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February 13, 2015

Good afternoon! We’re still slowly releasing fish from quarantine and adding them to our list after last week’s heyday. These Rainbowfish have already been on our list, but they’re so fabulous that I felt they deserved their own newsletter. Last week was all about the little Blue Eye types; this week, we’re going big!

Melanotaenia irianjaya “Irian Jaya Rainbow” is known only from the Bintuni Bay area of Irian Jaya/West Papua, Indonesia and, unlike many other rainbowfish, is known from biotopes nearly devoid of aquatic plants. Instead, these slightly skittish fish shelter under submerged branches and logs. Adult males will reach a maximum size of less than five inches and will exhibit gorgeous coloration – their backs are pale blue, bellies red, and tails are yellow with red striping. Keep a group of these beauties in slightly alkaline water with a temperature between 73° and 79°F and feed them occasional live food treats to bring out their best color.

Melanotaenia irianjaya

Melanotaenia goldiei “Goldie River Rainbow” is one of the most widely distributed Rainbowfish of Southern New Guinea. Unfortunately, we don’t know the collection point of this particular group -- the original collection point occurred at the Laloki River, a major tributary of the Goldie River, and the scientific name and derivative common name are obviously nods to the river system itself. Nevertheless, this fish is found in habitats from rivers to swamps and lakes, usually finding a home in deep pools formed by log jams. Given their wide range and the seasonal variance in water chemistry and parameters, these are incredibly adaptable fish, though parameters similar to that of the Irian Jaya are recommended. Males may reach an adult size of four inches and will likely feature a broken lateral line and red and blue-green striped appearance, though their exact color balance at adulthood is unknown – they are currently only showing a bit of color, including red fins and a powder blue sheen.

Melanotaeni goldiei

I’ve found references stating that Melanotaenia sp. “Dekai” “Golden Rainbow” may in fact be another example of M. goldiei collected from near the Dekai Village, but I suspect that it is more likely to be a member of the Maccullochi family with an adult size of three inches or less – they definitely look similar to the juvenile M. maccullochi that we see.   They are currently a pale yellow with a bit of red striping over their tails and their fins show a hint of pink – we expect the adults to feature brilliant yellow bodies with red stripes running nearly to their pectoral fins and a blue forehead and first dorsal fin.

Melanotaenia sp Dekai

Even more in question is our Melanotaenia senckenbergianus “Aru Rainbow” – occasionally referred to as M. sp. “Aru IV” “senckenbergianus”. It would seem that the original M. senckenbergianus collected in the Aru Islands were later examined and found to be another morph of M. goldiei. Many hobbyists and experts consider this fish to be of uncertain taxonomic standing – of course, which means we’re a little unsure ourselves. What we can say for sure is that this is an absolutely beautiful little Rainbowfish, even in its juvenile coloration – their bodies show bright blue iridescence with just a hint of red along the lateral line, their caudal fins are red and the rest of their fins are blue with red edges. One can expect the adult male to show a golden forehead and scale edges, a pink belly, and a dark, thick lateral line. Their fins will fade from red at the outer edges to yellow and green as they reach the body. The first dorsal fin should retain the blue coloration we’re seeing in the juveniles and the caudal fin should become brilliant cherry red.

Melanotaenia senckenbergianus

Thank you all for reading! Stay tuned; we have some special newsletters planned for you all in the near future!

Jessica Supalla