Results for “margin”

There are currently 24 described species of Serrasalmus, many of which look superficially similar. S. marginatus has at various times been considered a synonym of S. rhombeus and S. humeralis, but is currently considered to be distinct. It's main distinguishing feature is usually given as the thick, black, v-shaped marking in the anterior portion of the caudal fin. Juveniles are said to differ from similar-looking species such as S. compressus and S. altuvei because the dark body "spot...

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...

Also known as the common catopra, this is still quite a rare species in the hobby, although it's becoming more readily available due to captive breeding efforts. It makes an interesting addition to the larger community or oddball tank....

This species is occasionally marketed as 'Burmese Rainbow Barb' in the ornamental trade. others may have been exported in small numbers or as bycatch among shipments of other species. It was referred to as Mystacoleucus marginatus for decades, but that name is a simultaneous subjective synonym of M. obtusirostris following Kottelat (2013).

This species is traded under various other names including 'red arc pencilfish', 'Peruvian red pencilfish', 'ruby red pencilfish', 'red pencilfish', and Nannostomus cf. marginatus 'red'. It was initially described as a subspecies of N. marginatus but can be identified by the following combination of characters: pronounced sexual dimorphism with adult males exhibiting bright red pigmentation between the central...

Additonally, fin patterning in B. albimarginata, except the pectoral fins, consists of a broad white distal band, broad dark submarginal band with sharp outer margin and less sharp inner margin, and a plain red inner portion, while in B. channoides the dorsal fin is almost entirely red with only a thin white distal band and the dark submarginal band in the caudal fin does not extend into the uppermost portion of the fin. Base body colouration tends towards a brick-red shade in displaying male B. albimarginata, scarlet in B. channoides (pers. obv.).

The easiest way to distinguish these is by examining the throat markings, which vary according to species, and in the case of B. hipposideros form a black horse-shoe shape. It can also be separated from other group members by the following suite of characters: dark blotch on throat joined to black lower lip; presence of transverse bars in dorsal and caudal fins; absence of dark margin in anal-fin; opercle usually with gold scales, without iridescrent green scales; ventral margin of opercle brown; 6.5-7 subdorsal scales (mode 6.5); 9-10 postdorsal scales (mode 9.5); 31-32 lateral scales (mode 32).

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.

Among other Garra species from Southeast Asia and China, G. orientalis is most similar to G. salweenica and G. fuliginosa in that all three possess a roughly triangular, trilobed proboscis on the snout, the anterior margin of which is densely tuberculated, and the inferior margin not in contact with the depressed rostral surface, i.e., the proboscis projects forwards.

This species can be distinguished from congeners by the following combination of characters: body depth fits 2.5-2.7 times in SL; 28-31 +2-3 lateral line scales; 14-16 circumpeduncular scale rows; 5-5½ scale rows between the lateral line and dorsal-fin origin; a triangular distal blotch on the dorsal-fin; a few body scales with crescent-shaped black edges; a thin dark margin on the dorsal-fin, posterior to the distal blotch; a dark posterior margin on the caudal-fin; normally a single pair of rudimentary barbels present.

In live fish colour pattern is perhaps the most useful way to identify N. rubrocaudatus plus the closely-related N. marginatus and N. mortenthaleri. N. marginatus is immediately distinguished from the other two by the fact it lacks red pigmentation on the body in males, but N. mortenthaleri and N. rubrocaudatus are more easily-confused. Males of N. rubrocaudatus can be told apart fro...

At one locality in the Kalindhi drainage the water was clear, 1 m at its deepest point and flowing either side of a small check dam, below which the flow was stronger though still not particularly fast. The substrate was composed of rocks and cobbles with a thick layer of fine silt and sand above the dam. There were no aquatic plants but marginal grasses and shrubs were growing to the margins with some submerged roots protruding into the water.

The hill streams in which this fish can be found are generally shaded by the forest canopy and dense marginal vegetation. Substrates are typically composed of boulders, smaller stones, sand or gravel with submerged tree roots around the margins and quieter areas in which fallen branches and leaf litter collect. Other fish species occurring in the Tunga...

A. iridescens and its closest relative A. longipinnis can be distinguished from all other barred species of Acrossocheilus by the following characters: wider (vs. narrower) black vertical bars on the flank in adults, each five to eight (vs. no more than four) scales in width; a horse-shoe shaped (vs. arched) mouth gape; rostral barbel located posteriorly (vs. anteriorly) to a horizontal line through the anteriormost margin of the lower jaw; two postlabial grooves extending anteromedially beyond (vs. away from) a horizontal line through the roots of the rostral barbels.

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 among the smaller members of the family. It can be differentiated from all other Akysis species by the following combination of characters: caudal peduncle length 16.1-19.8% of standard length (SL); caudal peduncle depth 6.5-9.3% SL; length of adipose-fin base 25.6-29.5% SL; interorbital distance 42.0-46.0% of head length (HL), eye diameter 13.0-20.0% HL; length of nasal barbel 44.0-66.0% HL; lateral margins of the head appear straight when viewed from above; possession of 0-5 se...

A. gabunense is a good beginner's killifish as it is not an annual species, being found in permanent bodies of water in nature. It exists in several geographical colour forms which are sometimes referred to the subspecies Aphyosemion gabunense gabunense, A. g. boehmi and A. g. marginatum. The latter two are slightly smaller with a maximum standard lenth around 45 mm, and all three can be told apart by differences in colour pattern.

This was one of the first Aulonocara spp. to enter the hobby and its popularity has endured. It's known by several other vernacular names including 'Freiberg's peacock', 'fairy cichlid' and 'African butterfly' as well as the erroneous 'scientific' names Trematocranus trevori, T. jacobfreigbergi and T. regina. A naturally-occurring, yellowish form from Undu reef, Tanzania is often referred to as 'lemon jake'. It can be told apart from most other members of the genus by the broad, pale distal margins in the dorsal, anal and caudal fins, more deeply-forked caudal fin and larger adult size.

This species exists in two distinctive phenotypes, with male individuals from West reef and Eccles reef possessing a bright yellow stripe of colour running from the tip of the snout over the anterior portion of the dorsal surface and along the distal margin of the dorsal fin. This form is commonly referred to as 'sulphurhead' or 'sulfurhead' in the aquarium hobby. At Kande Island males exhibit a similar overall colour patterm but the dorsal stripe is whitish in colour and both males and females possess an enlarged lower pharyngeal bone. This population was described...

This species is traded under several names including 'royal danio', 'blue-spotted hill trout', and 'blue-dotted mirror fish'. It can be distinguished from congeners by possessing a single row of bluish-green spots along the length of the body, white margins on the dorsal and anal fins, 37-38+1 lateral line scales, and fleshy rudi...