Gigantic Hermit Crabs Found On Okinawa

Posted on October 5, 2019 by Admin11

Last year, a friend and I stumbled upon a local beach with gigantic hermit crabs. All of the hermit crabs were found adapting with non-native seashells.

Indonesian hermit crab (Coenbita brevimanus)

Where did these shells come from? The shell shack

The shell shack is an old wooden shed filled with boxes of imported craft shells from the Philippines. The hermit crabs found an opening and took advantage of this real estate.

Polished muffin (Ryssota ovum)

The most abundant shell was the polished muffin (Ryssota ovum) land snail. This shell is native to the Philippines and is twice the size of any land snail on Okinawa. The muffin shell is a perfect mobile home for the land hermit crabs. It’s lightweight, durable and large.

perspective photograph

The hermit crabs were healthy and doing well. I didn’t see any hermit crabs adapting with plastic or any twist top caps.

Land hermit crab (Coenobita cavipes)

Land hermit crab (Coenobita cavipes)

I also found hermit crabs adapting with a variety of marine shells from the Philippines at the same location.

Babylonia arealata (Coenobita purpureus)

hexaplex cichoreum (Coenobita cavipes)

Volema carinifera (Coenobita cavipes)

Melanella candida (Coenobita purpureus)

Casmaria erinaceus (Coenobita purpureus)

hexaplex cichoreum (Coenobita purpureus)

Turbo chrysostomus (Coenobita purpureus)

Tonna sulcosa (Coenobita cavipes)

Learn more about hermit crabs and adaptive behavior ” Crabs with beach trash homes ”

My Mission: To Protect and Preserve the Wildlife of the Ryukyu Islands for Future Generations. – If you would like to join my journey, check out my Patreon https://www.patreon.com/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.

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The Most Beautiful Bivalve In The World – Pedum spondyloideum

Posted on August 29, 2019 by Admin11

The Coral scallop (Pedum spondyloideum) is the most beautiful animal I have encountered underwater. The delicate bivalve lives within the hard coral its entire life.

Scientific name: Pedum spondyloideum
Distribution: Ryukyu Islands
Habitat: Hard corals in shallow water
Diet: Filter feeders
Average Size: 35mm-55mm

What purpose do they serve in the ecosystem? Researchers believe these beautiful bivalves serve a beneficial function among hard corals.

Provide circulation for feeding coral
Defend the host by expelling water when threatened by corallivorous marine life

The hard coral provides the bivalve with support and protection. The shell is very thin and fragile. Below is a great example of a protected piece of coral with an army of coral scallops.

The crown of thorns starfish is the most devesting predator of the coral. If the coral (host) dies the bivalve will not survive.

The coral scallop is very thin and fragile. The living animal is much more beautiful than the protective shell it produces. These specimens were given to me by a fellow researcher.

I first started photographing these beauties in 2010, below are some of my favorite images taken throughout the Ryukyu Islands.

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

Spiders, Webs and Warning Signs – Okinawa, Japan

Posted on August 25, 2019 by Admin11

In the last few months, I have been searching for spiders with unique web designs. The stabilimentum serves a different function for different species of spiders. The Oval St. Andrew’s Cross Spider is a master at designing its web with an obvious warning sign. Researchers believe the X-like stabilimentum serves as a warning to prevent birds from destroying the web.

Theories why orb-weavers have specialized web decorations

Stabilize the web
Make the spider look much larger
Disguise itself / Camouflage
lure prey in (ultraviolet light)
Serve as a warning sign for large birds
An attractive piece of art/lure in a mate

Argiope aemula -X-factor

Octonoba yaeyamensis has a very unique stabilimentum. The pattern reminds me of the mysterious design the Amami pufferfish constructs to lure in the female.

What purpose does this design serve?

Hide under the web /disguise itself
Beautiful design to lure in a mate or insects
Deterrent- scare off larger animals to prevent web damage

Octonoba yaeyamensis

When I first found this spider it was hiding under the stabilimentum. It serves as camouflage and protection from ultraviolet light (sunblock strand). I found it in the open sunlight on a branching leaf.

Octonoba yaeyamensis

Another strange design possibly used to attract a mate or hypnotize insects.

Cyclosa ginnaga (female)

Eriophora yanbaruensis has a simple design, possibly used to attract a mate.

Eriophora yanbaruensis

Gleaming light created this beautiful spider web prism.

Spider web prism

I have always wondered if spiders are unknown musicians. Their web has to produce some type of sound frequency. The tension of the web gently plucked by the spider or just blowing in the wind.

Do spiders use attractive frequencies to lure in insects or mates?

Spider web prism

The next step is to photograph the x-shaped stabilimentum under ultraviolet light. stay tuned to see my results.

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

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 Chinese soft-shell turtle – Aquatic turtles of Okinawa

Posted on July 15, 2019 by Admin11

This year we have had an abundance of rain on Okinawa. Locals have been finding a great deal of turtles on the road, specifically the Chinese soft-shell turtle ( Pelodiscus sinensis ). This soft shell turtle was originally introduced as a food source. This species is currently listed as vulnerable (VU) on the IUCN Red List.

