Fun Facts About Octopuses

  1. Masters of Camouflage: Octopuses are experts at blending into their surroundings. They can change their color and texture to match the environment, making them incredible escape artists and hunters.
  2. Three Hearts, Blue Blood: Octopuses have three hearts and blue blood! Their hearts pump copper-rich blood, which gives it a bluish tint and helps them survive in cold ocean depths.
    Greater Blue-Ringed Octopus

    3. Eight Arms, No Bones: Unlike most animals, octopuses don’t have any bones. Instead, their bodies are made of soft tissue, allowing them to squeeze through tiny spaces and contort their arms in all directions.

      4. Super Intelligent: Octopuses are highly intelligent creatures. They can solve puzzles, navigate mazes, and even learn through observation. Some species have been known to open jars to get to their food!

      Starry Night Octopus

      5. Short Lifespan, Rapid Growth: While octopuses are incredibly smart, they have relatively short lifespans. Most species only live for 1-2 years, but during that time, they grow rapidly from tiny hatchlings to full-grown adults.

        6. Jet Propulsion: Octopuses are capable of jet propulsion, which means they can quickly move through the water by expelling water from their mantle cavity. This helps them escape from predators and catch prey.

        Giant Octopus

        7. Incredible Problem-Solvers: Octopuses have been observed using tools in the wild, such as using coconut shells for shelter. They can also unscrew lids and manipulate objects with their arms, showcasing their problem-solving abilities.

          Isn’t it fascinating how these eight-armed wonders navigate the ocean with such unique traits?

          More about Octopus & other Indo-Pacific marine creatures you can find in the photo guide Coral Reefs Philippines

          Introducing: ‘Life on the Reef’ New Photo Guide

          A new photo guide “Life on the Reef:Corals, Sea Squirts, Sponges, Bryozoa, Comb Jellies, Marine Plants Indo-Pacific Field Guide” by Andrey Ryanskiy has just been published!

          Till May, 31 the special price on eBook, 13,49$, is valid. Link

          Corals, jellyfish, sponges, tunicates, and bryozoans form the very essence of a coral reef, representing most of its biodiversity. Their taxonomy has undergone significant changes over the past 15 years.

          Despite this, popular and accessible guides to these species have not been published for many decades. Andrey Ryanskiy’s new book in the Reef ID Books series aims to fill this gap.

          Together with this volume, the total coverage of the species in the Reef ID Books series of eight books reaches an incredible number of 8500 species!

          You can buy this eBook Travel Set at a special price of 99$! Link

          Featuring over 1,430 species and 2,100 photographs, this book offers a comprehensive look at the benthic community.
          It not only helps scuba divers, underwater photographers, and enthusiasts understand what they see underwater but also provides information and numerous examples of macrolife associated with corals, hydroids, sponges, and tunicates.

          The photo guide is also available as a paperback & hardcover on Amazon & eBook oon Apple store

          5 Facts you Might Not Know about Sea Stars

          These quirky creatures of the ocean have some fascinating facts that will leave you in awe.

          1.  Sea stars aren’t actually fish! They belong to a group of marine invertebrates called echinoderms, which also includes sea urchins and sea cucumbers.

          2.  Sea stars have a unique way of moving. Instead of using fins or flippers, they have hundreds of tiny tube feet on their undersides. It’s like they have their own built-in suction cups, making them the original “hands-free” explorers of the ocean.

          3. Most Sea stars can regenerate their limbs. If a Sea star loses an arm, it can actually grow it back! Talk about having the ultimate superpower of self-renewal.

          Torn-of-Crown Sea Star

          4.  Sea stars have a peculiar way of eating. They have a stomach that can be pushed out of their body to engulf their prey. It’s like having a conveyor belt of digestion! After a meal, they retract their stomach back into the body.

          5. Ever wondered how Sea stars reproduce? Well, some species have separate genders, but others can change their sex! They are true masters of adaptation and gender-fluidity.

          More about Sea Stars & other echinoderm like Sea Cucumbers, Sea Urchins & others you can find in the photo guide Starfishes and Other Echinoderms of the Tropical Indo-Pacific

          Fun Facts About Anemonefish

          Did you know that anemonefish, also known as clownfish, are not only adorable but also fascinating creatures? Dive into the vibrant world of these colorful reef dwellers with our fun facts:

          Spinecheek Anemonefish

           1. Mutual Relationship: Anemonefish have a unique symbiotic relationship with sea anemones. They live in the protective tentacles of the anemones, which provide shelter from predators, while the fish, in turn, bring food to the anemones and remove parasites.

