| Apteronotidae (Ghost knifefishes), subfamily: Apteronotinae |
| 18.4 cm TL (male/unsexed); 10.4 cm TL (female) |
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demersal; freshwater; pH range: 6.9 - 7.3, |
| Known from the main channel of the Amazon River in the western portions of the Amazon basin (Rio Negro and Rio Solimões in Brazil, Rio Ucayali in Peru. |
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Anal soft rays: 124-142. This species is distinguished from its congeners by the following characted: presence of a light brown body pigmentation (vs. pale straw pigmentation in P. gimbeli, and dark brown in P. gymnotus); one row of conical teeth on the dentary (vs. two); edentulous premaxilla (vs. presence of teeth); ossified second basibranchial (vs. unossified in P. gimbeli, condition unknown in P. gymnotus). It further differs from P. gimbeli by the absence of a distinct swelling on the chin (vs. presence of this structure), the total anal-fin rays (124-142 vs. 171–198), and the prepectoral-fin distance (14.1-17.0% of LEA vs. 10.3-13.5); from P. gymnotus by the distance from the posterior naris to the eye (1.7-3.8% of HL vs. 8.2-11.9), mouth length (12.4-27.4% of HL vs. 28.1-38.7), pectoral-fin length (72.7-89.0% of HL vs. 60.4-70.7) (Ref. 83661). |
| This species is known mainly from the main channels of large whitewater rivers such as the Rio Solimões(Amazon) and Río Ucayali. In the Tefé region, it was encountered only during the rising water period in January and February, and captured in waters of 2–4 m depth on beaches of alluvial silt and fine sand. Based on examined stomachs of four specimens, this species feeds exclusively on small, autochthonous, benthic insect larvae (of micro-caddis fly, biting midge and beetle). Most specimens had loose sand grains in the stomach (larger than the grains of sand in the caddis fly jackets), suggesting foraging on sandy substrates; one stomach contained many endoparasitic nematodes. All four specimens captured in the Tefé region had maturing, but not fully mature, gonads, suggesting that spawning occur during the rising water period, typical of riverine apteronotids (Ref. 83661). |
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Least Concern (LC); Date assessed: 21 July 2020 Ref. (130435)
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| harmless |
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