Brachyhypopomus hendersoni

distribution

Distribution: Central Amazon near Tefé, from blackwater lakes, and lower rio Negro, Brazil, and from Essequibo drainage, Guyana (Crampton et al., 2016 b).

Checklist of Gymnotiformes (Osteichthyes: Ostariophysi) and catalogue of primary types

biology_ecology

Ecological notes. In the region of the type locality B. hendersoni is common in marginal emergent plants (mainly wild rices, Oryza spp.), rafts of floating macrophytes (including grasses, e. g., Paspalum, and water hyacinths, Eichhornia spp.), and decaying plant matter along the edges of low-conductivity blackwater floodplain ria lakes (e. g., lago Tefé, lago Amanã, and lago Caiambé), and along river and oxbow lake margins (e. g., in the rio Tefé floodplain). The following water parameters were recorded in the rio Tefé floodplain: conductivity 7 - 18 µScm- 1, dissolved oxygen 3.0 - 6.7 mgl- 1, temperature 29.0 - 33.3 ° C, and pH 5.3 - 6.7. Brachyhypopomus hendersoni occurs in habitats that are not typically exposed to protracted and severe seasonal hypoxia. Crampton et al. (2008) documented the relatively small gill sizes of B. hendersoni relative to congeners that occur in seasonally hypoxic whitewater floodplain systems. Breeding occurs in floating macrophytes during the rising and high water period (WGRC unpublished data). Stomach contents of specimens from the type locality comprise aquatic insect larvae (primarily Chironomidae), and other small aquatic invertebrates (WGRC unpu

A taxonomic revision of the Neotropical electric fish genus Brachyhypopomus (Ostariophysi: Gymnotiformes: Hypopomidae), with descriptions of 15 new species

description

Description. Head and body shape, and pigmentation illustrated in Figs. 1 h and 30. Meristic and morphometric data for examined specimens presented in Tables 2 - 5 and 13. Body shallow to moderate in depth. Head short and shallow to moderate in depth. Dorsal profile of head convex from occiput to snout, ventral profile of head with areas of convexity near mouth and areas of concavity under eye, snout truncate to rounded. Eye moderate to large in size. No accessory electric organ over operculum. Gill filaments on first gill arch 32 - 34 (median 33, n = 4). Pectoral fin moderate in width, pectoral-fin rays 12 - 16 (mode 13). Precaudal vertebrae 15 - 17 (mode 16), with 1 - 2 (mode 1) transitional vertebrae. Anal-fin origin slightly (<0.25 HL distance) anterior to, or near, tip of pectoral fin. Anal-fin rays 192 - 210 (median 200). Dorsal rami of recurrent branch of anterior lateral line nerve not visible. Middorsal region of body scaled. Rows of scales above lateral line 5 - 7 (mode 6). Lateral line continuous. Sparse depigmented epidermal canals in posterior two thirds of body, present in three series: as an irregular, interrupted, single groove either side of dorsal midline along mo

A taxonomic revision of the Neotropical electric fish genus Brachyhypopomus (Ostariophysi: Gymnotiformes: Hypopomidae), with descriptions of 15 new species

description

urn: lsid: zoobank. org: act: A 0 D 96996 - 8 B 4 E- 4001 - A 700 - 64 F 9093 BFA 4 F (Figs. 1 h, 30; Tables 2 - 5, 13)

A taxonomic revision of the Neotropical electric fish genus Brachyhypopomus (Ostariophysi: Gymnotiformes: Hypopomidae), with descriptions of 15 new species