Rainbow Shark

Scavenging for food in the gravel, Soumyakundu's Rainbow Shark is a beautiful example of the Epalzeorhynchos frenatum species. A member of the Cyprinidae family, this fish is commonly stocked in the freshwater community fish tank.


The rainbow sharks blackish-green body is accented by colorful reddish-orange fins. Also known as the Red-finned Shark, or Ruby Shark, this fish is primarily a bottom, and mid-level dweller. They're happy eating most anything. Spinach, lettuce, tubifex worms, algae, and leftover fish food, make them happy.

The Rainbow Shark is a semi-aggressive fish, which can also be very territorial. It's suggested you have just one in the tank, and fish in similar size. Also, it's best to avoid combining the Rainbow Shark with other freshwater sharks, such as the Red-Tailed Shark and Black Shark. Here are a few more characteristics to consider:

  • Grows to 6 inches
  • Tank parameters: 73-80 F; pH 6.5-7.5; KH 10-15
  • Minimum tank size is 30 gallons; 50 gallons preferred
  • Requires moderate care
  • The rainbow shark is an Omnivore

Rainbow sharks are compatible with most barbs, danios, loaches, plecostomus, and the gourami. You just have to make sure and leave them space to establish a territory.

Breeding the rainbow shark in an aquarium setting isn't done due to the sharks aggressive behavior. If you've got the room in your fish tank, and proper companions, the rainbow shark can be a fun fish to keep.

Swordtail Fish

Full of eggs, and relaxing in her plastic breeder box, Statico's female swordtail (below) will soon be giving birth to young fry. Adding these live-bearing fish to your peaceful, community aquarium, make a welcome addition.


Many popular Swordtails (Xiphophorus helleri) found in pet stores are hybrids, and come in assorted colors. Marigold, Black Nubian, Pineapple, Neon , Red Wag, and Red Velvet Swortails, are just a few commonly found varieties of this species. You might think the name comes from the sword shaped caudal fin protruding off the lower end of the male. Actually, the swordtail name is derived from the male's anal fin. You can determine the sex of the fish though, by the "sword" shaped fin. Male swordtails have one. Females don't. Notice the lack of this on the female swordtail in the picture. If you're interested in stocking the swordtail in your communty fish tank, keep the following in mind:

  • Minimum tank size is 20 gallons.
  • Tank Parameters: 65-82 degrees F; pH 7.0-8.2; KH 12-28.
  • Swordtails are Omnivores.
  • Peaceful fish perfect for community tanks.
  • Grow to 4" in length.
  • Easy to care for.

As live-bearing fish, the aquarium hobbyist can try their hand at raising fry. You can learn more about swordtail breeding here. These fish are able to reproduce in high numbers. Unfortunately, in the wild, they have become a nuisance in some countries where they were introduced to an area not indigineous to the species.

I've had the swordtail fish in my own aquariums. They are very pleasant, and swim quietly around. You could easily keep them with the Guppy, Dwarf Gourami, and I have even stocked them with Tiger Barbs.