Tide pool in the context of Shore

Benthos (from Ancient Greek βένθος (bénthos) 'the depths [of the sea]'), also known as benthon, is the community of organisms that live on, in, or near the bottom of a sea, river, lake, or stream, also known as the benthic zone. This community lives in or near marine or freshwater sedimentary environments, from tidal pools along the foreshore, out to the continental shelf, and then down to the abyssal depths.

Light is an important energy source for shallow benthic systems. However, because light is absorbed before it can reach deep ocean water, the energy source for deep benthic ecosystems is often organic matter from higher up in the water column that drifts down to the depths. This dead and decaying matter sustains the benthic food chain; most organisms in the benthic zone are scavengers or detritivores.

A sculpin is a type of fish that belongs to the superfamily Cottoidea in the order Perciformes. As of 2025, this superfamily contains 5 families, 112 genera, and 405 species.

Sculpins occur in many types of habitat, including ocean and freshwater zones. They live in rivers, submarine canyons, kelp forests, and shallow littoral habitat types, such as tidepools.

Blue-ringed octopuses, comprising the genus Hapalochlaena, are four extremely venomous species of octopus that are found in tide pools and coral reefs in the Pacific and Indian Oceans, from Japan to Australia. They can be identified by their yellowish skin and characteristic blue and black rings that can change color dramatically when the animals are threatened. They eat small crustaceans, including crabs, hermit crabs, shrimp, and other small sea animals.

They are some of the world's most venomous marine animals. Despite their small size—12 to 20 cm (5 to 8 in)—and relatively docile nature, they are very dangerous if provoked when handled because their venom contains a powerful neurotoxin called tetrodotoxin.

The Mesozoic marine revolution (MMR) refers to the increase in shell-crushing (durophagous) and boring predation in benthic organisms throughout the Mesozoic era (251 Mya to 66 Mya), along with bulldozing and sediment remodelling in marine habitats. The term was first coined by Geerat J. Vermeij, who based his work on that of Steven M. Stanley. While the MMR was initially restricted to the Cretaceous (145 Mya to 66 Mya), more recent studies have suggested that the beginning of this ecological/evolutionary arms race extends as far back as the Triassic, with the MMR now being considered to have started in the Anisian or the Aalenian. It is an important transition between the Palaeozoic evolutionary fauna and the Modern evolutionary fauna that occurred throughout the Mesozoic.

The Mesozoic marine revolution was not the first bout of increased predatory pressure; that occurred around the end of the Ordovician. There is some evidence of adaptation to durophagy during the Palaeozoic, particularly in crinoids.