Deep: from the depths of earth’s oceans

Pleisticanthoides cameroni Ng & Richer de Forges, 2012

This species of deep-sea crab was discovered in deep water in the Bohol Sea in the Philippines. It is named after explorer and film director James Cameron in recognition of his role in deep-sea ocean exploration and inspiring exploration through his films.

The crab is covered in long hooked hairs on its body and legs which seem to trap mud and debris. Whether this is part of a camouflage mechanism is not known. The species is only known from the ASEAN region from deep water in the Philippines (Bohol Sea).

Attenuated Spider Fish
Bathypterois atricolor Alcock, 1896

This species is from a group of fish called tripod fishes because they use their elongated pelvic and tail fin rays to ‘stand’ on the ocean bottom. Their pectoral fin rays point forward and are used as a tactile organ.

The Attenuated Spider Fish is found in deep water worldwide. It has been found in water as deep as 5,150 metres. Within ASEAN, it is found in deep water in Indonesia, the Philippines and Thailand.

According to experts on the crab genus Rochinia who were on the expedition, over thirty species of Rochinia crabs are known and the SJADES 2018 Expedition will add at least three more.

Waterfall Centipede
Scolopendra cataracta Siriwut, Edgecombe & Panha in Siriwut, Edgecombe, Sutcharit, Tongkerd & Panha, 2016

This species of centipede was first discovered by an entomologist who observed it running toward (rather than away from) a stream when it was frightened. What is more, it was even observed to swim with undulating eel-like movements underwater. Thai scientists later described this species and named it after the Latin word for stream or waterfall. Though not strictly a denizen of the deep like the other species featured here, this species qualifies as a member of this category. Its ability to swim and underwater habits are unique among centipedes. This species is only known from ASEAN where it is found in Laos, Thailand and Vietnam.

Deepwood Crab
Vultocinus anfractus Ng & Manuel-Santos, 2007

In systematics, we reclassify animals into new groupings when we slowly learn more about them and better understand their relationships with each other. Rarely do we find something so “out of the blue” that it is immediately recognised as not just a new species, but also a new genus and a new family to boot.

The Deepwood Crab is one such animal. Discovered during a multinational biodiversity expedition to the central Philippines in the mid-2000s and described by Philippine and Singapore biologists, this bizarre crab is so peculiar that its exact affinities remain unknown— even though its DNA has been sequenced!

Supposedly associated with sunken wood in deeper waters (usually below 100 metres), almost nothing is known about its biology. How it has escaped discovery for so long is indeed surprising as the crab is not small, at some 20 mm in carapace width! Outside of ASEAN, this species is known from New Caledonia. Within ASEAN, it is only known from the Philippines.