THE AGE OF AQUARIUMS - It may be callow, it may be shallow, but lately you are nobody in this town unless you spend a good deal of time in the company of certain big fish. A tiger shark is most desirable (bad- boy radio host Howard Stern owns two of these fish-of-the-moment), but a dully glittering dragon-faced arowana will serve if you have a couple of thousand dollars. Carp are easier to come by; but you will make yourself ridiculous unless you build a Japanese koi pool in your living room to house them, with a silicon pond bed that has been entirely camouflaged by terraced Nipponese hemlocks (whose maintenance must be undertaken by a specialist).

Most people pinpoint the arrival of aquariums on the scene to the fall of 1995, when the up-market Barneys department store on Madison Avenue had two vast aquariums installed by a high-end fish curatorial service. Insecure customers who weren't sure if they were supposed to buy the tanks (they weren't) made enquiries to be on the safe side and, when they learned that they could possess a Jacques Cousteau-calibre waterworld for $10,000 or so, they called it a bargain. Before long, white-gloved fish technicians began ferrying plate glass, glue and nautical flora up and down SoHo, Park Avenue and Central Park West, bringing fish door-to-door for the inspection of the presumptive fish parents. Then, with the advent of the film Mission Impossible (in which Tom Cruise hurtles through a fish- filled restaurant picture window) aquariums flooded the sitcoms, and being aquariumless became a social disadvantage comparable to not belonging to a gym.

So New Yorkers were relieved when an aquarium-dominated bar called Orchard opened East of SoHo, allowing them to be seen in proximity to swimming fish; but by the end of January, Orchard had grown so overcrowded and underchaired that the fish were the only ones not forced to stand. At Greater New York Aquariums on 23rd Street, the staff maintained a mood of exultation for months. Manager Kerry Sprouse reports that women, who historically turn up their noses at fish husbandry, now routinely shell out generous sums for the new high-tech cabinet-built tanks, gourmet vegetarian fishflakes, Amazonian water supplements, and the glowing skulls that add menace to the underwater decor. Sometimes the fish manage to be more alarming than their surroundings, as in the case of the electric catfish - a bloated cigar with pinhead eyes and a nasty shock - and of the legendary meter- long Screaming Snakehead, Greater New York's most famous property, which kept patrons shrieking for years.

The Snakehead lived in a tank in the back of the store, David Mailman, who owns the business, explains. "We put a sign above it that said, 'I'm a Screaming Snakehead, I imitate the sound made by elephants at watering holes to terrify predators'." When a customer would stoop to peer at the grotesque creature an employee hiding behind a partition would suddenly bellow at the top of his lungs. "People's reaction was to scream," Mailman says. Sadly, the Screaming Snakehead jumped out of his tank one night and died, as he had lived, in silence. But whether New Yorkers invest in a Snakehead, a shark or a guppy, it's a comfort to know that when they tire of them, they will have an easy out; unlike a Dalmatian puppy - the last pet trend - they can always just flush them.