Lysiosquillina Learning

[Gonodactylus]

A couple of days ago I posted a reply to a question about stomatopod intelligence and I made a statement about Lysiosquillids not having to learn very much - just sit and strike when the correct prey comes along. That got me to thinking that I had never really looked at learning in lysiosquillids, so I set up a quick test. Our large L. maculata are fed using a feeding stick. Several are quite good at picking a shrimp off the end with a strike as the shrimp nears the surface of the water. Going back to some trials I ran a few years ago with Odontodactylus brevirostris, I went down to the local crafts store and bought two day-glow colored plastic rods - one orange and one green. I attached a stainless steel wire to the end of each. They make great feeding sticks and they are much easier to find around the lab than the wooden ones we had been using.

For the training, I selected one of our more aggressive feeders and gave it a shrimp on the orange stick. A few minutes later I came by and waved the green stick with no food over the burrow. Over the next day when I was in the lab, I repeated this varying the order of presentation, but always with a shrimp on the red stick. After just a couple of trials the male started to come up out of the burrow and prepared to strike as soon as he saw me pick up the stick. There is much less of a response to the green stick. This morning I came in and presented the bare green stick. Interest, but no strike. I then picked up the red stick with no shrimp. As soon as it came close to the lid of the tank (which was still on), whack! He tried to spear the stick hitting the lid. I tried the same thing again a few minutes later with the same result. In just half a dozen trials he has learned the color discrimination and associates the red stick with shrimp.

I guess I will revise my statement about learning in L. maculata.

Roy

 

[Dave Legacy]

Hmm... very interesting. I practically have to stick the food in my L. maculata's face to get it's interest. Maybe it's because it hasn't learned that the feeding stick means food yet.

Thanks for the interesting info.

 

[Fella]

Wow, that's very interesting. I was thinking about the mantis ability to learn the other day and was considering a similar experiment. Using 2 different coloured containers, place food consistently in one. Add them both to the tank simultaneously, and let the mantis break them both open and discover the food contained within one (lets say for instance red). Then in future add the food to the other container, and see if the mantis chooses to check the red one first.

A similar experiment but one I had thought of the other day.

Sounds very interesting though Roy, thanks for the feedback.

 

[sandlot13]

thanks Dr. Roy! I love hearing about the experiments and information you have come across with your stomatopods... in fact, if you would want to share some more experiments or interesting results, Im sure a lot of people would love to read about them! Thanks for making this forum possible

 

[Gonodactylus]

A technique that we developed 20 years ago to look at learning in O.s involves giving them artificial snails that they have to open to get a piece of shrimp.l The "snails' are actually plexiglass cubes with a hole drilled in on side. The shrimp is placed in the hole and sealed over with a piece of glass. The animal selects the cube, hauls it back to its burrow and breaks the glass to get the meat. We present two cubes with different stimulii - color, polarization, symbol, etc and they have to learn which one to take. The wrong one has no shrimp inside. They learn this really quickly. Several stomatopod researchers now use this technique to test the sensory capabilities of O. s. A recent study showed that they could tell the orientation of polarized light.

Roy

 

[sandlot13]

seriously, thats so interesting!! It is stuff like that which makes me want to pursue this hobby and turn it into a career..... thanks Dr. Roy

 

[venwu225]

you are awesome. so is what you do.

Are there lots of publications on classical conditioning of stomatopods?

Also have you been injured by your Lysiosquillinas ever?

 

[Gonodactylus]

Aside from an early paper where I described the use of artificial snails to demonstrate color discrimination in O. scyllarus, the most recent papers were by Marshall showing the ability to distinguish between different patterns of polarization.

The worst injury I have ever gotten from a stomatopod was indeed from a large (32 cm) male Lysiosquillina maculata. However, it was not from being struck. I was holding the animal in my bare hand so that it could not strike, but it jack-knifed its abdomen and its uropod spine sliced open the entire length of my index finger.

Roy

 

[sandlot13]

wow! you hold your mantis shrimps? thats crazy (and probably not a good idea to let everyone know its possible, cause i bet someone unqualified is going to try it and get lit up!) haha