mantis fry

[DMBillies]

I was looking in my mantis tank today and there are what look like little mantis shrimp all over in the tank (I can't imagine what else they would be if they weren't). I shut off the filter on my nano so that they wouldn't get sucked in and cut the light because they were attracted to it. I've tried raising peppermint shrimp before, but I can't afford the space to try to raise these guys. So, I'm wondering if there is anything I might be able to do in the nano that would increase the odds that a couple might pull through.

Now for some more of the story. This "birth" is a bit of a mystery to me. We had gotten one mantis about 2 months ago from the LFS that was carrying eggs. After putting her in we saw her a few times and then she disappeared. We assumed that she just didn't make the trip from the LFS ok and a couple of weeks later we bought another one (I am reasonably certain they were both N. wennerae). We've had that mantis for about 6 weeks and we see it at least once a day. We've never seen it carrying eggs. There's also no way we are confusing one for the other (they were a little bit of a different color) and we still haven't seen the one that was carrying eggs when she was added. So, based on the reproduction and gestation period of mantis (I know nothing about this), which is more likely: (1) The original mantis is probably still alive and the eggs she was carrying two months ago probably hatched, (2) The second mantis was somehow fertilized prior to being added to the tank and has given birth, (3) There have to be two mantis in the tank still and whichever one released the fry had to have been fertilized after being added to our tank. Thanks, in advance, for any info.

 

[Pea-brain]

If they are mantises then they will be highly cannabalistic. If you want a few to pull through then you need the following: Some containers. The larger the better. A turkey baster. a bottle of selco, a brine shrimp raising kit, and an airstone and air pump. suck them up and put them in containers. only 1 to a container. get some brine shrimp nauplii and put them in a container and heavily airate while adding some selco. let sit for ilke an hour and then ad them to containers. An hour later do a 40% water change. you could add the brines to the aquarium directly after selco addition, but it unlikely any will survive. They will starve within two days if not fed. good luck.....

 

[DMBillies]

Well, they aren't great, but I thought I'd post some pictures. I labeled them with the parts of the body so that you can get a better idea of what you're looking at.

Thanks for the info on raising the shrimp. Doesn't sound all that different from raising peppermints other than the seperate container business. I just don't have the time/patience right now to see it through.

 

[Dakafall]

those look like just regular pods to me, from what i've heard, it's very hard, if not impossible to raise mantis shrimp

 

[justinl]

Brian, since you can get a better look at them than any of us via a pic, Google image search "stomatopod larvae" and you'll get a few good pics of mantis larvae. Do yours look like them?

Yeah i agree that it is hard, harder than fish, but still not impossible.

 

[DMBillies]

They look like they would fit somewhere in between the 3rd and 4th stage in the picture, but I'm not turning anything up that shows exactly what they look like.

They really do look a lot like an adult mantis except they are clear (other than their silvery eyes), have exagerrated limbs (i.e., they have what looks like raptorial appendages that fold just like an adults, but they are bigger in comparison to their body size... in my second picture you can see that the length is almost 1/3 of the total body length), and their eyes are spread farther apart than you would expect given an adults proportion.

I wouldn't absolutely rule out that it could be something else, but the rock has been in my tanks upward of 5 months and I've never witnessed anything like these before and the only other tank inhabitants are snails, hermits, and a damsel. It was mentioned that they might just be some type of pod, but they are about the size of a small adult amphipod and I think it would be very strange for a swarm of 100+ adult pods to just show up all at once like they did. They were also very attracted to light, which most pods don't seem to be all that much. If I turned on my lights they stuck at the top of the tank. When I would shut them off, they would swim down to a spot where a little bit of light was coming through the blinds. Also, amphipods look a lot more like they have small legs under them. These things had really small swimmers under their tails. They were also suprisingly good at swimming. When I turned my lights off they would go to the bottom of the tank (where a small amount of light was coming in through the blinds). Then, when I flicked the lights on, they would swim to the top of the water pretty fast. They covered the distance from the bottom to the top (~18") in probably close to 3 seconds.

 

[justinl]

Okay yeah the photopositive behaviour you describe definitely sounds like larvae. It also sounds like you have mantis larvae dueto the oversized raps. They do stay benthic (on the floor) for a while, but im not sure how long. Enough time to develop to the stage you desscribe? maybe, im no pro.

If you want to raise them I would definitely take them out and put them in separate tanks. Volume is not a consideration, it's just to separate them. Or else maybe you could figure out a way to keep them in the display with separation? Like a bunch of little closed mini tanks around the edge? You could just take out some water and throw it in the display and replace with new morning and night. It would greatly simplify water changes and maintenance i think. Id imagine each compartment would need some light bubble action or something? Any one else with experience wanna input on this?

 

[Gonodactylus]

They are gonodactylid larvae. Egg to hatch is 3 weeks with another week until the larvae molt for the third time, lose the yolk and become transparent, free-swimming larvae attracted to light. To my knowledge, there are no more than a landful of people who have ever successfully raised gonodactylids from egg to postlarvae. I've done it before with Gonodactylus chiragra and two labs that I know of have reared N. wennerae and N. oerstedii. The trick is to get them to eat the first week since they usually starve in two or three days after entering the plankton. Live rotifers and copepods are good items to start with.

Roy