Classification / Names
Common names | Synonyms | Catalog of Fishes(genus, species) | ITIS | CoL | WoRMS | Cloffa
Teleostei (teleosts) >
Characiformes (Characins) >
Characidae (Characins; tetras) > Stethaprioninae
Etymology: Hemigrammus: Greek, hemi = half + Greek, gramma = letter, signal (Ref. 45335); machadoi: Named for Francisco de Arruda Machado, ichthyologist from the Universidade Federal de Mato Grosso, Brazil, for his tireless dedication in surveying the fishes of his native State, as well as for his struggle for their conservation and the conservation of the rivers from the Mato Grosso State. A genitive noun.
Eponymy: Dr Francisco de Arruda Machado is a Brazilian ichthyologist and ecologist whose master’s degree (1983) and doctorate (2003) were both awarded by the State University of Campinas. [...] (Ref. 128868), visit book page.
Environment: milieu / climate zone / depth range / distribution range
Ecology
Freshwater; benthopelagic. Tropical
South America: Rio Paraguai and rio Madeira basins in Brazil.
Length at first maturity / Size / Weight / Age
Maturity: Lm 2.7, range 3 - 2.72 cm
Max length : 3.6 cm SL male/unsexed; (Ref. 96864)
Short description
Identification keys | Morphology | Morphometrics
Dorsal soft rays (total): 11; Anal soft rays: 26 - 30; Vertebrae: 34 - 35. Hemigrammus machadoi can be distinguished from most congeners by its wide dark horizontal stripe across the eye (vs. eye stripe absent or, when present, vertical, except H. barrigonae, H. lunatus, and H. ulreyi and by its well defined narrow dark stripe at the basis of the anal fin (vs. dark stripe at the basis of anal fin absent, except H. barrigonae, H. boesemani, H. lunatus, H. mimus, and H. ulreyi). It differs from H. boesemani, H. geisleri, and H. mimus by having a distinct dark humeral blotch (vs. humeral blotch absent) and by the absence of a blotch on caudal peduncle or any distinct patch of pigmentation on caudal fin (vs. dark blotch on caudal peduncle present in H. boesemani and H. geisleri, a dark marking present at the basis of each caudal-fin lobe basis in H. mimus); from H. barrigonae and H. ulreyi by absence of a narrow, well-defined longitudinal midlateral dark stripe (vs. present) and by the absence of a discrete blotch on caudal peduncle (vs. present in H. barrigonae) and a dark pigmentation patch on the basis of anteriormost dorsal-fin rays (vs. present in H. ulreyi). It can be distinguished from Hemigrammus lunatus the following characters: a conspicuous vertically elongated dark humeral blotch, extending horizontally from second through sixth lateral-line scales, and vertically from third row above lateral line to first row below it (vs. a small roundish humeral blotch, extending horizontally from fourth through sixth lateral-line scales, and vertically from fourth through fifth scale rows above lateral line); 4-5 gill-rakers on upper branch and 9-10 on lower (vs. 6-7, and 11-12, respectively); the higher number of cusps on inner premaxillary, dentary, and maxillary largest tooth (5-7 cusps, mode 7, in premaxillary and dentary, vs. 5; 3-5 cusps, mode 5, in maxillary vs. 1-3); and 34-35 total vertebrae (vs. 32-33) (Ref. 96864).
Inhabits slow flowing, low-gradient streams and small rivers, with clear, sometimes slightly dark-stained waters and bottom composed mainly of sand and clay. Also found in clear water wetlands. In igarapé Barreiro and at some sites at the rio Guaporé, this species seemed to prefer its surrounding with abundant aquatic vegetation (Ref. 96864).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Ota, R.P., F.C.T. Lima and C.S. Pavanelli, 2014. A new species of Hemigrammus Gill, 1858 (Characiformes: Characidae) from the rio Madeira and rio Paraguai basins, with a redescription of H. lunatus. Neotrop. Ichthyol. 12(2):265-279. (Ref. 96864)
IUCN Red List Status (Ref. 130435: Version 2024-2)
Threat to humans
Harmless
Human uses
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Internet sources
Estimates based on models
Phylogenetic diversity index (Ref.
82804): PD
50 = 0.5000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.01202 (0.00496 - 0.02912), b=3.10 (2.92 - 3.28), in cm total length, based on LWR estimates for this Genus-body shape (Ref.
93245).
Trophic level (Ref.
69278): 3.0 ±0.4 se; based on size and trophs of closest relatives
Resilience (Ref.
120179): High, minimum population doubling time less than 15 months (Preliminary K or Fecundity.).
Fishing Vulnerability (Ref.
59153): Low vulnerability (10 of 100).
