Symbion

Symbion pandora wikipedia (en)

Symbion is a genus of microscopic, aquatic organisms known as symbionts, which are notable for their unique place in the tree of life and their symbiotic relationship with marine invertebrates, specifically Norwegian lobsters (Nephrops norvegicus). These tiny creatures belong to the phylum Cycliophora, a group that was only discovered in the 1990s, highlighting the vast unknown diversity of life in marine environments.

Description

Symbion organisms are extremely small, typically only a few hundred micrometers in size. They have a complex life cycle that includes several stages: feeding individuals known as feeders, reproductive individuals, and a larval stage. The feeders attach themselves to the mouthparts of the lobster, where they filter feed on small particles in the water, such as bacteria and plankton.

The body of a Symbion is divided into a few distinct parts: the buccal funnel, which is used for feeding; the trunk, containing most of the internal organs; and the adhesive disc, which secures the organism to its host. Their mode of reproduction can be sexual or asexual, depending on the life stage and environmental conditions.

Habitat and Ecology

Symbion species are exclusively found in marine environments, attached to the mouthparts or gills of specific species of lobsters and possibly other crustaceans. This symbiotic relationship is obligate, meaning that both the Symbion and its host are dependent on each other for survival. The exact nature of this symbiosis is still under research, but it is believed that Symbion does not harm its host and may even provide some benefits, such as cleaning the host's mouthparts from debris and parasites.

Discovery and Classification

The first species of Symbion, Symbion pandora, was discovered in the 1990s by marine biologists who were studying the mouthparts of the Norwegian lobster. Its discovery was significant because it represented not only a new species but also a new genus and even a new phylum, Cycliophora, which is a rare event in modern biology. The discovery of Symbion has prompted scientists to reconsider the complexity of life and the relationships between different organisms in marine ecosystems.

Research and Significance

Research on Symbion and other cycliophorans is ongoing, with scientists seeking to understand more about their biology, life cycle, and evolution. These organisms are of particular interest because they may provide insights into the early evolution of multicellular life and the development of symbiotic relationships. Additionally, studying Symbion can help scientists understand more about the biodiversity of marine ecosystems and the intricate relationships that sustain them.

See Also

• Cycliophora
• Symbiosis
• Marine biology
• Norwegian lobster