Typhlobelus auriculatus de Pinna & Zuanon, 2013

Family:  Trichomycteridae (Pencil or parasitic catfishes), subfamily: Glanapteryginae
Max. size:  2.98 cm SL (male/unsexed)
Environment:  demersal; freshwater
Distribution:  South America: Lower rio Xingu in Brazil.
Diagnosis:  Vertebrae: 54-56. This species can be diagnosed from all other trichomycterids (and, in the case of the former two characters, probably from all other catfishes) by three autapomorphic modifications: the pseudotympanus modified into a tympanic recess, visible as a deep, well-defined depression on the side of the head, and anteriorly connected via a superficial groove to the pterotic; absence of the laterosensory canal system on the body and head (except for the inner ear), reflected externally as a lack of sensory pores (except one modified pore incorporated into the tympanic recess and leading directly into the interior of the pterotic bone); and a supracleithrum not covering any portion of the lateral opening of the swimbladder capsule. It can be further distinguished from all its congeners by the following characters: absence of the anal fin (vs. presence); presence of one or two well-developed opercular odontodes (vs. absence); presence of anteroventral and dorsal processes of the opercle (vs. vestigial and absence, respectively). It further differs from both Typhlobelus macromycterus and T. guacamaya by having 4 branchiostegal rays (vs. 5 and 3, respectively); and from T. guacamaya and T. lundbergi by having some premaxillary teeth (vs. teeth absent) (Ref. 94274).
Biology:  Collected during late afternoon at the peak of the southwestern Amazonian summer when rivers are at their lowest level. The site was a marginal sand bank forming a small island. Found in an area with moderate current (approx. 40 cm/sec), depths up to 35 cm, markedly warm water (30-33uC on the surface), horizontal transparency varied between 2.5 and 3.2 m and pH 6.5-7.0.
IUCN Red List Status: Critically Endangered (CR); Date assessed: 01 February 2021 (B1ab(iii)+2ab(iii)) Ref. (130435)
Threat to humans:  harmless


Source and more info: www.fishbase.org. For personal, classroom, and other internal use only. Not for publication.