The freshwater angel fish (Pterophyllum scalare Schultze, 1823) is South American cichlid become very popular among aquarists. There is little information on their culture and aquarium husbandry. In this study growth performance and survival rate of angelfish subjected to different feeding frequencies were evaluated. Four groups of angel fish juveniles (0.87 ± 0.01 g; 3.98 ± 0.08 mm) were fed e...

Rudimentary quantification abilities are found in numerous animal species and in human infants all demonstrating the ability to discriminate between quantities differing in numerical size. An open question is whether individuals rely on different underlying systems to discriminate between large (analogue magnitude system (AMS) for number of items exceeding 3) and small quantities (object-file s...

Melanophores of the angelfish, pterophyllum scalare, have previously been shown to display approximately 2,400 microtubules in cells wih pigment dispersed; these microtubules radiate from a presumptive organizing center, the central apparatus (CA), and their number is reduced to approximately 1,000 in the state with aggregated pigment (M. Schliwa and U. Euteneuer, 1978, J. Supramol. Struct. 8:1...

Microtubular organization in the melanophores of the angelfish, Pterophyllum scalare, has been studied by serial thin sectioning. The course of microtubules has been followed in sets of transverse serial sections taken from the centrosphere and a segment of a cell process, respectively. Microtubules arise from a prominent zone in the cell center, the central apparatus, which is composed of nume...