The bluespotted sunfish (Enneacanthus gloriosus) is one of the smallest sunfish in the sunfish family (2-3in or 50-75mm) with a physical description similar to that of banded sunfish and spotted sunfish. The anal fin and the dorsal fin are covered with spines and rays. The anal fin has three spines and 10 rays while the dorsal one consists of 10 spines and 10-13 rays. The body is covered with silver and blue dots. These dots are more prominent in males than females. Juvenile fish sometimes have pale bars on the lateral side of the body, but they are rare.

The black-breasted leaf turtle has a dark, unpatterned undershell with a yellow border. Three raised ridges run from head to tail on the top of the shell, which is flattened with rough edges at the front and back to resemble a leaf, which is why they're called "leaf turtles." The turtles' feet are partially webbed and their large eyes stick out in an unusual way, giving an alert and curious expression. They don't have teeth – instead, their mouths have a hard, sharpened edge that they bite with, similar to a bird's beak. Females' tails are shorter and thinner than males.

The Silver Pearlfish (Encheliophis homei) is a very unusual fish with an out the ordinary lifestyle. During the day they spend their time inside the coelom of sea cucumbers, emerging to feed only at night. Being nocturnal they steer clear of light and will usually swim to the outer peripheries of ones dive lights, additionally because of their transparent nature and habit of swimming low and fast on the substrate they are difficult to pick out and to photograph. Numerically there do not appear to be many of them and they are not often seen. During the intermediate phase after transforming from larvae, they seek protection from the sea cucumbers and enter the coelom of the sea cucumber. During this stage they may be parasitic, but as they grow into adults so analysis of their stomach content shows that they feed on planktonic matter such as small Silver Pearlfish and crustaceans and the relationship with the host is commensal. This hypothesis is backed up by their teeth structure and they have a row of small teeth on the upper jaw and in the lower jaw the teeth are longer and slightly curved backwards which indicates a carnivorous lifestyle. They have been documented as making sounds, however the actual purpose of these sounds is unknown but may be used for territorial or mating purposes.

Evolutionary biologists have been arguing over seals' origins for more than a century. While relatively sure that pinnipeds evolved from land-dwelling carnivores, scientists are divided on the precise steps that occurred between terrestrial ancestors and modern marine mammals. Along with the three subclades of pinniped, the suborder Caniformia contains Ursidae (bears), Mustelidae (badgers, otters, weasels, and relatives), and Mephitidae (skunks and stink badgers). In 2007, a nearly complete skeleton of a new semi-aquatic carnivore from an early Miocene lake deposit in Nunavut, Canada, was discovered and became known as an evolutionary link between land mammals and seals.

The North Pacific Subtropical Gyre, otherwise known as the "Great Pacific Garbage Patch," is considered the world's largest accumulation of ocean plastic. It's so massive, in fact, that researchers found it has been colonized by species — hundreds of miles away from their natural home. Researchers found that species usually confined to coastal areas — including crabs, mussels and barnacles — have latched onto, and unexpectedly survived on, massive patches of ocean plastic. Coastal species such as these were once thought incapable of surviving on the high seas for long periods of time. Only oceanic neuston, organisms that float or swim just below the ocean surface, have historically been found near these patches, as they thrive in open ocean. This new community, researchers said, "presents a paradigm shift" in the understanding of marine biogeography. "The open ocean has long been considered a physical and biological barrier for dispersal of most coastal marine species, creating geographic boundaries and limiting distributions," researchers said. "This situation no longer appears to be the case, as suitable habitat now exists in the open ocean and coastal organisms can both survive at sea for years and reproduce, leading to self-sustaining coastal communities on the high seas."

Also known as sculpin, and ‘mother-in-law fish' because of its loud mouth and constant croaking, the Cabezon is a large, smooth and scaleless fish that is the only species under its genus. The cabezon (Scorpaenichthys marmoratus) is a unique fish living on the Pacific coast. Generally found near the ocean floor, the cabezon is known for being stubborn because of its temperament and its ability to remain nearly motionless until its next meal. They also have poisonous spines that match their attitude! Cabezon is Spanish for "big headed," which perfectly describes this fish. cabezon tend to settle in tide pools and eventually make their way to the kelp forest to live out their adult lives under rocks and hiding in the shadows. The coloration of cabezon is usually brown with shades of either green (females) or red (males). More than 90% of the green Cabezon fish are female, while more than 90% of the red Cabezon are males.

Orcas (Orcinus orca) are often called killer whales, even though they almost never attack humans. In fact, the killer whale name was originally "whale killer," as ancient sailors saw them hunting in groups to take down large whales, Today, orcas are recognized as among the most widely distributed mammals on the planet, occupying every ocean. They are incredibly social, diverse and ferocious marine predators with a diet ranging from penguins to great white sharks. Orcas are apex predators, at the top of the food chain. No animals hunt orcas (except for humans). Killer whales feed on many different types of prey, including fish, seals, sea birds and squid. They can also take down whales larger than themselves, such as minke whales, and they are the only animal known to predate on great white sharks, according to The Natural History Museum in London. Killer whales have even been reported to kill swimming deer and moose.

The Sauger is a freshwater fish that is bronze to olive in color with dark color blotches and has a white belly. It has an elongated body and has two dorsal fins; the first dorsal is spined while the second fin is soft-rayed. One of the ways to differentiate it from its closely-resembled relative, the walleye, check its tail if it has a white-tipped. If the white-tipped tail is absent, then it is a sauger. The sauger sometimes mates with its close relative, the walleye. The hybrid species is called "saugeye".

Dating back to 400BC, scallops have played a prominent part in man's religious, artistic and architectural development. The shell features in numerous works of art, the most famous example being Botticelli's masterpiece The Birth of Venus. In Greek mythology, Aphrodite (the Greek equivalent to the Roman goddess Venus) was born and arose from the sea foam that resulted from Cronus (the new order of gods) flinging the severed genitals of Uranus (the old order of gods) into the ocean. A giant scallop shell then carried her to the island of Cyprus where her reign began.

Tunas are highly specialized migrating species. They swim continuously to counterbalance their negative buoyancy, travelling hundreds of kilometers / miles. This strategy has a high energy cost, forcing them to move in search of food and has resulted in morphological and physiological adaptations for thermoregulation and high oxygen extraction efficiency. Therefore, temperature and dissolved oxygen concentration affect tuna behavior significantly. They also have a well-developed network of blood vessels below the skin that acts as a temperature-regulating device associated with long-term, slow swimming. Because of this vascular system, they are able to maintain the temperature of their bodies above that of the surrounding water, often between 5 and 12 °C (9 and 21.7 °F) above ambient water temperature.