Results for “nominal species”

This species is rare in the hobby though it's name is often attached to shipments of other Geophagus species. It's a member of the nominal G. surinamensis 'group' of closely-related species within the genus and can be identified by a combination of characters including: possession of dark preopercular marking; no vertical bars on the flanks; relatively large, roughly oblong-shaped dark midlateral marking; caudal fin brownish with 3-5 light stripes on upper lobe and less well-defined stripes or mottled pattern of light spots with narrow dark interspaces on lower lobe.

This species is relatively rare in the hobby but sometimes available from specialist retailers or private breeders. Though described in 1991 it was first collected much earlier and misidentified by Gosse (1976) as G. surinamensis. It's one of just five Geophagus species not to be included in the nominal G. surinamensis 'group' of closely-related species within the genus along with G. gottwaldi, G. grammepareius, G. harreri an...

This species is relatively rare in the hobby but sometimes available from specialist retailers or private breeders. Though described in 1992 it was first collected much earlier and has been in the hobby since the late 1970s, being known as 'Wangenstrich-Erdfresser' (cheek-stripe eartheater) in Germany. It's one of just five Geophagus species not to be included in the nominal G. surinamensis 'group' of closely-related species within the genus along with G. argyrostictus, G. gottwaldi, G. grammepareius and G. harreri.

This species is frequently confused with the congener D. aequipinnatus auct. but their identitities are in a state of confusion, particularly that of the latter. There are however a handful of characters which separate these two nominal species from one another. D. malabaricus possesses a moderately deep body, 35-38 scales in the lateral se...

A. dispar should only be considered a nominal species as demonstrated by Hrbek and Meyer (2003) who conducted an in-depth phylogenetic study covering the majority of the genus. It was found to represent a paraphyletic grouping meaning it cannot be considered to be a species following the phylogenetic species concept. A. mento, A. sirhani and especially A. ginaonis and A. richardsoni were found to be its closest surviving relatives. Hoedeman (1951) suggested that it should be moved into a separat...

The physical appearance of B. almorhae sensu stricto is something of a mystery. No pictures of live specimens appear in any scientific publications we've read and we've been unable to find a certified image of one anywhere meaning it's possibly never been seen in the aquarium trade. Instead the most commonly available members of the nominal species grouping seem to be B. lohachata, B. sp. 'Kosi' and B. sp. 'Teesta' (see individual notes below), plus the assorted hybrids that have appeared since the turn of the century (Grant, 2007).

Within the nominal species grouping suggested by Grant (2007) almost all B. rostrata sold in the hobby are B. sp. 'upper Brahmaputra' with B. rostrata sensu stricto rarely, if ever, available. Trade names include 'Gangetic loach', 'twin-banded loach' and 'ladder loach'. The defining characters of the group are "Pattern consisiting of 8-10 black to dark brown body bars that exhibit pale and numerous spots in juveniles, and in adults the bars can anast...

This species is often confused with the nominal congeners C. marulius (Hamilton, 1822) and C. melanoptera (Bleeker, 1855) with all three presenting taxonomic problems. For example, C. marulioides exhibits a number of variations in colour pattern depending on collection locality with the most common possessing a brownish base colour with a series of dark, chevron-like markings along each flank and some scales margined posteriorly in white.

This species is rare in the hobby although other species are sometimes sold under the name. It's a member of the nominal G. surinamensis 'group' of closely-related species within the genus and can be identified by a combination of characters including: possession of dark preopercular marking; four parallel, ventrally-inclined bars on each flank (normally visible only when the fish are stressed, spawning or preserved); dark lateral spot positioned within the second vertical bar; caudal fin red with variable pattern of large, iridescent blue to white spo...

This species is generally rare in the aquarium hobby though oddly appears to be one of the commoner species in Australia where it's often referred to by the vernacular name 'black-throated eartheater'. It's a member of the nominal G. surinamensis 'group' of closely-related species within the genus and can be identified by a combination of characters including: presence of dark preopercular markings; no vertical bars on the flanks even when stressed/preserved; base of filaments on the first gill arch mostly covered by a flap of skin; exposed part of bra...

This species is very rarely-traded since collections of fishes for commercial purposes aren't common in Suriname. It's a member of the nominal G. surinamensis 'group' of closely-related species within the genus and can be identified by a combination of characters including: no dark preopercular marking; six vertical/parallel bars on each flank (normally visible only when the fish are stressed, spawning or preserved); dark, squarish lateral spot positioned within the third vertical bar; sixth (posterior) bar elongate an...

It's a member of the nominal G. surinamensis 'group' of closely-related species within the genus and can be identified by a combination of characters including: presence of dark preopercular markings; seven parallel vertical bars on each flank (normally visible only when the fish are stressed, spawning or preserved); vertical bars four and five meet in such a way that they form a 'Y' shape; dark lateral spot positioned within the third vertical bar; caudal fin reddish with variable pattern of iridescent blue spots and stripes.

The smallest and most delicate of the nominal hatchetfishes. The rounded keel is shallower than related species, giving this fish a distinctive elongate profile. The family Gasteropelecidae is separated from other Characiformes by the following combination of characters: front...

This is the smallest member of the genus and rarely traded in numbers, though it's a relatively common contaminant among shipments of wild fishes from Manaus. Unlike other Nannostomus spp. it does not exhibit a specific colour pattern of spots or bars at night-time, rather displaying an overall paleness. The family Lebiasinidae is included in the order Characiformes and sometimes split into the nominal subfamilies Lebiasininae a...

There exist several different colour forms of this species depending on collection locality, and these should not be kept together in order to prevent hybridisation and preserve bloodlines. It has been classified in the subgenus Chromaphyosemion by some authors who consider that nominal grouping to represent a monophyletic branch of a paraphyletic Aphyosemion.

This species is also traded/referred to by the vernacular name 'Ceylon fighting fish'. It differs from its only congener, B. hasselti, by its overall reddish (vs. brownish-grey) body colouration, and absence (vs. presence) of a mosaic-like patterning in the unpaired fins. At least three putative phenotypes have been recorded. The nominative, and commonest, mostly inhabits clear streams in rainier zones...