Protoceratium reticulatum

Super Group: 
Alveolata
Phylum: 
Dinophyta
Class: 
Dinophyceae
Order: 
Gonyaulacales
Family: 
Protoceratiaceae
Genus: 
Protoceratium
Species: 
reticulatum
Authority: 
(Claparède et Lachmann) Bütschli
Synonym(s): 
Basionym: Peridinium reticulatum Claparède & Lachmann
Gonyaulax grindleyi Reinecke
Operculodinium centrocarpum (Deflandre et Cookson) Wall
Protoceratium aceros Bergh
Peridiniopsis reticulatum (Claparède & Lachmann) Starmach

Diagnosis

Diagnoses_species: This organism was originally described as a species of Peridinium.  Because of the obscure plate pattern, the same organism was described as a species of Gonyaulax by Reinecke in 1967, and it often appears in the literature under that name. The hypnospore, originally described from Miocene deposits (Matsuoka et al. 1997) was identified as O. centrocarpum, but its exact relationship to extant  P. reticulatum  is not certain. This dinoflagellate exists as unicells with an oval shape, occasionally becoming somewhat polygonal. The cingulum is displaced about one cingular width circumferentially (Figures 2 & 5), and is located anterior to the cell midpoint, making the hypotheca larger than the epitheca.  The sulcus does not reach the antapex (Figures 2 & 5). The cell surface is highly reticulate, which makes the plate pattern difficult to evaluate. The first apical plate (1’) has a ventral pore on its left side. Both Steidinger & Tangen (1997) and Throndsen et al. (2007) give a plate formula for the genus as Po,3’, 0a, 6’’, 6c, 6s, 6’’’, 0p,2’’’’.  The hypnocyst is spherical or subspherical and hyaline, with a smooth cyst wall and ornamented with 20-40 slender spines.  Spines have capitate ends and are about ¼ the length of the cyst diameter, though with some variation in length depending on salinity and temperature (Mertens et al. 2010).  There are numerous brown chloroplasts, which often obscure the plates. The longitudinal (trailing) flagellum does not extend very far beyond the antapex. P. reticulatum is a cause of extensive fish kills due to a group of lipophilic sulphated polyether toxins called yessotoxins (YTX), named after Patinopecten yessoensis, the mollusk in which they were first identified.

Bloom: Yes
Toxicity: Yes_YTX

Etymology

Adjective (Latin), reticulate, netted, marked with a network (Stearn 1973).

Type species

The type species (holotype) of the genus Protoceratium is Protoceratium aceros Bergh.

Ecology

Substrate: planktonic
Sociability: solitary
Sociability: colonial
Salinity: marine
Salinity: variable (estuary)
pH: neutral

Feeding: Photosynthetic

Life cycle

Phases_alternance: haplontic
Generation: <1 month

Reproduction_mode: asexual
Reproduction_mode: sexual
Resting_stage: cysts_sexual

Feeding behaviour

Photosynthetic

Mode of locomotion

Two flagella typical for Dinophyceae
Flagellum: 2
Motility: motile_swimming

Observation site(s)

SYMBIONTS

Displaying 1 - 1 of 1
Association with... Region origin Name of site In reference...
Parvilucifera sinerae Catalunya Harbor of Arenys de Mar R. Isabel Figueroa, Garcés, E., Massana, R., and Camp, J., Description, Host-specificity, and Strain Selectivity of the Dinoflagellate Parasite Parvilucifera sinerae sp. nov. (Perkinsozoa), Protist, vol. 159, no. 4, pp. 563 - 578, 2008.