haraldi (third, fifth, tenth, eleventh, twenty-first and twenty-second pairs). discus (eighteenth and twenty-fourth pairs) and S. aequifasciatus (fifth, tenth, eleventh, fifteenth, twenty-first and twenty-second pairs), S. (2008) described a multiple NOR system in S. aequifasciatus using silver nitrate staining. (2002) detected a single nucleolar organizer region (NOR) system in S. The karyotypes of the three species contain heterochromatic blocks, which are mainly located in the pericentromeric regions of all chromosomes, and in the proximal regions in the short and long arms of a few chromosomes ( Takai et al., 2002 Mesquita et al., 2008). The different karyotypic formula reported for different Symphysodon species may include errors, as the level of chromosome condensation surely interfered in the analysis, and most of authors did not use the terminology ‘microchromosomes’. The high diploid number detected in Symphysodon was explained as a consequence of polyploidization ( Thompson, 1976) it might also have arisen through chromosomal rearrangements, such as pericentric inversions, translocations and fissions/fusions ( Mesquita et al., 2008). All of the Symphysodon species have a high diploid number (2 n=60), with a predominance of meta/submetacentric chromosomes, inter- and intraspecific morphological variation in some chromosomal pairs, and microchromosomes ( Table 1).
Over the last 40 years, a few chromosomal reports, all of which have been restricted to Symphysodon aequifasciatus, indicated that Symphysodon has the highest diploid number of all cichlids ( Ohno and Atkin, 1966 Thompson, 1979 Takai et al., 2002). The Discus fish, genus Symphysodon ( Heckel, 1840), are the most intriguing and distinctive group among the South American Cichlidae due to their body morphology, beautiful colors and chromosomal features ( Feldberg et al., 2003 Ready et al., 2006).
#RARE DISCUS FISH SERIES#
This observation is unusual and we propose that the origin of meiotic multiples in males and females is based on a series of translocations that involved heterochromatic regions after hybridization of ancestor wild Discus species. We showed that the meiotic chromosomal chain was not sex related. Such chromosomal chains with a high number of elements have not been observed in any other vertebrates. discus only contains typical bivalent chromosomes. An intriguing meiotic chromosomal chain, with up to 20 elements during diplotene/diakinesis, was observed in S. We have confirmed that Symphysodon species are characterized by chromosomal diversity and meiotic complexity despite the fact that species share the same diploid number 2 n=60. Mitotic analyses in Symphysodon have shown some odd patterns compared with other Neotropical cichlids. haraldi, popular and expensive aquarium fishes that are endemic to the Amazon basin.
#RARE DISCUS FISH FREE#
Feel free to visit us at to see all of the available colors.As part of a program to understand the genetics of Amazonian ornamental fish, classical cytogenetics was used to analyze Symphysodon aequifasciatus, S. We cannot ship to Alaska, Hawaii nor Puerto Rico. If any fish arrive DOA- we cannot refund shipping costs- only the cost of the fish that arrive DOA. I cannot guarantee the fish once the bag is opened. If any of the fish arrive dead you must send me a picture of the dead fish in the unopened bag within 1 hour of delivery. We quarantine all orders for at least 5 days before shipping! Live arrival guaranteed. You will receive 4 Discus! Overnight delivery via UPS. 4 Live Discus Fish - RED SPOTTED GREEN DISCUS - RARE - FREE SHIPPING! Wholesale Price- You pay what the pet shops pay! All fish are between 1.5-2 inches in size. Item: 323661849924 4 Live Discus Fish- RED SPOTTED GREEN DISCUS - RARE Tropical Fish. Location: Berkeley Heights, New Jersey, US,
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