dinoflageladas

Dinoflagellates, or dinophytes, are a diverse group of mostly unicellular eukaryotic plankton found in marine and freshwater environments. Most species are motile, possessing two flagella arranged in distinct planes that enable a spinning or gliding movement. Many have a cell covering called a theca, formed by cellulose plates that gives an armored appearance, though some lineages lack a thecal plate. Their cells vary in size and shape, often with complex surface features that aid in identification.

Ecologically, dinoflagellates occupy the photic zone as primary producers, with photosynthetic species using chlorophylls a and c and the accessory pigment peridinin; others are heterotrophic or mixotrophic, ingesting prey or absorbing dissolved organic matter. They play a major role in marine food webs and biogeochemical cycles. A subset form symbiotic relationships with corals and other invertebrates as endosymbionts, contributing to coral reef productivity. Dinoflagellates reproduce mainly by asexual division, though sexual reproduction and resting cyst formation occur under stress, allowing survival through adverse conditions. Some species produce potent toxins that accumulate in shellfish and cause harmful algal blooms, which can affect fisheries and human health; others produce bioluminescence.

The fossil record of dinoflagellate cysts provides valuable biostratigraphic markers and insights into past environments. Overall, dinoflagellates are a highly diverse and ecologically significant group within aquatic ecosystems.