Results for “ray”

B. falx is included in the Betta picta group/complex of closely-related species within the genus, an assemblage comprising species with the following shared characters: unpaired fins rounded (anal-fin sometimes tapering to a blunt point); anal-fin rays I-III, 18-24; dark marginal band on anal and caudal fins, more pronounced in mature males; presence of pre-orbital and post-orbital stripes; presence of chin bar on throat; iridescent green, gold, or blue scales on opercle.

This species lends its name to the Betta foerschi group of closely-related species within the genus, of which members share the following set of characters: possession of iridescent blue or green unpaired fins; rays and interradial membranes in unpaired fins not contrasting; dorsal fin with thin, bright white distal band; opercle with two, reddish-yellow, vertical bars. Members are regarded as being closely-related to bubble nesting Betta specie...

B. imbellis is included in the Betta splendens complex of closely-related species within the genus, of which members share the following set of characters: head length short 22-31 % SL; often a brightly-coloured body; iris of the eye with iridescent green or blue patches; body elongate or slender; opercles parallel when head viewed dorsally; caudal-fin rays red or brown and contrasting with the iridescent interradial membranes; unpaired fins without an irides...

It can be told apart from other members of the B. pugnax group by the following characters: chin bar absent; prsence of transverse bars in the dorsal-fin; no transverse bars in caudal-fin; green iridescent scales present on opercle and body; anal fin with iridescent, light blue distal band; a pair black markings below the postorbital stripe on the opercle of females and juveniles; anal-fin rays 25-29 (mode 28); lateral scales 28-30 (mode 29); postdorsal scales 10-11 (mode 12); pelvic-fin length 34.8-50.6% SL; head length 33.4-36.8% SL; inter-orbital width 31.7-37.4% HL.

B. macrostoma 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 posterior end of maxilla 27-54 % HL; caudal-fin rounded in shape, occasionally with elongated median rays; pelvic-fin short and filamentous; dorsal and anal fins relatively pointed.

This species was known as B. sp. 'Mandor' or B. sp. 'ninja' prior to official description. It belongs to the Betta foerschi group/complex of closely-related species within the genus, of which members share the following set of characters: possession of iridescent blue or green unpaired fins; rays and interradial membranes in unpaired fins not contrasting; dorsal fin with thin, bright white distal band; opercle with two, reddish-yellow, vertical bars. Members are regarded as being closely-related to bubble-nesting Betta species since they share exhibit certain similarities in morp...

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 posterior end of maxilla 27-54 % HL; caudal-fin rounded in shape, occasionally with elongated median rays; pelvic-fin short and filamentous; dorsal and anal fins relatively pointed.

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 posterior end of maxilla 27-54 % HL; caudal-fin rounded in shape, occasionally with elongated median rays; pelvic-fin short and filamentous; dorsal and anal fins relatively pointed.

This species lends its name to the Betta picta complex of closely-related species, an assemblage of which members share the following combination of characters: unpaired fins rounded (anal fin sometimes pointed): I-III, 18-24 anal-fin rays; anal and caudal fins with dark distal margins, most pronounced in mature males; pre- and post-orbital stripes present; chin bar present; opercle with iridescent blue, green, or gold scales.

B. pinguis is 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 lanceolate with highly extended median rays in mature males; caudal fin usually with transverse bars; greenish or bluish iridescent scales on body of males in some species; opercle without iridescent scales except in juveniles.

It can be told apart from other members of the B. pugnax group by the following characters: chin bar present; no complete second postorbital stripe on opercle; presence of transverse bars in caudal-fin of males; caudal-fin in males broadly lanceolate; opercle scales iridescent blue; anal-fin with reddish subdistal band and black margin; caudal-fin without dark margin; 25-28 anal-fin rays; 28-31 lateral scales; 11-12 postdorsal scales; length of pelvic fins 26.6-43.8 % SL; length of head 27.5-35.2 % SL; inter-orbital width 32.4-53.0 % HL.

B. simplex is included in the Betta picta group/complex of closely-related species within the genus, an assemblage comprising species with the following shared characters: unpaired fins rounded (anal-fin sometimes tapering to a blunt point); anal-fin rays I-III, 18-24; dark marginal band on anal and caudal fins, more pronounced in mature males; presence of pre-orbital and post-orbital stripes; presence of chin bar on throat; iridescent green, gold, or blue scales on opercle.

This hypothetically-undescribed species appears to be a member of 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 posterior end of maxilla 27-54 % HL; caudal-fin rounded in shape, occasionally with elongated median rays; pelvic-fin short and filamentous; dorsal and anal fins relatively pointed.

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 posterior end of maxilla 27-54 % HL; caudal-fin rounded in shape, occasionally with elongated median rays; pelvic-fin short and filamentous; dorsal and anal fins relatively pointed.

At time of writing there exists no scientific evidence that the different populations of this species seen in the aquarium trade (see 'Distribution') represent anything other than a single, widely-distributed species although some exibit minor morphological differences including relative body depth, longer fin rays in the unpaired fins and yellow or orange colouration in the paired fins. There is apparently a form from the upper rio Negro which may turn out to be distinct but it's...

It can be diagnosed as follows: <30 lateral scales; two black body bands reaching ventral midline posterior to anal-fin; band above anal-fin also reaching ventral midline no black band on head, though the first band may touch the posterior margin of the eye; band above anal-fin not reaching ventral midline; 6 branched anal-fin rays; 7-8 predorsal scales. Brachygobius currently contains 9 described species but is likely to prove more diverse should a review be carried out. Alt...

B. sabanus is very similar to B. doriae and these two are easily confused. However in B. doriae most of the first-dorsal-fin and two-thirds of the pectoral-fin are black while in B. sabanus the last one or two rays of the first dorsal-fin are colourless and less than half of the pectoral-fin is black. In addition there are usually smaller dark 'saddles' betw...

This is a great oddball species for the Tanganyikan community tank, although it is not as attractive as the closely related Aethiomastacembelus ellipsifer. It is rarely seen in the hobby. The species in the family Mastacembelidae are known as "spiny" eels because the dorsal rays are stiffened. Care must therefore be exercised when handling them to avoid injuries. Spiny eels also have no swim bladder, an adaptation to their benthic lifestyle....

Very rarely seen in the hobby, this species makes an interesting oddball addition to the Tanganyikan community tank. The species in the family Mastacembelidae are known as "spiny" eels because the dorsal rays are stiffened. Care must therefore be exercised when handling them to avoid injuries. Spiny eels also have no swim bladder, an adaptation to their benthic lifestyle.....

This species' name is commonly misapplied to a number of similar-looking fishes and it can be difficult to identify if collection locality is unknown. In addition, colour pattern is variable and it's not clear whether this occurs between, within, or both between and within populations. In the original description, Steindachner did note that the first three dorsal-fin rays are completely black while the remainder is whi...