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

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

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

Ryukyuan Pygmy squids and hydroid-eating nudibranchs

Posted on April 14, 2019 by Admin11

In the summer of 2018, I documented some exciting animal behavior underwater. While searching for the blue-ringed octopus in a shallow reef cut, I stumbled upon the elusive pygmy squid (Idiosepius sp). I first photographed the Ryukyuan pygmy squid back in 2012 and was excited to see another one. This undescribed pygmy squid is only 10mm-14mm in size. It can be difficult to get an acceptable photograph of it free-swimming through the water.

Its amazing how fast squid can change color to blend into the sounding background. Look at that camouflage.

The pygmy squid has defined white nodules on the posterior end of the mantle used for attaching to seaweed and rocks.

I took a few photographs of the tiny squid and it eventually retreated into fireweed (Aglaophenia cupressina).

The fireweed looks like a harmless piece of seaweed but its actually a dangerous stinging hydroid. The fireweed delivers a painful sting causing redness, irritation and infection.

I returned to the exact location a few days later in search of the pygmy squid. I found the fireweed but it was much smaller, as if it was purposely cut down. These fireweed colonies have been in the same reef cut for over six years. What could have caused this devastation? Was it possible that a Scuba Instructor cut down the fireweed colonies for the safety of their students? I mention this because the hydroids are in a high-traffic swim-through area, and some days literally hundreds of divers swim through this reef cut.

My first thought was someone cut down the fireweed but I was wrong. It was actually a brightly colored nudibranch named Tenellia yamasui (Hamatani, 1993). The fireweed was infested with juvenile nudibranchs feeding on it.

You would think that the nudibranchs would be conservative and keep some food for the future. The sea slugs devoured the entire fireweed.

Ever wonder what this stinging hydroid can do to your skin? To learn more about the dangerous animals and treatments, check out my post on The Hazardous Marine Life of Okinawa.

Hydroid sting © Mark Kane

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

Searching for Cephalopods by Shawn Miller

Posted on April 13, 2019 by Admin11

Lately, I have been getting out a lot more on night dives. The conditions have been great for Scuba diving and underwater macro photography. Diving at night is exciting because you never know what you will find. My last dive I stumbled upon a few new brightly colored nudibranchs and an undescribed pygmy cephalopod known as the pharaoh cuttlefish.

Could this pygmy cuttlefish be an undescribed species or just a clever juvenile broadband cuttlefish resembling the sand?

Scientific name: Sepia sp
Common Name: Pygmy or Pharaoh Cuttlefish
Found: Kin bay, Okinawa
Habitat: Sand bottom @ night
Depth: 35feet
Size: 17mm

More than likely this pygmy cuttlefish is Sepiella inermis. The pharaoh cuttlefish is absolutely stunning. I found this large specimen sand-dwelling during a night dive.

If you have never been night diving I highly encourage you to try it. If you want to learn more about Cephalopods of Okinawa, check out my post on the beautiful Blue-ringed octopus.

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

Cowrie Shell Eating Octopuses of Okinawa

Posted on March 25, 2019 by Admin11

In 2010, a friend sent me some beautiful cowrie shells from Hawaii. I noticed that a few specimens had tiny pin holes between the teeth on the underside of the cowrie shell. I asked him what caused this and he stated an octopus. So I decided to test this, I collected a small octopus and placed it in aquarium with no other marine life in the tank.

I placed only live cowrie shells in the tank to see if this octopus would eat the mollusks. I was completely surprised to find out that he was 100% correct.

The tiny drill holes are difficult to see without a magnifying glass.

Strangely, two of the cowrie shells had a drill hole on the top and another on the bottom side. The other eight specimens only had one drill hole on the bottom side. Is it possible that the octopus learned a new behavior? Did it it figure out the most efficient way after the two previous attempts?

All octopuses have a two-part beak used to immobilize and feed on their prey. The beak looks fragile but it one of the toughest and most durable substances made by marine animals.

Cephalopod Beak

My curiosity led me to the questions below Why does the octopus have to drill a hole when there is already a large aperture to feed from? Does the octopus use venom to paralyze the mollusk inside the shell after it drills the hole? If so, does the venom narcotize the mollusk which could allow the octopus to suck out the animal from the shell aperture like a shotgunning effect?

