The Guppy takes its name from Robert John Lechmere Guppy, a conchologist, geologist and President of the Scientific Association of Trinidad. He was christened with several names, Robert John Lechmere Guppy but in his life he was simply referred to as Lechmere Guppy. Guppy is credited, as being the first person to discover and describe the wild Guppy, however he was in fact not the first as a Spaniard, De Filippi, found the fish on the island of Barbados in 1862, and assumed that it to be a new genus and species.

It is also known as the “millions” or “drain fish,” the common guppy is a familiar sight to many people in Trinidad and Tobago. It is found in almost every freshwater habitat in the country. Indeed, as well as throughout TT, guppies are also found naturally along the north-eastern coast of South America and as ornamental fish in aquaria all around the world. However, many are surprised to hear that over the last century this tiny fish has established itself in natural rivers and streams in at least 70 different countries, spanning every continent in the world with the exception of Antarctica.

In addition to being a mosquito-control agent and a popular pet, the guppy is also famous in the world of science. Biologists from all over the world regularly travel to Trinidad to study these fish, especially within the Northern Range, where the multiple parallel streams provide a “natural laboratory” for conducting hundreds of studies into ecology, evolution and animal behaviour, many of which get published in the top scientific journals. In fact, studies on guppies in the Northern Range are internationally renowned for providing some of the best evidence we have for evolution by natural selection.

A recently published study shows that guppies can change their eye colour from silver to black to signal aggression. Guppies are model species for studying evolution in the wild. The rivers in the Northern Range have natural barriers such as cascades and waterfalls, which prevent major guppy predators from inhabiting upstream areas. This has resulted in guppies living upstream (low predation sites) being quite different from guppies living downstream (high predation sites) in terms of life history, morphology and behaviour.