Tropical Fish Hobbyist - October 2010

been immortalized on postage stamps in Vietnam (1984), the Ivory Coast (1981), and the Philippines (1993).

MP. & C. Piednoir

Rainbow shark E. frenatus; one way to tell a rainbow shark E. frenatus from a red-tail shark E. bicolor is that the pectoral, dorsal, and anal fins of the rainbow shark are red.

Rainbow Shark

A close cousin of the red-tail shark is the rainbow shark E. frenatus. The torpedo-like bodies of these two species are very much alike, as are the red colors of the caudal fin, the black of the body, and the sharp-edged finnage. They look so similar, in fact, that one is very frequently sold as the other in pet shops. Don’t be fooled, however. Although these two sharks look very much alike, the difference in their dispositions is like night and day. A sure-fire way to distinguish a rainbow shark from a red-tail shark is to look at the coloration of the pectoral, dorsal, and anal fins, which are all red in the rainbow shark and black in the red-tail shark.

Naturally occurring in the warm, sluggish
aquaria or those overpopulated with too
many fish will not make the best homes for
E. bicolor, as such conditions only stimulate
the shark’s aggressive nature. Expect your
shark to attack and kill several of its
tankmates under such circumstances.

An albino rainbow shark E. frenatus.

radical swings in water chemistry, which can be highly detrimental to any species of freshwater shark.

Bear in mind that your red-tail shark may nibble more than a little on any live plants in your tank; Amazon swords and other large-leafed varieties are particularly at risk. While one shark—assuming it is well fed on a diet of flakes, shrimp pellets, and freeze-dried tubifex or bloodworms—will not usually inflict a fatal level of damage on a plant, serious nibbling can cause brown edges and unsightly discoloration.

First described by Smith in 1931, the red-tail shark is, sadly, almost certainly extinct in the wild. Hundreds of thousands of these gorgeous fish are supplied to the pet industry every year by hatcheries and fish farms in Thailand and Malaysia. These sharks are so popular and so aesthetically pleasing that they have

Iggy Tavares

backwaters of the Chao Phraya, Mekong, and Xe Bang Fai Basins of southern Asia, these sharks are omnivores in the truest sense of the word: They will graze on algae and plant matter, they will scavenge on detritus and animal carcasses, and they will prey upon small invertebrates, fry, and amphibian eggs.

Not nearly as hostile or aggressive as its red-tail cousin, the rainbow shark fares well in community aquariums that do not have occupants boasting excessive finnage, such as bettas and fancy guppies, as those elaborately finned and slow-moving fish are ripe targets for occasional fin nipping. Naturally a secretive and retiring species, the rainbow shark also needs an adequate amount of hiding places, caves, and dark retreats in which it can escape the bustle and flow of the general aquarium.