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Flamboyant Cuttlefish and Blue-Ringed Octopus Facts

The author is a research enthusiast. She studied botany and zoology as major subjects in her bachelor's program.

Let's learn about two most venomous cephalopods—Flamboyant cuttlefish and Blue-ringed Octopus

Let's learn about two most venomous cephalopods—Flamboyant cuttlefish and Blue-ringed Octopus

What Are Cephalopods?

Cephalopods belong to the molluscan class Cephalopoda, which is a Greek word meaning "head-feet." Squid, octopus, and cuttlefish all belong to the class Cephalopoda.

The study of cephalopods is known as teuthology, and it is a branch of malacology. Cephalopods became dominant during the Ordovician period (a geological period and system that belongs to the Palaeozoic era), and they have only two subclasses: Coleoidea and Nautiloidea, which are distinguished based on a shell.

This article focuses on two of the most interesting cephalopods: the flamboyant cuttlefish and the blue-ringed octopus. Let's take a look at them now.

Metasepia Peffefri

Metasepia Peffefri

Flamboyant Cuttlefish

This robust-looking species of cuttlefish has an oval mantle and blade-like arms. It is a small cephalopod with a dark-brown base color. It has an overlying pattern of yellow and white on the body.

Because of chromatophores, flamboyant cuttlefish can change color. It is one of the three known venomous species of cephalopod. The scientific name of this species is Metasepia Pfefferi, and it belongs to the family Sepiidae.

Physical Description

Flamboyant cuttlefish contains an oval-shaped mantle and broad arms that contain four rows of suckers. The male used a modified arm for fertilisation. The oral surface of the modified arm is swollen, wide, and fleshy.

The cuttlebone is small and positioned in the interior of the mantle. The dorsal surface is yellowish, convex, and lacks bumps. The average size of the mantle is 8 cm. Three pairs of large, flat, flap-like papillae are present on the dorsal surface of the mantle. Due to the small size of its cuttlebone, it can float only for a short time.

Habitat and Reproduction

It is found at a depth of 3 to 86 meters in shallow water and remains active during the day. After face-to-face copulation, eggs are fertilized. Female lays eggs in corals, rock, or wood. In beginning, eggs are white but turn translucent in later stages. The developing cuttlefish are visible through these transparent eggs.

Bright coloration of flamboyant cuttlefish

Bright coloration of flamboyant cuttlefish

Camouflage Tactics and Color Pattern

The Flamboyant Cuttlefish has superb camouflage. Specialized cells and structures in their skin allow them to instantly morph into ostentatious patterns. It spends most of its time in drab colors such as brown. Camouflage includes background matching and masquerade, and it is the most common primary defense against predators and is used offensively to approach prey closely.

It can adjust the color and texture of its body with the help of papillae and is well known for its "Flamboyant Display," which is a vibrant body pattern showing bright yellow, red, white, and brown colors with unique arm postures and dynamic skin bumps called papillae. It only uses its "flamboyant display" on rare occasions, such as to attract a mate, confuse a predator, or strike a rival suitor.

Flamboyant Cuttlefish, Poisonous or Venomous?

An animal that transfers its organic poison through bites or stings is said to be venomous. The flamboyant cuttlefish contains toxic material but can't inject it through bites, which means it is a poisonous cephalopod. To examine the negative effects of toxins, one must eat this cuttlefish.

Greater blue-ringed octopus (Hapalochlaena lunulata)

Greater blue-ringed octopus (Hapalochlaena lunulata)

Blue-Ringed Octopus

This venomous cephalopod has black and blue rings on its body. The color of the skin is yellowish. The size ranges from 12 to 20 cm. They feed on crabs and shrimp. There are four confirmed species of blue-ringed octopus, which include:

  • The greater blue-ringed octopus
  • The Southern blue-ringed octopus
  • The Blue-lined octopus
  • Hapalochlaena Nnierstraszi.

Hapalochlaena Nierstraszu is still being researched. It was first described in 1938 from the Bay of Bangle. The greater blue-ringed octopus is named because of the size of its blue rings, which help to distinguish it from other species.

The blue-lined octopus is relatively small, with blue or black streaks covering its body. The Southern blue-ringed octopus is considered a separate species because of its large body size compared to other blue-ringed octopuses.

Southern blue-ringed octopus

Southern blue-ringed octopus

Physical Description

Four pairs of tentacles are attached to the month. The blue rings on their skin are usually faint when they are at rest. But when agitated, they show off their blue and brown ring pattern. They have two well-developed eyes like vertebrates. Pigmented chromatophores are present around each ring, but there are no chromatophores above the rings, which is unusual for cephalopods.

Habitat and Reproduction

They are active at night, and during the day, they hide under rocks and other surfaces. They are mostly found in muddy and sandy stretches. After a storm, they can be seen in large numbers seeking bivalves and crabs. They are very possessive of their home and place. They fight with other octopuses and are solitary in nature.

For reproduction, the male uses a modified arm that transfers spermatophore to the female. Females lay about 50 eggs in their lifetime. Eggs are incubated underneath the female's arm for about six months. Females die soon after hatching.

Blue-Ringed Octopus Venom

The Blue-ringed octopus contains two kinds of venom: one for killing and the other for defense. The venom contains histamine, tryptamine, octopamine, acetylcholine, and dopamine. It is produced in the posterior salivary gland. A bite is necessary to be envenomated.

In danger, the first instinct of the octopus is to flee. But when the danger persists, it uses its defensive weapons and displays blue rings. In that case, never touch it; it may bite you.

Effects of Venom

A bite is painless and tiny, and most people remain unaware of the bite until their body starts paralyzing. Venom results in total body paralysis and the victim has no way to ask for help or to show discomfort. The venom is 1000 times stronger than cyanide. Because of paralysis, the respiratory system of the victim fails to work normally, which leads to death. Victims may experience the following symptoms:

  • Difficulty breathing
  • Numbness
  • A burning sensation
  • Nausea
  • Difficulty speaking
  • Weakness

First Aid Treatment

  • Put pressure on the wound and call emergency services.
  • Try to keep the person still as much as possible.
  • Apply a plastic band on the bitten area so that venom can't travel fast to the other parts of the body.
  • Try to arrange artificial ventilation as soon as possible. Because the venom directly affects the respiratory system of the victim.

Additional Facts About the Blue-ringed Octopus

  • All blue-ringed octopuses have two sharp Parrot-like beaks.
  • During incubation, the female doesn't consume any food and dies soon after hatching.
  • The newborn octopus is tiny, about the size of a pea.
  • The toxin is produced by bacteria, which is present in their salivary glands.


This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.

© 2021 EK Jadoon