The Safest Cobra You Can Keep

Black Cobra Guppies (Poecilia reticulata) belong to the family Poeciliidae which are referred to as either “toothed carps” or often just lumped into the “livebearer” family. After more than a century of captive breeding, the wide variety of color forms these two-inch-long fish can display is astonishing. Among all these, the designation “Cobra” indicates a body covered in stripes and spots, not unlike that of the venomous snake with the same name, and a tail that is usually more of a solid color, though often with slashes of iridescence. Like all color forms of Guppy, the Black Cobra is small, with males rarely getting larger than an inch and a half long, and females three quarters of an inch longer.

The original guppy was substantially less colorful, with females being nearly colorless, and males showing a variety of colors, though nothing as spectacular as what is seen today. It was “discovered” for western science by a British naturalist named Lechmere Guppy, (hence the name) who first documented these fish in Trinidad. The natural / original range of these fish is all over south America and (obviously) parts of the Caribbean. Their hardiness and popularity within aquaria have spread them all over the world. In addition, guppies have been introduced to a huge variety of areas as mosquito control, but those efforts have largely been ineffective. Now, whether by uninformed pet owners, honest mistakes or misguided mosquito control efforts, guppies have been found on every continent except Antarctica. Let this be a reminder to never release an aquarium fish into the wild.

Despite their hardiness, and ability to tolerate environments such as brackish (a mixture of salt & fresh water), and even full saltwater, guppies do tend to come from smaller, calmer bodies of fresh water and like dense vegetation. These incredibly hardy fish have very minimal aquarium requirements. A pair of guppies could be kept in tanks even smaller than our ten gallons minimum recommendation given proper heating, and filtration of the water. As long as you maintain a pH around 7, the temperature in the 70s Fahrenheit and keep nitrogen levels below 20ppm your Black Cobras will thrive. They are a great choice for small aquariums, even for those of you with naturally hard water.

We recommend a ten-gallon aquarium (or larger) because guppies will rapidly reproduce and fill any size aquarium with lots of motion and color. If not the easiest, then Black Cobra Guppies are at least on the list of easiest aquarium fish to breed. Provided with good food and water quality, healthy Black Cobras will reproduce rapidly to form a large colony. When the parents inevitably start reproducing, the young whose colors, shapes and general vitality aren't up to standard are removed. Over time, a desirable strain is isolated and indeed, this is how Black Cobra Guppies came about in the first place. If breeding Black Cobra Guppies is your intent, we recommend picking beautiful parent fish to start with, and adding a few females for every male.

Guppies are sexually dimorphic meaning that males and females look different. Females are generally drabber than the males, and are somewhat translucent so under close inspection, you can frequently see the babies developing inside of the mother! Males are smaller, with bigger flashier tails and are brightly colored. Guppies are born live, and few things are more exciting in aquariums for children and adults alike than watching the tiny replicas of the adults swimming around! A sponge filter or sponge coverings on filter intakes will help protect the babies from being sucked into filtration. Live plants can be beneficial to act as hiding spots for the smaller babies, and the adults will graze on algae that grows on delicate plant leaves.

In regard to feeding, the primary obstacle is one of size, Black Cobra Guppies are small and so food needs to be small enough to eat. They eat small insects and other invertebrates in the wild, and graze on algae. A well-rounded flake or small pellet is likely the best daily food for guppies and because of their penchant for grazing, they will nibble on things like Nutramar's Algae & Color Boost Shots. You can also supplement their diet with live or frozen aquarium food like tubifex or daphnia added for treats.

Black Cobra Guppies are hardy enough to live in a small aquarium with simple filtration, active & colorful enough to provide interest when watching your aquarium, and the ease of breeding them makes fun projects for aquarists of all ages and skill levels. They have the added benefit of really surprising people when you tell them that you're breeding Black Cobras. Head over to your LFS and ask them about getting you some Black Cobra Guppies today!