Results for “pigment”

This species is frequently mistaken for the similar-looking congener M. spechti Schreitmüller 1936, which is easily-identified by the absence of reddish pigmentation in the dorsal, anal, and caudal fins. There has been some debate as to whether these two represent the same taxon, however, with Winstanley and Clements (2008) proposing that M. erythropterus be considered a synonym of M. spechti because they were unable to separate the two species by morphological characters, and specimens with red pigmentation on the unpaired fins were coll...

While the surface-dwelling form of this species is fairly unremarkable and rarely-seen in the hobby, the blind form is very popular indeed. The two may have diverged as recently as within the last 10,000 years, with the blind form losing its eyes and much of its pigment. This probably happened because the fish needed better development in other sensory areas. Losing unnecessary and energy-consuming aspects of its physiology allowed it to devote more energy to developments such as increased numbers of taste receptors on the head.

This species is much rare in the hobby than its congener A. stigmatias, presumably a reflection of its more remote, restricted natural range. The red pigmentation on the body can vary in both extent and intensity, and apparently begins to fade when the fish have been maintained in aquaria for a period.

At least two similar-looking fishes have been available in the aquarium trade; one, usually referred to as 'Danio sp redfin', resembles the striped form of B. kyathit but is a smaller fish and the red pigmentation in the fins is comparatively more intense. The other is also striped with red fins but grows larger; it's usually labelled as 'Danio sp. KP01' or 'Burmese zebra danio'. It remains unclear whether these are regional variants of B. kyathit or undescribed species.

This unidentified species first appeared in the aquarium trade during 2009. It's easily told apart from similar-looking congeners by the patches of vivid red pigmentation surrounding the eye and sides of the mouth plus the thick, reddish, marginal band in the caudal-fin.

In addition, the colour pattern in aquarium fish traded or identified as C. fowleri is highly variable, but it is unclear whether such differences represent diversity within or between populations. Nevertheless, colour pattern is typically used to distinguish them, with fish from Peru possessing a greater extent of dark pigmentation on the body generally referred to...

The congener C. seussi, which is also native to the rio Mamoré, has a similar colour pattern but its snout is noticeably prolonged compared with that of C. gossei, plus there are some subtle differences in pigmentation. There is a third variant which has been referred to as 'CW069' in the aquarium hobby and appears to be somewhat intermediate, with a short, rounded snout as in C. gossei but a colour pattern more reminiscent of C. seussi.

It can be distinguished from the majority of other Corydoras species by its distinctive colour pattern, comprising a uniform, lightish base pigmentation with a dark arched stripe extending over the upper portion of each flank, from the tip of the snout to the caudal-fin base. This is shared with a few congeners, however, including C. arcuatus, C. narcissus, and C. urucu.

While separating some of the fish that may be found on sale as 'C. siamensis' is a tricky task, C. nigriloba is quite simple to identify. The dark lateral body stripe uniquely breaks up into a series of blotches when the fish are sparring, stressed or sleeping and the lower caudal fin lobe contains dark pigmentation suffused with red. The latter feature has given rise to the trade name of 'penguin flying fox'.

The ornamental albino variant is widely-available and has become extremely popular in the hobby and there is a commercially-produced anerythristic (lacking red pigment) mutation that has pale yellowish fins and has sometimes been misidentified as E. munense. Also worthy of note is that the specific name is sometimes misspelled 'frenatus'. Most members of Epalzeorhynchos were formerly regarded as Labeo spp. and are thus referred to as such in older literature. According to Rainboth (1996) they're characterised by absence of a dorsal spine...

Following the key of Romand (1992) this species can be told apart from congeners by the following combination of characters: adult size > 40 mm SL; large, dark, transverse bars and some reddish-brown pigmentation on flanks; longitudinal bands more-or-less defined; longitudinal bands composed of small red spots; caudal-fin subquadrangular caudal fin; 11-13 anal-fin rays; 16-17 dorsal-fin rays; 7-8 anal-fin rays located anterior to dorsal-fin origin.

G. filamentosa has appeared in the ornamental trade but is evidently delicate and therefore recommended only to experienced aquarists. It can be told apart from congeners by the following combination of characters: possession of filamentous dorsal and anal-fin rays in males; body transparent to translucent yellowish-brown colour in life; absence of a highly-extended second anal-fin spine; absence of carmine-red pigmentation in the dorsal, anal an...

Hemiodus species can be a very skittish when first introduced to the aquarium, but usually settle down over time, especially if a large number are being kept together. All of them look superficially similar, but can be distinguished by differences in patterning. None are particularly common in the hobby. H. ternetzi can be identified by the fact that the black lateral stripe extends to behind the eye, and thehas no pigmentation....

Vernacular names in Brazil include 'Cachorra' or 'Pirandirá', although these are also applied to congeners. It can be told apart from all congeners by the following combination of characters: head and body silvery with dark dorsal surface; an elongate dark blotch posterior to the opercle; dorsal, caudal and anal-fin rays reddish to orange proximally with some individual variation in intensity and tonality; adipose fin dark, with diffuse black pigmentation.

This species is uncommon in the aquarium trade although its name is sometimes applied to other species. It was originally described in the monotypic genus Pseudopristella, and can be distinguished from the vaguely similar Pristella maxillaris by possession of a relatively large (vs. relatively small) humeral spot and having black pigmentation in the anal-fin restricted to the first ray (vs. a prominent distal blotch).

At least two colour forms have been traded, one of which is more intensely-coloured and has been referred to as H. sweglesi 'red' or 'rubra'. The bright red pigmentation is retained in long-term captive specimens, suggesting that it is not considered to be an artefact of diet, but we suspect it might reflect conditions at the collection locality with the reddest fish putatively inhabiting blackwater and plainer forms clearwater environments. Zarske (2014) found the two forms to be identical in terms of morphology an...

Native to the lower Amazon river basin in Brazil with some populations exhibiting differences in colour pattern to one another, particularly in respect of the degree of red and blue pigmentation on the body and fins. Type locality is given simply as 'Amazon River, Brazil'. Field observations suggest it to display a pref...

This species is also referred to as 'Kretser's paradisefish' and 'spotted gourami'. There exist three colour forms, two of which exhibit a greater degree of reddish or violet pigmentation in the fins, respectively. The third is more bluish and was described as M. kretseri minor by Deraniyagala (1958).

This is possibly an undescribed species and has been marketed as 'Asian Cardinal Rasbora', 'flame red rasbora', M. sp. 'rose blue line' or M. 'thuzari' in the ornamental trade. It differs from M. rubescens by its larger adult size, possession of a greenish to bluish lateral stripe, and lesser extent of orange pigmentation on the body. It also appears to represent a distinct genetic lineage (Collins et al., 2012).

There also exist a number of minor differences in colour pattern between populations. For example some Peruvian forms have yellow pigmentation on the body and fins, and those from Guyana and Suriname possess a short red stripe on vertical scale rows 6-9, above the central dark stripe on the body. Rio Negro forms have a similar red stripe but overlapping the central dark stripe and extending along most of the flank, while a form from Colombia has an elongate red stripe which is broken in two beneath the dorsal-fi...