You most certainly can keep S.
nematodes, commonly called the
blackray (or high-fin) shrimp goby
for that extended dorsal filament
you describe, with its natural commensal
partner, which is Alpheus randalli, one of
the so-called pistol shrimps. In fact, I think
that combination would make a really neat
display in your 20-gallon (76-liter) setup.
When one of the shrimp gobies and its
respective pistol shrimp (there are many such
combinations in nature) take up residence
together, the shrimp, which has very poor
eyesight, digs and maintains the shared
burrow while the goby keeps a sharp eye
out for danger. Be sure to provide a substrate
consisting of a mixture of fine sand and bits
of rubble so the shrimp can build the burrow.
Do be aware, however, that putting
these two species in the same tank doesn’t
necessarily ensure they’ll choose to cohabit.
Oftentimes they will, and the odds are pretty
good if they’re collected together, but there
are no guarantees.
I’ve been told quarantine is
vital for marine fish, but it’s
a struggle for me to keep them alive in an
isolation tank. I dose medications based on
the manufacturer’s instructions, but I still
end up losing fish before they can be placed
in my display tank. Do you have any advice?
I have found some confusing
comments regarding quarantine
practices circulating on the Internet
over the years. Some aquarists
make it seem like a simple 10-gallon (38-liter)
aquarium, foam filter, heater, and air pump are
all that is needed to properly quarantine marine
fish. But while some species can survive under
such conditions, such a setup really doesn’t
take into consideration the delicate nature of
marine fish, and it can put them at undue risk.
Like the display, the quarantine tank must be
an adequate environment in which the fish can
thrive while being closely observed and treated
for potential pathogens.
Many aquarists caution against using live
rock in quarantine tanks. Yet live rock forms the
very basis of filtration in any marine system.
While typical quarantine tank treatments
like hyposalinity and copper can kill the
invertebrates found on live rock, they don’t kill
off its filtering bacteria. For this reason, I feel
that live rock is an essential addition to any
My recommendation is to place a few pounds
of dry rock into your main system’s sump (or
in the main display tank, if you don’t use a
sump) and allow it to cure over the course of
several weeks. After curing, remove the live
rock and place it in the quarantine tank, where
it will provide beneficial bacteria for biological
filtration. It’s possible that some copepods and
other tiny invertebrates may colonize it, but
it is unlikely to have larger animals within it.
So even if the tiny invertebrates die off due to
treatments during quarantine, it probably won’t
cause a large die-off and the rise in harmful
nutrients that would follow.
As far as tank size goes, it’s important to
remember that cramped conditions stress
marine fish. For this reason, I recommend that
quarantine tanks be between 30 gallons (113
liters) for smaller species and up to 60 gallons
(227 liters) for larger ones. That way it’s much
easier to maintain stable water chemistry, and
it provides the animals enough room and live-
rock hiding places to prevent stress.
Although a vital part of the process, water
movement is often neglected as well; it’s needed to
oxygenate water, remove nutrients, and maintain
a natural environment for fish, so make sure to
provide plenty of water flow. During quarantine
I also recommend performing frequent water
changes, so be sure to have a good quantity of
saltwater mixed and ready.
When I see aquarists suggest that quarantine
tanks are simple, cheap, and bare bones, I have
to disagree. A proper quarantine tank must be
The ornate leopard wrasse (Macropharyngodon ornatus); leopard wrasses are notoriously
difficult to feed in aquariums.
The blackray (or high-fin) shrimp goby (Stonogobiops nematodes) forms a commensal
relationship with the pistol shrimp Alpheus randalli in nature—the shrimp digs and lives in
their shared burrow while the goby keeps watch above.