I don't know what type of crabs these are. They are on the rocks near the pier and it smells like something has been dead awhile and some fishermen are likely to toss what they don't want to take home as they load their boats back on trailers. (Gulls approach fishermen and boats in the launch ramp, are getting habituated.)
Found dead on the beach.
Small one caught in Beaver Creek.
A pair of the small coral crab Tetralia cf. ferruginea, was found in a colony of the coral Pocillopora damicornis at Sesoko Island, Okinawa, Japan. The male is on the left, and the larger female on the right.
My M.S. advisor, Dr. Makoto Tsuchiya, studied the behavior of this and related crabs and shrimps that are obligate symbionts on some corals, including other species of Porites and Acropora corals.
These coral crabs are amazing; they live on the coral, among its branches. Some in situ observations (by colleagues) suggest that these crabs defend the coral colony from the large predator Crown-of-Thorns Starfish, Acanthaster planci, by pinching the starfish tube feet. It may provide some protection to the coral, but if the starfish is hungry, say, because there are few live coral in the area, the crab may not succeed.
Photo taken in the lab at the University of the Ryukyus, Okinawa, of specimens collected in the wild. The scale in millimeters. (the watermark is when I posted this photo at the now defunct website LightBox, not the observation; the exact date of observation is not know).
I wrote a paper on the species composition and population traits of these coral crabs, presented at the 7th International Coral Reef Symposium, Guam, 1992, and published in its proceedings in 1994. Let me know if you want a copy of the paper (you can email me at mollusca at gmail.com).
Found washed up (dead) on Agate Beach, Bolinas. This is the second one I've seen here but the first since I've had inaturalist.
The Atlantic Ghost Crab is a common species in Texas. It has a wide distribution, from Rhode Island to Brazil, including the Gulf of Mexico.
See more about this species at the Biodiversity of the Gulf of Mexico (BioGoMx) database at:
Not in iNat's database?
The stripes on the head diagnose this as Macrobrachium australe, a large freshwater prawn in French Polynesia. It is probably the most common native freshwater prawn the rivers of Moorea.
Atyoida pilipes--not in iNat's databases?
Notice how the two front pinchers are adapted to filter detritus and scrape algae from rocks.
A common small freshwter shrimp in French Polynesia. This is a gravid female.
The decapods or Decapoda (literally "ten-footed") are an order of crustaceans within the class Malacostraca, including many familiar groups, such as crayfish, crabs, lobsters, prawns and shrimp. Most decapods are scavengers. The order is estimated to contain nearly 15,000 species in around 2,700 genera, with approximately 3,300 fossil species. Nearly half of these species are crabs, with the shrimp (c. 3000 species) and Anomura (including hermit crabs, porcelain crabs, squat lobsters: (c. 2500 species), making up the bulk...