Proboscis worm

Proboscis Worm

The Proboscis Worm or Nemertea is a phylum of invertebrate animals also known as ribbon worms or nemerteans. They are noted for their elongated bodies and a unique proboscis used for hunting and feeding.

Anatomy and Morphology

The most distinctive feature of the proboscis worm is its namesake, the proboscis. This is a long, muscular, and often brightly colored organ that can be rapidly extended to capture prey. The proboscis is housed in a fluid-filled cavity called the rhynchocoel.

The body of a proboscis worm is generally slender and elongated, although there is considerable variation in size among species. The smallest species measure only a few millimeters in length, while the largest, such as the bootlace worm (Lineus longissimus), can reach lengths of up to 30 meters.

Habitat and Distribution

Proboscis worms are found in a wide range of habitats, from marine to freshwater environments, and from the tropics to the polar regions. They are typically benthic, living in the substrate or among seaweeds.

Diet and Behavior

Proboscis worms are primarily carnivorous, feeding on small invertebrates. They use their proboscis to ensnare and immobilize their prey, often with the aid of toxins.

Reproduction and Life Cycle

Most proboscis worms are dioecious, with separate male and female individuals. However, some species are hermaphroditic, possessing both male and female reproductive organs. Fertilization is usually external, and the larvae are planktonic.

Taxonomy and Classification

The phylum Nemertea is divided into two main classes: the Anopla, which have an unarmed proboscis, and the Enopla, which have a proboscis armed with a stylet.

See Also

• Invertebrate
• Marine biology
• Phylum