Some animals can chop off their own heads!

DID YOU KNOW that Elysia marginata is capable of decapitating itself when its body becomes infected with parasites?

Sounds fantastic, but it’s true!

What’s even more bizarre, the head gets around fine without its body. In three weeks, it regenerates a new body, perfectly functioning and parasite-free.

Elysia marginata

“We’ve known for a long time that sea slugs have regenerative capabilities, but this really goes beyond what we had thought,” said Terry Gosliner, senior curator of invertebrate zoology at the California Academy of Science.

To “puff up” is dangerous for pufferfish: myth or not?

Pufferfish will “puff up” as a defense mechanism if they are threatened. A shape that is more than double its original size, round and sometimes covered in spines is much more difficult to bite and isn’t very appetizing to a predator. 

However, just as people should stretch before exercising to avoid injuring themselves, puffers need to stretch out their muscles as well. Inflating yourself full of water so that your skin is stretched tight can be very painful, especially if your muscles aren’t used to it. Even though they sometimes do it just to stretch, puffing up often can be stressful for a puffer. So, it’s best if they do it only when they need to. 

Cyclichthys orbicularis.

Divers! Please avoid frightening puffers deliberately! It sometimes could be dangerous for them.

5 facts you didn’t know about pygmy seahorses.

Hippocampus bargibanti

All seahorses, including pygmies, are part of the family Syngnathidae. Ever since they were first discovered in 1969, pygmy seahorses have become stars of the reef and attract hordes of underwater photographers. 

So what do we know about pygmy seahorses?

  1. Pygmies range in size from 1.4 – 2.7cm, from the snout to the tip of the tail. Human finger nail to toe nail in size.
  2. Like other seahorses, it’s the male pygmy that becomes pregnant. He gives birth to around a dozen young after a gestation of 10-14 days.
  3. They feed on tiny crustaceans that share their local habitat.
  4. Pygmy seahorses differ morphologically from all other seahorses, possessing a single rather than paired gill openings in addition to a brood pouch located on the trunk, rather than the tail.
  5. They don’t have eyelids and are sensitive to light (photographers please note!).
Hippocampus waleananus

Want to know more about Pygmy Sea Horses and other fishes of Indo-Pacific region? Check photoguide Reef Fishes of the Coral Triangle by A.Ryanskiy.

5 facts you didn’t know about Sea hares

Sea hare is any marine gastropod of the family Aplysiidae (subclass Opisthobranchia, phylum Mollusca).Sea hare is characterized by a shell reduced to a flat plate, prominent tentacles (resembling rabbit ears), and a smooth or warty body.

Petalifera ramosa
  1. Sea hares eat large seaweeds. Their color is diet-derived from the pigments of the algae.

2. This amazing invertebrate grows up to 16 inches in length!

3. All are simultaneous hermaphrodites with fully functional male and female reproductive organs. 

4. As they commonly occur in quite crowded numbers during the mating season, it often leads to chains of three or more sea hares mating together. 

5. To protect themselves they release a noxious ink that irritates the would-be predator and stops them in their tracks, in much the same way a skunk protects itself.

Aplysia parvula

More about Sea Hares you can find in the photoguide Nudibranchs of the Coral Triangle by A.Ryanskiy & Y.Ivanov.

5 facts you didn’t know about frogfishes.

Latin name of the family is Antennariidae. There are about 47 known species of frogfish worldwide. Fascinating to divers and deadly for its prey, the frogfish is the ocean’s master of aggressive mimicry.

  1. Many of them can change color over time to camouflage within their surroundings. Unlike the chameleon, they are unable to change its color quickly. The process usually takes several weeks.
  2. Striated, or hairy, frogfishes usually mimic algae or soft corals, but can also mimic venomous black urchins.
  3. Their attack is amongst the fastest in the world, being able to trap prey in 0.006 seconds!
  4. The frogfish lacks a swim bladder. This structure is found in most swimming fishes; it maintains their buoyancy in a similar manner to a diver’s BC.
  5. Juvenile painted frogfish mimic toxic nudibranchs. Because of this behavior, they have little to fear from their own predators while being ignored by their prey, allowing easy ambush.

Unknown facts about well-known scallops

Iridescent Scallop Pedum spondyloideum @Jeanette Johnson

Every diver saw these scallops a lot of times. Some of us even tried to photograph them, fascinated by the row of unusual eyes between the tentacles. Less known it the fact that they help coral host to survive Crown of Thorns predation. Contact by starfish usually caused the scallops to generate repeated powerful jets of water, forcing starfish to move away. Scientists from the University of Queensland (L. M. DeVantier, R. Endean)

“Impact of the jets usually caused starfish to retract the sensory tube feet at the tips of the affected arm, raise the arm, and in most instances move away. However, in several interactions, starfish persisted in moving onto or over the scallop following initiation of the jets. On 2 occasions, this resulted in the starfish being lifted several cm above the coral surface by the continuing jets.”

As you probably already guessed, this clam is also a great subject for photography. More interesting facts and inspiring photos await you in the new book, available as paperback and Ebook.

Living Seashells of the Tropical Indo-Pacific is available

Reef ID Books is delighted to announce the launching of a new photo guide Living Shells of the Tropical Indo-Pacific!

If you are interacting with the ocean – diver, snorkeler, beach goers – you definitely find in the seas not empty shells, but live mollusks. These are  living shells, whose appearance is significantly different from museum specimens. This book serves as a tool for identifying such animals.

The book covers the region from the Red Sea to Hawaii, Marshall Islands and Guam. Inside the book:

  • Photographs of 1500+ species, including one hundred cowries (Cypraeidae) and more than one hundred twenty allied cowries (Ovulidae) of the region;
  • Live photo of hundreds  of species have never before appeared in field guides or popular books;
  • Convenient pictorial guide at the beginning and index at the end of the book.

All links you can find here.

Starfishes and Other Echinoderms of the Tropical Indo-Pacific is available!

Reef ID Books is delighted to announce the launching of Starfishes and Other Echinoderms of the Tropical Indo-Pacific photo guide by Andrey Ryanskiy. 

Sven Kahlbrock from Blue Water Dive Resort (Hurghada, Egypt) called it “A nice book for all, who try to identify these animals and can´t find good literature.”

Starfishes and Other Echinoderms of the Tropical Indo-Pacific is the most comprehensive photo guide to the starfishes and other tropical Indo-Pacific echinoderms. It covers the region from the Red Sea to Hawaii, the Marshall Islands, and Guam. Inside the book you will find:

  • Photographs of 450+ species, including 126 starfish of the region;
  • 100+ species have never before appeared in field guides or popular books;
  • Convenient pictorial guide at the beginning and index at the end of the book;
  • 60 photographs of echinoderm’s associates and predators

All links you can find here.

Night Dive Secrets: strange transparent fishes

Night dive in the tropical Indo-Pacific – it is always a possibility to find something new and strange. If you dived a lot after sunset you probably noticed strange transparent fishes slowly moving near the soft bottom.

Often the have a row of round dark spots running along the midline

They are hard to notice due to the transparent body and cryptic behaviour and not easy to identify to species. But I can suggest a family name: they are juvenile Lizardfishes, Synodontidae. Look again at the eyes and jaws and you’d recognise them!