Dinoflagellates

This specimen of Ceratium had a snack shown by the organge fluorescence of cryptophyte pigment- perhaps that of the ciliate Mesodinium rubrum

Plate 7. Alexandrium tamarense. Fig. 1. LM. Two cell chain: cells small to medium; slightly longer than wide, nearly spherical. Cingulum (C) deeply escavated and lipped. Left hypothcal lobe slightly larger than right. Nucleus (n) visible. Figs. 2-4. SEM. Fig. 2. Two cell chain: cingulum displaced 1X its width. Deep sulcus (s) widens posteriorly. Fig. 3. Epitheca: apical view. Apical pore plate (Po) rectangular; narrows ventrally. Po and first apical plate (1') in direct contact. Small ventral pore present on 1' plate. Fig. 4. Apical pore complex (APC): foramen large and fishhook shaped. Small round anterior attachment pore (aap) present (Hallegraeff 1991). Fig. 5. Line drawing. Fig. 6. LM. Oblong resting cyst with rounded ends, reddish lipid bodies; covered in mucilage.

Ornithorcercus heteroporus (probably) from Station 72 of the Tara Oceans Expedition.

Figs 1-7. Lateral view of a cell with reticulated thecal surface, a conical epitheca, wide and deep, displaced cingulum, and a trapezoid hypotheca. The apical pore complex is situated ventrally. The apical plate 1' is asymmetric and pentagonal. The hypotheca is ventrally indented forming two lobes separating plates 2'" and 5'". The cingulum is displaced and finely striated with small pores aligned along the cingular lists. Fig. 2.The apical pore complex is a recessed chamber with a centrally located raised dome surrounded by a collar; it includes the apical pore plate (PO) and canal plate (X). Fig.3. Lateral view of a cell: a conical epitheca, wide and deep cingulum, and trapezoid hypotheca. Fig.4. Architecture of the epitheca including the position of the apical pore complex. Intercalary plates 2a and 3a are separated by plate 3'. The intercalary bands are striated. EMu: Holotype SEM negative # 23040; SEM stub # ?; Field # 78-87; Accession # 407159; Catalog #1730; Figure # 1.

Plate 9. Cochlodinium polykrikoides. Figs. 1-7. LM. Fig. 1. Four cell chain. Single cell small and ellipsoid. Epitheca (E) rounded and conical. Hypotheca (H) divided into two posterior lobes (arrows). Numerous rod-shaped chloroplasts. Fig. 2. Cingulum (c) deeply excavated; circles cell 1.8-1.9 times. Fig. 3. Colony of single and chained cells. Fig. 4. Large nucleus (n) in epitheca. Figs. 5-7. Cysts. (Figs. 3,6,7 by Matsuoka & Fukuyo)

A heterotrophic dinoflagelate from the Amundsen Sea

Plate 10. Coolia monotis: Figs. 1-5. SEM. Fig. 1. Ventral view: spherical shape. Cingulum lipped and equatorial. Sulcus with flexible lists (arrowheads). Ventral pore present (arrow). Fig. 2. Dorsal view: apical pore plate (arrow), Po, located off-center on epitheca. Fig. 3. Antapical view: hypothecal plates. Fig. 4. Smooth edged thecal pores unevenly distributed. Fig. 5. Po about 12 _ long, slightly curved and narrow with a slit-like apical pore. Two supporting rib-like costae (arrows) and evenly spaced round pores surround the pore. Figs. 6,7. LM. Fig. 6. Ventral view of lipped cingulum and sulcus. Fig. 7. Planozygote with two longitudinal flagella (arrows). Fig. 8. Line drawing: thecal plate arrangement.

Tiny Sea Star: A Pentaster (siliceous internal skeleton) of the gymnodinid species Actiniscus pentasterias from the Arctic Chukchi Sea.

FIGS. 7-11. Scanning Electron micrographs of the surface morphology of Coolia tropicalis sp. nov. FIG. 7. Oblique dorsal view of C. tropicalis shows the apical pore and the equatorially located lipped cingulum. Cell surface is smooth with large scattered pores. FIG. 8. Cell is spherical in equatorial view shoving a deep cingulum and sulcus. Detritus adheres to the epitheca. FIG. 9. Antapical view of a cell show large unequal plates. FIG. 10. Apical pore is a narrow opening located in the epitheca. Fine detrital particles partially cover the thecal surface. FIG. 11. The apical pore is about 7 μm long straight and narrow slits with two supporting costae and evenly spaced round pores. Detritus attached to surface of apical pore plate. EMu:HOLOTYPE SEM NEGATIVE #166029; SEM STUB # 166; FIELD # 728-93;ACCESSION # 408431: CATALOG # 997; FIGURE # 7.

