Hyphessobrycon amapaensis

Hyphessobrycon: from the Ancient Greek υπελάσσων (hyphesson), meaning 'of lesser stature', used as a prefix in this case, plus the generic name Brycon.

amapaensis: named for the state of Amapá in northeastern Brazil.

Known only from a small area within the rio Preto and rio Maraca drainages in Amapá state, northeastern Brazil.

Type locality (translated from German) is 'Small savanna brook on the B156 from Camaipi to Santa Clara, around 11 kilometers from Camaipi (rio Preto area). Around 45 kilometers north of Macapá, Amapá state, Brazil'.

Collected from small streams flowing through savanna grassland containing clear, light brown-coloured water with substrates of sand and gravel and little in the way of submerged or riparian vegetation.

At the type locality pH varied between 5.8 – 6.3, GH and KH were both <1°, conductivity was 9-13 μs and temperature 24.7 – 27.2 °C76 – 81 °F.

Other fish species included the congener Hyphessobrycon takasei, plus a Nannostomus cf. beckfordi and unidentified members of the genera Aequidens, Acestrorhynchus, Leporinus and Rineloricaria.

An aquarium with base dimensions of 60 ∗ 30 cm24 ∗ 12 in or equivalent should be the smallest considered.

Perhaps looks best in an arrangement comprising a sandy substrate plus some driftwood roots and branches although it should also thrive in a planted set-up.

The addition of dried leaf litter would further emphasise the natural feel and as well as offering additional cover for the fish brings with it the growth of microbe colonies as decomposition occurs.

The latter are useful since they provide an additional food source for both adults and fry while the humic substances released by decaying leaves are also considered beneficial.

Likely to be omnivorous feeding on small invertebrates, crustacea, filamentous algae, fallen fruit and suchlike in nature.

In aquaria it may survive on a diet of dried foods but like most fishes does best when offered a varied menu which in this case should also contain live and frozen chironomid larvae (bloodworm), mosquito larvae, Daphnia, Moina, etc.

Very peaceful making it an ideal resident of the well-researched community aquarium.

It is best-maintained alongside similarly-sized characids, gasteropelecids, lebiasinids, smaller callichthyid or loricariid catfishes and non-predatory, small-to-medium-sized cichlids.

Try to buy a mixed-sex group of at least 8-10 specimens, include other schooling fishes to provide security, and you'll be rewarded with a more natural-looking spectacle.

Sexually mature females are noticeably deeper-bodied and a little larger than males.

An egg-scattering free spawner exhibiting no parental care.

When in good condition adults will spawn often and in a mature aquarium it is possible that small numbers of fry may start to appear without intervention, but if you want to maximise yield a more controlled approach is required.

The adult group can still be conditioned together but a smaller aquarium should also be set up and filled with mature water. This should be very dimly lit and the base covered with some kind of mesh of a large enough grade so that the eggs can fall through but small enough so that the adults cannot reach them. The widely available plastic 'grass'-type matting can also be used and works well, as does a layer of glass marbles. Alternatively, filling much of the tank with a fine-leaved plant such as Taxiphyllum spp. or spawning mops can also return decent results.

The water itself should be of slightly acidic to neutral pH with a temperature towards the upper end of the range suggested above. An air-powered sponge filter or air stone(s) should also be included to provide oxygenation and water movement.

When the adult fish are well-conditioned a single pair or group comprising one or two males and several females can then be introduced to each container and left in place until eggs are detected (typically the following morning).

Initial food should be Paramecium or a proprietary dry food of sufficiently small (5-50 micron) grade, introducing Artemia nauplii, microworm, etc., once the fry are large enough to accept them.

This species is sometimes referred to as 'red line', 'scarlet', or 'neon black red stripe' tetra.

