Oyster Reef Ecosystem Tank

[Michael Hoaster]

Spawning activity is so much fun to watch! It did look like one was trying to push her into his lair at one point.

Having one female to three males goes against the conventional wisdom of harems, but it seems to work fine in your tank. Not that all fish are harem spawners. Do you know of their social structure in the wild? Despite some mild aggression, no one is cowering in the corner, waiting for death, which happens a lot with other fish. Maybe the males' squabbling prevents the female from getting too much attention. There are many fish we are warned to not keep more than one male of, because they will fight to the death. Your males seem to tolerate each other pretty well!

Could this be the normal ratio for them? Maybe, in the murky world of oyster reefs, females are hard to find, so the males have to be more 'sensitive'. Whatever's going on seems to work well, and your fish are happy enough to spawn. And, it makes for fun vids!

 

[Chasmodes]

Thank you Michael! The ratio is probably more even in the wild. I had 5 males and 2 females until one went carpet surfing during QT. I will be doing a lot of collecting this summer (maybe not keeping, but sampling). I don't know if I can draw conclusions based on those samples or not, because I may not be collecting over ideal habitat (discarded shells vs. an actual oyster reef). But, from what I've learned from a scientist friend that I know that studies the genus, and also from the little bit of literature that I've found, that one male may spawn with many females, and the females may visit many more males at their oyster shells. Each female will lay eggs every two weeks or so in the wild, so I hope that happens in my tank. If I can add more females to the tank, this should take some of the pressure off of the one that I have. However, because this smaller version of my ecosystem is already crowded, I will wait until I get the big tank up and running to even up the ratio. That said, I may keep one female on a future collecting trip to ease things a bit.

What is interesting is how tough and brave these fish are. All but the largest of the males were relentlessly picked on almost their entire life by the largest male. Now they are all the same size except for one that is about a half inch smaller than the rest, and he is at the bottom of the pecking order. However, 3 other ones that were picked on their entire lives have really started standing their ground and fighting back, all in the last 3 weeks or so, once they established their territory. Each blenny seems to defend up to about 8" from their preferred shell. If their territories are closer together, that distance shrinks and, although some squabbles occur, for the most part, they tolerate each other. All that changes when a female gets between them (just like a movie drama)!

Also, in the wild, this genus establishes smaller territories and tolerate each other more than other combtooth blennies, as suitable empty oyster shells are at a premium. They tend to be in higher densities.

It's also interesting to watch the different ways that they encounter each other. It can be bluffing and displays, mild nipping, pushing matches or exchanging bites. One blenny may lose one battle, but might win the next, thus, each still able to defend their space.

I searched all of my unposted videos and don't have the encounter of when the male physically T-boned and pushed the female across the tank toward his shell. My guess is that if he did it once, he may do it again, and hopefully, my camera will catch it. I guess I need to set up a blenny cam!

 

[Michael Hoaster]

One of the takeaways I get from this, is that this hobby can be made easier if we chose sturdier fish to populate our aquariums. Thanks for reminding us!

 

[Chasmodes]

Indeed. Even despite me being the aquarist! :hmm4: My fish are almost bulletproof.

That said:

• I lost the smallest skilletfish the other day. It wasn't eating and shunned food. I didn't see any apparent disease symptoms. Even though it ate in the past, all of the other skilletfish grew to an expected adult size rather than this one. It's a mystery.
• My sticklebacks both disappeared without a trace. Both were eating pods like crazy and there seemed to be an endless supply of them. No fish carcass found around the outside of the tank or lid. My crabs and anemones seemed a bit extra fat and happy.

 

[Chasmodes]

I have some exciting news! After I got home from work, I went down to my tank to feed the fish and noticed that one of my skilletfish wouldn't leave his clam shell to come up and stick to the glass and beg for food. So, I shined a flashlight inside the shell, and when he moved away, I saw eggs on the upper shell half! He was guarding eggs and only feeding on food drifting by his shell. I made a point to plunge my hand into the tank in front of him with a pinch of frozen food, and he ate after a little bit of coaxing. It was weird because the other day, I only could find three skilletfish coming out for food, and I searched the tank high and low with a flashlight and couldn't find the fourth one. At that time, there were no eggs in any of the shells. So, apparently, the female skilletfish was the one that I couldn't find, and she was probably somewhere near the clam shell out of my view the entire time. I took a video of him guarding and fanning the eggs. I found it entertaining. Hope you all do as well.
https://www.youtube.com/watch?v=B4i3kLkCjIk&t=28s

Also, the gobies are acting differently, constantly flaring their fins and chasing each other, so my guess is that they will be next. The female blenny is about due to spawn again as well, as she is getting very plump.

 

[Chasmodes]

Update: I just completed a water change, and afterwards sat down to check on everything. I noticed that my skilletfish laid another batch of eggs, the third batch in two weeks. Also, my blennies laid eggs last night or this morning again. I wondered what happened to the older skilletfish eggs as they seemed to disappear...

...well, a few minutes later, I found out...I found fry swimming around my tank, most likely skilletfish but could be blennies, I guess. They're about 3/16 of an inch long right now. I think that a few went down the drain with the water change, I suspect!

 

[Michael Hoaster]

So cool. Happy fish!

 

[Chasmodes]

Thank you Michael! I guess I'm a Grandad now? LOL

They're a bit smaller than I thought, maybe 1/8" long at most. It wasn't easy, but I was able to get a short video of them:

https://www.youtube.com/watch?v=lgaPI6Ue-Ug

 

[Subsea]

Thank you Michael! I guess I'm a Grandad now? LOL

They're a bit smaller than I thought, maybe 1/8" long at most. It wasn't easy, but I was able to get a short video of them:

https://www.youtube.com/watch?v=lgaPI6Ue-Ug

Kevin,

As always, I enjoy your videos. On your music, what an eclectic mix of jazz and banjo. It for certain woke me up this morning.

