Mackerel’s life is more or less vertical: he goes down for adventure and up for the security of warmth and light. In his oblivion, Mackerel only knows two things for sure, and both are temporal, secular, reassuring as tides: he knows when he is hungry, and he knows when he is alone.

Some facts about Mackerel: He belongs to the family Scombridae, order Perciformes, whose members are found in the world’s temperate and tropical seas. Streamlined, his firm foot-long body is blue-green above and white below, and he sports a few pinstripes toward the front which are evidence, he believes, of his good taste and discretion. As for the rest, he is shaped like a torpedo with a tail that begins slim and keeled, and ends in a fork. A fish-fork? Perhaps. You do well to ask; an omnivore, Mackerel eats whatever he can catch, mainly plankton, but also small shrimps and oysters and occasionally caviar. Unlike others in his family, he has no air bladder, and prefers it that way, so that in winter he may easily sink seventy-five fathoms in search of a more temperate zone. Members of his family include the extravagant, green-pigmented larking-chubs, the ceros, the kingfishes, and the mighty los comersodors, who tend to plumpness, and languish ever fatter in the warm waters to the south. Tunas are his next nearest cousins in the family Scombridae, but if, Mackerel by far exceeds them in intellect, the members of this branch of his family enjoy a vast advantage in tonnage and for this reason he prefers to leave them alone. A third group, even more remote, are the Rastrelligers; once, his friend Marty told him that, like the kingfishes, they tend to be outsized Scombridae, but because they swim in far-away rivers like the Indus and the Ganges they are also unsuitable for visits. Mackerel would have liked to know more about Scombridae, except it happened one day that someone pulled Marty’s number—yanked him straight out of the water, mouth-first—and Mackerel was alone.

Time was, Mackerel swam with a crowd: they were content to drift around near the top, watching the surface in shallow light. Hunger was a flicker on the lee side of the gills; lust, unheard of. Happy life! Once in a while, they bickered in a good-natured way about gossip they’d heard, most of which was clearly fantastic: the story, for instance, about films in the water that you couldn’t breathe through; the one about the perch who found himself thrashing against a wall he couldn't see; how someone else had been dragged out and tossed back in later, minus a good bit of his tail. Others, improving upon already adventurous reputations, bragged about the things they’d seen further below, where one thudded against mysteries in the dark, and green and yellow spotlights flamed and receded in the twitch of a lidless eye. Occasionally Mackerel heard stories about hard, shining, emptied objects that smelled oily and familiar, with edges sharp enough to sever a fin absentmindedly brushed against them, but he never met a finless fish who could substantiate the story.

Disillusioned, Mackerel dumped these friends, reckoning he was better off alone. Ever since, he’s been feeling strange. For instance, in his forward fins he sometimes feels a momentary ache, a stretching-pulling feeling; it’s strongest when the water gets shallow, or when he rests on the bottom in the sand. There he pushes his forward fins against the sea floor, feeling his body lift from the effort. It’s inefficient to be sure, but something about it reminds him of something else, something on the very tip of his adumbrated tongue—a tension between the top of his jaw and the place where his head joins the rest of his body. Then, with a flick of his back, the moment is gone; he swims away, jackknifing through dappled water.

He left his friends because their stories were nothing compared to the problem of living within an order, a cosmology. Looking up, he sometimes saw big fish floating like angels, oblivious of him until they got hungry. No one ever knew when or even if he would be chosen. But if that was bad, the hagfish were worse, spurning the living to feed on the dead. Once in a while, one of these loners was sighted boring its way through a carcass, working forward from the anus, the ever-emptier carapace madly bumping up and down on the sea floor. But, Mackerel thinks, one should not be too quick to judge. It is necessary to have some compassion, to imagine your otoliths in the other guy’s head. Certainly it was not easy being a hagfish. They had no jaws, and they didn’t dream of eating the way he did.

When Mackerel is especially hungry, he hankers for fare more exotic than what’s usually available. If the craving isn’t too specific, he satisfies himself with smaller comestibles, mainly silversides, insects, and the odd wayward undersized herring. When he eats, his jaw drops and his mouth forms a bony omega, into which the little fish sometimes swim. Upon feeling the tell-tale tickle, he shuts his mouth and works the booty down with the strong muscles in his throat. But sometimes even these meals—which are truly Scombridae banquets, as he well knows—fail to satisfy, and indeed Mackerel barely tastes them. Though he has no words to describe what he wants, his desire is specific, if only dimly sensed at the openings of pipes and drains. So while Mackerel trawls open-mouthed, he dreams of things he cannot yet name—sausage, mushrooms, cheese and crackers. But the time will come. Meanwhile he flips, burps, and continues dreaming of the table, a still life with pitcher of lemonade, lemon slices circling. When he eats herring, he dreams especially of mayonnaise.