This very small Fluviphylax is found in the Estado do Amapá, Rio Taparabu, right tributary of rio Oiapoque, Juminán.

Fluviphylax palikur, is described from the rio Taparabu, rio Oiapoque basin, northern Brazil. It differs from all other species of the genus by the possession of numerous anal fin rays and vertebrae and by the shape of fourth and fifth ceratobranchials and second pharyngobranchial. Five synapomorphies shared by all species of Fluviphylax except F. palikur, in addition to characters supporting Fluviphylax monophyly, support a hypothesis of a sister-group relationship between the new species and a clade consisting of the remaining species of the genus. Miniaturization and reductive morphological conditions in Fluviphylax are discussed in a phylogenetic context. Miniaturization in Fluviphylax is hypothesized to correspond to a single event, with reductive conditions originating at the base of the Fluviphylax clade and in different intrageneric lineages.

These extremely small fish live in the mouths of smaller steams where they drain into larger rivers. There they form schools of a few thentals that feed at the water's surface on small insects that land on the water to deposit eggs and other floating food. I experienced firsthand how beautifully this species behaves in the wild when I went into the side creeks to look for Rivulus. They swim quietly together but at the slightest danger they shoot in all directions and therefore it is difficult to catch a group. They are very delicate fish that die quickly after being caught if one does not take the proper measures. To transport this species over a longer period, one absolutely must bring clean water as a kind of stock if one wants to keep them alive during the rest of the trip. Packing should be in breathable bags and preferably one fish per bag. For this I used small sealed bags that I have already made upfront for this kind of small delicate fish.

Breeding is not very easy either. The young are extremely small and are best fed with paramecium or other extreme small live food. Artemia will be good for the adults but cannot be eaten by the young. The water should be soft and slightly acidic with a pH of 6.5.

Remarks:

Max. size 0.0 cm.
Dorsal 00.0,
Anal 0.0,
D/A 0.0,
LL scale count (average)0.0
Pre- dorsal length to % SL – 0 %
Depth to % SL – 0 %

Costa, W.J.E.M. and P.-Y. Le Bail 1999. Fluviphylax palikur: a new poeciliid from the Rio Oiapoque Basin, Northern Brazil (Cyprinodontiformes: Cyprinodontoidei), with comments on miniaturization in Fluviphylax and other neotropical freshwater fishes. Copeia (4):1027-1034.