Oyster Reef Ecosystem Tank

[Chasmodes]

Thanks Michael and McPuff!

Michael, you are exactly correct. As long as there are plenty of escape routes and hiding places, this particular species of blenny can live in a higher density fish population. This fish density is almost what you'd see in the wild in our bay oyster reef locations. I've also noticed this at our collection spots, scooping with a dipnet over the same concentrated area will give up multiple specimens. I estimate that, based on our collections, the fish densities of both gobies and skilletfish are even higher in the wild!

I really need to get moving on the 100g. Once I get the electrical situation resolved, the rest is easy.

[Chasmodes]

The skilletfish in the clam shell at the back of the tank seen in my previous video spawned again last night. He seems to guard a new batch of eggs about every three days. I don't know how many females are laying eggs in his shell. My hunch is that it is more than one because of the frequency that new eggs appear. I'm not sure how many male skilletfish that I have. I think one, because he is the only one that always hangs out in his shell. The others tend to roam the tank and use shells as they please without any one being a "home" shell. I assume the other three are females, but again, it is difficult for me to tell.

The gobies have spawned a few times, but not in the last two weeks, that I have seen. If they have, then I can't see the eggs. All of the males hang out in their favorite shells but come out to feed. The lone female has a favorite shell too, much higher on the reef. I suspect that this is because the other males harass and flash her all of the time. I'm fairly certain that of my five gobies, that I have only one female. She is noticeably smaller than the rest of the gobies, and they're all the same age.

Since there is only one female blenny, it's easier to see how often she spawns with any particular male, as long as I can see the oyster shell with eggs. The female is smaller than the males, and has a different coloration pattern, more mottled and camouflaged than the males. The males have bright blue spots, peach colored cheeks, and orange tinted tail, dorsal and anal fins..

The male in the video below appears to occur about every week to ten days now. There could be spawning with the other males as well, one in particular, hides in a shell at the back of the tank, out of sight, so I don't know how often that has happened. The other male that I know has spawned prefers a shell toward the center of the tank, and she has spawned with him several times. There is a fourth male that has claimed four different shells, but has yet to settle on one, so I don't think he has spawned with her yet.

This next video, shot two days ago, shows the largest male blenny in the tank courting a female. He flashes her a few times, then tries to herd her toward his shell to lay eggs. He is also guarding eggs from a previous spawn. I also noticed something interesting about this male. The males have a blue spot on the dorsal fin (you can see it if the light hits it right). In his case, he is developing a second spot! I haven't seen this before.
https://www.youtube.com/watch?v=P2Su5xb6hI8&t=16s

[Michael Hoaster]

You've got some great spawning behavior to watch, for sure! That twitching is the flashing you referred to, right?

[Chasmodes]

Thanks Michael. Yes, that's correct, the twitching and shaking of their body to attract the female is what I refer to as flashing. I don't know if that is the correct scientific term, LOL. The gobies do it also, but not just to females, but also to rivals.

[Chasmodes]

On Friday night, while feeding my fish, I noticed, for the first time, the female striped blenny inside the oyster shell with the male striped blenny, presumably laying eggs, or about to. However, the feeding event caused her to leave the shell, and she never returned after that. On Saturday night, before I fed them, I set up the camera and tripod at an angle looking down to get a good video of both of them together in the oyster shell, hoping that she'd return. She did not. I also watched them for a long time last night, and she didn't return. The oyster shell is full of eggs, so perhaps, she was done. I have a video instead, of the eggs being tended by the male. I'll keep checking and hope to get a video of them in the act. I kinda feel pervy about it, LOL.

Here's the male tending his eggs:
https://www.youtube.com/watch?v=neRkyzpRmZ8

[Chasmodes]

This is another male blenny that guards an empty oyster shell in the front left side of my tank. Up until this video was shot two days ago, he had not yet spawned with the female, to my knowledge. I went to feed my fish on that day, and the female shot out of the same oyster shell with him still inside. I didn't capture it on video, but they must have just finished laying and fertilizing eggs. I managed to grab my camera and capture him tending his eggs for the first time. Once again, I just missed filming a blenny spawning event.

