TerraMagnus
Community Member
My wife & I have been on a bit of a Diamond Watchman Goby (Valenciennea puellaris) breeding journey, and I think we're making some progress. I thought I'd share what we've been up to with the hive mind. We've got a batch that hatched out this morning. I'll update this thread with photos, videos, and other notes as we go in the hopes that it might help to make this cool reef-safe fish commercially viable for captive breeding and take pressure off of wild caught populations.
This is really my wife's project. I'm her assistant. Her Igor.
It started sometime last year. We were at the LFS getting water jugs refilled and I was checking out the saltwater displays while we waited. I saw a pair of Diamond Watchman Gobies who were hanging close together, not sparring. And I snatched them up on the spot.
We keep them in a Red Sea Reefer 350 with an array of other fish and corals. They get along pretty well with everything, but I'm sure the small hermit crabs don't appreciate the involuntary relocations they are often subjected to by this pair.
They spawned pretty regularly in our tank but we never really got to see eggs or young. We had a six line wrasse in the tank, and we suspect that the wrasse was going into the spawning chamber and eating the eggs or the young before we could see anything. The wrasse disappeared one day without explanation or evidence anywhere. We suspect, but have no evidence, that the male goby snuffed the wrasse.
The parents spawn with great regularity. About every 2-3 weeks they do heavy terraforming of the substrate, and then disappear underneath of the hardscape. They close themselves in for a day or so. Then the female leaves the spawning chamber and closes the male in. 2-3 days after that, the male will open the spawning chamber but continue to protect the eggs.
It's at this point, where the male begins to open the spawning chamber, that we remove the egg mass. This timing seems to be best for high hatch rates. The method is to attach a length of airline to a syringe and probe around while drawing water into the syringe... just keep repeating this until the pink mass of eggs gets pulled into the airline.
I'll make a point of getting photos of the egg mass.
The eggs are relocated to a partially filled 10 gallon nursery tank with an airstone. All sides are covered and kept dark for another day. Then when the cover is removed and a light turned on above, this seems to trigger mass hatching of the eggs. A pipette is used to agitate the eggs and help the fry to break free, mimicking the gentle mouthing of the eggs that would normally be performed by the male.
So far so good. Up to this point, at the time of this posting, is reliable. It's raising the spawn that is the puzzle we're working.
Here is a video of the fry a few hours after hatching.
Early hypothesis was that the newly hatched fry might freshly hatched baby brine shrimp. This was quickly dispelled as the brine shrimp, even at time of hatching, are far too large.
Next we moved to S-strain rotifers, which are more appropriately sized. The young still died off 3-5 days after hatching, mostly with nothing in their digestive tracts in spite of dense offerings of rotifers available to them. Mostly nothing, I should say. We did see some along the way who had ingested green phytoplankton that had been introduced to sustain the rotifers.
Quite an array of packaged fry foods were tried, and all ignored by the fry.
So that brings us to today. We've got two strains of phytoplankton in with the newly hatched young now: isochrysis and tetraselmis.
We're also culturing S and L strain rotifers, can hatch out baby brine shrimp at any time, and are also culturing copepods (Parvocalanus crassirostris).
Young will be observed under the microscope daily so we can try to get an idea of what the young are eating, if anything. We've got the capability to get high resolution microscopy and video microscopy so I'll try to make a point to share documentation in this thread as we go.
This is really my wife's project. I'm her assistant. Her Igor.
It started sometime last year. We were at the LFS getting water jugs refilled and I was checking out the saltwater displays while we waited. I saw a pair of Diamond Watchman Gobies who were hanging close together, not sparring. And I snatched them up on the spot.
We keep them in a Red Sea Reefer 350 with an array of other fish and corals. They get along pretty well with everything, but I'm sure the small hermit crabs don't appreciate the involuntary relocations they are often subjected to by this pair.
They spawned pretty regularly in our tank but we never really got to see eggs or young. We had a six line wrasse in the tank, and we suspect that the wrasse was going into the spawning chamber and eating the eggs or the young before we could see anything. The wrasse disappeared one day without explanation or evidence anywhere. We suspect, but have no evidence, that the male goby snuffed the wrasse.
The parents spawn with great regularity. About every 2-3 weeks they do heavy terraforming of the substrate, and then disappear underneath of the hardscape. They close themselves in for a day or so. Then the female leaves the spawning chamber and closes the male in. 2-3 days after that, the male will open the spawning chamber but continue to protect the eggs.
It's at this point, where the male begins to open the spawning chamber, that we remove the egg mass. This timing seems to be best for high hatch rates. The method is to attach a length of airline to a syringe and probe around while drawing water into the syringe... just keep repeating this until the pink mass of eggs gets pulled into the airline.
I'll make a point of getting photos of the egg mass.
The eggs are relocated to a partially filled 10 gallon nursery tank with an airstone. All sides are covered and kept dark for another day. Then when the cover is removed and a light turned on above, this seems to trigger mass hatching of the eggs. A pipette is used to agitate the eggs and help the fry to break free, mimicking the gentle mouthing of the eggs that would normally be performed by the male.
So far so good. Up to this point, at the time of this posting, is reliable. It's raising the spawn that is the puzzle we're working.
Here is a video of the fry a few hours after hatching.
Early hypothesis was that the newly hatched fry might freshly hatched baby brine shrimp. This was quickly dispelled as the brine shrimp, even at time of hatching, are far too large.
Next we moved to S-strain rotifers, which are more appropriately sized. The young still died off 3-5 days after hatching, mostly with nothing in their digestive tracts in spite of dense offerings of rotifers available to them. Mostly nothing, I should say. We did see some along the way who had ingested green phytoplankton that had been introduced to sustain the rotifers.
Quite an array of packaged fry foods were tried, and all ignored by the fry.
So that brings us to today. We've got two strains of phytoplankton in with the newly hatched young now: isochrysis and tetraselmis.
We're also culturing S and L strain rotifers, can hatch out baby brine shrimp at any time, and are also culturing copepods (Parvocalanus crassirostris).
Young will be observed under the microscope daily so we can try to get an idea of what the young are eating, if anything. We've got the capability to get high resolution microscopy and video microscopy so I'll try to make a point to share documentation in this thread as we go.
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They are showing a clear preference for food between 25-50 microns in size.
