Galapagos Marine Iguana, Baltra Island, Galapagos
And now, dear viewers, that Galapagonian superstar, the Galapagos Marine Iguana (Amblyrhynchus cristatus), makes its first significant apperance in my photostream: .
According to Wikipedia,
"The Marine Iguana (Amblyrhynchus cristatus) is an iguana found only on the Galapagos Islands that has the ability, unique among modern lizards, to live and forage in the sea."
"It has spread to all the islands in the archipelago, and is sometimes called the Galapagos Marine Iguana. It mainly lives on the rocky Galapagos shore, but can also be spotted in marshes and mangrove beaches."
"On his visit to the islands, Charles Darwin was revolted by the animals' appearance, writing:
'The black Lava rocks on the beach are frequented by large (2-3 ft), disgusting clumsy Lizards. They are as black as the porous rocks over which they crawl & seek their prey from the Sea. I call them 'imps of darkness'. They assuredly well become the land they inhabit.'
[Editor's Note: So much for Darwin's scientific objectivity, eh?]
"In fact, Amblyrhynchus cristatus is not always black; the young have a lighter coloured dorsal stripe, and some adult specimens are grey. The reason for the sombre tones is that the species must rapidly absorb heat to minimize the period of lethargy after emerging from the water."
"They feed almost exclusively on marine algae, expelling the excess salt from nasal glands while basking in the sun, and the coating of salt can make their faces appear white."
"In adult males, coloration varies with the season. Breeding-season adult males on the southern islands are the most colorful and will acquire reddish and teal-green colors, while on Santa Cruz they are brick red and black, and on Fernandina they are brick red and dull greenish."
"Another difference between the iguanas is size, which is different depending on the island the individual iguana inhabits. The iguanas living on the islands of Fernandina and Isabela (named for the famous rulers of Spain) are the largest found anywhere in the Galápagos. On the other end of the spectrum, the smallest iguanas are found on the island on Genovesa."
"Adult males are approximately 1.3 m long, females 0.6 m, males weigh up to 1.5 kg."
en.wikipedia.org/wiki/Marine_Iguana
In The Voyage of the Beagle, Darwin describes how he repeatedly tossed a Marine Iguana into a salt-water pool to see what it would do. What it did was wait until it thought its tormentor had gone away (wrong!), make a beeline under water back to the point from which it had been thrown, and climb out onto dry land. In turn, Darwin would pick up the Marine Iguana and hurl it back into the water again.
From the Marine Iguana's constant striving to return to shore, Darwin deduced that Marine Iguanas were not, in fact, overly fond of being in the water. Darwin reasoned this was because, lacking terrestrial predators, Marine Iguanas didn't want to spend any more time than necessary in the water, home to their only predator, the shark.
Be that as it may, Galapagos Marine Iguanas probably also try to minimize time spent in the water because they're cold-blooded reptiles and the water around the islands can be pretty, er, "darned" cold depending on the season and location.