Threadfin Cichlid (Petrochromis trewavasae)

Remarks:  Threadfin cichlids are a species of Petrochromis which are a larger sized group of Tanganyikan cichlids They are known for their rarity, beautiful coloration, unique mouths, and highly territorial behavior. This particular species has an elegant coloration and pattern that is very similar to a juvenile Tropheus duboisi. Their bodies and fins are a dark gray or black with white spots being dotted all over their bodies and faces. Dominant males will also show gold egg spots on their anal fins and gold accents along their belly, back, and face making for some very attractive contrast. For some, this gold color will actually spread even further resulting in a gold fish with white spots! Both black and gold males will also develop long trailers on the tips of their fins which is where their common name originates. Many note this species is not quite as aggressive as other Petrochromis so they can be a great introduction to the genus.   Petrochromis are similar to Tropheus in that their natural diet is mostly comprised of algae and they are sensitive to protein, too much of which can cause bloat. Their large, protruding lips are indicative of this diet as they aid them in scraping rocks and other surfaces for algae. Another similarity they have with Tropheus is that they are best kept in a species only tank with at least 10-12 individuals in a ratio of about 5-6 females for every male. These large numbers are needed because while they feel the most comfortable and confident in groups, Petrochromis species are still extremely territorial and have a vicious pecking order. If there are not enough fish to spread out the aggression, the smallest or at least less dominant fish will be picked off until there is only one left. These cichlids also do not tolerate poor water quality or incorrect parameters. Therefore, to keep these fish in large numbers with lots of territory space and pristine water, the absolute minimum tank size would be a 150 gallon tank. 200 gallons or more is much more ideal, however. All these aspects make Petrochromis a fairly difficult species to keep long term but their fascinating behaviors, beautiful colors, and rarity make it worth it for the advanced keeper.