He's a cheap pickup, just a $35.99 lifetime commitment, but the dogface puffer has plenty of competition at Beldt's Aquarium, a longtime North County institution tucked in a corner of a Hazelwood shopping center. Beldt's is where your Uncle Bob bought that tiny arawana that grew into the giant that ate Cousin Bobby. The retail store features more than 275 tanks stocked with salt- and freshwater creatures, including baby barracuda, lionfish, pillow starfish, red oscars, crabs, anemones, horned cowfish, foot-long plecostamuses and three-eyed glow-in-the-dark goldfish that sing Don Giovanni. (Amazingly, during our recent visit, we couldn't find a single floater!) Beldt's also features a small selection of reptiles, amphibians and birds, and behind the retail store is a sprawling tropical-fish wholesale business, one of the biggest in the nation. A visit to Beldt's is an easy way to sedate a six-year-old wall-bouncer -- Look, Ma, look at this one! -- but beware: It's awfully hard to resist the urge to buy a 1,000-gallon tank and stock it with piranhas.