Clownfish

Most of the named clownfish in a shop are captive-bred colour lines of the ocellaris and percula: snowflake, picasso, black ice, the storms, DaVinci, platinum, mocha, Wyoming white and the rest. They are the same fish underneath and take the same care as a plain ocellaris, 3 inches (8 cm) and 20 gallons (75 liters), and they are among the hardiest marine fish sold. The maroon lines (lightning, gold nugget, gold stripe and white stripe maroon) are the exception: they are maroon clownfish and carry the maroon's size and temper. The catalog lists each designer form under its parent species so the care facts stay in one place.

Clownfish start life able to become either sex. In a group the largest becomes female, the next largest the breeding male, and the rest stay small; once a fish has become female it cannot go back. The way to get a pair is to buy two small juveniles of the same species at the same time and let them sort it out. Two adult females fight until one dies, two adults of unknown sex usually do, and different clownfish species fight in the same way. One species per tank, one pair per tank. The maroon clownfish is marked aggressive and listed as one to a tank: a maroon female rules a 40 gallon and only tolerates a male much smaller than herself.

Captive-bred clownfish have never seen an anemone and do not miss one; they host in a coral, a powerhead or a corner of the tank instead. The anemone is the harder animal by far: it needs a mature tank, strong light, stable water and a keeper who has already succeeded with corals. If you want the pairing, the bubble tip anemone is the one to try, marked medium, reaching 12 inches (30 cm) and listing 30 gallons (115 liters); the long tentacle anemone is the other medium option. The magnificent and sebae anemones are marked difficult, and the large carpet anemones (Haddon's, gigantea and Mertens') are difficult and eat fish. Each species profile lists which anemones that clownfish hosts, and every anemone profile lists the tank it needs.