Category Archives: Bony Fish

The Monster’s Veil

“Ugly food is good to eat.” You’ll find variations of that phrase in cultures around the world, particularly among cooks with a good sense of flavor and a lousy sense of decorative plating. Lumpy brown risottos with chunks of curious fungus might just be a truffle explosion, and properly-cooked soul food should arrive as one edible, semi-solid stain, falling out of the bun and preferably off the plate. The other day I found myself eating dinner with a friend of Korean descent, who cooked the gathering of friends a meal of bibimbap and stuffed kelp rolls that was both visually beautiful and gastronomically delectable. Offhand, I asked him what kind of fish was in the rolls. It was a dark, oily, muscular flavor; soft on the tongue but strong on the nose, deliciously assertive about its identity but frustratingly unfamiliar to me. “Monkfish,” he replied.

“Aha!” I said. “Damn, monkfish is good.”

We half-nodded in agreement.

“Pretty damn ugly, though.”

We half-nodded in agreement.

The next day, by chance, I ended up at the New England Aquarium, and was reminded that “pretty damn ugly” is an insult to pretty damn ugly fish.

Come closer, little girl...

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A Natural History of Leopard Print

As both an animal enthusiast and a rockabilly aficionado, it should come as a surprise to no one that I am a huge fan of leopard print. The primal power of leopard print is rooted in two wildly divergent strains of retro glamour, simultaneously stirring up cultural memories of a time before color photography and a time before agriculture. It is 1955 C.E. and it is 19,055 B.C.E. It is Cadillacs and wildebeest, hippies and hunter-gatherers, Zulu royalty and the Rolling Stones, Mickey Hartigay & Jayne Mansfield and Adam & Eve.

And part of me wishes they HAD been Adam & Eve.

Leopard print has never gone out of style — and has probably never not been in style, somewhere on Earth. (Many paleontologists believe that dinosaurs wore leopard-like spots.) Perhaps the reason for its endurance is that its parents are these two very different nostalgias. One is a deep-seeded yearning for the Paleolithic and pre-civilization, a length of time far longer than post-civilization humanity, when we as a species were in a more even conversation with nature and depended more on our physical prowess, our animal senses, and our understanding of the wilderness. To be sure, there are many people on Earth who are not far removed from this lifestyle, but for those of us in the “first world,” nostalgia for the time of spears and shamans exists as a distant cultural memory, perhaps stitched into the threads of our genetic code, like a dream we can’t quite remember yet which tugs on our hearts upon waking. We cannot shake the feeling that something, somehow led us astray from our true identity as the human ape, and adorning ourselves in leopard print reminds us of our species’ connection to wildlife of the world and our once-intimate relationship to it.

The other type of nostalgia, of course, is this:

My perfect world: 80% leopard print, 20% babe.

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In a recent visit to the Mystic Aquarium in Connecticut, I saw beluga whales. I saw Steller’s sea lions. I saw stingrays and sharks and electric eels. But nothing captivated my imagination like the school of homely mudskippers staring out at me from the water’s surface… from both above, and below.

"And I'm not impressed with either half."

The Four-Eyed Fish (Anableps anableps) of Central and South America does not actually have four eyes, but does indeed have four pupils. Each eye’s two pupils are divided by a span of iris. Four-eyed fish prefer to sit at the surface of a still pool in a brackish mangrove swamp, watching for insects to eat both above and below the water surface, and so their eyes are only half-submerged. The two pupils of each eye, therefore, not only watch the surface from both above and below it, but are calibrated to view both air and water differently. The lenses in the eyes change in thickness from top to bottom to account for the different refractive indices of air and water; as anyone who’s tried stealing quarters from a mall fountain knows, water tends to warp and slow down light when viewed from above, making objects underwater seem out-of-place. The optical illusion persists viewing the airy world from underwater. The four-eyed fish can view both sides without a bent image at all. So, two eyes, four different fields of vision, all blended into one seamless image in the four-eyed fish’s brain. Essentially, it has its own bifocals. Or, better yet, you know that look a teacher gives you over her glasses when you’re really in trouble? The four-eyed fish is that teacher.

