Results for “ray”

N. alestes is the only member of the genus in which the barbels are shorter than the head, with additional diagnostic characters as follows: 8-9 branched dorsal-fin rays; 12-14 branched anal-fin rays; 22-23 predorsal scales; body with a pronounced ventral keel.

This species occasionally appears in the ornamental trade, usually as 'striped hill trout' or 'banded hill trout'. It can be distinguished from congeners by the following combination of characters: lateral line complete with 40-42 scales; barbels absent; 10-13 anal-fin rays; body with 9-11 dark blue vertical bars; last dorsal-fin ray extending to caudal-fin base.

Following Bonou and Teugels (1985), P. africana can be distinguished from congeners by the following combination of characters: colour pattern unique, comprising a series of 8-11 dark, chevron-shaped markings extending along the body posterior to the pectoral fins; 19-24 scales in the transverse series; lateral line complete with 73-83 pored scales; 45-48 dorsal-fin rays 45-48; 32-35 anal-fin rays.

P. hystrix is sometimes sold as P. sp. "C", and is much sought after in the hobby. The species is usually recommended as a good beginners' ray due to its relatively small adult size. However due to current Brazilian legislation regarding the export of rays it's almost never available at present, and tends to command a high price when it is. The fish sold as hystrix in the trade are almost always Peruvian in origin and erroneously labelled. We've seen P. humerosa, P. yep...

This species is often confused with P. reticulata, P. humerosa and P. scobina. Such specimens are usually imported and sold as "teacup" stingrays and it is important to correctly identify what you are buying. There is also a ray sold as P. sp. "Nazca" that is often said to be P. yepezi; unlikely given that it is imported from Peru. This latter fish is one of the commonest rays seen in the trade and is usually quite reasonably priced, making it a good choice for newcomers to k...

In addition, there appear to exist two colour forms based on male dorsal-fin morphology and patterning; one in which the 4th ray of the first dorsal-fin is longest with a square bluish-black blotch on the anterior ⅔ of the fin, and a second in which the 2nd and 3rd rays of the first dorsal-fin are longest with the fin itself paler and lacking dark markings.

Not a commonly species in the aquarium hobby but sporadically available in shipments of wild fishes from Thailand. Following Kottelat (1990) it's a member of a group of species possessing a complete or near-complete lateral line, 8 ½ branched dorsal-fin rays, 17 branched caudal-fin rays and lacking sexual dimorphism (the latter is not strictly true - see above). Its colour pattern is quite distinctive, howe...

It is most similar to S. macropterus, but differs in absence (vs. presence) of a black spot on the base of the median caudal-fin rays, a higher number of pectoral-fin rays (I,8,i vs. I,7,i), males with somewhat more slender bodies (25.7- 30.5% in SL [range 26.3-28.8% in type series] vs. 30.4-34.6% in SL), an...

The fused pelvic fins form a structure normally referred to as the 'pelvic disc', a common feature among gobiids which is used to adhere to rocks and other submerged surfaces. In Sicyopus, as in Stiphodon, this is short-based and attached to the belly only between the fifth pair of fin rays whereas in other sicydiines it's attached between all five rays (Watson, 2005).

This species was referred to as S. sp. 'orange fin' or S. sp. 'ST01' prior to being offically named and is one of the more commonly-traded members of the genus, though often in batches containing only one gender, a mixture of species, or misidentified under an incorrect name such as S. zebrinus. It can be told apart from congeners by the following combination of characters: usually 9 soft second dorsal-fin rays; 15 soft pectoral-fin rays; first dorsal-fin in male poin...

This species is rare in the aquarium trade and normally expensive when available. It's one of the most easily-identifiable in the genus by the combination of usually 14 pectoral-fin rays, 10 segmented second dorsal-fin rays, relatively small adult size, unique colouration in males and the shape of the first dorsal-fin in males in which the fourth and fifth spines are...

This species is not traded commercially at present and the specimen pictured above was brought back from northern Papua New Guinea by private collectors in 2008. It's diagnosable from other members in the genus by possession of 10 segmented rays in the second dorsal fin, males with filamentous spines in the firstandusually with 14 rays. Colour patterning in males is also distinctive (see 'Sexual Dimorphism'). The Gobiidae is the most speciose vert...

The genus Acrossocheilus is restricted to southern China, northern Vietnam and northern Laos. It can be distinguished from related genera by the following combination of characters: rostral fold present; lips fleshy and continuous around corners of mouth; lower lip with a median interruption; mouth inferior; horny sheath on lower jaw; two pairs of barbels; last simple ray of dorsal fin osseous with a serrated or smooth posterior margin.

This species is also traded as 'yellow-finned', 'yellowtail' or 'blue Congo' tetra and is occasionally bred on a commercial basis, although not on a scale comparable to its better-known relative Phenacogrammus interruptus. No recent key to the genus exists but based on Géry (1977) and images in Mbimbi Mayi Munene and Stiassny (2012) it can be told apart from congeners by a combination of: extended median caudal-fin rays in adult males; absence of prominent dar...

Annamia spp. may be confused with related genera such as those of the genus Balitoropsis. They can be identified by their more depressed body shape, elongate lower caudal-fin lobe, and the presence of a single unbranched ray in the pectoral and pelvic fins. At least one undescribed member of the genus is thought to exist.

This species is sometimes referred to as 'false corydoras' or 'sixray corydoras'. A. pauciradiatus can be distinguished from congeners by possession of 6 soft dorsal-fin rays, as opposed to 7 in other Aspidoras species, plus its distinctive colour pattern. Aspidoras species are distinguished from the very...

This species is also known by the alternative vernacular name of 'Zamora woodcat', and is often misidentified as A. thoracatus. The latter is a valid species and very similar to A. coracoideus in that the coracoid bone is exposed ventrally and covered only by a thin layer of integument in both species. The two differ principally in the number of anal fin rays...

The genus Baryancistrus can be distinguished from all other loricariids by possession of an enlarged membrane located posteriorly to the last branched dorsal-fin ray. This membrane may or may not reach the supporting structure of the adipose fin and in this way members can be told apart from the genera Oligancistrus, Parancistrus, and Spectracanthicus, in which the dorsal and adipose fins are completely connected, and Hemiancistrus...

At time of writing there exist 18 recognised members of the genus though only B. kweichowensis is well-known in the trade with B. szechuanensis unlikely to have been exported. According to Chen, Huang and Yang (2009) it can be distinguished from similar congeners by the following suite of characters: 1 branched and 17-20 simple pectoral-fin rays...

B. channoides and B. albimarginata together comprise the Betta albimarginata group/complex of closely-related species within the genus, these differing from all other members of the genus in colour pattern and by possession of 9-12 anal-fin spines (vs. 0-4). They look very similar to one another but differ in the following characters: anal fin spines 9-11 in B. albimarginata vs. 12 in B. channoides; anal fin rays 21-23 vs. 23-25; lateral scale rows 26-27 vs. 27.5-28; trans...