Results for “fin”

This species is also referred to by the vernacular name 'Malay combtail'. In terms of external characters it differs most obviously from its only congener, B. signata by its overal brownish grey (vs. reddish) body colouration and presence of a mosaic-type patterning in the unpaired fins (vs. absence). The position of relatedness of the genus Belontia with respect to other anabantoids remains somewhat...

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...

This species is often confused with B. krataios in the aquarium trade, the latter having been known as B. sp. 'Kapuas' prior to description. The two can easily be told apart as the caudal-fin is rounded in B. krataios but spade-shaped and in adults, highly-extended in B. dimidiata. Together these two comprise the B. dimidiata group of closely-related species within the gen...

This species is the only member of the B. edithae group within the genus, and separated from all other Betta spp. by the fact that the branchiostegal membrane and posterior portion of the opercle are opaque or translucent. The original diagnosis by Vierke also states that it has relatively small eyes and short fins with a typical pattern of partial barring.

B. ibanorum is uncommon in the hobby and is apparently more frequently fished for food than the aquarium trade. It's included in the Betta akarensis group/complex of closely-related species within the genus, of which members share the following set of characters: possession of pre-orbital and post-orbital stripes (the post-orbital stripe is faint or interrupted in some species); chin bar present; caudal-fin lance...

This species was traded as B. sp. 'Kapuas' prior to its formal description and continues to be mislabelled B. dimidiata. The two can easily be told apart as the caudal-fin is rounded in B. krataios but spade-shaped and in adults, highly-extended in B. dimidiata. Together these two comprise the B. dimidiata group/complex of closely-related species within the genus, members of which can be characterised b...

It can be told apart from other members of the B. pugnax group by the following characters: caudal fin rounded in both males and females; chin bar and second postorbital stripe absent; adult males possess intensive blue or bluish-green iridescent (blackish in preservation) colouration on the sides of the head and throat extending from the snout tip to posterior edge of opercle; possession of two central body stripes, the upper extending from the pec...

This species is included in the Betta unimaculata complex of closely-related species within the genus, of which members share the following set of characters: body long and slender with depth at dorsal fin origin 18-25 % SL; head large and blunt with width 19-24 % SL; long maxilla and lower lip with distance from tip of lower jaw to poste...

It can be told apart from other members of the B. pugnax group by the following characters: second postorbital stripe on opercle complete; no transverse bars in caudal-fin; 20-22 predorsal scales; preanal length 50.6-54.8 % SL. Not all authors consider it a member of this group, however, with some placing it in the B. picta complex, e.g., Schindler and Schmidt (2006). The genus is th...

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).

The genus Danio contains only the type species, D. dangila, separated on the basis of its larger size and the shape of the caudal-fin, which in adults is only slightly emarginate or even truncate in shape, a feature it shares only with Tinca tinca (the common tench) among other cyprinids. The remaining species, of which B. rerio is thought to be the most ancient, are included in the revalidated genus Brachydanio Weber & de Beaufort, 1916.

This potentially-undescribed species first became available in 2002, and males and females were marketed as 'Danio sp. hikari yellow' and 'D. sp. hikari blue', respectively. Subsequent DNA testing in the United States revealed them to be the same species and genetically distinct from the very similar B. kerri. It can be told apart as the central body (P) stripe always extends into the caudal fin whereas in B. kerri it terminates at the caudal peduncle. Only a single population of B. kerri was sampled in the stu...

Adult size is comparable to B. nigrofasciata, and in the description paper the authors hypothesise that the two are closely-related given they share other features such as similar barbel length (plus some additional merisitic counts), absent lateral line and spotted pelvic fins. The two are easy to tell apart, however, since in B. tinwini the P+1 stripe is composed of a series of spots (vs. solid), it possesses an indistinct P+2 str...

Gasteropelecids are commonly-referred to as 'freshwater hatchetfishes' due to their heavily-keeled body shape which has evolved in such a way due to possessing an enlarged, heavily-muscled pectoral girdle, and which resembles the shape of a hatchet head. They are sometimes said to be capable of propelled flight above the water surface by beating their pectoral fins but in fact this is not the case and was disproven by Wiest (1995) who used...

The genus Centromochlus is diagnosable by members having the proximal anal-fin radials enlarged and fused to each other at the base, forming a single ossified structure. It's sometimes included in the putative subfa...

This species was considered a synonym of Channa melasoma for a number of years prior to its revalidation by Ng. et al. (1996). Specimens larger than around 120 mm SL can be distinguished by possession of a black spot in the centre of numerous body scales and a barred caudal-fin pattern, characters which are missing in both C. melasoma and the similar-looking C. cyanospilos.

This species can be told apart from the similar-looking congener C. baramensis (once considered synonymous with C. melasoma) by absence (vs. presence) of a black spot in the centre of numerous body scales and absence (vs. presence in specimens larger than 120 mm SL) of a barred caudal-fin pattern.

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.

This fish belongs to a very distinctive genus of mochokid. There are almost 50 species of Chiloglanis described to science, but most are never imported and even the commoner species, such as this one, are seen only rarely. They are very difficult to identify down to species level, as many are very similar in looks. Some are strongly sexually dimorphic with the males having thickened or enlarged anal and caudal fins. Chiloglanis are also sometimes confused with the other 2 genera of African sucke...

This species is also referred to as 'royal knifefish' in the aquarium trade but arguably has no place in the ornamental hobby given its adult size and specialised requirements. It can be distinguished from congeners by presence of many small, dark spots on the anterior portion of the body which merge to form oblique, irregular stripes extending onto the anal and caudal fins posteriorly.