Does myopia persist in our species due to sexual selection?

Consider for a moment the genius of this adaptation. The four-eyed fish is literally looking into two different worlds at once. Perched at the water’s surface, its eyes half in and half out, it simply splits its vision. Like a medium with half her mind in some spirit realm, it can foresee both fortune and doom, predators and prey from either world with uncanny accuracy.

"You will kill your father and marry your mother. Also, you need to tie your shoes."

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Five Feet High and Rising

The creek behind my uncle’s house here in Western Ohio is flooding; normally a laconic and nameless little tributary with quietly dipping mallards, last night’s thunderstorm and rapidly melting snow has raised the water level almost twelve feet and transformed it into a swollen, churning torrent. As I sit here watching the lawn furniture and Fisher Price playsets rush downstream, I thought it’d be appropriate to talk about animals for whom floods are home.

I’ve written before about the flooded forests of the Amazon basin, the Amazon river dolphin in particular, but it’s worth another visit. The Amazon is sometimes referred to as the River Sea, and the reason why becomes clear when the water level rises 30 feet and covers three times its already substantial area. During the Spring floods, a gondola navigating the trees in the rainforest might come upon a pair of giant otters chasing each other through the water, or glide into a mysterious pool of shimmering gold which, on closer inspection, turns out to be a school of piranhas. Here in the varzea, the underwater forest, the Amazonian manatee does the dead man’s float while grazing on submerged meadows, and the anaconda rolls like water boiling. And if you’re lucky, you may find the dragon of the Amazon: the arapaima.

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The Fish That Climb Trees

All children are essentially monkeys. Ever since I was tall enough to reach the lowermost branches of a tree and strong enough to swing myself up, arboreal life was the life for me. I remember climbing the mastheads of swaying pines, reading books in the crooked elbows of maples, and challenging myself to steal the most unreachable apples. I felt safer in trees; they seemed less like a high wire and more like a net to me. They held me safely out of sight of real siblings and imaginary enemies. They put me closer to the birds I loved. Throughout my childhood, I felt myself pulled up into the treetops by some plant magnetism, and pushed up there by some rambunctious animal urge.

I may need a boost.

I want to go to there.

When I went to college, I decided to study canopy ecology. And one of the things that sparked my interest was a story I heard from a professor about fish living in the trees. It went like this: when the Amazon River floods, the water level can rise enough to temporarily cover the lower branches of trees. Small fish, my professor told me, will sometimes lay their eggs in the submerged bromeliads on the tree branches, and when the floodwaters subside, the eggs hatch in a leafy fishbowl of water, replenished by rain and oxygenated by the plants themselves. Voila, fish in the trees.

Of course, I can find ZERO evidence to support this claim. And if fish ever do wind up imprisoned in tree branches, it would be by accident; after all, guppy fry in an epiphyte would soon make a nice snack for a hungry coati. But it turns out that there are a few fish in the world who head for the trees on purpose. Their existence challenges the public preconception about the definition of “fish,” and serves to help us understand the soul of a tree.

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Fans of the Hitchhiker’s Guide to the Galaxy will remember Slartibartfast, the planet architect who was very proud of his award-winning design for Norway. The fjords, he explained, were designed to give the continent a “baroque” feel. And a fjord is indeed a very splendid thing. A fjord, by definition, is a long and narrow inlet to the sea, flanked by very steep cliffs, and carved by glacial activity. (Or Slartibartfast.) While Norway coined the name “fjord,” they have no trademark on the geological flourish. You will find fjords anywhere there are mountains that meet the sea, and freezing temperatures to support glaciers, including the coast of Chile, New Zealand, and the Northwest coast of North America.

First Prize!

From time to time I like to take electronic expeditions to rare places on Earth, to see what I can find. Readers know I have a passion for fractals, and subscribe to something I call Fractal Earth Theory; the theory that the patterns of the planet are self-repeating ad infinitum. It was thinking about the true lengths of coastlines that led Mandelbrot to discover fractals in the first place; fjords make for rough edges in the world, wrinkling the land into a series of nooks and hidey-holes in which any manner of animal might live.

