Distressed Gobies

[natlmar]

Hi everybody,

Longtime member, first time poster. I have a year-old 29 gallon mini reef with three firefish, a single pajama cardinalfish, a bunch of mushroom corals and zoas, and a mated pair of hi fin banded gobies (Stonogobiops nematodes) with their tiger pistol shrimp symbiont (Alpheus bellulus).

I am having problems with my gobies currently. About two weeks ago, my once-outgoing pair of gobies suddenly became reclusive and skittish. At the slightest movement of a fish into their field of vision, the two would dive into their cave (shared with the shrimp and the occasional firefish), and it seemed to be getting worse by the day. I suspected that the two were mating (although I cannot distinguish the two by gender).

Things reached a head today when I came home from school to find one of my gobies in the front of the shrimp's cave as normal and the other goby clear across the tank looking a bit pale, but with no other external symptoms. I fed it small pieces of jumbo krill until its color returned, but it stayed in the corner of the tank and would not budge.

My question is if I should do anything right now to solve any problems that my goby may be having. Is it about to lay eggs? Is it sick? Or did my pair of gobies just have a divorce?

My ammonia, nitrites, and nitrates are all 0. I am running a month-old Prizm protein skimmer and a fluval 405 canister filter. My light is a compact fluorescent fixture with an actinic bulb, and it runs on a 12-hour cycle. I have a minor flatworm problem that I control via siphoning. The only bully present that I could think of would be my pajama cardinalfish, which has had an attitude problem ever since I bought him (he has killed several tankmates). Finally, I performed a 30% water change yesterday.

Thanks in advance for the help.

 

[returnofsid]

Welcome to Reef Frontiers, finally!!!

Let's move this to Lee's Marine Fish Discussion, for the best advice, from Lee!

 

[natlmar]

Thanks, Returnofsid. Very glad to be here. I just wish that my first post could have been on a lighter note. XD

A small update with some good news. I found my goby at the front of the tank today with flared gills and heavy breathing, but no obvious parasites. He's still pretty listless, but a little more animated. When I hand-fed him the jumbo krill, he took it rather voraciously (a good sign?). Should I quarantine and treat for parasites, or should I wait a bit longer to see how the situation unfolds?

Also, I called my LFS and they said that I was keeping my salinity a bit high at 1.028, and this was the reason that my goby became sick. I've been keeping it at 1.028 for about four months on the advice of my biology teacher (for coral health)...any thoughts about this?

Thanks again!

 

[returnofsid]

Imo that's too high for corals or fish. Higher salinity will usually result in lower oxygenation of the water. I'd bring it down to 1.025.

 

[NWDiver]

Hi Natlmar, and welcome.
+1 to Sid's comments and a question: When and with what did you last calibrate your refractometer? I recently helped a friend who had a disaster due to a refract going way out of cal.
It might be well worth checking or have it checked at a LFS.

-Todd

 

[leebca]

We tend to keep our marine fishes at a slightly lower sp. gr. more for the sake of saving salt costs than comfort of the fishes. There is no problem with with the higher salt content, provided the system itself isn't stressed. If you perform the calculation of gas dissolved in 1.024 v. 1.028 sp. gr. water, you'll find the difference in the not quite significant range.

Probably the most significant effect of a lower salinity is that the fish uses less energy in osmoregulation. THAT is the single greatest benefit in ornamental marine fish husbandry. The allocation of energy of our captive marine fishes is important to their captive well being. This should not be construed as it being important to lower your salinity. Again the difference for fish kept properly is not of high significance.

Fish behavior is hard to understand. The problem with most hobbyists is that they don't know what normal behavior is like, so they can't understand what abnormal behavior is like. How many hobbyists have kept multiple fish of the same species over decades? or have dived a few dozen times to study a single species in the wild?

That said, we can usually only go by previous behavior and current behavior. From the description of these fish, I can find no pathogen cause for their current behavior, or a pathogen cause for their change in behavior. There are no other symptoms that point to a pathogen. This leaves a rather large array of possible causes for such behavior shifts. They include:
nutrition
water quality
environment (other tank inhabitant issues, as well as mating)
lifespan or
a combo of any of these.

All I can suggest at this point is keep looking for disease and also look towards correcting nutrition issues and any others from the above list.

 

[natlmar]

Thank you very much for your help, guys. Unfortunately, I had to euthanize my goby today--I found it this morning barely breathing, lying on its side on the bottom. It was extremely pale and looked like it was going to perish anyways. Hopefully I didn't make a rookie mistake in euthanizing it. =(

In response to Lee's points:
1. I feed once a day with either ocean nutrition formula one flakes or with frozen food (sort of a mixture of different items--algae, sea urchin, etc.). I make sure that everybody eats and I target-feed with a pipette to my gobies and shrimp (only as much as they can eat in 30 seconds).
2. Water parameters are all zero, including phosphate after my water change. I cannot think of any pollutants or aerosols that would have entered the system, but it is certainly possible that something I had on my hands earlier got into the tank and stressed the goby.
3. My cardinalfish seems to be a persistent bully to all of his tankmates--maybe stressed the goby?
4. I am not quite sure how old my gobies were when I purchased them.

In response to NWDiver, I use a hydrometer to measure my salinity on my LFS's advice. My LFS told me that refractometers are not necessary for my system because my organisms are fairly hardy--are they incorrect?

Thanks again for all of your guys' help. =)