Parvilucifera is a genus of marine alveolates that parasitise dinoflagellates. Parvilucifera is a parasitic genus described in 1999 by Norén et al. It is classified perkinsozoa in the supraphylum of Alveolates. This taxon serves as a sister taxon to the dinoflagellates and apicomplexans. Thus far, five species have been described in this taxon, which include: P.infectans, P.sinerae, P.corolla, P.rostrata, and P.prorocentri. The genus Parvilucifera is morphologically characterized by flagellated zoospore. The life cycle of the species in this genus consist of free-living zoospores, an intracellular stage called trophont, and asexual division to form resting sporangium inside host cell. This taxon has gained more interest in research due to its potential significance in terms of negative regulation for dinoflagellates blooms, that have proved harmful for algal species, humans, and the shellfish industry (Norén et al. 1999).
History
The genus was first described by Noren and Moestrup in 1999 and was isolated off the west coast of Sweden. The discovery was made through the collection of dinoflagellates Dinophysis on the Swedish West Coast, which were found to contain round bodies that were assumed to be products of sexual reproduction. After preservation in the refrigerator for two weeks, the dinoflagellates had all died but what had remained were the round bodies. These were further found to be sporangia of parasitic protist, later described as Parvilucifera infectans.
Initially, it was assumed that the observed zooids would grow into dinoflagellate cells, and there was much debate that sporangia did not arise from parasites. However, when very similar observations of the round bodies were made with plankton material also from the Swedish West Coast, led to further investigation (Norén et al. 1999). Through combined examination of light and electron microscopy alongside DNA sequencing of the emerging sporangia from the zooids displayed a relationship with Perkinsus. Differences of the ultrastructure of zooids arose in terms of the flagellum and were noted in contrast to dinoflagellates and apicomplexans. This led to a designation of a new phylum, Perkinsozoa. This phylum encompasses Perkinsus, Parvilucifera and Psammosa (Norén et al. 1999).
Following the discovery of P.infectans, the next Parviluciferao be discovered was P.sinerae (Figueroa et al. 2008), which is also the closest relative to P.infectans. Then followed the discovery of P.prorocentri (Hoppenrath & Leander 2009), P.rostrata (Karpov & Guillou 2013), and P.corolla (Reñé et al. 2017).
Parvilucifera can be broken up into 'parvi' which means small and 'lux' which means light. So overall, small light; although also means refractile zooids.
Habitat
The presence of Perkinsozoa has been demonstrated in freshwater, marine waters, and sediments (Reñé et al. 2017). P.infectans has been found in coastal Sweden where it was first discovered, especially being commonly found in marine sediment (Alacid et al. 2015). Nearly all of the species of Parvilucifera have been found to be generalist parasites for dinoflagellates, but increasing studies are allowing a better understanding for the preferences of specific species for particular species of dinoflagellates (Reñé et al. 2016).
Taxonomy
There are five recognised species in this genus. The type species is Parvilucifera infectans. Parvilucifera sinerae Parvilucifera corolla Parvilucifera rostrata Parvilucifera prorocentri
Anatomy
The zoospores are 1.2-1.8 micrometers in diameter and possess two flagellae — an anterior (transverse) one and a shorter posterior one. They also possess alveoli, a refractile body, a mitochondrion with tubular cristae, micronemes, rhoptries and a pseudoconoid. They also have a heteromorphic pair of central microtubules in the anterior axoneme. The micronemes have bulbous posterior ends and are associated with the pseudoconoid.