Gambierdiscus carpenteri Kibler, Litaker, M.A. Faust, W.C.

Ramos-Santiago, Research Article Ana E., Band-Schmidt, Christine J., Leyva-Valencia, Ignacio, Fernández-Herrera, Leyberth J., Núñez-Vázquez, Erick J. & Okolodkov, Yuri B., 2024, Gambierdiscus carpenteri (Dinophyceae) from Bahía de La Paz, Gulf of California: morphology, genetic affinities, and mouse toxicity, Botanica Marina (Warsaw, Poland) 67 (4), pp. 309-324 : 312

Gambierdiscus carpenteri Kibler, Litaker, M.A. Faust, W.C. Holland, Vandersea et P.A. Tester 2009

Sampling locality: La Gaviota Island, BahÍa de La Paz, Gulf of California, Mexico.

Vegetative cell size: Cells in apical view presented a length of 84.39 ± 6.18 µm and a width (transdiameter) of 87.03 ± 8.81 µm (n = 48). The cell length in anteroposterior view was 55.87 ± 6.82 µm (n = 10). The cell width in anteroposterior view was 85.48 ± 8.49 µm (n = 8).

Description: Solitary cells, with active movement, are attached by a mucilage filament that allows their attachment to the bottom of culture tubes ( Figure 1A–C ). Anteroposteriorly compressed cells, oval-shaped (lens-shaped = lenticular) in apical and antapical views ( Figure 1D–G ). Numerous brown-green chloroplasts are present. Cingulum narrow, median, deeply excavated (cavozone), ascending, and displaced twice the cingulum width, with no offset of its ends ( Figure 1H–J ). Resting oval shape cysts, with a thickened wall, colorless theca, where the protoplasm is concentrated in the center of the cell ( Figure 1K ). Temporary cysts with one membrane, oval-shaped, dark brown ( Figure 1L ).

The apical plate 1′ is hexagonal, connected to the apical pore plate (Po) and to the plates 2′, 3′, 1″, 2″, 6″ and 7″ ( Figures 2A–D, F–L , 3A and 4F ). The apical 2′ is the largest of the epitheca, long, rectangular, connected to plates 1′, 2′, the apical pore plate (Po), and the precingular plates 2″, 3″ and 4″ ( Figure 2A–L ). The Po is oval, surrounded by pores and fishhook-shaped ( Figures 3B and 4C ). The Po plate measured 9.51 ± 1.46 µm in length and 6 ± 1.25 µm in width (n = 10). Aberrant cells were observed where plate 2′ appeared to have three divisions; such an arrangement of apical plates is not consistent with what is currently reported for the genus Gambierdiscus ( Figure 4A ). The 2″, 3″ and 4″ precingular plates are elongated ( Figures 2A–L , 4A–B and 5A ). Plate 4″ is quadrangular and asymmetrical ( Figure 2C ). Plate 2″″ is asymmetrical and connected to plates 2‴, 3‴, 4‴, 1″″ ( Figures 3C–I , 4D and 5B–F ). Thecal surface has a high density of rather homogeneously distributed medium-sized and smaller pores ( Figure 5G–H ). The average diameter of the medium-sized pores is 0.41 ± 0.04 µm (n = 14), and that of the smaller pores is 0.10 ± 0.02 µm (n = 10).

Plate formula: Po, 3′, 7″, 6c?, 6–7s?, 5‴, 1p, 2″″ ( Hoppenrath et al. 2014; Litaker et al. 2009).

Figures

Figure 1: Light micrographs of Gambierdiscus carpenteri. Strain GCARBAPAZ-1: (D, F–H, K, L); strain GCARBAPAZ-3:(A–C, E, I, J).(A) Culture in K medium. (B) Mobile cells joined by mucilage (m). (C) Ventral view, epitheca (yellow contour), hypotheca (red contour), cingulum (Ci) and sulcus (Su). (D, H and I) Apical-ventral view (H and I – empty thecae). (E and F) Antapical view; pusules (Pu) are shown. (G) Apical view; white arrow – eyespot. (J) Ventro-lateral view,cingulum displacement shown.(K) Temporal cyst with a thin cell wall.(L) Non-motile cells with a thick cell wall, showing the process of encystment (formation of resting cysts). Red arrows show the cell wall. (B–D, F–I, K and L): in bright field; (E): in phase contrast; (J) in epifluorescence regime. Scale bars: 2.5 cm in (A); 160 µm in (B); 25 µm in (C, E, I and K); 20 µm in (J, D, F–G and L).

Figure 2: Light micrographs of Gambierdiscus carpenteri from the Gulf of California, thecae and their fragments. Strain GCARBAPAZ-1: (A and B); strain GCARBAPAZ-3:[C–L (C,F,I, K and L – thecaefrom inside)].(A–D,F–L) Apical view,apical (′), precingular (″) and the pore (Po) plates.(E) The 2′ plate,hatchetshaped.Po – the apical pore plate. (A–F,H and I): in bright field; (G and J–L):in epifluorescence regime.Scale bars: 20 µm in (A, B, C,F,G and K); 10 µm in (D, E, I, J and L); 30 µm in (H).

Figure 3: Light micrographs of Gambierdiscus carpenteri, thecae and their fragments.Strain GCARBAPAZ-1:(C and I); strain GCARBAPAZ-3:[A, B, D and E-H (A,C,D and I – thecae from inside)].(A) Apical-ventral view.(B) The hook-shaped apical pore plate (Po).(C) Antapical view,postcingular plates (‴). (D) Ventroantapical view,1‴, 5‴, 1″″ and 2″″ plates.(E, G and H) Antapical view, postcingular (‴), antapical (″″) and posterior intercalary (1p) plates.(A, C,D, F and I): in bright field; (E, G and H): in epifluorescence regime. Scale bars: 10 µm in (A and H); 5 µm in (B); 25 µm in (C, D and E); 30 µm in (F); 20 µm in (G and I).

Figure 4: Scanning electron micrographs of Gambierdiscus carpenteri, strain GCARBAPAZ-1, from La Gaviota Island, Bahía de La Paz, Gulf of California. (A) Cell in apical view:the apical (′) and precingular (″) plates; and the 2′ plate is split into three plates (a–c), and plate 3′ is split into two plates (a and b). (B) Apical-left-side view,showing precingular plates and the apical pore plate (Po).(C) The apical pore plate (Po);variation in the number and arrangement of thecal pores is shown.(D) Antapical-right-side view,postcingular (‴),antapical (″″) and posterior intercalary (1p) plates.(E and F) Apical view,a fragment of the epitheca. Scale bars: 20 µm in (A, B and D); 2 µm in (C); 5 µm in (E); 2.5 µm in (F).

Figure 5: Scanning electron micrographs of Gambierdiscus carpenteri, strain GCARBAPAZ-3, from La Gaviota Island, Bahía de La Paz, Gulf of California. (A) Apical view.(B, D and F) Antapical view,postcingular (‴), antapical (″″) and posterior intercalary (1p) plates.(C) Antapical-ventral view,transitional plate (t), sulcal right posterior plate (S.d.p.), precingular (″), postcingular (‴) and antapical (″″) plates. (E) Cells bound by mucilage (m). (G and H) Fragments of thecal surface, white arrows indicate the smaller pores. Scale bars: 20 µm in (A, B and D); 10 µm in (F); 30 µm in (E); 1 µm in (G and H).