12 replies to this topic

[MattMudCrab]

So I collected my brackish fish in some warm water. Some even Uncomfortably hot to the touch. Forgot my thermometer. According to a few web sites that record temps the water where I got most was 80. I know that these parts of Virginia can drop to freezing and I believe the water can get into the upper 30s. My question is does keeping these fish at room temperature, in my house ranges from 78 down to 68 at times in the winter, have any negative effects on the Fishes well-being? For example does not having a winter cooldown shorten their lifespan because their metabolism doesnt have a chance to slow down? Ive read that some of these species in the 70s is actually the temperature in which they reproduce and Ive also wondered if that means theyre stuck in a constant state of breathing condition?

[Chasmodes]

Matt, my oyster reef tank had several blennies (one female and 5 males), 6 naked gobies, and 5 skilletfish.  I kept them at room temperature, where winter water temperatures in my basement were 58 degrees, and in the summer, 78 degrees.  All three species bred when the water temperature was about 62 degrees, laying and guarding eggs all summer long.  Your fish will do well with your water temps.  

 

In the wild, all three species go deep seeking warmer water.  In the winter, in deep water, those temperatures in the Chesapeake are about 42-44 degrees, depending on how cold the winter is.  When the Bay freezes over up my way, deep water temps are probably about 40 degrees.  How deep do they go?  Probably between 20-30' deep, seeking refuge on hard oyster bottoms or other reef type structure.

 

In the summer, they can be caught in very warm water.  During our last collecting trip a month ago, surface temps were in the low 90s, and the water temperature at the deepest end of the dock on the bottom was 88 degrees in about 7' of water.  Bottom temps in 3' of water were in the low 90s.  We caught gobies in the shallows, but no skilletfish or blennies.  All of the latter were caught in the deeper water, 5'-7' deep.

[MattMudCrab]

So instead of adapting to the cold temps they just go to where the water is water. Or at least more stable. That makes sense.

[Chasmodes]

Yep.  And for your fish, they've moved from an extreme environment where they have to adapt or die, to something comparable to a Florida retirement home where they can breed as much and often as they like!  

[MattMudCrab]

What salinities have you tried them at this far? I collected mine at 1.012 and 1.014. The strange thing is when I test it before I top the tank off it drops to 1.010-11. I always thought the salinity would increase when water evaporated. My wife has a tank of several small thin striped hermits that she intends to slowly move to full marine as they grow.

[Chasmodes]

I've kept them from about 1.009 to 1.019.  I try and keep them about 1.016.

[Chasmodes]

If you are going to keep them with reef fish, then yeah, you can raise them to full seawater.  But, keeping them brackish is cheaper...use much less salt!

[MattMudCrab]

Well today she has decided that scars or monos would be the best.

[MattMudCrab]

My flowerhorn died today so I now have an open 40 gallon. So I believe we will combine our tanks.  4C7B5B6B-32A4-41CD-9AB9-84F0D63DD2F5.jpeg   111.73KB   0 downloads

[MattMudCrab]

Scratch that idea I found some info that says the mud crab enjoys eating hermit crabs

[Chasmodes]

I had both in my tank without any issues...except adult blennies (4-5") could perhaps attack them.  That happened in my tank, so I moved the hermit crab to my other tank.  But, the mud crabs were totally peaceful.  That said, Harris mud crabs will attack each other, but they are pretty good at avoiding each other.  And, their claws grow back.  

[Chasmodes]

My theory is that if you keep the blennies well fed, they pretty much leave tank mates alone.

[MattMudCrab]

I discovered that one of the large mud crabs that I collected had lost both of its claws by the time I got it into the final tank. I just found him the other day with two very small light colored claws. I had seen him basically cramming his face onto the oysters attempting to get whatever food he could find. He mustve been successful enough to keep himself alive till he molted.