The Paintpot Cuttlefish – Cephalopods in Okinawa

Posted on October 13, 2019 by Admin11

The Paintpot cuttlefish (Metasepia tulbergi) is one of the most beautiful marine animals in Okinawa. The skin of the paintpot cuttlefish is toxic (poisonous) if consumed. The paintpot cuttlefish contains a neurotoxin called tetrodotoxin (venom) used to paralyze its prey. Avoid handling or harassing this beautiful animal. If bitten, seek immediate medical treatment.

Scientific name: Metasepia tulbergi
Common name: Paintpot cuttlefish or flamboyant
Distribution: Ryukyu Islands
Habitat: Sandy bottom and coral reefs
Diet: Crabs, shrimp, and fish
Average size: 50-80mm
Color: Golden-yellow with red coloration

Cool facts about the Paintpot Cuttlefish

They have eight arms and two tentacles
They are capable of producing a dark cloud of ink to escape from predators
They have a parrot-like beak used for eating prey
They use jet propulsion to move quickly through the water
They can change their texture, pattern, color, and shape
They use their arms to walk on the sand
They are considered venomous and poisonous

When threatened, the paintpot cuttlefish produces vibrant colors to warn predators that they are toxic. The scientific term for this is aposematism.

They have a two-part parrot-like beak used for feeding.

Cephalopods can produce a cloud of ink to confuse and escape from predators when threatened.

Below is a sequence of images, displaying their ability to change texture, shape, and color. They are masters of camouflage. An example of how well they blend into their environment.

If detected or threatened, they will display colorful warning signs.

Every year, I look forward to finding the gigantic paintpot cuttlefish named Paintpot-Zilla.

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

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

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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

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

Crown of Thorns Starfish – Hazardous Starfish of Okinawa by Shawn Miller

Posted on June 28, 2018 by Admin11

The crown of thorns starfish (Ancanthaster planci) plays an important role in the underwater world. They generally feed on the fastest growing corals, allowing the slower growing coral to establish ground. They are the coral moderators, the gardeners of the sea and help increase the diversity of coral species on the reef.

Mature Crown of thorns starfish © Shawn Miller

Animals that feed on coral are known as corallivores.

Natural coral bleaching © Shawn Miller

In Okinawa, we have a variety of Corallivorous marine snails ( Drupella sp). These small snails have also caused serious damage to coral reefs.

Corallivorous snails © Shawn Miller

The venomous sea star has sharply pointed spines that deliver a painful sting. The spines inject venom which causes extreme pain, discomfort and nausea. Most injuries occur because recreation Scuba divers cut up the starfish with a dive knife and the spine penetrates the hand. The starfish serves a purpose in the ecosystem so leave it alone. They are a native marine animal of the Ryukyu Islands.

COTS of Okinawa © Shawn Miller

In Okinawa, we have had massive COTS outbreaks in the past. These outbreaks have devastated some of the most beautiful shallow water coral reefs.

Possible Outbreak Causes

A natural cycle of nature
The decrease in natural predators that feed on COTS
Increase in food source caused by agricultural runoff, causing a blooming effect.

Coral crabs are one of the natural protectors of the coral reef. The coral provides shelter and food for the coral crabs. The crabs are on call to defend against the coral-eating starfish and other marine predators.

COTS have many natural predators. Over the last twenty-five years, I have observed marine snails, harlequin shrimp, sea anemones and fish feeding on healthy and injured COTS in the wild. I was not able to get photographs of all of this behavior taking place, many natural observations occurred before I purchased an underwater camera.

The trident trumpet (Charonia tritonis) is sought after by fisherman and shell collectors worldwide. The meat is a popular food source and the beautiful shell is valuable.

These large snails are capable of eating mature COTS. Overtaking has reduced populations of this of this predatory snail. More effort needs to be directed to the protection of this species. I have personally observed populations drastically decline over the years.

The Harlequin shrimp feed on juvenile COTS in the wild and captivity. Harlequin shrimp populations are decreasing as well due to the over-collecting for the pet trade market.

Sea anemones are vicious predators and known to feed on the crown of thorns as well.

Red soil runoff contributes to coral reef bleaching and fertilizers entering the water. Could fertilizers, sewage or pollution really be the cause for a massive bloom in plankton causing an outbreak of healthy numbers of baby COTS?

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

Tag Archives: Dangerous marine life of Okinawa

The Paintpot Cuttlefish – Cephalopods in Okinawa

Ryukyuan Pygmy squids and hydroid-eating nudibranchs

Cowrie Shell Eating Octopuses of Okinawa

Parasitic slugs of Okinawa

Crown of Thorns Starfish – Hazardous Starfish of Okinawa by Shawn Miller