Cestida

Cestida is an order of comb jellies (phylum Ctenophora) known for their unique body structure and locomotion. Members of this order are commonly referred to as "ribbon comb jellies" due to their elongated, ribbon-like bodies.

Description

Cestida are characterized by their flattened, ribbon-like bodies that can reach several meters in length. Unlike other ctenophores, which have a more rounded or oval shape, Cestida have a distinctively elongated form. Their bodies are transparent and gelatinous, allowing them to blend into their surroundings in the open ocean.

Anatomy

The body of a cestid is divided into two main parts: the oral and aboral surfaces. The oral surface contains the mouth, while the aboral surface is opposite to it. Cestida possess eight rows of ciliary combs, which they use for locomotion. These comb rows run along the length of their bodies and beat in a coordinated fashion to propel the animal through the water.

Feeding

Cestida are carnivorous and feed on small planktonic organisms. They use their tentacles, which are equipped with colloblasts (sticky cells), to capture prey. The tentacles can be retracted into specialized sheaths when not in use.

Reproduction

Cestida are hermaphroditic, meaning each individual possesses both male and female reproductive organs. They can reproduce both sexually and asexually. During sexual reproduction, they release eggs and sperm into the water column, where fertilization occurs externally.

Habitat

Cestida are found in marine environments, typically in the open ocean. They are pelagic, meaning they live in the water column rather than near the sea floor. They are distributed worldwide, from tropical to temperate waters.

Classification

The order Cestida includes the following families:

• Cestidae

Notable Species

Some notable species within the order Cestida include:

• Cestum veneris - commonly known as the "Venus' girdle"

Related Pages

• Ctenophora
• Comb jellies
• Plankton
• Marine biology