The genus is characterised by its elongated body which is anteriorly prolonged to a point, its complex flagellar apparatuses which attach to the ventral side of the cell, and the unique features of its nucleus.
[5] There is a broad scope of literature concerning the genus, as it is commonly used in laboratory studies investigating the evolution of protist lineages and responses to environmental changes.
[4] It has been suggested that Oxyrrhis could be an “emerging model organism” as it is widely distributed, small, easily traceable, and useful in addressing a range of ecological questions.
[3] In a survey of 36 papers from 1990-2011 that mention O. marina in the title, approximately 55% were aut- or synecologically based, roughly 40% examined an aspect related to evolutionary or genetic biology, and 5% were associated with distributional patterns.
[3] Oxyrrhis is unlikely to be exclusively intertidal and is probably a small component of coastal and oceanic plankton communities, while there is anecdotal evidence that it occasionally grows in shallow embayments.
[2] Oxyrrhis is highly important in marine communities, playing an essential role in pelagic food webs as they both consume phytoplankton in addition to ciliates, bacteria, and the eggs, early nauplii stages, and adults of some metazoans, amongst other prey items.
[1] By feeding on and being predated upon by a broad range of organisms, Oxyrrhis significantly affect food web structure, carbon cycles and energy flows within the marine planktonic community.
[2][10] These apparatuses are asymmetric and very complex, with each flagellum having a longitudinal and a transverse basal body, giving rise to eight structurally different components.
[10] The striated fibrous roots that arise from each basal body show similarities to the costa of some trichomonads, despite these organisms having different mitotic mechanisms.
[10] A striated fibrous connective attaches to the basal body and extends towards the cell’s right ventral surface before terminating at the sub-thecal microtubular system.
[1] For instance, throughout the cellular cycle, the nuclear chromosomes remain condensed, and as with other dinoflagellates, there are fewer of the proteins that make up the structural basis of nucleosomes than is typically seen in the chromatin of eukaryotes.
[1] Other unique features of Oxyrrhis include their many long, thin chromosomes that are separated by many electron-dense bodies, in addition to a single histone-like DNA-associated protein which is not found in other dinoflagellates.
During division, the nuclear envelope does not invaginate to form cytoplasmic channels with microtubules present, as in other dinoflagellates, and instead the microtubular mitotic apparatus is intranuclear.
Additionally, O. marina has not been found to exhibit the birefringent periodic banded or arched chromosomal structure that is typically observed in dinoflagellates.
[13] O. marina meets a range of criteria that combined, could deem it suitable as a ‘model organism’ for answering many different types of questions relating to other similar protists.
[4] This is due to the early divergence of O. marina from the branch leading to the dinoflagellate lineage, resulting in shared morphological, cytological and genetic features with closely related taxa, in addition to some characteristics that are species specific.
[4] This, in addition to high-throughput sequencing becoming more accessible, means that O. marina is likely to be increasingly used in evolutionary and comparative genomic studies of alveolates in the near future.
[4] For instance, O. marina has been used to investigate the impacts of infochemicals, such as the environmentally important trace gas dimethyl sulphide, on foraging behaviours.
Calculated impacts on natural populations suggest that large-scale culturing of O. marina could be used to successfully manage the red tides that result from H. akashiwo blooms.
[6] Domain: Eukaryota Kingdom: Chromista Superphylum: Alveolata Phylum: Dinoflagellata Class: Dinophyceae Order: Oxyrrhinales Family: Oxyrrhinaceae Genus: Oxyrrhis [13][16]