Scientific name: Pelodiscus sinensis
Common name: Chinese softshell turtle
Distribution: Introduced to most of Japan and the Ryukyu Islands
Habitat: Ponds, drainage ditches, rice paddies and farm fields.
Diet: Insects, fish, frogs, snails, and plants
Average size: 30-35cm
Color: Olive gray

An adult soft turtle found in the farm fields at night.

A large female I found laying eggs on the bank of a small water source.

A closeup of a soft turtle infested with leaches. Stop staring!

Meet chunky

The beautiful farm fields of Okinawa, prime habitat for aquatic turtles.

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

Your donations will help worldwide 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

Cryptic fish, Comets and Stars by Shawn Miller

Posted on July 1, 2019 by Admin11

The Comet (Calloplesiops altivelis) is a type of marine betta found in the beautiful waters of Okinawa. They hide in caves during the day. At night they come out to feed on small crustaceans. They are a mysterious fish and can be challenging to photograph. Comets are uncommon, yet very little is know about the behavior of these cryptic animals.

Scientific name: Calloplesiops altivelis
Common Name: Comet (Marine betta)
Distribution: Ryukyu Islands
Habitat: submarine caves
Diet: crustaceans and fish
Average Size: 20cm

Calloplesiops altivelis © Shawn Miller

Calloplesiops altivelis © Shawn Miller

Look close, can see the resemblance between the comet and the spotted moray eel?

Gymnothorax meleagris © Shawn Miller

When threatened the comet will stick its head into a hole and expose its tail end, which mimics the head of the a dangerous moray eel. The caudal fin also has detailed white lines that resemble the razor sharp teeth.

Calloplesiops altivelis © Shawn Miller

Having trouble getting close to marine life during your night dives? I recommend using the Light & Motion Sola 1200 red light feature. This feature enables the user to photograph marine life during the night without disturbing them. Most marine animals do not see the color red or react less to the red light.

Underwater setup with sola 600

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

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

Masters of Evasion – The Bobtail Squid of Okinawa

Posted on June 10, 2019 by Admin11

The spotty bobtail squid ( Eumandya parva ) is a small cephalopod found in the beautiful waters surrounding Okinawa. They are hard to find due to their small size. Persistence, patience, and diving with a buddy with good eyes will increase your chances of finding them.

Scientific name: Eumandya parva
Common Name: Bobtail Squid
Found: Ryukyu Islands
Habitat: Open water @ night
Average Size: 15mm – 25mm

Bobtail squid have eight arms and two tentacles used to capture prey. They have a two part parrot-like beak used for feeding. They primarily feed on small crustaceans free swimming in open water.

What’s really impressive about cephalopods is that they are masters of evasion. They are equipped with advanced mirroring cells. These cells can change shape and color to match their surrounding. These vibrant chromotophores are also used for communication and attracting a mate.

The bobtail squid has the ability to produce a large ink cloud (smoke screen) when in danger. This cloud of ink will confuse predators and give the squid a chance to escape safely.

Squid have wing-like fins used for precision movement through the open water. Their siphon is used for jet propulsion, allowing a clean getaway from predators.
They can also evade predators by covering up with sand to avoid detection.

I found this large Euprymna brenneri covering itself with sand to avoid detection. I have only seen two of these in the waters of Okinawa. A new species decribed in December 2019.

Mating season occurs in the summer months.

Look close and you can see the white bundle of spermatophores produced during the mating process. The eggs will be fertilized and attached to a safe location under a reef ledge. Tiny bobtail squid will hatch from their eggs in three weeks.

If you would like to learn more about the Cephalopods of Okinawa, check out my previous posts on the blue-ringed octopus, pygmy squid, pharaoh cuttlefish and the shell eating octopuses of Okinawa.

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

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

Get Fa-Millerized with the Nature of the Ryukyu Islands – – – SUBSCRIBE BELOW

The Shorelines of Iheya Island Turn Red

Posted on May 28, 2019 by Admin11

Mass coral spawning took place this weekend on Izena, Iheya and Noho Island. I have been waiting a very long time to see this natural wonder.

Coral spawn slick

Coral spawning takes place late at night during high tide. When many species of coral spawn on the same night it naturally forms a mass of gametes know as a coral spawn slick. These coral slicks eventually wash ashore the next morning. These brightly colored coral slicks give off a very strong odor that will stick in my memory forever.

Coral spawn slick

Coral spawn slick art

Iheya beach – RW&B

While exploring the island we stumbled upon more bright coral slicks. We often explored beaches polluted with single use waste. As you can see our trash is a series problem in our oceans and the shorelines worldwide.

Coral spawn slick and trash

Pink Coral spawn slick

Look close and you can see single-use waste and micro plastic floating on the surface of the water

Coral colored spawn slick

Red coral splash

Noho Island had a thick smelling coral slick at the local fishing port. A group of locals showed up to go swimming but immediately decided it was a bad idea and went to another location.

