Tag Archives: dangerous aquatic animals of Okinawa

Parasitic Isopods of the Ryukyu Islands

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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.

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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.

Renocila bollandi from

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?

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Scorpionfish Okinawa

Scorpaenopsis diabolus scorpionfish

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

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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

Deadliest Marine Fish of the Ryukyu Islands by Shawn Miller

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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?

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Reef stonefish ( synanceia verrucosa ) Sunabe, Okinawa

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

37059972063_6a80c038b1_oThe reef stonefish will also bury itself in the sand. Does that make it a sand stonefish?
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The false stonefish is much smaller and is usually found in shallow water. Its a master of concealing itself from visual detection.

43841230074_9a32ff9591_oThe false stonefish is more active than the reef stonefish. It generally gives predators a warning sign by displaying its brightly colored pectoral fins.

False stone fish

Most of the false stonefish and scorpionfish will fluoresce beautifully under blue light.
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 Ways to avoid injury

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

 

    • Maintain good buoyancy control

 

  • Wear exposure protection- felt bottom booties

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!

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

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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.

Cots

Mature Crown of thorns starfish © Shawn Miller

Animals that feed on coral are known as corallivores.

Natural coral bleaching

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 Drupella sp

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

COTS of Okinawa © Shawn Miller

COTS Venomous spines

COTS venomous spines © 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.

Juvenile COTS feeding

Juvenile COTS feeding © Shawn Miller

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.

Coral crabs (Calcinus minutus)

Coral crabs (Calcinus minutus) © Shawn Miller

Coral crabs (Cymo melanodactylus)

Coral crabs (Cymo melanodactylus) © Shawn Miller

Protective Coral crab (Trapezia sepata)

Protective Coral crab (Trapezia sepata) © Shawn Miller

Coral hermit crab (Pagurita vittata)

Coral hermit crab (Pagurita vittata) © Shawn Miller

Gall crab, Maeda point

Gall coral crabs © Shawn Miller

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.

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Marine snails feeding on COTS © Shawn Miller

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.

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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.

Trident trumpet © Shawn Miller

Trident trumpet © Shawn Miller

Trident trumpet feeding

Trident trumpet feeding © Shawn Miller

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.

Harlequin shrimp feeding

Harlequin shrimp feeding © Shawn Miller

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

Sea anemone

Sea anemone © Shawn Miller

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?

Okinawa agricultural runoff

Okinawa agricultural runoff © Shawn Miller

 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

 

Searching for The Blue Ringed Octopus at Maeda Misaki -Okinawa

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The Blue Ringed Octopus (Hapalochlaena lunulata) is one of the most beautiful marine animals in Okinawa. It’s only the size of a golf ball, but extremely venomous.

    • Scientific name: Hapalochlaena lunulata

 

    • Common name:  Blue-ringed octopus

 

    • Distribution:  Ryukyu Islands

 

    • Habitat: Tide pools and shallow water coral reefs

 

    • Diet: Crabs, shrimps, and fish

 

    • Average size: 8-12cm

 

  • Color: Golden-yellow with blue rings
Blue Ringed Octopus

Blue Ringed Octopus © Shawn Miller

Interesting facts about octopuses in general 

  1. Yes- you got it. The plural of octopus is octopuses.
  2. They are capable of producing a dark cloud of ink to escape from predators
  3. They have a parrot-like beak used for eating prey
  4. Octopuses have eight arms and are capable of regrowing them
  5. They use jet propulsion to move quickly through the water
  6. The Blue-ringed octopus can kill a human with one bite

I first photographed the Blue-ringed octopus at Maeda point in 2011.  This intense octopus was published on National Geographic Your Shot Daily Dozen.

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Blue-ringed octopus -Nat Geo © Shawn Miller

They are hard to find due to their small size. Persistence, patience, luck and a diving with a buddy with good eyes will increase your chances.

Blue-ringed octopus

Blue-ringed octopus © Shawn Miller

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Blue-ringed octopus on a shell © Shawn Miller

Blue-ringed octopus

Blue-ringed octopus blending in © Shawn Miller

Blue Ringed Octopus

Blue Ringed Octopus © Shawn Miller

Blue-ringed octopus

Blue-ringed Octopus spread out © Shawn Miller

Mating season occurs in the summer months. A rare event that happens quickly.

Octopus mating

Octopus mating © Shawn Miller

People often ask me what is your most memorable experience underwater.  Definitely swimming along the reef with a Blue-ringed Octopus.

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Blue-ringed octopus swimming © Shawn Miller

The difficult part is locking on focus and photographing it when the moment happens.

Blue-ringed octopus in open water

Blue-ringed octopus in open water © Shawn Miller

Blue-ringed octopus in open water © Shawn Miller

Blue-ringed octopus in open water © Shawn Miller

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

Cephalopod ink

Cephalopod ink blob © Shawn Miller

My dive & jive buddy spotted this Blue-ringed octopus feeding on a crustacean during a night dive recently.

Blue ringed Octopus feeding

Blue-ringed Octopus feeding © Shawn Miller

The two-part parrot-like beak cephalopods use for feeding.

Cephalopod Beak

Cephalopod Beak © Shawn Miller

The single Blue-ringed Ocellated octopus (Octopus ocellatus) is scarce in Okinawa. I have seen and documented only one live animal.

Ocellated Blue ringed Octopus

Ocellated Blue-ringed Octopus © Shawn Miller

If you would like to increase your chances of getting better photographs of Cephlapods, I recommend using the Light & Motion Sola 1200 underwater modeling light. The red light feature allows the user to get in close without disturbing the marine life.

Underwater setup with sola 600

Underwater setup with sola 600

Anyone in Okinawa that would like to try a Light&Motion Sola light, I will gladly let you test one of my personal lights on a night dive.

Learn more about the Light & Motion Sola series.   http://www.lightandmotion.com/choose-your-light/sola

 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