A heterotrophic dinoflagellate from the Amundsen Sea

FIG. 12. Coolia tropicalis sp. nov. A) apical view of epitheca, and B) antapical hypotheca.

Plate 11. Dinophysis acuminata. Figs. 1-5. SEM: lateral view. Fig. 1. Cell oval and rotund; thecal surface with shallow depressions and scattered pores. Left sulcal list (LSL) extends beyond midpoint of cell. Well-developed cingular lists: anterior cingular list (ACL); posterior cingular list (PCL). C=cingulum. Fig. 2. Long and narrow cell with prominent surface areolae, each with a pore. Antapex tapered and ventrally off-center. Small posterior protrusion present (arrow). Fig. 3. Long and narrow cell. Thecal surface smooth with small scattered pores. Megacytic zone (M) void of pores. Posterior protrusions on antapex (arrow). Figs. 4-5. LM: lateral view. Fig. 4. Surface areolae and tapered antapex (from Larsen & Moestrup 1992: fig. 1d). Fig. 5. Large dorsal nucleus (N). Small, blunt projections on tapered antapex (arrow). Fig. 6. Line drawing.

Dinoflagellate from the Aegean Sea. Lugol's-fixed specimen from 75 m depth.

Plate 12. Dinophysis acuta. Fig. 1. SEM: lateral view. Cell oblong and robust; theca heavily areolated. Well developed cingular lists (CL) and left sulcal list (LSL). Pointed antapex. Figs. 2-3. LM: lateral view (from Larsen & Moestrup 1992: fig.s 2a,d; scale bars=20 _). Fig. 2. Large areolae, each with a pore (arrows). Fig. 3. Widest point below mid-section (dashed line) aligned with third sulcal rib (arrow). Fig. 4. Line drawing.

Image by D.W. Coats

Plate 13. Dinophysis caudata. Figs. 1-2. SEM. Fig. 1. Large, long and distinctive cell with extended ventral hypothecal process. Cingulum narrow; lists supported by ribs (arrowhead). Strong left sulcal list (double arrows). Right sulcal list present (single arrow). Fig. 2. Ventral view: cell compressed laterally. Figs. 3-4. LM. Fig. 3. Large posterior nucleus (n). Fig. 4. Left sulcal list with three supporting ribs (arrowheads); posterior projection with small knob-like spines (arrows). Surface areolae evident. Fig. 5. SEM. Paired cells joined at dorsal expansion (arrow). Fig. 6. Line drawing.

Plate 14. Dinophysis fortii. Fig. 1. SEM: lateral view. Left sulcul list (LSL) long and well-developed. Right sulcal list (RSL) present. Cingulum (C) obscures low and small epitheca. Thecal surface covered with areolae. Figs. 2-3. LM: lateral view. Fig. 2. Cell subovate with a wide round posterior bottom (dorsal bulge)(arrows). Fig. 3. LSL supported by three strong ribs (arrows). Smoothly convex dorsal margin. Fig. 4. Line drawing.

Image of live specimen showing the dinoflagellate nucleus characterized by chromosomes which appear to be always condensed. See a video of the specimen : http://www.obs-vlfr.fr/LOV/aquaparadox/html/VideosPage.php

Plate 16. Dinophysis norvegica. Fig. 1. SEM: lateral view. Cell heavily areolated with pointed antapex and posterior protrusions (arrowheads). Ventral margin concave below left sulcal list (LSL)(arrow). Well developed cingular lists (CL) and LSL. Figs. 2-5. LM: lateral view. Fig. 2. Cell less robust than in Fig. 1; pointed antapex. Fig. 3. Robust cell with rounded antapex. Heavily areolated. Ventral margin straight below LSL (arrows). Fig. 4. Deepest point of cell through mid-point (dashed line), just above third rib of LSL. Fig. 5. Large posterior nucleus (n). Pointed antapex with posterior projections (arrows). Fig. 6. Line drawing. Right sulcal list depicted (RSL).

Heterotrophic dinoflagellate from the Etang de Thau

Plate 18. Dinophysis sacculus. Figs. 1-3. SEM: lateral view. Fig. 1. Cell oblong with rounded posterior. Hypotheca long, margins undulate. Thecal surface coarsely areolated. Short left sulcal list (LSL). Cingulum with two well developed lists. Small blunt posterior projections (arrow). Fig. 2. Cingulum lined with pores. Right sulcal list (RSL) visible. Fig. 3. Smooth thecal surface with pores. Metacytic zone (M) devoid of pores. Figs. 4-5. LM: lateral view. Fig. 4. Hypotheca sack-like with deep thecal pores. Posterior end with two blunt projections (arrows). Fig. 5. Large posterior nucleus (n). Fig. 6. Line drawing: morphotype from Stein (1883).