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Authority

G.Karst. (Karsten, 1905: 99, pl. 11, fig. 5)

Class

Diatomophyceae

Order

Centrales

Family

Rhizosoleniaceae

Synonyms

?Rhizosolenia murrayana Castrac. (Castracane, 1886: 72, pl. 24, fig. 12)

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Basionym

N/A

Additional References

Hendey (1937: 313), Hustedt (1958: 133), Manguin (1960: 266, pl. 4, fig. 58a, b, 59, 60; pl. 26, figs 319–321; pl. 27, fig. 322a, b), Sournia et al. (1979: 191, figs 17, 29), Priddle & Fryxell (1985: 78, figs A–E), Priddle et al. (1990: 118, pl. 15.3, fig. 2), Moisan & Fryxell (1993: 293). See Armand & Zielinksi (2001) for additional references.

Description

Cells in short chains, weakly silicified, cylindrical, almost rectangular in girdle view; pervalvar axis 47–112 µm (fide Manguin, 1960). Valves flat or slightly convex; apical axis 20–28 µm (26–32 µm fide Hendey, 1937; 12–19 µm fide Manguin, 1960). Process arising from the valve margin, short, stout, hollow at the base. Otaria lacking. Intercalary girdle bands 2–3 in 10 µm, arranged in 2 lateral (cf. dorsiventral) columns forming zig-zag rows; bands finely striate; striae 18–23 in 10 µm. Chloroplasts small, numerous.

Distribution

Weddell-Scotia Confluence (Garrison et al., 1987); Bellingshausen Sea (Hendey, 1937; Ligowski, 1993); Terre Adélie (Manguin, 1960); sub-Antarctic (Hasle, 1969); Antarctic (Sundström, 1986).

Comments

Rhizosolenia chunii is poorly known from modern Antarctic studies. Sundström (1986) noted that this species stands out because of its “short” pervalvar axis. He also indicated that re-circumscription was warranted due to the conspecificity with Castracane’s R. murrayana and the incomplete observations he (Castracane) had made. Sediment records are limited, and the species requires further study (Armand & Zielinski, 2001).

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