Acestridium

Acestridium is a genus of freshwater ray-finned fishes belonging to the family Loricariidae, the mailed catfishes, and the subfamily Hypoptopomatinae, the cascudinhos. The catfishes in this genus are found in South America.

Taxonomy

Acestridium was first proposed as a monospecific genus in 1911 by the American ichthyologist John Diederich Haseman when he described Acestridium discus, meaning that A. discus is the type species of this genus by monotypy.^[1] The genus is sometimes classified in the tribe Hypoptopomatini.^[2] A study in 2015 found that Acestridium was the sister taxon to Niobichthys and that the clade formed by these two genera formed a sister taxon to the clade comprising Oxyropsis and Hypoptopoma.^[3] This subfamily is classified within the subfamily Hypoptopomatinae, sometimes called cascudinhos, of the suckermouth armoured catfish family Loricariidae, in the suborder Loricarioidei of the catfish order Siluriformes.^[4]

Etymology

Acestridium suffixes the Latin diminutive -idium, indicating similarity, onto the Greek akestra, which means "needle", this is assumed to be an allusion to the long spines at the tip of the snout of the type species, A. discus.^[5]

Species

Acestridium contains the following valid recognized species:^[6]

Distribution and habitat

Acestridium species are native to small streams of the Amazon region of Brazil, Venezuela, and Colombia.^[7] Species of this genus are found in litter banks.^[8]

Characteristics

Members of this genus typically are long and thin, or 'twiglike' and superficially resemble the genus Farlowella of the same family. Adult length is 5–7 cm and each species shows adaptation for camouflage in the water margins - bright green leaf like in Acestridium dichromum^[9] and variegated brown in other species.^[10]

References

1. ^
2. ^ Gauger, Marco F. W. & Buckup, Paulo Andreas (2005). "Two new species of Hypoptopomatinae from the rio Paraíba do Sul basin, with comments on the monophyly of Parotocinclus and the Otothyrini (Siluriformes: Loricariidae)". Neotropical Ichthyology. 3 (4): 509–518. doi:10.1590/S1679-62252005000400008
3. ^ Rodriguez, M. S.; M. L. S. Delapieve; R. E. Reis (2012). "Phylogenetic relationships of the species of Acestridium Haseman, 1911 (Siluriformes: Loricariidae)". Neotropical Ichthyology. 13 (2): 325-340. doi:10.1590/1982-0224-20140129. hdl:10923/13458
4. ^ Richard van der Laan & Ronald Fricke (eds.). "Eschmeyer's Catalog of Fishes Classification". Eschmeyer's Catalog of Fishes. California Academy of Sciences. Retrieved 25 March 2026.
5. ^ Christopher Scharpf (28 February 2026). "Family LORICARIIDAE: Subfamily HYPOPTOPOMATINAE Eigenmann & Eigenmann 1890 (Cascudinhos)". The ETYFish Project Fish Name Etymology Database. Christopher Scharpf. Retrieved 26 March 2026.
6. ^
7. ^ Retzer, Michael E. (2005). "Description of a new species of Acestridium (Siluriformes: Loricariidae) from Colombia". Zootaxa. 972: 1–6. doi:10.11646/zootaxa.972.1.1. Retrieved 2009-06-25.
8. ^ M. F. Catarino, A. L. Val. "Abundance and distribution of fish in litter banks of the Amazon". Archived from the original on 2011-07-06. Retrieved 2009-06-25.
9. ^ "Loricariidae :: Acestridium dichromum". Planet Catfish
10. ^ "Acestridium discus picture". FishBase