Chain-Forming Diatoms - Phytoplankton Identification

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Asterionellopsis nipponica (A. nipponica)

Chain-forming diatom

Silicule frustules, needle-shaped and form star-like chains

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Cerataulina pelagica (C. pelagica)

Chain-forming diatom

Cylindrical, silica frustule, can cause mechanical irritation to gills of fish

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Chaetoceros convolutus (C. convolutus)

Chain-forming diatom

Silica frustules, bullet-shaped w/ large spines, oceanic

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Chaetoceros debilis (C. debilis)

Chain-forming diatom

Elliptic cylinders, connect by crossing of adjacent spines, late winter/spring, neritic

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Chaetoceros decipiens (C. decipiens)

Chain-forming diatom

Touching of cell corners and fusing of adjacent spines, resting spores present

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Chaetoceros didymus (C. didymus)

Chain-forming diatom

Two large plate-like chloroplasts (one in each valve), crossing of adjacent spines, neritic

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Chaetoceros radicans (C. radicans)

Chain-forming diatom

Centric diatom, connection by crossing of adjacent spines, one chloroplast

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Chaetoceros similis (C. similis)

Chain-forming diatom

Centric diatom, connection by crossing of adjacent spines, distinct figure 8 shaped aperture

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Chaetoceros sociales (C. sociales)

Chain-forming diatom

Centric, large globular mucous covered colonies, connect by crossing of spines w/o direct contact of bodies, bundles of long spines come together in centre of colony

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Dactyliosolen fragillisimus (D. fragillisimus)

Chain-forming diatom

Centric, cylindrical, short central spine fitting into depression of adjacent cell, loosely united as straight chains

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Detonula pumila (D. pumila)

Chain-forming diatom

Centric, cylindrical, cells connected marginally by ring of small spines which splits off into two gelatinous threads joined to the spines of the adjacent cell in distinctive zigzag patterns

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Ditylum brightwellii (D. brightwellii)

Chain-forming diatom

Centric diatom, triangular prism, usually solitary but sometimes in short chains, connected by large spines

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Eucampia zodiacus (E. zodiacus)

Chain-forming diatom

elliptical cylinder, curved, cells flattened usually in helical chains

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Guinardia deliculata (G. deliculata)

Chain-forming diatom

Centric diatom, cylindrical, large irregularly-lobed and strongly pigmented chloroplast

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Guinardia striata (G. striata)

Chain-forming diatom

Centric diatom, curved/cylindrical, when ingested may negatively impact copepod reproduction, usually in helical chains and intercalary bands sometimes visible

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Lauderia annulata (L. annulata)

Chain-forming diatom

Centric, valves directly touching, sexualisation is positively correlated with light intensity

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Leptocylindrus danicus (L. danicus)

Chain-forming diatom

Centric diatom, cylindrical and form long straight chains

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Leptocylindrus minimus (L. minimus)

Chain-forming diatom

Centric diatom, cylindrical, very small, united in straight or gently undulated chains

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Mesosera moniliformis (M. moniliformis)

Chain-forming diatom

Centric, pill-shaped, connected in straight chains by mucous pads

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Odontella longicruris (O. longicruris)

Chain-forming diatom

Centric, elliptical cylinder, cells connected in straight chains and sometimes solitary,

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Skelotenema costatum (S. costatum)

Chain-forming diatom

Centric diatom, connected in long straight or slightly undulated chains,

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Pseudo-nitzschia

Chain-forming diatom

Pennate diatom, narrow and fusiform cells, chains are motile

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Stephanopyxis turris (S. turris)

Chain-forming diatom

Centric, drum-shaped, usually connected in straight chains

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Thalassionema nitzschoides (T. nitzschoides)

Chain-forming diatoms

Pennate, connected by mucilage pads, star-shaped or zigzag chains

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Thalassiosira anguste-lineata

Chain-forming diatoms

Centric, drum-shaped, adjacent cells connected by multiple threads spreading through margins

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Thallassiosira rotula (T. rotula)

Chain-forming diatoms

Coin-shaped, centric, connected by thick bundle of organic threads

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Thalassiosira nordenskioeldii/aestivalis/pacifica (T. nordenskioeldii/aestivalis/pacifica)

Chain-forming diatoms, centric, drum-shaped, threads extending from margins