Have you ever wondered how the Okinawans catch small octopuses? Below is a colorful handmade lure made from cone shells and beads. I found it years ago at Awase flats.

My Mission: To Protect and Preserve the Wildlife of the Ryukyu Islands for Future Generations

If you would like to help me make a difference Please check out my Patreon Site 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.

#MakeTheSwitch4Nature

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

Parasitic slugs of Okinawa

Posted on March 2, 2019 by Admin11

Gymnodoris nigricolor Is a tiny nudibranch that attaches to the fins of gobies. It is found in the winter months and then it seems to completely disappear when the water warms up. This nudibranch is by far the hardest to photograph because of its size and it stays attached to it’s host. When the goby feels threatened, it retreats into its burrow taking the tiny slug down the hole with it.

In order to photograph sand-dwelling gobies you will generally need a 50mm-100mm macro lens.

Be patience and move slowly. If your lucky the goby will accept your presence without retreating.

February 2018, I was fortunate to find Gymnodoris nigricolor crawling on the sand in search of a host

When the slug finds a host it will attach onto the closest fin.

Look close and you can see the buccal apparatus of the slug clamping down.

Once its locked down, the goby cannot shake the slug off.

No one really knows what happens next. Why does the nudibranch attach to the fins of its host？ Does this specialist feed on only the fins of gobies or is there another reason？

If you would like see stunning photographs of more sea slugs check out my post on nudibranchs

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 Fishing Spiders of the Yanbaru forest By Shawn Miller

Posted on February 8, 2019 by Admin11

The Okinawan fishing spider (Dolomedes orion) is one of the most unique spiders we have on the Island of Okinawa.

My fishing hole

Most fishing spiders are ambush predators. They have the ability to catch prey on the land, on the surface of the water and even underwater. Fishing spiders use vibrations to attract insects like water striders. The spiders vibrations simulate a helpless insect floating on the surface of the water.

Dolomedes sp, Iriomote Island

I have seen amazing photographs of these fishing spiders eating frogs. I personally have observed Dolomedes orion eating insects only.

Dolomedes orion hunting

The beautiful color contrast allows them to blend in with their surrounding environment to avoid being seen.

Dolomedes orion feeding

It is thought that the white reflective leg sections are used to lure in prey when hunting during the daytime, but do they serve a purpose at night?

MYN Technique

Look close, the female fishing spider handles her egg sack with extreme care.

Female protecting her egg sack

Meet Spi-Zilla, This is an average healthy specimen found in the Yanbaru forest.

Huge spiders on Okinawa

I used my iPhone to compare the size of this huge spider, I kept my distance for sure.

Iphone comparison, Thanks R Shobe

Please be respectful to the wildlife. If they show any signs of stress or aggression give them their space and move on. Learn more about the Huntsmen spiders of Okinawa

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.

The lonely hermit crab adapting with a lug-nut cover by Shawn Miller

Posted on December 22, 2018 by Admin11

This week I went out camping with some friends on Miyagi Island. While searching for fire wood I stumbled upon a blueberry hermit crab (Coenobita purpureus) adapting with a metal lug-nut cover. I have previously found many hermit crabs adapting with other man-made items such as pet bottle caps, glass bottles, light bulb ends, laundry detergent caps and various scoops. I was pretty excited about this and had to show off the interesting find to my friends.

The blueberry hermit crab is temporarily making due with the available lug-nut cover. It will eventually switch to a shell when it finds an appropriate size. If you would like to learn more about this adaptive behavior please check out my post on “Crabs with Beach trash homes”

* All Coenobita species on Okinawa are recognized as a living natural monument of Japan.

This slideshow requires JavaScript.

I also photographed the hermit crab on white for the Meet Your Neighbours Project. The technique eliminates distracting elements out of the background and shows the true beauty of the animal. The images are used for conservation awareness and educational purposes.

Later I offered lug nut a Turbo seashell and within five minutes he switched over to his new home.

Okinawa hermit crab

We were fortunate to have beautiful weather. Don’t forget to get out for some Nature Therapy! We all need a break from our busy lifestyles.

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

paypal.me/maketheswitch4nature

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.

