Results for “morphology”

Previously included as a member of the genus Cichlasoma, the midas cichlid is often confused with the red devil, A. labiatus. The two can be distinguished through differences in morphology. As suggested by its scientific name, A. labiatus often possesses characteristically large lips, although this is variable and should not be used as a defining indicator of species. More reliable differences include the bigger nuchal hump and more thick-set appearance in A. citrinellus. The midas exists in many n...

Previously included as a member of the genus Cichlasoma, the red devil is often confused with the midas cichlid, A. citrinellus. The two can be distinguished through differences in morphology. As suggested by its scientific name, A. labiatus possesses characteristically large lips, although in reality this is variable and should not be used as a defining indicator of species. Certainly, tank bred fish tend not to have these large lips. More reliable differences include the bigger nuchal hump and mo...

This species differs from all other described members of the genus by the presence of dark blotches at the dorsal and ventral base of the pectoral fins. Three very similar-looking fishes have been assigned the codes A106, A107 and A108 under the DATZ system and are also known in the aquarium hobby as A. sp. 'rotpunkt' (this form has been in the hobby for decades with its precise origin unclear), A. sp. 'rotpunkt Orteguazas' (the paratype form of A. alacrina) and A. sp. 'rotpunkt Guayas', respectively. It remains to be seen whether they're conspecific with A. alacrina or not since they exhibit some differences in colour pattern and morphology.

Prior to its description this species was considered a geographic variant of A. iberus but the 2002 paper revealed the pair to be genetically quite distinct and also highlighted some morphological differences. It is distinguished from A. iberus by possessing 8-9 (usually 8 ) branched dorsal-fin rays (vs. 8-9, sometimes 10), 9-11 branched anal-fin rays (vs. 8-9), a deeper, more elongate body shape, noticeably shorter snout, relatively thick (vs. thin) vertical bars in males and a flank patterning consisting of a few la...

All Algerian Aphanius populations were considered to be representative of A. iberus until this species was described in 2006. It differs both morphologically and genetically from A. iberusand A. baeticus, probably diverging about 5.3 million years ago during the opening of the Straits of Gibraltar. It is most easily distinguished by the distinct mottled body patterning which in males of the other two species forms distinct vertical bars and in females dark spot-like markings. A. iberusis now k...

This fish has yet to appear in the aquatic trade and only been exported in extremely limited numbers to date. Specimens collected from the Wahumiam River close to the settlement of Shella Bholaganj by Peter Cottle and Andrew Rao in 2006 were initially considered an undescribed species and referred to as B. sp.'Wahumiam River' or B. sp. 'terracotta', but later found to match B. tuivaiei in terms of morphology, meristics, etc. (S. van der Voort, pers. comm.).

This species is one of several traded variously as 'butterfly loach', 'butterfly plec', 'Hong Kong plec(o)', 'Chinese hillstream loach' or simply 'hill stream loach'. In many countries it's the most common balitorid in the shops but is also often found in mixed shipments containing members of other genera. Like all balitorids it's an obligate bottom-dweller with specialised morphology adapted to life in fast-flowing water. The paire...

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...

Brachyplatystoma spp. are distinguished from all other catfishes by two synapomorphies. The first comprises several morphological characters relating to the skull, specifically that the mandibular suspensorium (that which connects the lower jaw bone to the skull) is greatly expanded mediodorsally to form a large plate approaching the parasphenoid bone, with the hyomandibula and metapterygoid similarly enlarged.

This species is popular in the aquarium hobby and unlike the majority of congeners tends to spend a fair amount of time away from the substrate, often forming groups in midwater. It has been placed in the unofficial 'C. elegans group', which contains a number of species exhibiting similarities in morphology and colour pattern, some of which remain unidentified in scientific terms.

C. guapore is a sought after aquarium fish although it is not often traded. It exhibits slightly different behaviour to the majority of congeners in that it tends to form aggregations in midwater and spends a large proportion of its time away from the substrate. Its morphology exhibits corresponding adaptations towards a pelagic existence with a relatively large eye, a more terminal mouth position, more strongly-forked caudal-fin, and more symmetrical body shape than most other Corydoras species.

It exhibits slightly different behaviour to the majority of congeners in that it tends to swim in midwater and spends a large proportion of its time away from the substrate. Its morphology exhibits corresponding adaptations towards a pelagic existence with a relatively large eye, a more terminal mouth position, more strongly-forked caudal-fin, and more symmetrical body shape than most other Corydoras species.

It also exhibits morphological adaptations to an existence among rocks in a flowing environment, such as a cryptic colour pattern, reduced spine length in the dorsal and pectoral fins, ventrally-oriented pectoral fins, slightly emarginate caudal-fin, and reduced body depth. Reduced fin spines and body depth are typical features associated with the related genus Aspidoras, but the...

This species is currently the only described member of its genus although colour pattern and morphology vary considerably across its range. You may see reference to this species being the only fish species to possess infra-red vision, but other species also possess this ability and we suspect that infra-red plays an important role in the reproductive cycle of many fishes.

C. latius isn't often available in the trade but makes an excellent alternative to more commonly-offered members of the genus should you be lucky enough to find some. Shipments of similar-looking Indian Garra species such as G. mullya or G. gotyla sometimes contain the odd specimen. It exhibits morphological differences when compared with other members of the genus and may be assigned to a separate taxon at some point in the future.

There are currently 20 species of Ctenopoma, most of which most are seldom seen in the aquatic trade. Originally the genus was significantly larger, but a number of original members were reclassified by Norris in 1995. Whilst describing what were apparently two new Ctenopoma, he discovered sufficient morphological anomalies in the fish to erect a new genus for them. The name Microctenopoma was chosen, although this does not relate to the size of the fish. Similar defining characteristics were al...

Tends to be most common in brackish to hypersaline environments such as coastal salt marshes, lagoons and estuaries. On San Salvador Island, Bahamas, it appears to be the parent of a species group occurring in sympatry and exploiting diverse but specific resources with some spectacular morphological adaptations.

This species is available in the trade on occasion and has been sold as Danionella sp. 'neon green' or 'flourescent green'. The specific name was inspired by its jaw morphology which according to current knowledge is unique among cypriniform fishes. Both upper and lower jaws contain a series of toothlike odontoid processes; these are only rudimentary in females but in males appear to form rows of teeth of which the front pair is large and fang-like. The upper fangs project th...

D. ashmeadi is the type species and exhibits differences in dental morphology compared with other members of the genus. It can also be told apart from D. halei by the red/pink (vs. orange) colouration in the dorsal and anal fins and serrated (vs. smooth) dorsal spine. D. schroederi is also similar-looking but as it matures the prominent dark dorsal blotch fades to a thin dark distal band whereas in D. ashmeadi it is retained throughout life.

E. sinensis was initially included in the genus Protomyzon where it remained until 2004 when Kottelat found sufficient geographical and morphological differences between members of the group inhabiting the island of Borneo and those from mainland East/South East Asia to warrant their separation. The genus Erromyzon was erected to accommodate the mainland fishes and there are currently three...