[2] Lepidodinium chlorophorum is known to cause sea blooms, partially off the coast of France, which has dramatic ecological and economic consequences.
[3][4][5] Lepidodinium produces some of the highest volumes of transparent exopolymer particles of any phytoplankton, which can contribute to bivalve death and the creation of anoxic conditions in blooms, as well as playing an important role in carbon cycling in the ocean.
[8] The first specimen obtained off Helgoland, in the North Sea, where its bloom was causing the water to turn green at the surface.
This was primarily due to the fact one of the characteristic features initially listed for Lepidodinium genus was the presence of plates and none were observed on the chlorophorum species.
[4] In the Bay of Biscay, France, these blooms have occurred annually since 2007 with increasing abundance, generally between April and August, reaching a peak in the summer.
[13] The blooms are associated with high concentrations of ammonia and phosphates, along with transparent exopolymers particles, which results in localised hypoxia in the area.
Another common feature in dinoflagellates present in Lepidodinium is the presence of a peduncle (characteristic of mixotrophic organisms) located next to the transverse flagellum and associated with a dense body at its base.
The presence of mucocysts and also ecysis allows L. chlorophorum to excrete Transparent Exopolymer Particles in some of the largest quantities of any phytoplankton,[5] associated with significant ecological impacts.
Each lens shaped plastid has three appressed thylakoids and interlamellar pyrenoids and is all enclosed by a double membrane envelope.
Although MGD and TGD are known to have nucleomorphs, the observation of a green algal nucleus in Lepidodinium proper remains controversial.
L. chlorophorum possesses the GAPDH which is a plastid-targeted gene originated from a haptophyte, an alga taken up by other dinoflagellates but not currently present in Lepidodinium.
It has been suggested that at least three different plastids have led to the development of the Lepidodinium genome, along with horizontal gene transfer from prey.
[21] Although not examined in L. viride, L. chlorophorum appears to have a unique N-terminal pre-sequence (thought to be associated with plastid targeting) within the dinoflagellates.
This represents one of at least three independent secondary endosymbiosis events involving a green algae in the eukaryotes, the others being in the Euglenophytes and Chlorarachinophytes.
The endosymbiont has lost a large number of genes, including those involved in essential functions, showing a high level of integration as an organelle.
[4] These blooms are also harmful due to their high viscosity which is the result of L. chlorophorum extracellular polymeric substances overproduction.
For bivalves, the typically observed response to hypoxia is reduced feeding and oxygen consumption, thought to negatively affect their growth and survival.
[24] It is thought that these blooms are becoming more common with climate change as waters become warmer and the elemental composition of seawater alters.
[4] It has been suggested that this is due to L. chlorophorum impairing the filtration ability of C. gigas by producing acid glycoconjugates and transparent exopolymer particles.
[4] Marine mixotrophic protists such as Lepidodinium play an important role in oceans in terms of nutrient cycling as well as in the food chain.
The carbon rich Transparent Exopolymer Particles (TEP) known to be produced by L. chlorophorum are important in the sedimentation of organic matter which enables bacteria abundance.