Since this blenny's shell is so close to the front of the tank, I was able to see a lot more. The blenny that I previously took a video of guarding eggs is about 8" to the right of this guy. The female blenny, meanwhile, looked really fat last night, so maybe I'll luck out and catch them in the act again soon.

https://www.youtube.com/watch?v=AUfQJtrEr9s&t=2s

[Michael Hoaster]

That fish moves around in his shell like Harry Houdini!

[Chasmodes]

That fish, I think, is bigger than his shell. Wait until you see two fish in there (coming soon, but not that shell)! But, he seems happy in there.

[Chasmodes]

Last night, I ventured downstairs to feed my fish, and lo and behold, one of the oyster shells seen in previous videos that had a male striped blenny guarding eggs had company. A female poked her head out of the shell, the ducked back inside. At that point, I set my camera up on my tripod and began to film the event, despite my front glass having some algal growth on it, making the video a little blurry. I apologize for that, but I didn't want to scare her out of the shell, so I felt it best to capture the moment and clean it later. The angle that I had to use may also contribute to the blurriness, but that was the best way to see what was going on inside the shell. Anyway, hope you enjoy this video of a pair of spawning striped blennies!

https://www.youtube.com/watch?v=pLbGDvx1OJc

[Michael Hoaster]

Don't they look cozy in their tiny house! Lots of um, positions… Bow chika bow…

[Chasmodes]

That's funny. I kinda felt a bit pervy after filming them!

As I reflect on that event, pervy or not, I think that my video is the first time that anyone has captured this species spawning on video, at least to my knowledge, and at least on YouTube. I've searched high and low for videos on striped blennies, and there aren't many of them, and none showing spawning activity of any kind. I'm kind of excited about it.

My next goal is to catch the male successfully herding the female into the shell and begin the spawn. I've captured the herding activity, albeit unsuccessful, and I've captured the spawn successfully, but I want the entire event on film. I'm sure that I'll witness it, but having my camera ready is the key. I try and bring it with me each time I visit and watch my fish.

I'm sure that most people don't really care about this stuff, or how significant it is, and that's OK, because these fish, and many other temperate species aren't on many people's radar with regard to fish keeping. I feel obligated now to bring this and other wonderful temperate species into the public eye. If I can get a few other people excited about these fish, then awareness about them will increase for the sake of the species and oyster reefs in general. Why the need to do that? People who harvest oysters, even those involved in oyster conservation, just let bycatch species, like the species in my tank, fall out of the oyster baskets on dry land and just let them die, with little attempt to save them. I guess this is because they aren't "endangered" or "protected". Maybe if these people come across my videos, they'll see how cool these creatures are and give them the respect that they deserve. To all of those that follow my threads and videos, thank you for watching and participating.

[Michael Hoaster]

That's pretty cool! You're on the frontier of photography, for these fish and the oyster reefs in your area. That is something to be proud of. Chapeau!

[Chasmodes]

Thank you Michael!

Here's another video, just cruising the tank, checking up on the fish...
https://www.youtube.com/watch?v=skETBb9KXz4&t=15s

[Chasmodes]

I've posted a bunch of videos of late, and realized that I don't have that many recent pictures.

A lot has changed in the last 6 months. The fish are all full size adults now, and all three species are breeding. They have their favorite shells that they hang out in, and don't stray far from them, especially the male blennies. When these fish are guarding eggs, most of the time, only their heads peek out of their oyster shells. They venture out and check out their perimeter of about a radius of 4", now and then, and further only at feeding time. They will eat, then bolt back to their shell. The female blenny is the lone exception, as she roams the tank and breeds with all of the males.

Much of the tank range of these fish are determined by these established territories, and these territories seem to be based on a pecking order, with the blennies claiming the best spots and defending them rigorously, especially against each other. However, since they don't stray far from their shell, confrontations are few.

The three species, for the most part, tolerate each other except when a fish moves too close to their favorite shell, and is chased off. The pecking order appears to be that the blennies are the most dominant, but pretty equal against each other, followed by the skilletfish but not far behind. Male skilletfish tend to defend their shells rigorously as well. The gobies are probably the least aggressive, but very brave, as they will put up a good defensive front against the other species and try to chase them away. They tend to back down and flee if challenged in return, though.

