In this episode of Animal Society we explore marine invertebrates, focusing on three key groups: corals, jellyfish, and octopuses. We will discuss the unique characteristics, life cycles, and ecological roles of these diverse creatures.

Corals are primitive invertebrates that form colonies of polyps, secreting a hard calcium carbonate exoskeleton. They have a symbiotic relationship with photosynthetic algae, which provide them with energy. Corals reproduce both sexually and asexually, and their colonies can grow into vast coral reefs over thousands of years.

Jellyfish are another ancient group of marine invertebrates, ranging greatly in size and exhibiting complex life cycles involving multiple stages, from egg to larval planula to polyp to free-swimming medusa. They are carnivorous, using their tentacles to capture prey, and can form massive blooms or swarms.

Octopuses are highly intelligent and adaptable cephalopod molluscs, known for their eight arms, camouflage abilities, and venomous bites. They are solitary, predatory creatures that use a variety of hunting strategies and can even detach their arms as a defensive mechanism. Octopuses have complex mating rituals and parental care behaviours, with females often dying shortly after their eggs hatch.

Together, these three groups of marine invertebrates play crucial roles in their ecosystems, serving as both predators and prey, and contributing to the overall diversity and productivity of the world's oceans.

Animal Society is a documentary series about the different social behaviors of various animal groups and individual species, from seabirds to insects, schooling fish to great cats.