did you know that...

• Oysters are alive when you eat them; they don't die immediately after being shucked.
• Light can travel about 3280 feet (1,000 meters) into the ocean under the right conditions, but there is rarely any light below 656 feet (200 meters).
• Mastigias papua are jellyfish whose habits are influenced by the sun (they have zooxanthellae, which use energy from the sun for respiration), and as a result are found in shallow waters during the day to bathe in sunlight, and lower parts of the water when the sun sets.
• An octopus can live out of water for a maximum of sixty minutes.
• Octopus beaks are venomous (the blue-ringed octopus is the most deadly to humans; they have enough poison to paralyse the diaphragm of over ten humans, suffocating them).
• Coral reef get their colour from algae that live in them. When the temperature is too high or the pH too low, they die. The corals get stressed and expel the algae.
• Pacific salmon spawn only once in their lifetime. They return to the place they were born to spawn, after which they start to rot from the inside. Most last a few days, but some salmon can live for weeks. For this reason they are also called zombie salmon.
• Man o' war is often called a jellyfish, but is actually a species of siphonophore, a group of animals that are closely related to jellyfish. Their tentacles contain nematocysts (microscopic capsules loaded with coiled, barb tubes) that deliver venom capable of paralysing and killing small fish and crustaceans.
• Lionfish contain neurotoxic venom in their spines that is released upon stinging, causing swelling and extreme pain.
• Atolla jellyfish are bioluminescent, and give off flashes of blue light, possible to attract or dazzle its prey. The blue flashes may also startle predators, or attract even bigger predators that can chase off its assailants. Due to this strategy they are also known as the 'alarm jelly'.
• There is an endosymbiotic relationship between the green Volvocean alga and the spotted salamander. The algae grow better in water populated with salamander embryos (they penetrate and live in the embryo cells) and the salamander embryos are healthier when more algae are present.
• Jellyfish are 95% water.
• Horsehair worms are parasites that grow in a praying mantis's gut until the worm is matured enough. The worm then influences the host's nervous system and compel them to jump in water, allowing the worm to leave the host's body. (Horsehair worms can also grow in other insects like crickets, cockroaches, etc.)
• Alligators eat fish, snails, and other invertebrates, birds, frogs and mammals that come to the water's edge. If the prey is very large, they will bite it, then spin on the long axis of their bodies to tear off easily swallowed pieces.
• Humpback whales can go without food for several months. They do this to dedicate their energy to migration and reproduction. Females fast even after reproduction to prioritize nursing their calf. Humpback whales contain a hormone called leptin which acts as an appetite suppressant and also helps break down fat in the blubber.
• Crocodiles can go up to a year without eating. They're ectotherms, and rely on the heat of the sun to warm them, which frees up a tremendous amount of energy for other uses, and allows crocodiles to go without food if necessary. However, if they can help it, they don't go that long in between meals and most crocodiles eat every 3-10 days depending on the size of their meals.
• Cockeyed squid have one "normal" eye and one giant, bulging, yellowish eye. The large eye is specifically adapted for gazing upwards, searching for shadows of fellow sea creatures against the rapidly fading sunlight, while the small eye is adapted for gazing downwards, scanning deeper and darker waters for flashes of bioluminescence (which could signal danger or potential prey).
• Turritopsis dohrnii is an animal that can reverse its life cycle, and has been dubbed the immortal jellyfish. When the medusa (adult jellyfish) of this species is physically damaged or experiences stresses such as starvation, instead of dying it shrinks in on itself, reabsorbing its tentacles and losing the ability to swim. It then settles on the sea floor as a blob-like cyst. Over the next 24-36 hours, the blob develops into a new polyp (the jellyfish's previous life stage) and after maturing, the medusae bud off. This process is known as transdifferentiation and is extremely rare.