Blue Streaks of Light by Shawn Miller

Posted on December 3, 2018 by Admin11

The Common Kingfisher (Alcedo atthis) is one of the most beautiful birds of the Ryukyu Islands. They are a common species found near freshwater sources. I have observed these tiny birds four hours at a time. I know a few local nature photographers that have dedicated their lives to documenting the behavior of this beautiful bird.

Scientific name: Alcedo atthis
Common Name: Common Kingfisher
Distribution: Worldwide
Habitat: Forests near rivers and ponds
Diet: Fish and prawn
Average Size: 16cm

The Common Kingfisher spends most of the day patiently waiting on tree branches above the water.

They watch from above and pick out the perfect sized fish.

They dive bomb with very little warning. Below is the sequence of the catch.

After the feast, the Kingfisher preens itself.

Look close and you can see the process of the Kingfisher casting a pellet. They can’t digest the exoskeleton of prawn and fish scales. They regurgitate the waste in a pellet form.

I challenge you to get outdoors for some Nature Therapy.

People often ask me what is the purpose of conservation photography? Having the ability to affect some form of positive change in the environment and make a global difference with the photographs. Hopefully, the images will inspire people to care more about nature and make a positive difference in the environment.

If you would like to use any of my photographs, please contact me directly. Have a great day!

Deadliest Marine Fish of the Ryukyu Islands by Shawn Miller

Posted on November 27, 2018 by Admin11

The reef stonefish is the most venomous fish found on Okinawa. The stonefish resembles an encrusted rock and sometimes has algae growing from its skin. The reef stonefish is an ambush predator and spends its day patiently waiting for a fish to pass by. The stonefish is not aggressive at all. It is extremely dangerous because it doesn’t show any flashy warning signs. The spines deliver an extremely painful sting with strong venom injected into the body.

Reef, rock, sponge or fish?

If you spend any time exploring the ocean, I encourage you to look at these images and get familiar with these deadly facial features.

The reef stonefish will also bury itself in the sand. Does that make it a sand stonefish?

The false stonefish is much smaller and is usually found in shallow water. Its a master of concealing itself from visual detection.

The false stonefish is more active than the reef stonefish. It generally gives predators a warning sign by displaying its brightly colored pectoral fins.

Most of the false stonefish and scorpionfish will fluoresce beautifully under blue light.

Ways to avoid injury

- Be respectful and avoid harassing, touching and feeding marine life

- Maintain good buoyancy control

Wear exposure protection- felt bottom booties

If you would like to use any of my photographs, please contact me directly.

Have a great day!

Fly like a gray-faced buzzard eagle by Shawn Miller

Posted on November 14, 2018 by Admin11

The Gray-faced buzzard (Butastur indicus) is one of the most fascinating predatory birds of the Ryukyu Islands. They are a common species that migrate to Okinawa in the first week of October. I have observed these mid-sized predatory birds feeding on small insects, rodents and lizards.

Scientific name: (Butastur indicus)
Common Name: Gray-faced buzzard hawk or eagle
Distribution: Winters in Okinawa
Habitat: Forests, parks, farm fields, and local neighbors
Diet: Lizards, grasshoppers and a variety of insects
Average Size: 50cm

They are mainly found perching high in trees. Notice how well they blend into the surrounding environment.

They are also found perching high on electrical poles, wires, and rooftops.

Look close and you can see the nictitating membrane, its used to protect and moisten the eye.
I recommend using a telephoto lens to photograph these shy birds. They have a tendency to fly away as soon as you point the camera lens at them.

In recent years I have noticed an increase in the population of these beautiful migratory birds.

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

Okinawa Nature Photography

沖縄自然写真 By Shawn Miller

Category Archives: Animals of Okinawa

Parasitic Isopods of the Ryukyu Islands

Ryukyuan Pygmy squids and hydroid-eating nudibranchs

Searching for Cephalopods by Shawn Miller

Cowrie Shell Eating Octopuses of Okinawa

Parasitic slugs of Okinawa

The Fishing Spiders of the Yanbaru forest By Shawn Miller

The lonely hermit crab adapting with a lug-nut cover by Shawn Miller

Blue Streaks of Light by Shawn Miller

Deadliest Marine Fish of the Ryukyu Islands by Shawn Miller

Fly like a gray-faced buzzard eagle by Shawn Miller