There are three species of Galapagos iguanas: Marine, Land, and Hybrid.
There are seven sub-species of Marine iguanas (Amblyrhynchus cristatus). The ones shown here are the A.c. mertensi, found on Islas San Cristobol and Santiago. They are small (up to 18" or so) and shades of very dark grey, nearly black. They spend hours lying on rocks, soaking up sun to raise their body temperature to nearly 140 degrees. This enables them to plunge into the water (hence "marine") and remain submerged for up to 10 minutes, feeding on red and green algae clinging to submerged rocks.
There are seven sub-species of Marine iguanas (Amblyrhynchus cristatus). The ones shown here are the A.c. mertensi, found on Islas San Cristobol and Santiago. They are small (up to 18" or so) and shades of very dark grey, nearly black. They spend hours lying on rocks, soaking up sun to raise their body temperature to nearly 140 degrees. This enables them to plunge into the water (hence "marine") and remain submerged for up to 10 minutes, feeding on red and green algae clinging to submerged rocks.
There are two species of Galapagos Land Iguana. Only Conolophus subcristatus.
is widely distributed. They are large (up to about 3' long, and 30 lbs.). They are
the most shy of all the land animals we encountered, and like to keep a safe distance from
humans. Adults feed primarily on the Opuntia cactus.
There is a Hybrid Iguana, supposedly the product of marine and land iguanas interbreeding
(given the size difference, a seemingly improbable act). In size, they more resemble the
marine iguana; but in color are closer to land iguanas, particularly about the head
and feet. Like the land iguanas, they feed on the Opuntia cactus. Some sources
say they are probably sterile, but they are plentiful in some locations. Also, some sources
picture a less colorful animal. Whatever the truth, these shown below were identified by
our guide as Hybrid Iguanas.
