Protoperidinium mediterraneum (Kofoid) Balech 1974

Krakhmalnyi, Aleksandr F., Krakhmalnyi, Maxim A., Terenko, Galyna V. & Goncharenko, Igor V., 2023, Dominant Species Of The Genus Protoperidinium Bergh (Peridiniales: Protoperidiniaceae) In The Black Sea, Zootaxa 5339 (5), pp. 427-448 : 437

Protoperidinium mediterraneum (Kofoid) Balech 1974 . Rev. Mus. Argent. Cienc. Nat. “ B. Rivadavia ”, Hydrobiologia 4 (1): 62. ( Figs. 59–64 ) .

References: Delgado and Fortuno, 1991: 10, Lam. XVI c, d; XXI c.

Basionym: Peridinium steinii subsp. mediterraneum Kofoid 1909 : Pl. II, Figs. 1–11 .

Synonyms: Peridinium mediterraneum (Kofoid) Balech 1964 .

Description: Cells pyriform (rounded in apical view), with an elongated apical horn, and long antapical spines bearing well-developed lists. The epithecal plate pattern comprises seven precingular plates (7ʹʹ), four apical plates (4ʹ), three anterior intercalary plates (3a), 1ʹ plate – “meta”, 2a – “penta”. The thecal surface finely reticulated, with densely scattered pores. The cingulum median, slightly ascending, broad, shallow, bordered. The sulcus straight, shallow, with developed left list that merges with the left spine list. Dimensions: 67.2–73.3 μm long and 31.6–38.8 μm wide.

Nomenclatural note: The species is close to P. steinii and P. pedunculatum in terms of its morphology and distribution. Protoperidinium mediterraneum differs from P. steinii in longitudinally elongated cells with rounded lateral sides. Protoperidinium pedunculatum can be distinguished from P. mediterraneum by smaller size (30–51 μm long and 25–35 μm wide), even more rounded shape, and relatively short apical horn.

The species was first mentioned for the Black Sea in 2007. However, P. mediterraneum is now reaching a significant abundance off the coasts of Ukraine, Russia, and Turkey ( Krakhmalnyi et al. 2018).

Distribution: Mediterranean Sea, Black Sea ( Krakhmalnyi 2011). Data on the distribution of P. mediterraneum are given from the GBIF.org (2022) ( Fig. 90 ).

Figures

FIGURES 59–64. Protoperidinium of the Black Sea. 59–64—P. mediterraneum. Designations: 1ʹ—first apical plate. 59–63— DIC; 64—epifluorescence. Scale bars: 10 µm.

FIGURES 1–10. Protoperidinium of the Black Sea. 1–2—P. achromaticum; 3–4, 7—P. brevipes; 5, 10—P. quadrioblongum; 6, 8–9—P. excentricum. Designations: 1ʹ—first apical plate, 2a—second intercalary plate. 4, 6–9—epifluorescence; 5, 10— transmitted light. Scale bars: 10 µm.

FIGURES 11–22. Protoperidinium of the Black Sea. 11–12—P. bipes; 14–15—P. brochii; 13, 16—P. crassipes; 17–19—P. claudicans; 20–22—P. depressum. Designations: 1ʹ—first apical plate, 2a—second intercalary plate. 11, 13, 15–16—DIC; 12, 14, 18–19, 22—epifluorescence; 17, 20–21—transmitted light. Scale bars: 11–12, 14–15 = 10 µm; 13, 16–22 = 20 µm.

FIGURES 86–94. Global distribution maps of some Protoperidinium species. 86—P. excentricum; 87—P. granii; 88—P. knipowitschii (Krakhmalnyi, 2011); 89—P. leonis; 90—P. mediterraneum; 91—P. pallidum; 92—P. pellucidum; 93—P. pentagonum; 94—P. pyriforme.