Porcelain crab
Porcellanella triloba

Porcelain crab filter feeding

Porcelain crabs are decapod crustaceans in the family Porcellanidae, which superficially resemble true crabs. They are a good example of carcinisation, whereby a non-crab-like animal (in this case a relative of a squat lobster) evolves into an animal that only a specialist would know is not a true crab.
Porcelain crabs can be distinguished from the true crabs by the apparent number of walking legs (three instead of four pairs, the fourth pair is actually hidden under the carapace), the apparent lack of a wrist (carpal) segment on the chelipeds, and long antennae originating on the front outside of the eye stalks. The abdomen of the porcelain crab is long and folded underneath it, free to move. In fact, when alarmed, the crab might swim by flapping its abdomen.

Porcelain crabs share the general body plan of a squat lobster (Galatheidae), but their bodies are more compact and flattened, an adaptation for living and hiding under rocks, as well as squeezing into little nooks and crannies. The porcelain crabs are quite fragile animals, and will often shed their limbs, hence their name. This trait is useful for these crustaceans because it helps them escape if a limb is grabbed by a predator or caught between rocks shifting in the current. A broken-off piece of limb may still continue to move for a short while, distracting the would-be predator as the crustacean flees. The lost appendage can grow back over several moultings. Porcelain crabs have large chelae (claws), which are used for territorial struggles, but not for catching food.

Feeding is accomplished instead by combing plankton and other organic particles from the water using long setae (feathery hair or bristle-like structures) on the mouthparts, where they will later be scraped off and consumed into the mouth. These animals will also scavenge on the sea floor for detritus.

A Lionfish is any of several species of venomous marine fish in the genera Pterois, Parapterois, Brachypterois, Ebosia or Dendrochirus, of the family Scorpaenidae. The lionfish is also known as the Turkey Fish, Dragon Fish, Scorpion or Fire Fish. They are notable for their extremely long and separated spines, and have a generally striped appearance, red, brown, orange, yellow, black, maroon, or white.

The lionfish is one of the most venomous fish on the ocean bottom floor. Lionfish have venomous dorsal spines that are used purely for defense. When threatened, the fish often faces its attacker in a head-down posture which brings its spines to bear. However, a lionfish's sting is usually not fatal to humans. If a human is envenomed, that person will experience extreme pain, and possibly headaches, vomiting, and breathing difficulties. A common treatment is soaking the afflicted area in hot water, as very few hospitals carry specific treatments. However, immediate emergency medical treatment is still advised, as some people are more susceptible to the venom than others.

Lionfish are voracious predators. When hunting, they corner prey using their large fins and then use their quick reflexes to swallow the prey whole.

The lionfish have very few natural predators, but the grouper and other lionfish have been found with lionfish remains in their stomaches.
Giant Frogfish
Antennarius commersonii

Commerson's frogfish is of the family Antennariidae (Frogfishes) and the order Lophiiformes (anglerfishes).

The Giant Frogfish has a variable colour, yellow, orange, brown, black, green. Relatively smooth skin peppered with small dark spots, or covered with fouling. Illicium longer than the 2nd dorsal spine, very fleshy, with a membrane not very appearent. 30 cm.
When it is not yet at the maximum size, it can be confused with Antennarius pictus and Antennarius maculatus. The former has skin with large dark spots mimicking the sponge oscules, the second has prominent warts. A. commersoni has smoother and more uniformly coloured skin. Larger specimens can be covered with fouling, but these are identified by the size.

The color of frogfishes is extremely variable; they generally match their surroundings very well. If the background color is changed, they may in a few weeks dramatically change color, as from red or yellow to black.

One of the interesting things about this fish is that its pectoral fins have evolved into limb-like appendages that have an "elbow" joint. The pectoral fins also are prehensile, that is, the fish can grab onto things with them. The frogfish uses its prehensile pectoral fins to hold onto the surface where it is perched.

Frogfish eat little crustaceans and other fish. They have really big mouths for their size, and they can engulf a fish longer than themselves. The frogfish family (Antennariidae) are among the fishes known as "anglerfish," because their first dorsal spine is adapted into a little lure that they can extend and wiggle above their mouths to attract prey.

Frogfish tend to have a very small range, since they don't swim around much. This means that once a diver has located a fish of this species, it's usually easy to find it again and again.

A Commerson's Frogfish can grow to about a foot (30 cm) in length.