Gall Crabs – Coral-Inhabiting Micro Crabs of Okinawa

Posted on June 16, 2018 by Admin11

Gall crabs are coral-dwelling crabs that spend their entire life living inside a hole of the hard coral. These micro crabs are only 7mm-10mm in size. They are hard to find and photograph due to their small size.

Gall crab in Favia Coral © Shawn Miller

These tiny crabs are considered to be safe keepers or guardians of the hard coral. The gall crabs defend against coral eating predators such as starfish and snails. The coral provides shelter and food, making it an ideal habitat for the micro coral-dwelling gall crab. I have found these crabs in a variety of coral species in Okinawa. They are usually found in shallow water corals, but recently I found a healthy colony of crabs at sixty-five feet.

Gall crab claws out © Shawn Miller

Large algae covered gall crab © Shawn Miller

Gall crab closeup © Shawn Miller

If you’re lucky you might see a gall crab searching for food during the night.

Unidentified gall crab © Shawn Miller

Gall crab searching for food © Shawn Miller

Unidentified gall crab © Shawn Miller

The only reason I found this beauty was because she was leaving the gall to release her eggs.

Some of the gall crabs fluoresce using the specialized Light & Motion Nightsea underwater blue light.

After the crabs die, the galls become a new shelter opportunity for snails, fish, and reef crabs.

Prime Coral real estate © Shawn Miller

Bicolor blenny in coral - fish of okinawa

Bicolor blenny in coral © Shawn Miller

Yaeyama blenny © Shawn Miller

Blenny in coral gall © Shawn Miller

Blenny in coral gall © Shawn Miller

I found this hard coral washed up on Iheya Island. Look close and you can see that hole made by the gall crab.

Stony coral and gall

My Mission: To Document and Preserve the Wildlife of the Ryukyu Islands

This site is also designed to help people identify the beautiful animals of Okinawa, basically to serve as an online nature reference guide. If you would like to make a contribution to support my mission, please click on the donation link paypal.me/maketheswitch4nature

Your donations will help conservation initiatives as well as bring solutions to the worldwide pollution issues on our beautiful shorelines. Thank you for your support, Shawn M Miller.

#MakeTheSwitch4Nature

The Coconut Crab – Terrestrial hermit crabs of the Ryukyu Islands

Posted on July 5, 2017 by Admin11

Coconut crabs are the largest terrestrial hermit crabs of the Ryukyu Islands. They are scarce on the Island of Okinawa due to over-hunting. They are sold in local fish markets for high prices. The meat of the coconut crab is sought after and considered a delicacy. No conservation programs are set in place to protect this native crab. It is currently listed as data deficient on the IUCN list of Threatened species.

Scientific name: Birgus latro
Common name: Coconut crab, robber crab and palm thief
Distribution: Majority of the Ryukyu Islands
Habitat: Coastal forest
Diet: Seeds, fruit and carrion
Average size: 20-40 centimeters
Color: Purple, blue or orange

Coconut crab- Okinawa © Shawn Miller

How to tell the difference between a coconut crab and a hermit crab. They look very similar to the blueberry hermit crab at first, but the coconut crab has protective spines near its eyes. Hermit crabs do not have these spines since they have adapted to retreat into a shell to protect their eyes. The coconut crab does not depend on a seashell as it gets larger. I still have yet to find a juvenile coconut crab adapting with a seashell.

spines that protect the eyes © Shawn Miller

Terrestrial hermit crabs live in the coastal forest where the treeline and coastline meet. They are the caretakers of the coastal forest. They mainly feed on plants, flowers, fruits, and seeds in the treeline. They also help disperse seeds in the forest, specifically the screw pine tree seeds.

The Climber- Adult coconut crab © Shawn Miller

Pandanus trees with spiky sword-shaped leaves provide a perfect environment for the Coconut crabs to thrive.

Pandus odifer – favorite food © Shawn Miller

A juvenile climbing on Pandanus tree searching for food.

Juvenile coconut crab © Shawn Miller

Okinawa’s harsh limestone coastline. The female must make the journey over this rough terrain to lay her eggs in the ocean.

Coconut crab – Onna village © Shawn Miller

Photographed on a white portable outdoor studio for the Meet Your neighbours project. ( Connecting people worldwide with the wildlife in their community )

Coconut crab- MYN technique © Shawn Miller

In the 1970’s and 1980’s, taxidermy was popular in the Ryukyu Islands. I still find coconut crabs displayed on walls in restaurants and hotels.

Coconut crab mounted © Shawn Miller

Meet Crabzilla! – The most aggressive crab I have encountered on Okinawa. Coconut crabs are fearless and have bone crushing power. You do not want to get caught by the claw, You play you will Pay!!

Crabzilla -Okinawa © Shawn Miller

Meet the Bone Crusher! This monster crab was over four pounds. Do not pick these crabs up if you do not know what you are doing. They can crack bones.

Coconut crabs © Shawn Miller

Coconut crabs spend their day hiding in burrows. They venture out searching for food late at night. This juvenile was found crossing the road.

Let’s dance- Coconut crab © Shawn Miller

Have a great day! Please consider making a small donation to support my mission.

The Light & Motion Stella 2000 rocks part 1 – Okinawa, Japan

Posted on September 5, 2016 by Admin11

The Stella 2000 offers lightweight professional lighting for photographers and videographers. It delivers 2000 lumens of beautiful wide light on high power. It is waterproof to a depth of 100 meters and extremely durable.

Stella 2000 waterproof lighting © Shawn Miller

My favorite features of the Stella 2000

Waterproof to 100 meters
Can be mounted on the camera hot-shoe, light stand, loc-line arms or ball mounts.
Quick adjustable power output control
Fast charging and the ability to use the light when it’s charging

I tested the Stella 2000 in the humid jungle and on the shorelines of northern Okinawa. I used it as a spotting light, hiking light, camera modeling light and video light. I tested the light with the 120-beam angle with no modifiers, with custom-made soft-boxes attached, studio umbrellas and with the combination of on-off camera flash.

I concentrated on the reptiles, amphibians and land crabs of northern Okinawa. Below are some of my favorite photographs.