Sternarchorhynchus mesensis Campos-da-Paz, 2000
Mesensis tube-snouted ghost knifefish

Family:  Apteronotidae (Ghost knifefishes), subfamily: Apteronotinae
Max. size:  24.9 cm TL (male/unsexed)
Environment:  benthopelagic; freshwater
Distribution:  South America: Tocantins River basin.
Diagnosis:  Dorsal spines (total): 0-0; Dorsal soft rays (total): 0-0; Anal spines: 0-0; Anal soft rays: 171-189; Vertebrae: 80-110. Distinguished from its congeners by the following combination of features: mouth length 5.4-6.4 %HL; postocular distance 36.4-41.0 %HL; pectoral fin length 27.0-35.3 %HL; scales always present above lateral line at anterodorsal region of body, in 11-13 rows above lateral line at midbody; anterior unbranched anal-fin rays 23-28; and a white to yellowish-white (sometimes indistinct) band on frontal portion of head and middorsum; caudal fin with 13-15 rays (Ref. 36352).
Biology:  Collected from caves within the São Domingos karst region in the upper portions of the Rio Tocantins basin. The species occur in both subterranean and surface drainages and appears to be well adapted to epigean habitats as indicated by the overall condition and sexual maturity of the individuals from cave habitats (Ref. 84053).
IUCN Red List Status: Least Concern (LC); Date assessed: 07 November 2018 Ref. (126983)
Threat to humans:  harmless

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