[2] V. litorea is a common intertidal species of coastal brackish waters and salt marshes of the Northern Atlantic, along the coasts of Europe, North America and New Zealand.

The species-level classification of Vaucheria has undergone considerable changes over the past century, involving the assignment of species to subgeneric sections and subsections.

The dark green, filamentous dioecious algae forms loose interwoven bundles or dense sods, attached to the substrate by branched rhizoids.

Reproduction is vegetative (fragmentation), asexual (large multinucleate synzoospores), and sexual (fertilization of a non-motile ovule by a motile multiflagellate antherozoid).

[8][12] The evolutionary history of Vaucheria indicates that the ancestral form produced antheridia and oogonia as separate structures, possibly adjacent.

The dioecious condition of Piloboloideae is suggested to be a derived state, and the presence of a gametophore distinguishes a monophyletic clade (sections Vaucheria, Corniculatae).

Vaucheria litorea are consumed by the sea slug Elysia chlorotica, but are only partially digested by them in order to retain the photosynthetic chloroplasts in a process called kleptoplasty (plastid retention).

This association is not only specific but also obligate, as the sea slug cannot complete metamorphosis and mature into an adult without its algal prey and plastid uptake.

[15] It was hypothesize that the evolution of kleptoplasty and photosynthesis in the sea slug parallels other tertiary-evolved photosynthetic organisms, involving endosymbiosis and potential horizontal gene transfer (HGT).

[16] The plastid-encoded phosphoribulokinase (PRK) in V. litorea catalyzes the irreversible reaction generating the substrate ribulose-1,5-bisphosphate (RuBP) for Rubisco-dependent CO2 fixation supporting the Calvin cycle.

The long-term viability of the symbiotic association between V. litorea and E. chlorotica necessitates the acquisition of a prk gene that is thought to be through HGT.