Lagena

Lagena is a genus of amoeboid protists belonging to the phylum Cercozoa. These organisms are typically found in marine and freshwater environments, often inhabiting sediments or attached to substrates. A key characteristic of lagena is the presence of a test, which is a rigid outer covering. This test is usually flask-shaped and possesses a single aperture through which the pseudopods of the organism emerge.

The test of lagena is typically composed of organic material, though some species may incorporate foreign particles. The shape and size of the test can vary between species, aiding in their identification. Lagena are heterotrophic, meaning they obtain nutrients by consuming other organisms, such as bacteria or smaller protists. They capture food particles using their reticulopods, which are fine, branching pseudopods that can extend and retract from the test's aperture.

Reproduction in lagena can occur both asexually, through binary fission, and sexually, though the details of their sexual reproduction are not always well-documented for all species. The distribution of lagena is widespread, with various species identified across different aquatic ecosystems globally. Their ecological role often involves contributing to the decomposition of organic matter and serving as a food source for larger organisms.