Ultrastructure of a Marine Dinoflagellate, Peridinium quinquecorne Abé (Peridiniales) from South Africa with Particular Reference to its Chrysophyte Endosymbiont

Abstract

The micro-morphology and the Ultrastructure of a marine dinoflagellate, Peridinium quinquecorne Abe were studied. The dinoflagellate shows a wide range of morphological variation, including cell shape and length of the antapical spines. The thecal plate arrangement is: pp, x, 3", 2a, 7", 5c, 5"', 2"" 4s. Detailed study of the sulcus and the cingulum, which was not undertaken by the original author was carried out. The ultrastructural investigation revealed that all the chloroplasts belong to an endosymbiotic alga which is separated from the host cytoplasm by a single unit membrane. The host cytoplasm (dinokaryotic cytoplasm) revealed typical dinoflagellate organization. The eyespot is bounded by a triple membrane and is located in the host cytoplasm. The structure of the endosymbiont is simple and contains only a eukaryotic nucleus, mitochondria, dictyosomes and chloroplasts. The ultrastructural features of the chloroplasts suggest a chrysophyte affinity for the endosymbiont.

Bloom of Peridinium quinquecorne abé in la Ensenada de la Paz, Gulf of California (july 2003)

“…Balech (1974) transferred the species to the genus Protoperidinium, making the new combination Protoperidinium quinquecorne (Abé) Balech. Since this organism has 3 apical plates, 2 anterior intercalary plates, 7 precingular plates, 5 cingular plates, 5 postcingular plates, and 2 anteapical plates, we agree with Fukuyo et al (1990) that it is not appropriate to place this species in the genus Protoperidinium, because this genus is characterized by possessing four cingular plates, including a transitional plate (Horiguchi & Pienaar, 1991). However, taxonomically its generic position is still controversial, with the further possibility that this species may belong to the genus Pentapharsodinium (Steidinger & Tangen, 1997).…”

“…However, taxonomically its generic position is still controversial, with the further possibility that this species may belong to the genus Pentapharsodinium (Steidinger & Tangen, 1997). Peridinium quinquecorne has a wide geographical distribution, ocurring along the coasts of Belize, Brazil, China, India, Malaysia, Mexico, Japan, Russia, South Africa, Spain, Tunisia, and the USA (Abé, 1981;Dodge, 1985;Konovalova et al, 1989;Horiguchi & Pienaar, 1991;Shamsudin et al, 1996;Tomas, 1998: Trigueros & Orive 2000Turki & El Abed, 2001;Faust et al, 2005;Barón-Campis et al, 2005;Gárate-Lizárraga et al, 2006a;Proença et al, 2006, Okolodkov et al, 2007.…”

Morphological differences and molecular phylogeny of freshwater blooming species, Peridiniopsis spp. (Dinophyceae) from China

“…Several dinoflagellates are known to possess an endosymbiotic diatom or diatom-like alga which is separated from the dinoflagellate cytoplasm by a single membrane (Schnepf and Elbrächter 1999 Kempton et al 2002), Peridinium quinquecorne Abé (Horiguchi and Pienaar 1991), Dinothrix paradoxa Pascher (Horiguchi and Chihara 1993), Gymnodinium quadrilobatum Horiguchi et Pienaar (Horiguchi and Pienaar 1994) and Galeidinium rugatum Tamura et Horiguchi (Tamura et al 2005). Takano et al (2008) recently described two freshwater dinoflagellates, P. kevei and P. penardii, from Japan, which also had a similar type of endosymbiont.…”

Spatio-temporal distribution of the dominant Diatom and Dinoflagellate species in the Bay of Tunis (SW Mediterranean Sea)

“…The presence of a chrysophyte endosymbiont could represent an advantage in comparison with marine dinoflagellates (HORIGUCHI & PIENNAR, 1991), being more competitive and in bloom under these conditions.…”