Live rock and Mantis Shrimp

[Gonodactylus]

I'm curious how often people who purchase LR actually end up the proud owner of a stomatopod. Reading this forum, one gets the impression that just about every box brings a mantis shrimp or two. I find that surprising. Much of I work in the field involves pulling LR to the surface and smashing it to bits to extract all of the stomatopods. Some of my studiy sites are with a stones throw of Tampa Bay's culture beds. I will often break several hundred pounds of rock in a day and get only a handfull stomatopods. A typical yield would be two or three per 50 lb bag - and most of those are tine juveniles. I have a pretty good eye for finding stomatopods and rocks that they occupy and I just don't find the densities that these reports of mantis showing up in live rock suggest.

Roy

 

[mogurnda]

In case you need negative data, I got zero in 40lbs of TBS live rock.

 

[Kara]

I have 50lbs of live rock and never got one.


I called all my LFS (froom West Palm Beach to the Keys) to find a Peacock Mantis. In my conversations with the LFS people, one of them said...

'We are ordering about 400lbs of Tampa live rock. We always get a few of them that are crawling around in the bottom of the shipping boxes. Give us a call next week.'

I can only imagine how many are still in the rock!

He also said I was the 4th person to call them looking for a Mantis Shrimp!

 

[Creade]

badluck

badluck

I used to run a pet store, and have an insane amount of liverock myself. Ordering about 100lbs of liverock every 2weeks for a year, Id never seen one until they showed up on a stock list to order. /shrug Bad luck maybe! (back then it was good luck)

Creade

 

[Osprey]

I have "rescued" 4 found mantis shrimp from stores over the last 10 years but I have not brought any home unintentionally in the rock I have purchased.

 

[lllosingit]

I found 3 so far in 50Lbs TBS live rock 2 large 1 small.

 

[slylie]

I've found none. I don't know anyone personally that has found one. Maybe by the time the liverock makes it up here to canada the stromopods die?

Also, I live in toronto, and there is plenty of marine FS, but none seem to have Mantis-es...

 

[zhorne]

I just got 30lbs from Gulf-View and got a single Mantis, along with 3 starfish.

 

[jdieck]

Got one mantis in 330 lbs of fully cured LR.

 

[Squidman]

1 mantis in 120 lbs. of Fiji(?) LR. I didn't think mantis's were supposed to be in Fiji.

 

[Gonodactylus]

O.K., I'm starting to get the picture and it is not much different from what I find in my collecting from these areas - one adult animal in every 5 - 10 pieces of LR.

Neogonodactylus wennerae are tough and "lightly" curing LR doesn't get rid of many of them. Unless the rock almost completely dries, they can remain in their cavity for hours - even days. All that is necessary is that the gills remain damp and that the temperature doesn't drop below the mid-60's or above the mid-90's. I have had animals survive for two days in a rock sitting on a dry bency in my lab.

Roy

 

[isildursbane]

I think the question that needs to be asked, is why are you breaking several hundred pounds of rock into bits on our reefs? I live in Florida, and I value the Reef ecosystem. I think you should reexamine your research, and take a much less destructive route.

 

[Gonodactylus]

We use stomatopods to monitor the health of biological structured habitats like live coral reefs and sea grass beds which should not be destructively sampled. Dead coral and coralline algae rubble (what is sold as LR) is a renewable resource. Natural beds turn over frequently due to burying and unburying, etc. and if there is loss, it can be replaced using natural bleached rubble from shore or quarried carbonate. In fact, I testified and some of our studies looking at the fate of LR using tagged pieces were used several years ago when the decisions were made on the harvesting of live rock and approval to culture it. Because stomatopods are mobile predators that live in association with reefs or sea grass beds, are abundant, and live sufficiently long to provide demographic data on recruitment and/or episodes of mortality, they have been very useful in tracking the health of these environments without the need to rip apart live coral or sea grasses.

About all else that I can say is that we have all necessary state and federal permits to conduct the monitoring and stricktly adhere to the provisions in those permits.

Roy