Results for “morphology”

Field observations have revealed that individuals almost always position themselves facing into the flow, either along the sides, behind or under rocks, their specialised morphology (see 'Notes') allowing them to feed and maintain position without being swept away. Not many fishes have been able to successfully colonise this narrow ecological niche, but syntopic species in nature include Gastromyzon extrorsus (Petagas River), G. introrsus, G. lepidogaster (Pad...

In fact G. farragus and G. ocellatus represent one of 12 pairs of cryptospecies to be found in the genus, differing in subtle aspects of patterning. Cryptospecies are defined as morphologically similar, but reproductively isolated species which in fishes often inhabit adjacent river basins but in some cases occur sympatrically. The phenomenon may be a result of parallel evolution, and is not normally considered to represent an early stage of speciation.

Field observations have revealed that individuals almost always position themselves facing into the flow, either along the sides, behind or under rocks, their specialised morphology (see 'notes') allowing them to feed and maintain position without being swept away. In nature G. monticola occurs sympatrically alongside Garra borneensis, Osteochilus ingeri, Gastromyzon auronigrus, G. cornusaccus, Nemacheilus olivaceus,...

This stunning species must surely rank among the most attractive Loricariids available in the hobby. There are several colour forms available, depending on collection locality. These vary in base colour and in the number, size and positioning of the spots on the body. The true identity of this fish is shrouded in confusion. It may or may not be Hemiancistrus subviridis, also known as the green phantom plec (L200), which it resembles very closely in morphology. The two are also found in diffe...

There is some confusion as to where this species should be placed taxonomically. It is currently the only species in the genus Hemisynodontis but it has been regularly moved between Synodontis, Hemisynodontis and Brachysynodontis. The main morphological differences that set it apart are the presence of additional gill rakers in this species and the fact it has relatively few mandibular teeth compared to Synodontis species. It also possesses the chracteristic "moustache", which is in fa...

The genus Homalopteroides was revalidated by Randall and Page (2012) and is told apart from the related Homaloptera by the following character combination: dorsal-fin origin above pelvic-fin; ≤ 60 lateral-line scales; ≤ 30 predorsal scales; oral morphology consisting of two thin and widely separated rostral barbels on each side of the mouth, thin crescent-shaped lips, the absence of any structure such as a mental pad or lobes between the lateral portions of the lower lip, and a chin that extends anterior to the lateral portions of the lower lip.

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...

This undescribed species is part of the Hypostomus cochliodon complex, all of which were previously included in the genus Cochliodon. This is now considered a synonym of Hypostomus. Members of this group can be distinguished from congeners by several differences in morphology, most notably the hump-backed profile of mature fish and spoon-shaped dentition. These features, along with the fishes tendency to eat wood, are shared with the Panaque genus of the Ancistrinae subfamily, but the two genera...

This species is part of the Hypostomus cochliodon complex, all of which were previously included in the genus Cochliodon, which is now considered a synonym of Hypostomus. Members of this group can be distinguished from congeners by several differences in morphology, most notably the hump-backed profile of mature fish and spoon-shaped dentition. These features, along with the fishes tendency to eat wood, are shared with the Panaque genus of the Ancistrinae subfamily, but the two genera are known ...

This undescribed species is part of the Hypostomus cochliodon complex, all of which were previously included in the genus Cochliodon, which is now considered a synonym of Hypostomus. Members of this group can be distinguished from congeners by several differences in morphology, most notably the hump-backed profile of mature fish and spoon-shaped dentition. These features, along with the fishes tendency to eat wood, are shared with the Panaque genus of the Ancistrinae subfamily, but the two gener...

This undescribed species is part of the Hypostomus cochliodon species complex, all members of which were previously included in the genus Cochliodon, now considered a synonym of Hypostomus. Members of this group can be distinguished from congeners by several differences in morphology, most notably the hump-backed profile of mature fish and spoon-shaped dentition. These features, along with the fishes tendency to eat wood, are shared with the Panaque genus of the Ancistrinae subfamily, but the tw...

Originally described as a member of Barilius (Annandale, 1918) but Howes (1980a) considered it more closely related to cheline cyprinids (Chela and Laubuca spp.) based on morphological characters and erected the genus Inlecypris for it (Howes, 1980b). Fang (2003) supported Howes' conclusions in her 2003 phylogenetic study of the genus Danio, hypothesising that Inlecypris and Chela together form a sister group to Devario.

This little-known, relict species possesses some unique morphological and behavioural traits when compared with its congeners and the genus Kosswigichthys was erected for it in the original description. It has a much more elongate body profile than other Aphanius spp., almost total absence of scalation on the body and three rows of conical (as opposed to tricuspid in all other species) teeth which set it apart. Work by Franz and Villwock in the 1970s revealed it to be a member of Aphanius and showed ...

A very stylish looking plec, L. galaxias can also be seen for sale as the vampire or tusken plec. Both these names relate to features of morphology that are shared by all members of the genus. The latter arose from the presence of a characteristic growth on the head of the fish. The vampire moniker, meanwhile, is derived from the unique upper jaw dentition, consisting of, you guessed it, two large teeth or "fangs". The exact use for these is unknown, but they're probably utilised ...

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...

The genus Mchenga was erected in 2006 by Stauffer and Konings and currently numbers half a dozen species, all of which are previous members of Copadichromis. The reclassification was based on various morphological and behavioural traits, including habitat preference and breeding strategy. Together with Copadichromis, Mchenga spp. form an exclusive group of Malawian cichlids commonly referred to as "Utaka" (prounounced "ooh-taw-kuh"). They're specialised to a pelagic l...

Populations from the upper Pearl River (Nanpan Jiang basin) differ in several morphological characters from those inhabiting Guangdong, Guangxi, and Guizhou Provinces, and Hainan Island. Those from Vietnam also seem to be different (Gan et al., 2009), the implication being that there may be several species currently included under the name M. lineata.

Described from close to the city of Beira, Mozambique and for many years thought widely-distributed between the Kruger National Park, South Africa to the Kwa-Kwa River north of the Zambezi delta. Populations from the south and north of this range exhibiting differences in colour pattern and morphology have now been described as N. pienaari and N. krysanovi, respectively, meaning N. rachovii sensu stricto is restricted to the area between the lower Pungwe and Zambezi river basins in eastern Mozambique.

This infrequently seen (in the trade) species is also known as the two spot glass catfish, for fairly obvious reasons. It is more than likely that a number of separate species are currently considered within this one, as there are clear morphological differences between populations. Pending a taxonomic revision, these currently all remain classified as O.bimaculatus. This would also seem to explain the apparent toleration of the fish to wildly different water chemistry. Xanthic and albino forms ...

Pangasianodon is separated from other pangasiid generea primarily on the basis of some morphological differences including a lack of teeth and massively reduced barbels in adult specimens. Sadly it's numbers are declining rapidly in nature, through a combination of unsustainable fisheries, damming and habitat destruction. Since 1990 wild stocks are thought to have undergone a decrease of over 80%. From an annual catch of over 60 specimens in 1990, only 8-11 were being caught per year in ...