Today, we look for the unique wildlife of the fjords. I use a basic set of hypotheses as a compass:

1. Wherever life can exist, life will exist.
2. Where ever a habitat is geographically separated in any physical way, unique life will exist.
3. The more severely isolated a habitat is, the greater the number of unique species.

Fjords, however unique as geologic structures, are not very isolated: their cliffs connect with the mainland, and their inlets connect with the ocean. Their main aspects of geographic distinguishment are the steep angles of their cliffs, on which only certain wildflowers can grow, and the murky, silty, brackish water below. Fjords are often estuarine, with freshwater running as a river into their channels, which will certainly exclude many sensitive saltwater animals. The turbid, murky water is caused by violent tidal action, which in turn is caused by the water rushing over the lip of the terminal moraine left by the glacier at the fjord’s edge; this turbulence may also make the habitat even more exclusive, and more unique. But all in all, a fjord is not as isolated as a lake or an island, and we can’t expect a great number of unique species. But a few, sure. Some modifiers to the original compass:

4. The cold temperatures and low salinity will lead to a lower general biodiversity for animals, compared to a tropical habitat.
5. The cold water, with its high level of dissolved oxygen, will nonetheless support a high overall biomass.
6. The prediction of high aquatic biomass makes it more likely that any unique species are aquatic.

With these in mind, we set out to explore the nooks of the fjords, seeking life found nowhere else on Earth. And what we’ll find is a series of ecosystems among the most mysterious and little-known in science.

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The Glass Menagerie

“Is there such a thing as an invisible animal? In the sea, yes. Thousands! millions! All the larvae, all the little nauplii and tornarias, all the microscopic things, the jelly-fish. In the sea there are more things invisible than visible! I never thought of that before. And in the ponds too! All those little pond-life things—specks of colourless translucent jelly! But in air? No!… If a man was made of glass he would still be visible.”
–H.G. Wells, “The Invisible Man”.

I have written about invisible animals before, and all the ways in which one can become invisible, of which transparency is only one. I’ve spent some time thinking about transparent animals, from the Glass Frog of Central America:

to the Glass Squid of the deep oceans:

The transparency of the frog is obvious as a means of camouflage, but it is less certain in the case of the squid. Does its transparency serve to make it invisible? Or is there simply so little available light that producing pigments of any sort is wasteful? A great number of deep-ocean animals are transparent, including the Phronima, a type of amphipod with a glass-like exoskeleton, and the sea cucumbers which make up 90% of the complex animals on the abyssal plain. But the depths are not the only dark places on Earth; in the subterranean grottoes live the “troglobites,” animals adapted to the life in the sub-basement of the world:

The Alabama Cave Shrimp:

The Transparent Cave Crayfish:

And the Glass Goby:

Where these animals live, there is not even a stray photon bouncing off the stalactites, and so even the term “invisible” is inherently useless. There’s no such thing as “visible” there. To make an admittedly silly pop culture reference, I’m reminded of the character Invisible Boy from the 1999 film Mystery Men. On a team of quirky superheroes with dubious “powers,” Invisible Boy’s abilities are the most useless: He can only turn invisible when no one’s looking. The majority of “invisible” animals have the same superpower: their transparency is just a by-product of another adaptation, because where they live, nobody could see them even if they were day-glo orange.

“Visibility depends on the action of the visible bodies on light. Either a body absorbs light, or it reflects or refracts it, or does all these things. If it neither reflects nor refracts nor absorbs light, it cannot of itself be visible. You see an opaque red box, for instance, because the colour absorbs some of the light and reflects the rest, all the red part of the light, to you. If it did not absorb any particular part of the light, but reflected it all, then it would be a shining white box… A glass box would not be so brilliant, not so clearly visible, as a diamond box, because there would be less refraction and reflection. See that? From certain points of view you would see quite clearly through it… And if you put a sheet of common white glass in water… it would vanish almost altogether, because light passing from water to glass is only slightly refracted or reflected or indeed affected in any way.”

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