Deep: from the depths of earth’s oceans

These animals engender a literal sense of profundity and are a reminder of how little we know about the largest habitat on the planet

By Lee Kong Chian Natural History Museum

Lee Kong Chian Natural History Museum

Pleisticanthoides (2006-06-02) by Peter K. L. NgLee Kong Chian Natural History Museum

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.

Pleisticanthoides cameroni (2007-05-20) by Peter K. L. NgLee Kong Chian Natural History Museum

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) (2018-03-27) by SJADES 2018Lee Kong Chian Natural History Museum

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.

Attenuated Spider Fish (Bathypterois atricolor) (2018-03-27) by SJADES 2018Lee Kong Chian Natural History Museum

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.

Rochinia sp. (2018-03-27) by SJADES 2018Lee Kong Chian Natural History Museum

Rochinia sp.

Three new species of crabs of the genus Rochinia were collected during the SJADES 2018 Expedition. One species collected at a depth of between 800 and 1,200 metres was nicknamed “clinger”.

This name was given because the crab was found clinging to deep sea stalked lilies. It is not known if this is their only habitat but expedition scientists believe it has a preference for these sea lilies.

Rochinia sp. (2018-03-27) by SJADES 2018Lee Kong Chian Natural History Museum

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.

Rochinia sp. (2018-03-27) by SJADES 2018Lee Kong Chian Natural History Museum

The “clinger” is also interesting for having deep red eyes. It is currently not known from outside the ASEAN region and only from deep water off Java, Indonesia.

The “clinger” is also interesting for having deep red eyes. It is currently not known from outside the ASEAN region and only from deep water off Java, Indonesia.

Waterfall Centipede (Scolopendra cataracta) (2013-10-08) by Somsak PanhaLee Kong Chian Natural History Museum

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) (2005-05-25) by Peter K. L. NgLee Kong Chian Natural History Museum

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.

Deepwood Crab (Vultocinus anfractus) (2005-05-25) by Peter K. L. NgLee Kong Chian Natural History Museum

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!

Deepwood Crab (Vultocinus anfractus) (2005-05-25) by Peter K. L. NgLee Kong Chian Natural History Museum

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.

Attenuated Spider Fish (Bathypterois atricolor) (2018-03-27) by SJADES 2018Lee Kong Chian Natural History Museum

Covering over 70 percent of our planet’s surface, the ocean’s depths are the last true frontier of exploration. The cliché about the moon’s surface being better studied than the oceans’ depths still holds true.

Credits: Story

Text:

Attenuated Spider Fish
Lee Kong Chian Natural History Museum
(National University of Singapore, Singapore)

Deepwood Crab
Peter K. L. Ng
(National University of Singapore, Singapore)
Marivene Manuel-Santos
(Philippine National Museum of Natural History, the Philippines)

Pleisticanthoides cameroni
Peter K. L. Ng
(National University of Singapore, Singapore)

Rochinia sp.
SJADES 2018
(Indonesian Institute of Sciences, Indonesia and National University of Singapore, Singapore)

Scolopendra cataracta
Somsak Panha
(Chulalongkorn University, Thailand)


Images:

Attenuated Spider Fish
Rochinia sp.
SJADES 2018
(Indonesian Institute of Sciences, Indonesia and National University of Singapore, Singapore)

Deepwood Crab
Pleisticanthoides cameroni
Peter K. L. Ng
(National University of Singapore, Singapore)

Scolopendra cataracta
Somsak Panha
(Chulalongkorn University, Thailand)

Credits: All media
The story featured may in some cases have been created by an independent third party and may not always represent the views of the institutions, listed below, who have supplied the content.
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