Parvilucifera

Parvilucifera is a genus of marine parasitic protozoa that parasitise dinoflagellates.

History

The genus was first described by Noren and Moestrup in 1999 and was isolated off the west coast of Sweden.^[1]

Taxonomy

There are three recognised species in this genus. The type species is Parvilucifera infectans.

Description

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.

Life cycle

Zoospores (the infectious stage) enter the host cells wherein they develop into round bodies (sporangia).

The immature sporangia are 5–15 micrometers in diameter and contain spherical bodies and amorphous spaces. The mature sporangia are ~20–25 micrometers in diameter when they become enveloped by a wall with a convoluted mid layer. The mature, dark colored sporangia are released from the dead dinoflagellate cells by the breakup of the host's theca.

The sporangial cytoplasm divides into many minute zoospores which after their release subsequently infect new hosts. The zoospores escape from the cyst through a germ tube ~4–5 micrometers in diameter and 10–15 micrometers in length.

References