           2. Gender-Bending: Anemonefish have the ability to change their gender! When the dominant female dies, the dominant male transforms into a female, and the next in line becomes the new male. It’s an extraordinary adaptation for maintaining a healthy population. 

          Pink Anemonefish

          3. Protective Parents: Anemonefish are incredible parents. After laying their eggs on a flat surface close to the anemone, the male diligently guards and aerates them until they hatch. Once the eggs hatch, the parents continue to protect and care for their tiny offspring.

          Twoband Anemonefish aerating its eggs

          4. Immune to Anemone Sting: Anemones have stinging cells that can harm other fish, but anemonefish have a special mucus coating on their skin that protects them from the anemone’s sting. They can safely navigate through the anemone’s tentacles without getting hurt. 

          Western Anemonefish also known as Nemo

          5. Communal Living: Anemonefish are social creatures and often live in small groups called “clans” or “schools.” Within these groups, there is a strict hierarchy, with the largest and most dominant female being the leader.

          More about Anemonefishes & other beautiful Indo-Pacific fishes you can find in the photo guide Reef Fishes of the Coral Triangle

          Scorpionfish: Facts You Might Not Know

          Have you ever come across the enigmatic scorpionfish during your underwater explorations? Today, we are excited to share some fascinating facts about these incredible creatures that you may find intriguing.

          Ruby Scorpionfish

          1. Scorpionfish are masters of camouflage, often blending seamlessly with their surroundings due to their mottled and sometimes colorful skin patterns, making them highly effective ambush predators. 

          2. These fish are equipped with venomous spines on their dorsal, anal, and pelvic fins, which they use for self-defense. Their venom can cause intense pain, swelling, and in rare cases, even death in humans, making them a hazard to unwary divers and fishermen. 

          Ocellated Scorpionfish

          3. Scorpionfish have a unique hunting technique, using their pectoral fins to “walk” along the seafloor and disturb the substrate, flushing out potential prey such as small fish and crustaceans. 

          4. They are generally solitary and territorial creatures, often remaining in the same area for extended periods, waiting patiently to ambush passing prey.

          Filamentous Scorpionfish

          5. Scorpionfish are known for their elaborate courtship displays, with males performing dances and visual demonstrations to attract females before spawning. 

          6. Despite their venomous nature, scorpionfish are a popular target for recreational fishermen and are considered a delicacy in many parts of the world, though handling and preparing them requires caution.

          Ambon Scorpionfish

          More about Scorpionfishes & other beautiful Indo-Pacific fishes you can find in the photo guide Reef Fishes of the Coral Triangle

          Nudibranch Spanish Dancer – the Most Iconic & Beautiful Sea Creature

          This mesmerizing creature is one that divers around the world strive to see during their night dives. Let’s uncover some fun facts about this captivating species:

           1. Spanish dancer earned its name due to its graceful, rhythmic movements that resemble a flamenco dancer’s twirling skirt. 

          2. These nudibranchs are known for their striking coloration, featuring bright red or orange bodies. Their vibrant appearance serves as a warning to potential predators that they are toxic or distasteful.

          3. Spanish dancers are quite large for nudibranch standards, reaching lengths of up to 60 centimeters. Their size, combined with their vivid colors, makes them a popular subject for underwater photographers. 

          4. Unlike most nudibranchs, Spanish dancers are not strictly herbivorous. They primarily feed on toxic sponges, which contain chemicals that they can store in their own bodies for defense.


          5. During mating, Spanish dancers engage in a beautiful courtship dance involving synchronized movements. They release their eggs and sperm into the water, where fertilization occurs externally. 

          6. Nudibranchs, including Spanish dancers, are hermaphrodites, meaning they possess both male and female reproductive organs. This allows them to mate with any other mature individual they encounter.

          More about Spanish Dancers & other beautiful nudibranchs you can find in the photo guide Nudibranchs of the Coral Triangle

          Red Sea Fish Guides for scuba divers and underwater photographers

          For many of us, the Red Sea is the place of our first scuba dives. And the place of the first acquaintance with the world of tropical fish and corals. A world of bright colours and such unusual sea animals that you want to understand what you are looking at.

          This is where books come to help us. My first book – of course it was yellow Debelius! Red Sea Reef Guide, to be precise. First published in 1997, this book has only changed its cover since then. And this is my first love in the world of fish identification books. No one has ever asked the question – is this book about the fish of the Red Sea? The answer will be given later.

          I soon realised that I was seeing a lot of things underwater that were not in this book. Lieske-Myers arrived on time – Coral Reef Guide Red Sea, much more detailed and comprehensive. But some time passed and I asked myself the same question. Is this book about the fish of the Red Sea?

