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.

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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.

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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.

Find all purchase links 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!

Meet Hippocampus nalu, new Pygmy Seahorse from South Africa

Extremely cryptic and always cute, Pygmy Seahorses are very popular among scuba divers and underwater photographers. First of them, Hippocampus bargibanti was described in 1970 and until 2003 remained alone, later accompanied by Hippocampus denise & Hippocampus colemani (2003) Hippocampus pontohi  (2008) Hippocampus satomiae & Hippocampus waleananus (2009), all from Western Pacific. Hippocampus japapigu was described from Japan (2018). Finally, 2 days ago (May 19) Hippocampus nalu was described from Sodwana Bay, South Africa. For me, this is the day of victory for underwater photographers and citizen science.

Hippocampus nalu.  Photo: Dr Richard Smith

The Sodwana pygmy seahorse was described by Drs. Louw Claassens and Richard Smith. But it was actually discovered three years before, when a local dive guide Savannah Olivier found and photographed this tiny creature. Dr Louw Claassens and Dr Dave Harasti arrived in Sodwana in 2018 looking for an entirely different animals. We can just imagine how shocked they were after dive guide demonstrated a photo of local pygmy seahorse! Definitely undescribed one, found 8000 miles away from other members of the group!

If you photographed pygmy seahorses you know it is far from easy! Sodwana Bay reefs are exposed to waves action and conditions for underwater macro photography are challenging. Congratulations to scientists and Savannah Nalu Olivier, Instructor and Dive Master, Pisces Diving, Sodwana. Great job!

Pygmy Sea Horses: more information and photos: Reef Fishes of the Coral Triangle

Crown of Thorns: the frightening beauty

Acanthaster planci (Crown of Thorns) juvenile, 1.5 cm.

First of all about the beauty: Crown of Thorns juveniles are really handsome in their own spiky-snowflake way. They develop spines and begin to feed on coral only about one year of age, drifting as planktonic larval before that age. Getting bigger and bigger they are gaining more and more brutality and spike length.

Acanthaster planci (Crown of Thorns) juvenile, 5 cm. with commensal shrimp

Adult Crown of Thorns can grow up to a huge size – more than metre in diameter! A few interesting facts:

– Crown of Thorns are a natural part of the coral reef ecosystem. An increase in their numbers only occurs when the reef is unhealthy.

– In healthy reefs Crown of Thorns are playing a positive role by eating some of the faster-growing corals and giving the slower-growing corals a chance.

Acanthaster planci (Crown of Thorns) young adult

– Adult Crown of Thorns can survive without feeding for up to nine months. The normal lifespan of a Crown of Thorns is about four or so years.

Acanthaster planci adult
Acanthaster planci feeding on branching corals