Long Island Sound Biotope Tank

Chris Baker · Feb 20, 2018

I work for a marine education nonprofit in Connecticut and doing some tank maintenance today we found some unidentified critters/growth in our tank and our canister filter. The tanks are stocked with Fish, snails, and crustaceans caught in a nearby brackish cove.

We use NBW (Natural brackish water) from the cove when it is warm and treated tap water when it is cold. Salinity is about 30 ppt but swings since we don’t have any kind of ATO and our schedule does not always allow us to regularly top off. Fortunately our stock is well adapted to salinity swings and they are usually within the range we measure in the cove.

We keep the tanks around 68 degrees Fahrenheit but on a cold night it will drop quite a bit lower.

First critter: These are growing in our canister filter in a Killifish tank. Our best guess is some kind of tunicate.

Next is some kind of growth on the glass. We get a brownish film algae but never anything this red or round in growth. It’s also shown up in two different tanks and doesn’t come off the glass easily. On has blue crabs, European green crabs, Asian Shore Crabs, and Killifish. The other has a Blackfish and Killifish.

Thought I would pose something a little different to the forum. Let me know if you have any ideas.

ThunderGoose · Feb 20, 2018

If this was a typical reef tank I would agree with the tunicate ID and add that the hard to remove spots on glass Looks like coralline algae.

Chris Baker · Feb 20, 2018

We were thinking it looked like coralline as well but there has been no chance for contamination. All our equipment has been in our tanks for the last year.

Anyone know if there are any similar algae that grow in the area that might fit the bill?

Maritimer · Feb 20, 2018

Many's the rock I've flipped in Long Island Sound to find patches of wine-red flat against the stone. As a lad, I couldn't keep the stuff alive (under incandescent or T-12 fluorescent), but wouldn't be surprised to find that it's some form of coralline. Does it seem to have a calcified surface if you touch it?

The little glob in the filter ... I usually expect to see two openings in most of our local non-colonial tunicates/sea-grapes, this guy seems to have one? I can't really put a finger on that one, but maybe @KJ or @Lovemyreef2015 have seen its like.

Your setup brings me back to the days when I would spend my summers in tidepools, and collected as many as 50 species of critters for my LIS tank. You couldn't do it legally today, as many of those were juveniles of things like blue crabs, porgies, blackfish and winter flounder.

~Bruce, down at the west end, in Norwalk

Lovemyreef2015 · Feb 21, 2018

I'm not to familiar with brackish water tanks but it looks like the first image is a type of sponge and the second looks like red algae on the glass. To get specific names I would go to your local library and/or try to research the cove you are getting your water from. I wish I could be more help. Nice tanks BTW.

Chris Baker · Feb 21, 2018

The algae has a little texture. It’s going to take an effort to get it off the glass so maybe we’ll let it grow out a little bit and see how it grows. The tanks it has been growing in have no light except the fluorescents we light the room with and some natural light filtering in through the windows. A sponge would make sense for the blob. Thanks for the help!

We have a scientific collectors permit that we use to gather specimens in the Summer. The kids catch the specimens and care for the tanks whenever possible. We also bring creatures from the tanks for classroom lessons during the seasons when we can’t go into the field.

I’ll throw in some pictures of our current inhabitants for anyone who’s interested.

Blue crab munching on leftover green crab legs from a dissection lesson.

Our oldest and most distinguished Tautog

We think this guy is an American Plaice trying his best to blend in during a camouflage lesson.

A blurry picture of a freshly molted broadclaw hermit crab pretending to be a shrimp

bo0sted2g · Feb 21, 2018

From a former Long Island resident (Stony Brook) this is pretty cool!

sfin52 · Feb 21, 2018

Really cool set up

AC1211 · Mar 16, 2020

Its been years but I am going to open up this thread due to me considering creating a similar setup today using orchard beach livestock. Collection will be mostly cast nets. Also some of those donax clams I can collect by hand in the shallows.

Phildago · Mar 16, 2020

I love it. I had one of these setups as a kid, but the tank was too small. One day I'd like to give it a Go again with a tank that can handle these fish appropriately

AC1211 · Mar 16, 2020

How much momey do you think I should put into this project? Should I mix fish and clams from ny waters with stuff like catalina gobies and such?

flsalty · Mar 16, 2020

AC1211 said:
How much momey do you think I should put into this project? Should I mix fish and clams from ny waters with stuff like catalina gobies and such?

I kept a tank that was entirely stuff I caught in the Intracoastal waterway down here in Florida. For me it was very satisfying to keep a tank full of fish I didn't spend a dime on. Plus, it just seemed more pure to keep it to the natives. I had other tanks to put exotics in.

AC1211 · Mar 16, 2020

flsalty said:
I kept a tank that was entirely stuff I caught in the Intracoastal waterway down here in Florida. For me it was very satisfying to keep a tank full of fish I didn't spend a dime on. Plus, it just seemed more pure to keep it to the natives. I had other tanks to put exotics in.

The difference is I think I would need a heater and a chiller to keep it stable. I may also use catalina gobies and similar in the system.