The video brought back a memory imprinted from 30 years ago on a Transocean semo-submersible in 100' of water at the mouth of the Mississippi River. On the surface, the water was fresh, full of nutrients and very muddy with little light penetration. As a semi-submersible, the rig must remain over the wellhead. In a 3-4 knot current, six 30 ton anchors with another with another 500 tons of anchor chain the rig was prone to be moved off location. As a Subsea Engineer, I was responsible for all well control equipment, riser tensioning system including flex joint on wellhead and ball joint at rig floor. To monitor rig offset from wellhead, I would lower underwater camera till slack in cable indicating that camera frame was landed on BOP frame. I would raise winch cable 5' to look at flex joint angle bullseye. When subsea camera lights were turned on, at max, 5 seconds were available to see flex joint angle indicator before a horde of multicolored squiggly things blocked view.

 

[Heuristic]

That's awesome! And the free quality fish food is a great added bonus LOL

 

[Chasmodes]

Thank you Patrick and Heuristic! I'll try and raise them one day, but for now, they're on their own but most likely will become a nutritious meal for someone in the tank!

Wow, Patrick, that must have been a pretty amazing job. What was the weirdest thing you saw on such dives?

 

[Chasmodes]

Update:

The skilletfish lay eggs weekly now. The blennies lay them about every three weeks that I can tell. The fish fry from either species hang around for a few days and become fish food, I suspect. All of the fish are really fat these days!

I love this picture, male striped blenny, Chasmodes bosquianus, lookin' right at'cha!:

 

[Michael Hoaster]

That is a great pic! So cool your fish are spawning! Jealous…

 

[Chasmodes]

Thank you Michael.

Here's a better video of the fish fry that are in my tank. I'm not sure if they are a mix of skilletfish and blennies, or all of one of a species. There are much more than usual. Right now, there are two blennies guarding eggs (and only one female in the tank) and at least one skilletfish guarding eggs. These guys hatched yesterday morning and by last night, had the calmer surface water in my tank covered. The fry are there for a few days and either die or get eaten. Someday, I'll set up grow out tanks and try to raise them. Right now, I don't have room and it's not in my budget. So, they'll be fish food unless a miracle happens and some live longer. I feed my tank Reef Nutrition Oyster Feast and frozen baby artemia for the filter feeders. I hope the fry will eat these foods and live longer, but I doubt it. They oyster eggs are small enough, less than 50 microns, but from what I've heard, the blenny fry like live rotifers. Anyway, for now, it makes for a fun video:
https://www.youtube.com/watch?v=OEsUdl25SEA&t=44s

I also have another project going on, not a marine tank, rather, a freshwater 75g US native stream tank to house minnows, shiners and darters. I'm almost done building a DIY styrofoam faux rock wall as an in-tank background for the aquarium. I constructded it by carving and gluing styrofoam foam board, filled in the gaps with spray foam and stream rocks to reduce buoyancy, and painted it with Drylok. The first coat was plain Drylok gray, and this coat is a mix of Drylok, charcoal cement dye, and a dab of yellow paint that matches the base color of a rock formation found near my local river (where I will collect my fish). My next steps will be to stipple various lighter shade versions of the same color to bring out the realism of the color and reduce the monotone gray look. I will also add some other colors as well (subtle greens, browns, reds) to bring out the stratification of the rock a bit more. I really am having fun with this project. Although, it's not a marine tank, it is a cool project that perhaps might give you all some ideas for something to build in your reef tanks, so I'll post a couple updates on that now and then along with updates of my oyster reef tank. Hope you all like this short video of that project:
https://www.youtube.com/watch?v=_SrmoWCchnw

 

[Michael Hoaster]

Wow that's a lot of fry! It says a lot that your fish are so well cared for they spawn regularly. Great job Kevin!

Please keep us posted on your fake rock progress. I'd love to see sequences of the color scheme evolving. It looks awesome!

 

[Chasmodes]

Thank you Michael on all counts.

The rock wall is coming along nicely. I'm curious how it will turn out as well. I was going to paint last night but couldn't get motivated after a longgggg day at work. All I could do was feed and watch my fish. The oyster reef tank needs the front glass cleaned and a water change, but all I could do was sit there and continue to be fascinated by these fish.

The fry are just about gone. I don't know if they starve and die off or are being eaten by the other fish. I have yet to see any fish going for them at the surface. But, there are more eggs in the shells that will hatch in a day or so. I may try and transfer some fry to the other tank that is currently fishless. Maybe they'll have a better chance at survival if they can avoid the three anemones in there. It would be cool to raise a few of these guys. I guess I'd better consider what to do with them though!

 

[Chasmodes]

Not much has changed with the oyster reef tank. I bought a small fine mesh net and will try and move the fish fry to my other tank so that they don't have as many predators, no powerhead to chop them up or a HOB filter to suck them into oblivion. We will see if there is enough food in the tank already to rear them.

I made progress on my 75 gallon stream build DIY 3D sytrofoam rock wall background though. I stippled a lighter shade of Drylok paint mix with a sponge to give it a more realist effect:

 

[Michael Hoaster]

That looks amazing! Great technique!

 

[Chasmodes]

That looks amazing! Great technique!

Thank you Michael!

 

[Chasmodes]

I tried moving some of the fish fry to my other tank. The lasted a couple days there. I think that they all became chow for my three anemones, and perhaps eaten by shrimp, crabs and worms. Right after adding them, I saw three go into the large anemone. I thought that might happen. I need to have tanks set up to specifically raise them without predators. They also might be starving, so I'd need to start up a live rotifer culture. I don't have the space to do this yet, but perhaps down the road.