Squat lobsters, hermit crabs, true crabs and sea urchins. Part 3 of my documentary, “Mucky Secrets”, about the fascinating marine creatures of the Lembeh Strait in Indonesia. Watch the full 90-minute documentary at
In this video we first look at more marine crustaceans. First we meet squat lobsters. The elegant squat lobster, Allogalathea elegans, lives commensally on the arms of crinoid feather stars. It feeds on plankton collected by its host, and its colour often matches the crinoid for camouflage.
Next we encounter squat lobsters of the Galathea genus fighting for territory on branching sponges at TK 2.
Hermit crabs don’t have a hard carapace like other crabs, so they recycle an empty gastropod shell to protect their soft abdomen. They carry their adopted home around with them, and long eye stalks ensure that the crab has a wide angle of view. We encounter whitespotted hermit crabs, Dardanus megistos, living in empty cone shells and conch shells. We also meet an anemone hermit crab, Dardanus pedunculatus, carrying sea anemones on its back in a classic example of mutual symbiosis.
We then meet a pair of wingless box crabs, Cycloes marisrubri. The male box crab carries the female everywhere with him until she has moulted her shell and is ready to mate.
Camouflage is important for Lembeh’s true crabs. We encounter a rear-spined elbow crab, Aulacolambrus hoplonotus, and a decorator spider crab, Achaeus sp., perfectly camouflaged in their environment.
A zebra crab, Zebrida adamsii, clings to the spines on the underside of a highly venomous flower urchin, Toxopneustes pileolus, using the last segment of its legs which has evolved into a hook.
Blue-spotted urchins, Astropyga radiata, are also highly venomous and gather in groups at dive sites such as Hairball. Juvenile emperor red snappers, Lutjanus sebae, often shelter amongst these sea urchins in a commensal relationship.
There are English captions showing either the full narration or the common and scientific names of the marine life, along with the dive site names.
The full Mucky Secrets nature documentary features a huge diversity of weird and wonderful marine animals including frogfish, nudibranchs, scorpionfish, crabs, shrimps, moray eels, seahorses, octopus, cuttlefish etc..
Thanks to Tom Cusack of Leafy Lane Productions ( for the music track, “Mystery 2” and to Kevin MacLeod of for the music track, “Covert Affair”. These tracks are licensed under a Creative Commons Attribution 3.0 Unported license.
Thanks to the staff and keen-eyed divemasters of Two Fish Divers ( for accommodation, diving services and critter-spotting.
The video was shot by Nick Hope with a Sony HVR-Z1P HDV camera in a Light & Motion Bluefin HD housing with Light & Motion Elite lights and a flat port. A Century +3.5 diopter was used for the most of the macro footage.
Full list of marine life and dive sites featured in this video:
00:05 Elegant Squat Lobster, Allogalathea elegans, Aer Perang
00:29 Squat Lobster, Galathea sp., TK 2 (Teluk Kembahu)
00:58 White-Spotted Hermit Crab, Dardanus megistos, Two Fish Divers house reef
01:22 White-Spotted Hermit Crab, Dardanus megistos, Retak Larry
01:35 Anemone Hermit Crab, Dardanus pedunculatus, TK 2 (Teluk Kembahu)
01:56 Wingless Box Crab, Cycloes marisrubri, TK 1 (Teluk Kembahu)
02:55 Rear-Spined Elbow Crab, Aulacolambrus hoplonotus, Nudi Falls
03:08 Decorator Spider Crab, Achaeus sp., Makawide
03:25 Zebra Crab, Zebrida adamsii, Jahir
03:33 Flower Urchin, Toxopneustes pileolus, Jahir
03:40 Zebra Crab, Zebrida adamsii, Jahir
03:56 Blue-Spotted Urchin, Astropyga radiata, Hairball
04:34 Emperor Red Snapper (juvenile), Lutjanus sebae, Jahir
04:42 Bluespotted Stingray, Neotrygon kuhlii, Hairball