• It is necessary to remove the eggs from the parent’s tank, ideally 1-2 days before hatching. • One should check the tank daily for a male hiding in the cave. You may not be able to see the eggs themselves—R. duospilus prefer to place them into the deepest area of the cave, in my case, into the impeller assembly of the filter—but you would know of their presence by the male’s reaction to food. If the male is willing to leave his cave to eat, then no spawning has occurred yet, he is simply manning the cave hoping for a female to visit. • Time the removal of the cave to twelve days after you observed the male guarding. • Precautions should be taken against fungus affecting the eggs and immobile fry. Unlike many other species both the eggs and immobile fry need strong water movement. Use an airstone strong enough that most of the surface of the container is agitated; do not decrease the aeration when the fry hatch.
Thanks R. duospilus were the first fish I’ve bred, and in retrospect, objectively the most difficult. Knowing nothing about this species’ specifics, I was pretty lucky to make some right moves, for example timing the removal of the eggs correctly. I would never have been able to get any fry to survive without very close supervision by Colin T. in Perth, Australia, as well as Jeff Bollbach here at GCAS. While neither had dealt with R. duospilus before, their experience with other goby species proved invaluable in making the right guesses. I am thankful for the chance to meet Jeff and Colin, and I have learned a lot from them.
Photos by Author
• Newly hatched artemia should be sufficient. Live rotifiers and microworms can be used to supplement. Avoid powder and liquid foods, the fry will not touch them anyway.
Modern Aquarium - Greater City A.S (NY)
June 2009
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