Happy Valentine's Day! Rock-paper-scissors, anyone?

Forget about love, flowers, chocolates, teddy bears, etc. etc. Common side-blotched lizards decide on their Valentines by playing rock-paper-scissors. True story.

Here are three specimens of this species, Uta stansburiana, from our collection, HERR 7589, 7594, and 7595, collected in Texas in 1971:


So the way this crazy love (or not... love...) game works is like this. Male common side-blotched lizards come in three different forms. There are orange-throated males, yellow-throated males, and blue-throated males. Here's a pic, taken from the website of Barry Sinervo, one of the biologists who first figured out the rules of this lizard's game.


Orange-throated males are largest and the most aggressive of them all and as such they're able to defend large territories with lots of females in them. They can easily overpower the blue-throated males, which are of a medium build.

Orange-throated males cannot defend against yellow-throated males, however. Yellow-throated males are the smallest of them all and look like females! Given this, they're able to sneak into the territories of orange-throated males unnoticed and mate with any of the females there who might be tired of bloated orange-throated machismo.

The stealth strategy of the yellow throats is powerless, however, against the medium-size blue-throats. The blue-throated males keep small territories and work together to guard their females. As a result, the yellow-throated males can't fool the watchful blue-throats like they can with the orange-throats.

So to sum up, orange beats blue, blue beats yellow, and yellow beats orange. Pretty cool if you ask me.

The success of these different mating strategies depends on the the rarity of each form in a given population. For example, if there are too many yellow-throated males, their "sneaker" strategy becomes ineffective, because well, it's not very sneaky anymore if everyone is doing it, too. So the prevalence of any given form will cycle every few years in a given population of common side-blotched lizards. In some years, there will be more blue-throated males, other years more orange-throated males, and in other years, more yellow throated males. When one form becomes too common, the others start to be more successful.

Sources:

Sinervo, B. and Lively, C.M. 1996. The rock-scissors-paper game and the evolution of alternative male strategies. Nature 340:240-246

Corl, A., Davis, A. R., Kuchta, S. R., Comendant, T. and Sinervo, B. 2010. Alternative mating strategies and the evolution of sexual size dimorphism in the side-blotched lizard, Uta stansburiana: a population-level comparative analysis. Evolution 64: 79–96.

Singing Toadfishes in Space

Like the Lizardfishes from a few posts back, here is another fish family named for a land-dwelling look alike. The toadfishes make up the family Batrachoididae and are benthic ambush predators that use their ugly appearance for camouflage as they lie in wait for their prey. They're quite hardy creatures, too! Some individuals have remained alive for more than 24 hours out of the water (Paxton and Eschmeyer 1994).

Here are some pictures of YPM 8923, species Opsanus tau, collected on October 6, 1932, off of Long Island, NY:





The most interesting thing about toadfishes, I think, is that they are known for their singing. During mating season different toadfish species produce a variety of sounds using their swim bladders. Opsanus tau in particular produces a loud "boatwhistle" sound that is famous for keeping people living near the shores of North America's east coast awake (Paxton and Eschmeyer 1994). It's no wonder that they make such a loud noise, too-- the muscles in their swim bladder that contract to make this noise are the fastest contracting vertebrate muscles known (they contract at a rate of 200 Hz). The next fastest muscles known are those at the base of the tail in rattlesnakes, and they only contract at half the rate of Opsanus tau's (Rome et al. 1996).

And yet another interesting fact about species Opsanus tau-- NASA has sent a bunch of these guys to space! NASA scientists use them to perform experiments designed to better understand balance disorders that affect astronauts in space. Why toadfishes for this task? The structure of their inner ear--the place that helps control balance--is very similar to ours, making it a good model organism. Who would have thought...


References:

Paxton, John R., and W.N. Eschmeyer. 1994. Encyclopedia of Fishes. Academic Press, San Diego.

Rome L.C., D.A. Syme, S. Hollingsworth, S.L. Lindstedt, and S.M. Baylor. 1996. The whistle and the rattle: the design of sound producing muscles. Proc Natl Acad Sci USA 93:8095-8100.

YPM ICH 5971 & 22495: Sea devils at the Peabody

Happy Halloween! In Halloween spirit, here are some ghouls and goblins:



Sailors dating at least to the 16th century would find these horrors at sea and often brought them back to shore as evidence for their stories of sea monsters, sea devils, and the like. What are they exactly? Called "Jenny Hanivers," they're actually just dried-out specimens of skates, rays, and guitarfishes!

Skates, rays, and guitarfishes make up the superorder Batoidea, and what you see in the pictures are the undersides of the animals. The nostrils and mouths of these creatures are positioned perfectly, as you can see, such that they look like a demonic face. (The eyes are actually on the top sides of the animals.)

Here is YPM ICH 5971, a guitarfish of species Aptychotrema vincentiana, collected in 1968 off the coast of Adelaide, Australia. Here's the underside of the animal, where you can see the "Jenny Haniver" face:


Here is the top side of the animal, where you can see the true eyes:


Of course, this specimen isn't properly a Jenny Haniver in the full sense of the term. But it's halfway there! To make a Jenny Haniver, once you've caught a skate, or a ray, or a guitarfish, you should dry it out, not fix it with formalin and preserve it with ethanol as we did with this one. It's when they're dried out that they really take their ghoulish shape.

You should then carve it and shape it to make it look even more grotesque. Sailors in Antwerp, Belgium, were famous for the Jenny Hanivers that they carved on their docks and then sold to superstitious tourists. In fact, it's thought that the term "Jenny Haniver" might come from these sailors. The French phrase jeune d'Anvers means ('young [person] of Antwerp'). The thinking is that British sailors then turned this phrase into the personal name "Jenny Haniver."

