Two of the most popular species is the golden pencilfish (Nannostomus beckfordi) and dwarf pencilfish (Nannostomus marginatus). Generally they are rather shy and would sometimes become motionless, swimming at the same spot. The tank that houses the fish should be a well-planted aquarium with at least 50 percent of overall area covered with dense vegetation to provide a good hiding spot. I even took the effort to add some small empty clay pots so that the fish feels more like at home for them. Pencilfish prefer to move in groups and if possible get at least 7 -8 of them or you can even consider adding neon fish, zebra danio, hatchet or killifish as they all make perfect tank companion.
Feeding the pencilfish can be quite a challenging task because your main concern is that since their mouth size is so small, there are only certain types of food that can fit into it. For my pets, I usually offer them occasional feed of brine shrimps and I add the finely crushed food flakes that are specially made for tiny fish. Sometimes I even took the effort to introduce a variety of foods to enrich their diet such as growing live daphnia or collect these from ponds coupled together with mosquito larva if I happen to bump across these as well. What I notice is that my pencilfish simply love these until I find myself unable to find constant food supply to feed them. Nevertheless, spending my time in search for their favorite food is always something worth the effort.
Breeding the pencilfish can be quite tough to achieve because basically what you will need to do is to construct a proper egg collection mechanism to prevent their own parents from gobbling up and make a good meal out of their own eggs. What I did was to purchase a type of fine wire mesh and put the layer on top of the aquarium surface so that when the eggs are dropped to the bottom, the parents won’t be able to reach them. Identifying which of the pencilfish is a male or female is a close to impossible feat to achieve as they all look almost the same. I could only tell the different gender apart based on their activity when the males start to chase after the females. Once the eggs hatched, it will take about 5 to 6 days before the fry become free swimming in search of food.
Guest post contributed by Mark Edgar (California)
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