Fishy Dreams continued

After waking up from the fishy dream I wrote about last week, I leaped out of bed, flew to the pet store, and came home with a Betta. His tiny body is the blue-black of a moonless night, but his translucent fins and tail are the blue of the stained glass windows of Chartres. I have named him Tristan.

I have furnished his watery home with a layer of aquarium gravel, a couple of plants, and a cave-like gizmo where he hangs out when he feels the need for privacy. Bettas are notoriously undemanding, but because of their tropical origins I have given Tristan his own little heater to keep the water between 70F and 80F. And because I worried that the cat Telemann would harass him, my spouse made a wooden lid for the vase, with a little knob for a handle. So far, however, Telemann has only shown interest in the jar of fish flakes.

I’ve been reading up on the aptly named Betta splendens, which evolved in the swamps and rice paddies of Thailand and Vietnam. As such, they can tolerate stagnant water with low oxygen content (not that Tristan will ever have to worry about that). In addition to getting oxygen from the water through their gills, in the traditional manner, they have a lung-like labyrinth organ that allows them to get oxygen from the air as well. In a way they are almost amphibians, which would explain some of the curious stuff I’ve been learning about them.

For example, one of the best predictors of Betta longevity, aside from clean water and a moderate diet, is mental stimulation. People train Bettas to swim through hoops, jump out of the water for treats, and toss around a ping-pong ball. One study used them to model the effects of Prozac, since their serotonin transporter pathways are comparable to ours (Prozac decreased aggression in male Bettas). But how big can a Betta’s brain be? The size of a sesame seed? It’s obviously big enough for some to learn circus tricks, and for my first Betta to fulfill his emotional needs by swimming to my submerged finger to be petted.

If you are thinking that getting Tristan an Isolde to keep him company would be a good idea, it would not. Bettas have weird reproductive habits, so weird that one wonders if natural selection was napping while they evolved.  First the male makes a bubble nest that floats on the surface of the water. Then, to stimulate the female to lay eggs, he loops himself around her in what is known as a “nuptial embrace.” Ecstatically entwined, they sink to the bottom. He fertilizes the eggs as they emerge and then chases her off before she has a chance to guzzle them down (in an enclosed space, he will kill her if she can’t get away). Then, exhibiting a great deal of self-control, he carries the eggs in his mouth, deposits them in the nest, and guards them until they hatch.

Isolde being out of the question, I’m looking for other ways to keep Tristan entertained. I keep him next to my computer, and for the past few days I’ve simply been putting my finger against the glass, hoping that he will approach to investigate. Just now he came up and hovered close to it, which is a first. Then he swam away, flaring his veil-like fins while I stared and wondered at his sapphire splendidness and the workings of his teensy brain, and made a note to get him a ping pong ball to play with. On the whole, I think Tristan is having a pretty good time—and so am I, though the writing is definitely suffering.