Alexandrium tamutum

Super Group: 
Alveolata
Phylum: 
Dinophyta
Class: 
Dinophyceae
Order: 
Gonyaulacales
Family: 
Goniodomataceae
Genus: 
Alexandrium
Species: 
tamutum
Authority: 
M.Montresor, A.Beran & U.John in Montresor et al. 2004

Diagnosis

Elliptical in shape. Cingulum excavated with its right end displaced posteriorly one cingular width. Plate pattern: Po, 4', 0a, 6'', 6C, 9S, 5''', 0p, 2''''. The first apical plate is irregularly rhomboidal and contacts Po. A small ventral pore is present on the anterior right margin of the first apical plate. The sixth precingular plate (6'') is as wide as long. The posterior sulcal plate (Sp) is roughly rectangular, wider than longer. Thecal plates are thin and smooth, with small pores. Cysts are circular (26–32 µm diameter) when seen from above and kidney shaped (16–20 µm high) when seen from the side. Cyst wall is thick and surrounded by amucous layer; cyst content is granular and a brownish accumulation body is present.

Etymology

The word tamutum is composed by the first part of the word ‘‘tamarense’’ and the last part of the word ‘‘minutum’’ and indicates the morphological relatedness of A. tamutum with both A. tamarense and A. minutum.

Type illustration / Type locality / Type specimen

Type locality: Gulf of Naples, Tyrrhenian Sea, Mediterranean Sea

Ecology

Substrate: planktonic
Sociability: solitary
Salinity: marine
pH: neutral

Feeding: Photosynthetic

Life cycle

Phases_alternance: haplontic
Generation: <1 month

Reproduction_mode: asexual_binary
Reproduction_mode: sexual_heterothallic
Resting_stage: cysts_sexual (Resting cysts described in Montresor et al. 2004). 
Resting_stage: cysts_asexual

Feeding behaviour

Photosynthetic

Mode of locomotion

Two flagella typical for Dinophyceae
Flagellum: 2
Motility: motile_swimming

Attached phylogeny

Observation site(s)