Akashiwo sanguinea
Diagnosis
Diagnosis_Genus: Akashiwo G. Hansen & Moestrup. Unarmoured dinoflagellates with chloroplasts containing peridinin as major carotenoid. Nuclear envelope of typical eukaryotic apparearance (i.e. lacking envelope chambers). Dorsal connective between the flagellar apparatus and the nucleus absent. Apical groove curves around the apex in a clockwise direction.
Diagnosis_Species: A. sanguinea G. Hansen & Moestrup. The cell has a large number of elongate yellow or brown chloroplasts that radiate from the cell center. The nucleus is just above the cingulum in the epicone, and distinguishable in living cells by appearing as a clear area. The trailing flagellum is quite long, often longer than the cell itself. Akashiwo sanguinea is exclusively planktonic and has a worldwide distribution in temperate and tropical waters. It is nearly always found in coastal and estuarine locations. This species is a cosmopolitan red tide former that has been associated with fish and shellfish mortality events. This species is highly variable in size and shape. Cells are large, slightly dorso-ventrally flattened and roughly pentagonal. An apical groove is present. The epitheca and hypotheca are nearly equal in size. The epitheca is rounded and conical, and the hypotheca is deeply intended by the sulcus creating two posterior lobes. The median cingulum is left-handed and displaced 1-2 times its width. The sulcus does not invade the epitheca, but expands posteriorly into the hypotheca. This species has numerous large, spnidle-shaped, reddish-yellow-brown chloroplasts radiating from the center of the cell. The large nucleus is slightly off-center. Cells can vary from heavily pigmented to pale yellow or nearly colorless.
Body_length: 40-80 µm
Toxicity: No
Bloom: Yes (Daugbjerg et al. 2000)
Etymology
akashiwo (Japanese)= red tide. Sanguinea=Adjective (Latin), blood-red (Stearn 1973), describing the resulting color of the water after a red tide event.
Type species
This is the type species (holotype) of the genus Akashiwo.
Type illustration / Type locality / Type specimen
Type locality: NW Pacific Ocean: Kozusa-ura, Gokasho Bay, Japan (Faust & Gulledge 2002: 43). Holotype: (Faust & Gulledge 2002: 43).
Ecology
Substrate: planktonic
Sociability: solitary
Salinity: marine
Salinity:variable (estuary)
pH: neutral
Feeding: photosynthetic
Feeding: predatory. Preys on ciliate, Bockstahler & Coats 1993. See also Jeong et al. (2005).
Life cycle
Phases_alternance: haplontic
Generation: <1 month