Genus Pyrodinium Plate, 1906
Cells armoured. Monotypic genus with 2 varieties: Pyrodinium bahamense var. bahamense, Pyrodinium bahamense var. compressum. Cells medium sized with distinct and prominent apical and antapical spines and lists. Plate sutures with strong crests. Thecal surface covered with evenly distributed pores and surface markings. Apical pore plate (Po) with closing plate (cp). Plate formula: (Po, cp), 4-5', 6, 6c, 6s, 6''', 2''''. Chloroplasts present. Form cysts.
Warm water species.
Remarks: Established differences between varieties: 1) var. bahamense with a prominent apical horn and well developed winged apical spine, whereas var. compressum with a shorter, less pronounced apical horn; 2) var. bahamense not a chain-former, while var. compressum is most often found in chains of 2-32 cells; 3) var. bahamense with smaller thecal pores and more prominent thecal spines than var. compressum, which bears pustules between trichocyst pores; 4) var. bahamense is bioluminescent and non-toxic, var. compressum is a toxin producer responsible for PSP events; 5) var. compressum is anterio-posterorly compressed; and 6) var. bahamense bears a narrow oblong apical pore (AP) along the cp margin (Faust, M., pers. comm.).
Species included from this genus:
Pyrodinium bahamense Plate, 1906 var. bahamense
Pyrodinium bahamense Plate, 1906 var. compressum (Böhm) Steidinger et al., 1980
(Pyrodinium bahamense var. bahamense )
( Pyrodinium bahamense var. compressum )