930, 10, 20.4-35.5 mm SL, 2 c&s (27.8-35.0 mm SL), MZUSP 92609, 2, 29.4-31.0 mm SL, LIRP 5928, 10, 20.8-33.9 mm SL, 2 c&s (25.9-33.9 mm SL).


Type locality: Poço Encantado cave, on the left margin of the rio Una (a right affluent of rio Paraguaçu), Municipality of Itactê, State of Bahia, Brazil, elevation 340 meters (12°56'41.8"S, 41°06'17.3"W).

Also known from: Lapa Doce II, Gruta da Artemizia, Gruta Torrinha, Gruta Azul, Gruta Pratinha, Gruta Fanzenda Umburana and Canoa Quebrada (all in the Irece drainage), Gruta Natal, Lapa do Bode, Gruta do Moreno and Poco Azul do Milu (all in the Una-Utinga drainage) (Bichuette et al. 2015).


Bichuette et al. (2015) concluded that Rhamdiopsis krugi is monophyletic but that there are two morphotypes in two separate groundwater basins. These are Rhamdiopsis krugi Una morphotype in the Una-Utinga drainage and Rhamdiposis krugi Irecê morphotype in the Irecê drainage.

Biological Notes

Lapa do Bode has ten cave-restricted species, including springtails, harvestmen, spiders, a beetle, a millipede, a silverfish, a palpigrade and R. krugi. However, only three of those species are currently described: the carabid beetle Coarazuphium cessaima (Gnaspini, Vanin and Godoy 1998); the pholcid spider Metagonia diamantina (Machado, Ferreira and Brescovit 2011); and R. krugi (see Cardoso et al. 2022).

Conservation Status

[NE] [VU B1ab(iii):3.1:2011]

Rhamdiopsis krugi is endemic to Brazil, being extremely specialized and known only from limestone caves in the region of Chapada Diamantina, central Bahia, in the Paraguaçu River Basin. It is known from ten caves, which represent six locations, in an extent of occurrence of 125km2. All caves are outside the Conservation Unit and some are subject to impacts, such as the presence of livestock around the cave, causing burial (Lapa do Bode), pesticide and nitrogen pollution from cow urine (Pratinha Systems), activities (Blue Well) and the disorderly exploitation of groundwater through artesian wells, which may lead to declining groundwater (Iraquara region). These activities have led to a continued decline in habitat quality. Thus, Rhamdiopsis krugi was categorized as Vulnerable (VU) in criterion B1ab (iii). It is essential to organize and supervise these activities, in addition to the urgent implementation of management plans for these caves. [Google Translate].

Museum Holdings

As above only.

Key References

Trajano, E. Journal Article 1993 Considerations about systematics and the evolution of behavior in Siluriform cave fishes
Mendes, L.F. Journal Article 1995 Observations on the ecology and behaviour of a new species of troglobitic catfish from northeastern Brazil (Siluriformes, Pimelodidae)
Trajano, E. and Menna-Barreto, L. Journal Article 1995 Locomotor activity pattern of Brazilian cave catfishes under constant darkness (Siluriformes, Pimelodidae)
Trajano, E. Journal Article 1997 Food and reproduction of Trichomycterus itacarambiensis, a cave catfish from south-eastern Brazil
Trajano, E. and Bockmann, F.A. Journal Article 2000 Ecology and behaviour of a new cave catfish of the genus Taunayia from north-eastern Brazil (Siluriformes: Pimelodidae)
Britto, M.R., Lima, F.C.T. and Santos, A.C.A. Journal Article 2005 A new Aspidoras (Siluriformes: Callichthyidae) from rio Paraguaçu basin, Chapada Diamantina, Bahia, Brazil
Ribeiro, AC Journal Article 2006 Tectonic history and the biogeography of freshwater fishes from the coastal drainages of eastern Brazil: an example of faunal evolution associated with a divergent continental margin
Bockmann, F.A. and Castro, R.M.C. Journal Article 2010 The blind catfishes from the caves of Chapada Diamantina, Bahia, Brazil (Siluriformes: Heptapteridae): description, anatomy, phylogenetic relationships, natural history and biogeography
Bichuette, M.E., Rantin, B., Hingst-Zaher, E. and Trajano, E. Journal Article 2015 Geometric morphometrics throws light on evolution of the subterranean catfish Rhamdiopsis krugi (Teleostei: Siluriformes: Heptapteridae) in eastern Brazil
Trajano, E., Gallao, J.E. and Bichuette, M.E. Journal Article 2016 Spots of high biodiversity of troglobites in Brazil: the challenge of measuring subterranean diversity
Gallão, J.E. and Bichuette M.E. Journal Article 2018 Brazilian obligatory subterranean fauna and threats to the hypogean environment
Pereira, E.H.L., de A. Santos, A.C., de Pinna, M.C.C. and Reis, R.E. Journal Article 2019 An enigmatic new Loricariid (Actinopterygii:Siluriformes) from relictual upper reaches of Chapada Diamantina, Bahia, Brazil
Cardoso, G.M., Bastos-Pereira, R. and Ferreira, R.L. Journal Article 2022 Two new troglobitic species of Iansaoniscus from Brazilian caves (Crustacea, Isopoda, Pudeoniscidae)