Author: Irina

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.

“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.

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. 

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

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!).

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.

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.

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.