Noho – Fishing port

Coral spawn slick washed up

Noho fishing port

Learn more about making a difference, TEDx talk | Adapting to or Changing Environment by Shawn M Miller

My Mission: To document and preserve the wildlife of the Ryukyu Islands

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

Testing the Nauticam NA-D500 Underwater housing

Posted on May 4, 2019 by Admin11

It’s been a blast shooting with the Nikon D500 DSLR combined with the Nauticam Na-D500 housing. I am pleased with the superior quality and design of the entire system. My underwater rig is setup for shooting macro with two Sea & Sea YS-D2 strobes and a variety of Sola lights. I customized it slightly by mounting a Light & Motion Sola compact tray and loc-line arm kit to the bottom of the housing. This allows me to easily attach other Sola lights underwater based on my vision.

Nauticam NA-D500 shower

My favorite features of the Nauticam NA-500 Underwater housing

Internal camera lock-to prevent movement
Vacuum and leak detection system, Green is good!
Port lock system and audible housing lock latches
Super responsive optic flash system
Comfortable hand grips

I tested the Nikon D500 system with the Nikon AF-S Micro NIKKOR 60mm f/2.8G ED lens and the Nikon AF-S DX Micro NIKKOR 40mm f/2.8G lens. Both are responsive and quality pieces of glass. The great news is that they 40mm is compatible in the NAU-18701 port as well.

Below are my favorite fourteen photographs taken with the D500 underwater in the beautiful waters of Okinawa.

Bobtail Squid – D500|40mm

Hermit crab – D500|40mm

Reef squid D500|60mm

Nudibranch D500|40mm

Chromodoris hintuanensis D500|60mm

Paintpot cuttlefish D500|60mm

Dinahs Goby D500|60mm

Flatworm D500|60mm

Ryukyu Eyes D500|40mm

Pontoh’s Pygmy Seahorse D500|60mm

Fluorescence Nikon| 60mm

Bobtail squid D500|60mm

Eyes of Okinawa D500 | 60mm

If your planning on buying a Nauticam underwater housing online, I recommend Bluewater Photo, they are extremely knowledgable and have outstanding customer service.

I want to thank Black Fin Grouper, Light & Motion and Nightsea for all their continuous support over the years. Thank you!

Get Fa-Millerized with the Nature of the Ryukyu Islands – – – SUBSCRIBE BELOW

The Eyes of the Underwater World by Shawn Miller

Posted on May 2, 2019 by Admin11

Okinawa offers some of the best Scuba-diving in the world. I really enjoy the art of underwater macro photography. Macro subjects can always be found, it just takes some imagination and good framing to create beautiful underwater abstracts. Animal eyes are challenging and exciting areas to focus on. Below are some of my favorite photographs of vision taken on the Island of Okinawa.

Get Fa-Millerized with the Nature of the Ryukyu Islands – – – – SUBSCRIBE BELOW

Parasitic Isopods of the Ryukyu Islands

Posted on April 27, 2019 by Admin11

Scorpionfish, lionfish and stonefish all belong to the family Scorpaenidae. They all are well camouflaged and highly venomous. Their defensive spines can deliver a painful sting. It’s best to wear exposure protection and maintain good bouncy control to avoid getting envenomated by these ambush predators.

In the 1980’s Robert Bolland stumbled upon an interesting underwater find. He found a tiny undescribed isopod hitching a ride on a scorpionfish. 1984 the parasitic isopod Renocila bollandi from Okinawa was named after him.

Over the years I photographed a dozen of these orange Isopods (Renocilla bollandi)

I have always wondered,

What is the relationship between the two?
Is the relationship mutualism, commensalism, and parasitism?
Why does the isopod only prefer venomous fish (scorpionfish) as its host?
Why does the isopod always stay close to the eye?

See why they call it the bearded scorpionfish (Scorpaenopsis cirrhosa).

Learn more about the hazardous marine life of Okinawa.

Learn more about Robert Bolland and his research at The Okinawa Slug Site.

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

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

Get Fa-Millerized with the Nature of the Ryukyu Islands – – – – SUBSCRIBE BELOW

Okinawa Nature Photography

沖縄自然写真 By Shawn Miller

Category Archives: Scientific finds

Gigantic Hermit Crabs Found On Okinawa

The Most Beautiful Bivalve In The World – Pedum spondyloideum

Spiders, Webs and Warning Signs – Okinawa, Japan

The Chinese soft-shell turtle – Aquatic turtles of Okinawa

Cryptic fish, Comets and Stars by Shawn Miller

Masters of Evasion – The Bobtail Squid of Okinawa

The Shorelines of Iheya Island Turn Red

Testing the Nauticam NA-D500 Underwater housing

The Eyes of the Underwater World by Shawn Miller

Parasitic Isopods of the Ryukyu Islands