It is very similar to the flag tetra, H. heterorhabdus, which also displays three lateral body stripes but has a relatively less broad red stripe, and the central stripe is golden (vs. white or creamy-coloured in H. amapaensis). In addition, the lower (black) stripe is often reduced to a horizontally-orientated humeral spot in H. amapaensis.

H. amapaensis further differs from H. heterohabdus in the following characters: maxillary with two teeth, one tricuspid and one conical (vs. four conical teeth in H. heterohabdus); dentary with five to six tricuspid and four to five conical teeth (vs. four tricuspid and three to four conical teeth); 18-20 branched anal-fin rays (vs. 21-23); 30-32 scales in the longitudinal row (vs. 32-34); 13-17 gill rakers (vs. 19).

It may be distinguished from two other similar species, H. eschwartzae and H. montagi, by colour pattern; in the former the dark lateral body stripe is continuous from humeral spot to caudal peduncle (vs. reduced or absent towards caudal peduncle in H. amapaensis), and the latter possesses two distinct humeral spots (vs. a single spot in H. amapaensis).

H. amapaensis is a member of the putative ‘H. heterorhabdus-group’ of closely-related species within the genus as proposed by Géry (1977). This originally comprised around 15 members characterised by a 'longitudinal pattern' consisting of a thin, usually dark, lateral body stripe, but has since been modified on a number of occasions.

Most recently, Lima et al. (2014) proposed a putatively monophyletic H. heterorhabdus-group containing only three species; Hyphessobrycon heterorhabdus, H. amapaensis, and H. eschwartzae. These all possess: a well-defined, elongate humeral blotch which is continuous with a dark, well-defined midlateral stripe that becomes blurred towards the caudal peduncle; a longitudinal red stripe extending along the body above the midlateral line; upper half of the eye red.

This pattern is different to that presented by several members of Géry's H. heterorhabdus group, such as H. vilmae, H. cachimbensis, and H. stegemanni, which possess a continuous, solid dark lateral stripe on the body and no obvious humeral blotch, but is similar to that of Géry's H. agulha group. The latter contained species with a colour pattern comprising "lower half of the body dark, especially above anal fin; usually a horizontally elongate humeral spot, more or less united with the assymetrical, broad band", and included H. agulha, H. loretoensis, H. peruvianus, H. metae, and H. herbertaxelrodi.

Hyphessobrycon was raised by Durbin in Eigenmann (1908) as a subgenus of Hemigrammus, differing from the latter by the absence of scales on the caudal-fin.

The grouping was revised by Eigenmann (1918, 1921) while Géry (1977) created artificial groups of species based on colour pattern, and these definitions are still widely used today, e.g., the H. agulha group, the H. heterohabdus group, etc. These cannot be considered to represent monophyletic assemblages, however, and their concepts continue to be redefined.

Weitzman & Palmer (1997) hypothesised the existence of a monophyletic assemblage within the genus based on colour pattern and male fin morphology that they termed the ‘rosy tetra clade’, with one of the characters supporting its monophyly being presence of a prominent dark marking on the dorsal-fin. This assemblage, plus other morphologically similar species, is considered to represent Hyphessobrycon sensu stricto by some authors, with the remaining species included in a much-expanded H. heterohabdus group.

Others have proposed conflicting, typically more restricted, views of both the genus and/or its constituent species groups, and significant confusion remains. What is clear is that, as currently recognised, Hyphessobrycon is a polyphyletic lineage containing several genera.

The process of splitting it up has already started, and Malabarba et al. (2012) revalidated the genus Ectrepopterus Fowler, previously considered a synonym of Hyphessobrycon. They also analysed its relationships within the Characidae in the context of Mirande's (2010) previous work, but included the type species, H. compressus, for the first time in such a study. The results demonstrated that H. compressus is more closely-related to 'rosy tetra' representatives such as H. eques, H. pulchripinnis, and H. socolofi than other members of the genus including H. anisitsi, H. bifasciatus, H. elachys, H. herbertaxelrodi, and H. luetkeni.