          The answer in both cases is the same and lies on the surface – you should carefully look at the covers and first pages of the books. Both books are about the Red Sea and surrounding seas. And a large proportion of the fish presented in these wonderful books have never been seen in the Red Sea. Gulf of Aden, Somalia, Oman. Not spoiled by the attention of tourists. But they are interesting in terms of marine biology. And the authors’ desire to share with readers photographs of fish from this region is understandable. Let it be towed to the Red Sea. But this sometimes creates funny situations. Like pages where none of the fish are present in the Red Sea – but only experts notice this.

          Both of the books mentioned above are great. And with their help it is possible to identify hundreds of species of fish from the Red Sea – 436 in the first and 556 in the second. But the years passed – and then decades. Dozens of new species of Red Sea fish have been described, many have changed their names. I already lived in Sharm el Sheikh in Sinai. And when it became difficult to identify my underwater photographs with old books, I prepared and published Red Sea Marine Life book in 2022. More than 800 species of fish, 260 species of corals. A total of 2120 species, including nudibranchs, crustaceans and others. My friends helped me with photographs of many rare species, but two thirds of the photographs in the book are mine.

          My job of identifying my own underwater photos has been made a lot easier! Actually, this is why the book was created, like my other books. The only problem is that I continue to scuba dive in the Red Sea. And while diving I continue to find new interesting fish and other reef animals. Time for an update? But it will be endless! On the other hand – why not?

          The material is a subjective opinion and therefore does not contain conclusions. But it contains objective information

          Best Regards, Andrey Ryanskiy

          5 Things You Might not Know About Rays

          Rays are fascinating creatures that inhabit our oceans and have some surprising characteristics.

          Round Ribbontail Ray

          1. Rays Are Not Actually Fish: Contrary to popular belief, rays are not classified as fish. They belong to a distinct group of cartilaginous fishes called elasmobranchs, which also includes sharks. 

          2. Electric Rays: Some species of rays, known as electric rays, have the incredible ability to generate and discharge electric shocks. These shocks are used for various purposes, such as hunting prey and self-defense.

          Blackspotted Electric Ray

          3. Winged Swimmers: Rays are renowned for their unique flat body shape, which resembles a pair of wings. This design allows them to gracefully glide through the water, effortlessly maneuvering and often appearing as if they are flying.

           4. Venomous Stingers: Many ray species possess a venomous stinger located at the base of their tail. These stingers are primarily used for defense and can cause painful injuries if stepped on or accidentally touched.

          Spotted Eagle Ray

          5. Rays Reproduce Differently: Unlike most fish, rays have a unique reproductive system. Instead of laying eggs, female rays give birth to live young. These pups develop within the mother’s body and are nourished through a placental connection until they are ready to be born. 

          Next time you encounter a ray, remember these fascinating facts and appreciate the remarkable diversity of these mesmerizing creatures in our oceans!

          More about rays you can find in the photo guide Coral Reefs Maldives

          Strange Ocean Animals part 1 – Fringed Worms

          The small city of Dahab in southern Sinai is famous for its variety of underwater habitats. Some of them are difficult to find anywhere else. The rounded rocks near the bridge in the middle of town remind me of a couple of dive sites in Anilao. Basura and Mato Point, and it’s not easy to remember the same ones in other places.

          Many people, including scuba divers, enter the water every day in this place, next to which there are two diving centers. But no one explores shallow places, less than 2-3 meters deep. Meanwhile, you can find a lot of interesting things there and I will talk about these finds from time to time.

          Cirratulids are also called fringed worms because their bodies appear to have a fringe of fine threads along the length. This fringe, in fact, is the gills. Each thread is hollow and is flooded with hemoglobin-bearing blood.

          Colonies of Tharyx spp. with a diameter of 12-15 cm, most often found under the edges of stones, 1.5-2 m deep. I used underwater camera with +10 wet lens to make this super-macro shot. To the naked eye, they are tiny underwater creatures with thread-like gills thinner than a human hair.

          This is what a larger fragment of a densely populated colony of these underwater creatures looks like. As far as I know, only species of the genus Tharyx of this family drill into calcareous substrates – shells and corals. I have not found any mention of findings of marine worms of this genus in the Red Sea. It is very likely that they have not yet been described by marine biologists.

          I thank Dr. Vasily Radashevsky for his help in identifying these strange ocean creatures. More information in my book – The Weird and Wonderful World of Marine Worms

          Best, Andrey Ryanskiy