The Egg Rocker from Cobatl Aquatics is a new ingenious device that african cichlid breeders have been making and using for years. Usually relegated to a DIY project, egg tumblers have been around for a long time as a concept, but as far as we know Cobalt’s Egg Rocker is the first such mass produced product of its kind.
The premise is simple: using principles of airlifts and basic sponge filters, the Egg Rocker uses an air pump to create suction within the main device and a central inverted standpipe delivers a gentle constant flow to a parabolic base. On the base is where large fish eggs, fish masses and newly hatched larvae rest and are gently ‘tumbled’ with a fresh flow of aerating water.
Egg Rockers and Egg Tumblers are nurseries for the spawn and progeny of captive bred fish, usually mouthbrooders. While the Egg Rocker as a device is probably going to get a lot of usage from the African Cichlid breeders, this type of device could also do wonders for increasing the clutch size and hatch rate of our beloved banggai cardinalfish.
Pterapogon kauderni aka banggai cardinalfish are remarkably easy to breed, but the male’s mouthbrooding of the young is a bottleneck which usually produces a limited number of young fry, and incapacitates the father for weeks during mouthbrooding, and for weeks after while he recuperates. With a protocol of stripping males of their clutch shortly after mouthbrooding commences and placing the developing eggs inside the Egg Rocker, it could be possible to increase hatch and survival rate of the young while also reducing the toll that the natural affair places on the father banggai cardinalfish.
It remains to be seen how many uses the intrepid captive breeders of the world might come up with for the Cobalt Aquatics Egg Rocker. The Egg Rocker comes in two sizes, a 65mm model for $49 and an 80mm model for $59 with actual retail prices probably coming in a little under that when they hit the streets in June this summer.