The females of each species are the most mobile and hold more vague territories, not necessarily restricted to a single shell. Here are some recent pics:

Female striped blenny (Chasmodes bosquianus)


Male striped blenny:


Male striped blenny, guarding eggs:


Skilletfish (Gobiesox strumosus):


Female naked goby (Gobiosoma bosc), the males look the same but are a bit larger:

[Michael Hoaster]

Nice pics! Great update! It's hard to believe all that happens in a 20 gallon tank!

[Chasmodes]

Originally Posted by Michael Hoaster

Nice pics! Great update! It's hard to believe all that happens in a 20 gallon tank!

Thanks Michael. I'm pretty amazed that this size tank worked out so well. And, it's easy maintenance, really. I've been a bit lazy lately, but, with all fish seemingly healthy and breeding, why not just let nature take its course? Every time I get ready to do a water change, I see fish fry on the surface. I guess it shouldn't matter since they won't survive on their own anyway. I guess this weekend... I have had the same line of reasoning with regard to the cyano too. It's not really out of hand like it was before, and I think that is because the light cycle is shorter (3 PM until midnight), and I may shorten that. I guess I'll try a few things to reduce it a bit.

I really need to get to work on my build though. Right now, $ is extremely tight.

I had a thought last night, prior to me taking those pics, that maybe some people don't want to take the time to watch a video, and that maybe they'd enjoy seeing pictures instead, and I hadn't taken any in quite a while. I guess that is why they call pictures "eye candy" and don't necessarily do the same for videos.

[Michael Hoaster]

I would imagine that you're learning a lot from what you've got going on in that tank, that will help you with the big one. You're gaining valuable experience.

The money thing is always an issue for me too. That's probably why I keep my setup so simple, and do a bunch of DIY stuff. Maybe there are some zero-cost things you can do, to make some progress and get you excited.

Good idea posting some pics. I like the vids too. They do take a little more commitment to watch, so a balance of both makes everyone happy. I should post more vids.

[Michael Hoaster]

Whoops, double post. RC can go wonky on you, but it's good to be here!

[OllieNZ]

Very cool build and fish. Definitely good to see something outside the norm.

[Chasmodes]

You're right Michael. Right now, getting the electrical work done is my biggest hold up, and buying materials for the DIY piece (lumber, etc.).

Thank you Ollie!

[McPuff]

Those gobies are great! Assuming they would not do too well in warmer waters... is this true? Same for the skillets. I'd add some to my tank if they were available.

[Chasmodes]

I think that they'd all do OK in warmer water. The naked gobies and skilletfish are also found in Florida. The blennies can be found from Delaware all the way down to Cape Canaveral, Florida, and two other blennies in the genus can be found in other Florida and Gulf waters. These fish can be found in the shallows in the summer in the Chesapeake, and during hot summers, the temps can be in the 80's. These fish live in extreme conditions, from cold winters through hot summers in our area. I don't see any problems with them being able to adapt to a warm reef life.

[McPuff]

Originally Posted by Chasmodes

I think that they'd all do OK in warmer water. The naked gobies and skilletfish are also found in Florida. The blennies can be found from Delaware all the way down to Cape Canaveral, Florida, and two other blennies in the genus can be found in other Florida and Gulf waters. These fish can be found in the shallows in the summer in the Chesapeake, and during hot summers, the temps can be in the 80's. These fish live in extreme conditions, from cold winters through hot summers in our area. I don't see any problems with them being able to adapt to a warm reef life.

Very cool. I'll have to see if I can find a way to get some, perhaps in the spring.

[Chasmodes]

Are you thinking of coming down this way? Let me know if you do and I'll take you to my collecting spots.

[McPuff]

Originally Posted by Chasmodes

Are you thinking of coming down this way? Let me know if you do and I'll take you to my collecting spots.

Not that I know... but who knows, I may find a car that I need and it happens to be in Maryland. :0)