OK, Tracey, here's the article I promised.

If you don't see eyes after four days, the eggs may be infertile or the
temperature may be to low.

Best wishes,

Naomi


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Breeding the Bumble-bee Goby

Among the gobies kept by aquarists, bumble-bee gobies are probably the
closest to being true “bread and butter” fishes. Naturally then, much has
been written on them. Even so, I receive more email questions about them
than any other gobies. For this reason, I decided to write a short article
with my own tips on breeding the bumble-bee goby.

Species in the Hobby

The genus Brachygobius includes about ten species of small black and yellow
gobies. According to Helen Larson, who is
currently working on a revision of the genus, the most frequently sold
species in Australia is Brachygobius doriae. Probably this is also the
species most often kept by aquarists in the U.S. and Europe, but B. sabanus
and possibly B. nunus also show up in hobbyist tanks. B. xanthozona
(placed in Hypogymnogobius by some ichthyologists) is significantly larger
than the others, but it is rare in its natural habitat and is unlikely to be
available.

Care of the Adults in Preparation for Breeding

A great variety of recommendations have been made on the general care of
bumble-bee gobies, so I will only briefly touch on that. Whether or not
you plan to breed them, I recommend keeping about 8-10 individuals in a five
or ten gallon tank. In such groups, most aggressive behavior is minimized
and territorial quarrels are less severe. Another advantage of keeping them
in groups, if you are planning to breed them, is that the probability is
very high that you will have both males and females. Bumble-bee gobies can
easily be sexed by the shape of the urogenital papilla, which is pointed in
the male and shorter and blunt in the female. However this structure is not
always visible at the time of purchase.

Theoretically it is possible to keep them with other species, but
especially in small tanks that can be difficult. Most fishes are more
voracious feeders than these gobies (which often refuse all but live food
animals) and food competition can be a problem. In soft water especially, a
little salt, about 1-2 teaspoons per gallon should be added to the water.
Higher salinities are tolerated but not necessary.
A temperature of 79-85 degrees is ideal for both maintenance and breeding.
Small caves should be provided for spawning. Snail shells are a favorite
nesting site, but if you are planning to artificially hatch the eggs, it is
better to use a flatter surface, such as a small stone pressed lightly into
the substrate with an overhang under which the gobies will spawn. If the
substrate is soft (i.e. sand) then the males will dig out the small caves.

I have tried many foods, including brineshrimp, blackworms,
whiteworms, and daphnia, but my favorite food for bumble-bee
gobies is chopped earthworm. I once fed chopped earthworms
almost exclusively to a tank of them for eight months. During that time the
females spawned on average once every 4 weeks and none of the fish showed
any sign of nutritional deficiency. Later I
occasionally augmented the diet with live mosquito larvae, which seemed to
result in slightly larger larvae.

Spawning

If conditions are to their liking, bumble-bee gobies will spawn in the
regular maintenance tank. Although some authors recommend a partial water
change to a lower salinity to encourage spawning, I have never found such
actions to be necessary.

Courtship usually begins the day before spawning. The black bands on the
courting male become very pale (Photo 2.1) giving him an overall yellow
appearance. In a ripe female the mature eggs can
easily be seen through the large yellow band (Photo 2.2). If she is
receptive to the male’s advances, her black bands also become pale, giving
her an overall gray appearance. After spawning is completed, the male
chases the female away and assumes the responsibility of the brood until the
eggs hatch (Photo 2.3).

Hatching

Various sources differ on the amount of time before hatching. Most books
say they hatch in four or five days. In my experience, the
larvae of bumble-bee gobies hatch almost simultaneously on the
evening of the seventh day. The male enters the nest, fans the eggs (Photo
2.4), and the larvae hatch out and immediately spread throughout the
midwater. Many hobbyists new to gobies are
surprised to see that the tiny, almost transparent, larvae drift
throughout the midwater of the tank rather than hide among the gravel. This
is the normal behavior of bumble-bee goby larvae, and in fact the larvae of
the great majority of gobies. With some
exceptions (e.g. desert gobies, round gobies and others), gobies have a free
swimming (planktonic) larval period where they drift in the water column and
feed on small free floating organisms.

To hatch the eggs artificially, take the nest away from the father on the
6th day and place it in a small tank (about one gallon capacity)with heavy
aeration. Do not let air touch the eggs when you are moving the nest.
Although in my experience, air does not directly damage the eggs of most
freshwater gobies, it will cause some of the eggs to become unattached from
the nest, making them nearly
impossible to hatch. When the eggs are due to hatch, usually in the evening,
observe the nest. If not all the eggs have hatched by the next morning, try
gently rubbing them with your fingers, as the
father goby would have fanned them, to stimulate hatching. The
larvae should soon start to hatch. If this does not work, wedge the nest of
eggs in a plastic cup full of clean water and swirl the water around in the
cup. This usually causes most of the larvae to hatch quite quickly. Pour
out the larvae, a few at a time, and repeat until all the eggs are hatched.

Rearing the Fry

The aeration needs to be gentle once the larvae have hatched. Sometimes the
larvae hatch with a small remaining yolk sac, but usually they need to be
fed right away. I prefer to raise the larvae of a single nest of bumblebee
gobies in two one-gallon tanks for the first week. Small tanks are easier
because the food is nearer to the
larvae. About 10% of the water needs to be changed each day.

Because the larvae are free swimming, they need food that is
available in the middle reaches of the tank. In general, rotifers
are the best food choice. I have had equally good success with marine and
freshwater rotifers. Although marine rotifers do not move in the typically
very low salinity of the bumble-bee goby rearing tanks, the larvae manage to
find them anyway. Strained egg yolk can sometimes work for a day or two if
the aeration is adjusted to keep it lightly suspended, but it causes too
much waste buildup in the tank to be very practical long term. In my
experience, the young larvae grow relatively quickly and are large enough to
take newly hatched brine shrimp in as little as 5-7 days.

To determine whether they are large enough for brineshrimp, add a very small
number of newly hatched brineshrimp on the 5th day. If the larvae are able
to eat them, you will soon see their guts full of pink-orange brine shrimp.
If they are not large enough, siphon out the uneaten brine shrimp, and try
them again the next day. Be sure to use newly hatched brineshrimp, as older
ones are too large and powerful for small bumble-bee goby larvae. Some
brands of brine shrimp are smaller than others, so it pays to try several
brands. After all the larvae are eating brine shrimp, they can be
transferred into a larger rearing tank. I recommend waiting to feed
microworms until the larvae are at least two weeks old, as they can wiggle
out of the fry's gills, sometimes causing the death of the fry. Vinegar
eels do not seem to be as much of a problem.

After about one week the larvae begin to show small amounts of black
pigmentation. At about three weeks the fry settle to the
bottom of the tank, develop the characteristic black bands (the
yellow comes later) and begin acting like miniature adults (Photo 2.5). Soon
after this point, they can be fed small grindal worms in addition to the
newly hatched brineshrimp (and, actually even the adults will eat
brineshrimp). Juveniles grow relatively slowly, and maturity is reached
after about 10 months.

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