A Sally Lightfoot Crab on Espanola Island
The crab Grapsus grapsus (known variously as “red rock crab”, “abuete negro”, and, as “Sally Lightfoot”) is one of the most common crabs along the western coast of South America. It can also be seen along the entire coast of Central America and Mexico, and nearby islands. It is one of the many charismatic species that inhabits the Galápagos Islands, and is often seen in photos of the archipelago, sometimes sharing the seaside rocks with the marine iguanas. The Sally Lightfoot is a typically-shaped crab, with five pairs of legs, the front two bearing small, blocky, symmetrical chelae. The other legs are broad and flat, with only the tips touching the substrate. The crab’s round, flat carapace is just over 8 cm (3 inches) in length. Young Sally Lightfoot’s are black or dark brown in color and camouflage well on the black lava coasts of volcanic islands. Adults are quite variable in color. Some are muted brownish-red, some mottled or spotted brown, pink, or yellow. Sally Lightfoot crabs are thought to have been named for a sultry nightclub dancer from Guayaquil, whose alluring performances in her red and yellow dress, captivated 19th century sailors. This crab lives amongst the rocks at the often turbulent, windy shore, just above the limit of the seaspray. It feeds on algae primarily, sometimes sampling plant matter and dead animals. It is a quick-moving and agile crab, and hard to catch, but not considered very edible by humans. It is used as bait by fishermen.
The White Sea is an inlet of the Barents Sea, in the northwest coast of Russia. Its waters are cold and apparently devoid of life—until you do deep and discover an alien world full of colorful creatures that look from other planets.
The author of these photos works at the White Sea biological research station of the Moscow State University as a head of the diving department and as an underwater photographer. In the cold waters of the White Sea there are a lot of little and big creatures. Unfortunately naturalists’ profession is not popular nowadays so the guy takes such pictures more as a hobby.
(Photo found here)
That weird blue thing is a pyrosome. Pyrosomes, genus Pyrosoma, are free-floating colonial tunicates (marine filter-feeders, see this post) that live usually in the upper layers of the open ocean in warm seas, although some may be found at greater depths. Pyrosomes are cylindrical or conical shaped colonies made up of hundreds to thousands of individuals, known as zooids. Colonies range in size from less than one centimeter to several meters in length. The individuals that make up this giant, floating, colonial tunicate are only about 1 in (2 cm) long, but the giant pyrosome colony, which resembles a gigantic hollow tube, can be large enough for a person to fit inside. Each individual lies embedded in the wall of the tube, with one end drawing in nutrient-laden water from outside and the other end expelling water and waste inside. The expelled water is used to propel the giant pyrosome colony as a whole. A wave of bioluminescent light travels along the community if it is touched.
TAKE US CLOSER TO ONE OF THE LITTLE ONES
When you take a moonlit stroll on the beach, how often do you think about the tiny grains of sand creeping in between your toes? From above, sand seems like a bunch of tiny brown rocks, perhaps peppered with occasional shells or cigarette butts. But sand has a far more fascinating story to tell.
Composed of the remnants of volcanic explosions, eroded mountains, dead organisms, and even degraded man-made structures, sand can reveal the history—both biological and geologic—of a local environment. And examined closely enough, as the scientist and artist Gary Greenberg has, sand can reveal spectacular colors, shapes, and textures.