Mantis Shrimp: Haptosquilla trispinosa

I am going to start building a collection of posts about specific species of mantis shrimp; including photos, general information, and the research that they have been a part of. I will make an index for these posts and update them periodically with additional information. First up is the mantis shrimp that I spent most of my summer with:

Haptosquilla trispinosa

Haptosquilla trispinosa

  Stomatopoda (Order)
    Gonodactyloidea (Superfamily)
       Protosquillidae (Family)

Adult size: Up to 44 millimeters
Distribution: Northeast Australia,
                    East Indonesia

General information and care: Roy’s List

H. trispinosa is very common at our field site, living in small burrows in coral rubble. We typically collect them from intertidal habitats, but they can be found deeper as well. Though they appear a drab tan or cream color at first glance, they actually have some beautiful color accents up close. These include orange antennae, blue spots on the back, and beautiful blue maxilliped mouthparts that are held front and center, just below the head.

A clearer, slightly enhanced view of the blue maxillipeds.

Much of the recent research on this mantis shrimp has focused on these blue maxillipeds. The light coming from them is polarized and they are almost certainty used for visual communication. Also, their wide habitat depth distribution has made them ideal for studying the adaptation of photoreceptors to variable light environments through tuning of light filters in the eyes. Social interactions and chemosensory have also been studied in H. trispinosa.

I predominately use these animals for behavioral learned choice experiments, in which I train them to associate a food reward with a particular light stimulus. Thus we can ascertain the functional limits of their visual systems. These experiments exploit the intrinsic predatory behavior of this mantis shrimp. For the majority of the day they will sit in the entrance to their burrow, scanning the water column for a potential snack. When something delectable drifts by, they lunge out, snare their target and dive back into their burrow. This behavior, called “hawking”, gives us a clear response when we present them with a stimulus choice.

Here is the best video I managed to get fo this behavior from an animal in one of my artificial burrows in an aquarium:

Selected research about H. trispinosa:


Brutal

Epomis beetle larvae eating a toad.

Apparently, there is a genus of predatory ground beetles, Epomis, whose larvae specialize in snaring and consuming amphibians alive through prey-reversal. They lure the unsuspecting tetrapods in by acting all prey-like, wiggling around in a seductive dance, but when the amphibian attacks, the beetle deftly dodges and counters. The beetle latches on to the side of the amphibian’s mouth and begins to dine. In all 420 predatory events in a recent study, the amphibians failed to snag the beetle larve, and were themselves consumed.

You can read more and watch some videos at Wired, or check out the original research paper at PloS ONE.

I can’t find any information about these beetles being found in Australia, so hopefully Plugg is safe… gulp

The evolution of vision, now in info-graphic

Check out this great graphic detailing important steps in the evolution of a visual system, created by Voltier Creative:

I think it does a really good job of presenting the classical example of eye evolution by gradual changes, each stage of which is observable today in nature. The only thing I take any exception to is the “most evolved” statement regarding the mantis shrimp eye. Truth be told, many biologists use the same language when talking about any especially complex biological system. However, that doesn’t really sit right with me. Everything has been evolving for exactly the same amount of time. Nothing is more or less evolved, and complexity does not necessarily mean that more evolutionary “work” has gone into it. Modern animals with less complex eyes, like Euglena, are not less evolved; their visual system is continuously evolutionarily tuned to be as close to ideal for its lifestyle as possible.

A better way to put it would be something along the lines of, “mantis shrimp have the most diverse photoreceptor array of any animal.” Furthermore, mantis shrimp don’t really represent sight perfection either. Because of damning resolution limitations inherent of compound eyes, almost any animal with a camera eye has much better spatial resolution. Even through they have the second best spatial resolution among animals with compound eyes (behind dragonflies), mantis shrimp are still well below humans in that regard.

Field Notes: Pop-quiz

My stint in Australia has been extended by two weeks to finish up some behavioral work. Since I’ve finally got the shrimp circus preforming, it would be a waste to pack it up with so many experiments left to do.

In the mean time, here is a little pop quiz:

Who can tell me what this is?

???

Field Notes: Prepare for cuteness overload!

Here is a set of adorable (non stomatopod) animals that I have come across here at Lizard Island. I know, only two are arthropods, and I don’t usually like to post about cephalopods that aren’t being bludgeoned to death by mantis shrimp, but these are still really cute/awesome animals.

A baby blenny that rode our salt water system into the aquaria facility. Luckily he dropped into a cleaner wrasse tank, and not one of my mantis shrimp tanks.

A swimming isopod, caught at night. Many pelagic nocturnal creatures are attracted to light, so we bring them in with dive lights and scoop then up with fine mesh nets.

One of the thousands of small skinks around the station.

A baby cephalopod caught during a night dive. It is about a centimeter in size a is disgustingly adorable. Squeee! Check out the chromatophores and iridophores.

Finally, an ant that I found chugging the ink out of my fountain pen for over an hour last night. Its abdomen is usually brown, but has turned dark black as it filled with ink. Eventually she just wandered off, to a fate unknown. You may also notice some raw SCIENCE! in the background.

Field Notes: What’s a half-billion years?

Two mantids, cousins hundreds of millions of times over.

Convergent evolution is fun!

Taking this crummy photo was not fun, however. These were probably the two least cooperative subjects I have ever tried to work with. People in the movie biz harp about the inherent difficulty in filming animals and children. Well these are two petulant, child-like animals that had no interest in participating in my attempt at creating a cheesy, gee-wiz Powerpoint intro slide. I was literally sweating trying to herd these two into decent poses.

Field Notes: Under the sea

I’ve been pretty busy lately with my work, but I’ve had a little bit of time to explore the reefs around Lizard Island and make use of our new underwater camera (Panasonic Lumix TS3). Here is a collection of my favorite photos from under the sea:

A pretty bit of shallow reef, right off of the research station beach.

A Moorish Idol couple.

Some small fish hovering above their coral head sanctuary.

Pink Anemonefish and their so-neon-yellow-it-looks-fake anemone.

More beautiful reefiness

Red fan coral

Giant clam (Tridacna) with brilliant electric-blue patterning.

Plugg plugging.

Field Notes: Plugg

Meet Plugg:

Plugg

Plugg is a green tree frog (Litoria sp?) that lives in our bathroom at the Lizard Island Research Station. Here he is perched on our sink, but his favorite spot is over the shower drain, hence his name. We like to think that Plugg it is the same frog from year to year. He’s definitely pretty cute for a chordate.

Field Notes: The beast’s lair

Yesterday, we took advantage of spectacularly low tides to scout out some Lysiosquillina maculata burrows on the mud flats.

A monster lives here.

Sure, it doesn’t look like much, but the sphincter shaped hole is deceiving. That is just the tiniest opening for the eyes of the monster that lurks below: the largest known species of mantis shrimp.

Anyone home?

The burrow and the door is made from mucus excreted directly from the mantis shrimp. The burrows go down up to 75cm (corrected from 2 meters as per the comments below), and typically contain a mated pair of mantis shrimp. The male, with larger eyes and raptorial appendages is on top, and explodes out through the entryway if any fish happen past. The female is usually below tending to the eggs, and only hunts if the male is gone. Currently it is believed that these animals mate for their lifetime, which is likely on the order of several decades.

I’ll be coming back to these flagged burrows when the tide comes up tomorrow to see if anyone is home. You may be interested to see what we have to do to catch them.

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