---
title: Jellyfishes (Scyphozoa)
scientific_name: Scyphozoa
common_name: Jellyfishes
rank: Class
published: 2024-11-19T18:41:51.573Z
updated: 2026-08-03T21:02:01.151Z
tags: Jellyfishes, Scyphozoa, Red Sea, Marine Life, Diving
url: https://redseacreatures.com/taxon/invertebrate/stinging/jellyfishes
---

# Jellyfishes (*Scyphozoa*)

## Quick facts

- **Rank:** Class
- **Scientific name:** Scyphozoa
- **Body shape:** Invertebrate - Not a fish - coral, mollusc, crustacean, echinoderm and other invertebrate groups.
- **Species listed here:** 8

## How to recognise this group

- gelatinous, often translucent, bell-shaped body
- rhythmic bell pulsations for movement or passive drifting
- multiple tentacles hanging from bell margin
- four or more frilly oral arms extending downwards

Jellyfishes (Scyphozoa) possess a bell-shaped, gelatinous body largely composed of water, with bells ranging from shallow domes to flatter discs. Their diameters commonly measure from a few centimeters up to 50 cm (20 in) in the Red Sea. Most are translucent, but some species display white, blue, or brown hues, occasionally with iridescent highlights. Tentacles, varying in number and length, hang from the bell margin, often alongside four or more thick, frilly oral arms extending downwards from the central mouth. Both tentacles and oral arms bear stinging cells (cnidocytes).

These cnidocytes are used to capture planktonic organisms, small fish, and crustaceans, and also for defense. Many species drift passively in the water column or near the surface, while others use rhythmic bell pulsations for directed movement. They occur in various habitats, from shallow lagoons and reef flats to open water, sometimes forming large seasonal aggregations. Certain species host symbiotic algae (zooxanthellae) within their tissues, which contribute to their energy supply through photosynthesis. Contact with their stinging cells typically results in a painful skin reaction.


## Species (8)

- [Crown Jellyfish (Nausithoe punctata)](https://redseacreatures.com/taxon/invertebrate/stinging/jellyfishes/crown-jellyfish)
- [Crowned Jellyfish (Cephea cephea)](https://redseacreatures.com/taxon/invertebrate/stinging/jellyfishes/crowned-jellyfish)
- [Mauve Stinger (Pelagia noctiluca)](https://redseacreatures.com/taxon/invertebrate/stinging/jellyfishes/mauve-stinger)
- [Moon Jellyfish (Aurelia solida)](https://redseacreatures.com/taxon/invertebrate/stinging/jellyfishes/moon-jellyfish)
- [Nomad Jellyfish (Rhopilema nomadica)](https://redseacreatures.com/taxon/invertebrate/stinging/jellyfishes/nomad-jellyfish)
- [Orsini's Jellyfish (Crambionella orsini)](https://redseacreatures.com/taxon/invertebrate/stinging/jellyfishes/orsinis-jellyfish)
- [Purple Jellyfish (Thysanostoma loriferum)](https://redseacreatures.com/taxon/invertebrate/stinging/jellyfishes/purple-jellyfish)
- [Upside-down Jellyfish (Cassiopea andromeda)](https://redseacreatures.com/taxon/invertebrate/stinging/jellyfishes/upside-down-jellyfish)

---

*Source: [Red Sea Creatures](https://redseacreatures.com/taxon/invertebrate/stinging/jellyfishes)*
*Updated: August 3, 2026*