There are 47 different species of seahorses and 14 of those were discovered in the last eight years, including Pontoh's pygmy seahorse (Hippocampus pontohi), which was officially named in 2008. Seahorses’ ability to change their color and shape to blend in with their environment makes identification of individual species challenging. Because of this, some researchers previously thought there were as many as 200 seahorse species in the world, while others thought there were as few as 20. However, advances in genetic research are helping to clarify some of the differences between closely related species.

It's a pygmy seahorse (Hippocampus bargibanti), found in Indonesia's biodiverse Coral Triangle and one of the smallest seahorse species in the world! They can change colors like a chameleon to blend into their environment. This helps to protect them from predators and ambush their prey.

Seahorses range in size—from as small as a pine nut to as large as a banana. The largest seahorse species (pictured here) is Hippocampus abdominalis, or the big-bellied seahorse, which can reach more than a foot long (35 cm) and lives in the waters off Southern Australia and New Zealand. The smallest seahorse, Satomi's pygmy seahorse (Hippocampus satomiae), which was only described in 2008, is only half an inch long (13 mm)! It lives in the waters of Brunei, Indonesia and Malaysia.

Most wild seahorses (here the thorny seahorse Hippocampus histrix) are monogamous and some species mate for life. Searching for mates can be difficult and risky since seahorses are poor swimmers, found in low densities and rely on camouflage to hide from predators. By remaining faithful to one partner, the pairs have more time to undergo more pregnancies during a single mating season and, ultimately, have greater reproductive success. The pair-bonds of monogamous seahorses are reinforced by daily greetings (see next slide).

Seahorse couples (such as these Hippocampus histrix) greet each other every morning with a unique dance that sometimes involves changing color. The couple promenades and pirouettes together for several minutes before separating for the rest of the day. They greet each other as a way to confirm the other partner is still alive, reinforce their bond and synchronize their reproductive cycles.

Instead of females, male seahorses carry the developing seahorse embryos in a kangaroo-like pouch. During mating season, the female deposits her eggs into the pouch, and the male fertilizes them. After about two weeks of development, out pop the seahorse fry, ready to swim off and explore the ocean world. Here is a very pregnant short-snouted seahorse (Hippocampus breviceps) in Australia.

Seahorses are not just tropical creatures. They can be found in colder waters like those found off New Zealand, Argentina, Eastern Canada, and the UK. This long-snouted seahorse (Hippocampus guttulatus) can be found in UK waters.

Seahorses are the only fish species that can hold your hand! Unlike most fish that use their tails for swimming, seahorses, such as this big-belly seahorse (Hippocampus abdominalis), use their monkey-like tails to hold onto objects in their environment, like corals or seagrass.

Lindsay Aylesworth is a PADI dive instructor, marine biology consultant and PhD student with Project Seahorse at the University of British Columbia. Lindsay has carried out monitoring and survey work in the tropical marine environment for ten years, starting as an undergraduate on the coral reefs in the Yucatan coast of Mexico. As a Fulbright Scholar, Lindsay worked in Brazil to identify the habitat preferences of the longsnout seahorse, Hippocampus reidi. She holds a Master's in Coastal Environmental Management from Duke University and a B.S. from Georgetown University. Lindsay's PhD research focuses on implementing international policy for conservation action using seahorses as a case study.