Reef ID Books: photo guides about marine animals

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.

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.

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

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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.

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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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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!

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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.

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.

– 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.

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