Here is YPM ICH 22495, one more almost-Jenny Haniver from our collection. It's a skate of species Bathyraja maccaini that was collected on a 2009 Yale research voyage to Antarctica. Here's its underside:


And here's its top side:

YPM ICH 7720 & 12449: Lizardfishes!

I'm afraid the title of this post gives it all away: these fish look exactly like lizards! Here is YPM ICH 7720, a lizardfish of species Synodus variegatus, collected in the Indian Ocean's Seychelles Islands in 1957:


As you can see, the head of a lizardfish looks, well, like a lizard, but they were actually named for their posture, which is also eerily lizard-like. They like to sit at the bottom of shallow seas in sandy areas, with their head raised like a lizard, propped up by their fins. Here's a picture that shows this:


The above shot was taken this summer by Alex Dornburg, a Yale Ecology and Evolutionary Biology Phd candidate, who was in Curacao collecting specimens for his research on marine fish macroevolution.

Many of our museum specimens are actually still preserved in the lizard posture! Here's one, YPM ICH 12449, species Synodus foetens:


Man, I wish I had posture like that. Mom would be proud....

Here's a final picture, a headshot of YPM ICH 12449:



Source:

Paxton, John R., and W.N. Eschmeyer. 1994. Encyclopedia of Fishes. Academic Press, San Diego.

Poll: Is our star-nosed mole hotter than the NYT's star-nosed mole?

My last two posts have touched on aesthetics-- namely two specimens that paralleled things in our human world that most of us would find aesthetically pleasing. Here I'm going to touch on aesthetics again, but in the opposite direction-- namely a specimen that is ugly! Well, ugly according to the New York Times, at least.

About a month ago, the NYT ran an article about the science of ugliness that examined why we find some animals to be attractive and cute, and others repulsive and ugly. In it, the star-nosed mole, Condylura cristata, was the posterchild for ugly animals. Here's the image of it that they featured in the article:


The scientists who were interviewed explained that we tend to be repelled by the star-nosed mole because the pink nose causes us to identify with it-- that is, flesh color reminds us of a human face-- but at the same time it is not what a human face should look like, which makes us recoil. Here are some tidbits from the article that explain this more fully:

The more readily we can analogize between a particular animal body part and our own, the more likely we are to cry ugly. “We may not find an elephant’s trunk ugly because it’s so remote,” Dr. Dutton said. “But the proboscis on a proboscis monkey is close enough to our own that we apply human standards to it.”

As scientists see it, a comparative consideration of what we find freakish or unsettling in other species offers a fresh perspective on how we extract large amounts of visual information from a millisecond’s glance, and then spin, atomize and anthropomorphize that assessment into a revealing saga of ourselves.

Later in the article Dutton noted that “No one would find the star-nosed mole ugly if its star were iridescent blue". I don't know of any blue star-nosed moles, but here at Peabody VZ, we do have a star-nosed mole that is completely brown! YPM MAM 5852 was collected in Old Lyme, Connecticut in 1940, and it's brown now because it has been preserved in ethanol, which has caused it to lose its pigmentation. Here are two pics:



So what do you think? Is this brown star-nosed mole as ugly as a live one with all of its pink and fleshy pigment? Or, without the flesh color, is it a bit easier on the eyes as the scientists from the article would predict? Please chime in! I think our museum specimen offers a fun test of their hypothesis.

YPM ICH 7062: More eel-imitating art

This eel, YPM 7062, is a reef dwelling species, Gymnothorax favagineus, and it was collected in the Indian Ocean's Seychelles Islands during the Yale Seychelles Expedition of 1957-58. It reminds me a ring that my best friend wears every once in a while. Here are two pics of the eel:




And here are two pics of the ring:



Certainly the artist who fashioned this ring wasn't directly inspired by this eel (well, maybe he or she was! I'm guessing not, though). But the precision of this convergent aesthetic, I think, is quite extraordinary.

Speaking convergent aesthetics, I think my husband wins the convergent aesthetic contest from my last post. We just found this picture of a steel floor. Pretty much an exact match to the scales of the Synaphobranchus kaupii specimen:

YPM ICH 13045: Art imitating eel scales

I am no artist, but I do remember a technique I learned in a middle school drawing class called cross hatching. This eel, YPM ICH 13045, is a cutthroat eel of species Synaphobranchus kaupii, and was collected on July 29 2002 by Jon Moore at a depth of 1388 meters at Bear Seamount, an underwater volcanic mountain in the Atlantic Ocean off the coast of New England. Its scales remind me of cross hatching:


Cross hatching is used in drawings to create dimension, depth, and texture. Here are two examples of it that I found using Google image search at this site and this site, respectively:



In a previous post I talked about convergent evolution, which is the phenomenon where similar biological traits and forms evolve in unrelated lineages. A great example of convergent evolution is the wings of birds and bats-- although they both have wings, their wings evolved independently. It is not a trait that they both have through common ancestry.

Cutthroat eels tend to dwell on the slopes of continental shelves, where it might be useful to have scales that create texture to blend in with habitat there (I couldn't find any studies discussing the function of the scales, but this is my hypothesis. If you're wondering if light penetrates at these depths, see the discussion in the comments below). As I mentioned above, artists use cross hatching to create texture in their drawings. These eels have perhaps evolved criss-crossed scales to create texture; humans have developed cross-hatching to create texture. I am going to dub this convergent texture creation! (Presumptuously assuming, of course, that my hypothesis is correct...).

Here are more pictures of the scales, along with a full body shot for scale (although these eels can get much bigger than this).




My husband actually thinks the scales look more like the texture of a common type of steel flooring (pictured below), rather than cross hatching. What do you think?