Crabs & Shrimps at Night – Reef Life of the Andaman – Part 27

Description

Night diving offers the opportunity to see many crustaceans that are typically hidden in the reef during daylight, but are highly active under the hours of darkness. This video features 13 species of crab and shrimp.

At Koh Doc Mai, near Phuket in Thailand, and in the Similan Islands, we see banded coral shrimps (Stenopus hispidus) plucking plankton from the water to eat. Rock cleaner shrimp (Urocaridella sp.) are busy cleaning a large snapper and a fimbriated moray eel (Gymnothorax fimbriatus).

Space is at a premium on the reef. In the Mergui Archipelago in Burma (Myanmar) we see a fimbriated moray sharing its home with a variable coral crab (Carpilius convexus).

Female crabs carry their eggs under their apron for a few months while the embryos develop. We witness the dramatic sight of a spendid round crab (Etisus splendidus) releasing her brood. As she pumps her lower body, thousands of tiny larvae are released and drift away in the current.

At Thailand’s Boonsung wreck, a crucifix crab (Charybdis (Charybdis) feriata) tries to appear as large and intimidating as possible by spreading its claws, before escaping into the shelter of the wreck, while at Western Rocky Island we see a tiny bull crab (Naxioides taurus) crawling across a gorgonian sea fan.

The flat rock crab, Percnon planissimum, is a common sight in the Andaman Sea, as is the swimming crab, Charybdis sp., which we see defending its territory by fighting off a passing common decorator crab (Schizophrys aspera). This decorator crab has large claws and covers itself with other marine organisms such as stinging hydroids for camouflage and defence. The horrid elbow crab (Daldorfia horrida) becomes completely encrusted with growth, while the spider decorator crab (Camposcia retusa) covers itself with sponges which continue to grow while on the crab, and enable it to blend in with the reef. The sponge crab, Dromia dormia, carries a large spone with its rearmost legs. We see one fling itself off the edge of the reef in an attempt to escape our lights.

Hermit crabs live inside empty snail shells in order to protect their soft abdomen. We see white-spotted hermit crabs (Dardanus megistos) in a variety of different shells. Anemone hermit crabs (Dardanus pedunculatus) carry live sea anemones on its shell as an extra defence. At Honeymoon Bay we a pair of them, perhaps in a dispute over territory.