Cnidaria

Cnidaria is a phylum of perplexing organisms that we consider some of the most unique in the Yonderverse. With over seventy thousand jellyfish and around a hundred thousand coral species in the A To Zoo, we are vocal about these very misunderstood organisms.

These animals are often some of the first to evolve on planets due to their simple physiologies. Most inhabit marine waters, some in fresh and brackish waters, and some cnidarians even exist on land and in skies.

Scientific Classification

DOMAIN: Eukarya

KINGDOM: Animalia

SUBKINGDOM: Eumetazoa

CLADE: ParaHoxozoa

PHYLUM: Cnidaria

Medusae vs Polyps

Most Cnidarians have two basic forms, medusae and polyps. Medusae are mobile, such as jellyfish, while polyps are sessile, stuck to surfaces.

This, of course, is not a universal rule for Cnidarians, but is common.

The simple diagram below shows the life cycle of a false island jelly, native to planet Kyrophis.

False island jellies have the same reproductive stages as any other jelly species in Ulmaridae. Life starts as an egg, which is fertilised when males release strings of sperm into the water and is ingested by females. Eggs will hatch into larva, which settle on the seabed forming polyps.

The polyps will asexually reproduce, bud, and form strobila, also known as budding polyps. These buds break off and form ephyrae, which turn into medusa, the most commonly known form of a jellyfish.

— Excerpt from "False Island Jelly"

False Island Jelly Life Cycle by Mochi

Anthozoa

Cottonball Anemone by Mochi

Anthozoa contains billions of sea anemone and coral species. Most are sessile, meaning they are stationary, stuck to seabeds or other surfaces.

Anthozoans have incredible capabilities to support life - coral reefs are some of the most diverse ecosystems on any planet with large bodies of water.

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subclass Hexacorallia

order Actiniaria

order Antipatharia

order Corallimorpharia

order Rugosa

order Scleractinia

order Zoantharia

subclass Octocorallia

order Alcyonacea

order Helioporacea

order Pennatulacea

subclass Ceriantharia

order Penicillaria

order Spirularia

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Medusozoa

Flower Garden Jellyfish by Mochi

Medusozoa contains many classes of jellyfish and other animals. These animals are characterised by the medusa in their life cycles.

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class Hydrozoa

subclass Hydroidolina

order Anthoathecata

order Leptothecata

order Siphonophorae

subclass Trachylinae

order Actinulida

order Limnomedusae

order Narcomedusae

order Tatalidoae

class Cubozoa

order Carybdeida

order Chirodropida

class Scyphozoa

subclass Coronamedusae

order Coronatae

subclass Discomedusae

order Rhizostomeae

order Semaeostomeae

class Staurozoa

class Polypodiozoa

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