Climacosphenia soulonalis Lobban & Joon S. Park, 2022

Lobban, Christopher S., Ashworth, Matt P., Camacho, Terance, Lam, Daryl W. & Theriot, Edward C., 2022, Revision of Ardissoneaceae (Bacillariophyta, Mediophyceae) from Micronesian populations, with descriptions of two new genera, Ardissoneopsis and Grunowago, and new species in Ardissonea, Synedrosphenia and Climacosphenia, PhytoKeys 208, pp. 103-184 : 103

Climacosphenia soulonalis Lobban & Joon S. Park sp. nov.

Fig. 31

Diagnosis.

Differing from C. moniligera in apical stria density and delicate craticular bars throughout, seamless except for complex unions in the most basal 1-4 bars and from C. scimiter in straight outline, presence of complex unions, and cell width.

Description.

Valves straight, gradually tapering from apical pole almost to basal pole (Fig. 31A-C ), only a short basal part with parallel sides. Length 390-530 µm, width 29-35 µm across apical pole (measured on valvocopula; total valve width including mantles 50 µm), 10-12 µm across basal pole at last craticular bar (Fig. 31A-G ). Annulus narrower at apical pole (Fig. 31C-E ), widest 15 µm, steadily tapering to 4 µm, apparently open at basal pole (Fig. 31E ). Stria densities 18-20 in 10 µm in lower part of the periphery, 28-29 in 10 µm in periphery at apical pole, about 16 in 10 µm in middle part above basal pole (Fig. 31E ). Spines present on apical pole and a small patch of irregular areolae (Fig. 31D ). Costae apparently poorly developed. Valvocopula fimbriate with narrow, widely spaced craticular bars that have seamless unions except for the most basal 1-4 (Fig. 31B, F ); a row of pores on pars interior just around basal pole (Fig. 31F ). Copula not positively identified.

Holotype

(designated here). Specimen at 17.8 E, 10.9 mm S of the mark on slide 153; deposited at ANSP, accession number GC20109. Fig. 31A-C .

Registration.

Phycobank http://phycobank.org/103247.

Type locality.

Federated States of Micronesia: Chuuk: Northeast Pass into Chuuk Lagoon, 7.514°N, 151.967°E, on algal turf from farmer fish territory, lee side of Moch I., collection number TK4!, 30 May 1991. C.S. Lobban and M. Schefter leg.

Additional materials examined.

Chuuk: TK28!, exposed reef, ca. 6 m deep, southeast corner of Northeast Passage.

Etymology.

Belonging to Sou-lon, "the Chuukese god of ocean depths and storms, equivalent, perhaps to Neptune" (W.M. Peck 1992, Chuukese Testament. Storyboard: A Journal of Pacific Imagery 2: 44).

Taxonomic comments.

Valves resemble C. moniligera in size and stria densities (Table 5 ) but differ in the valve shape and the narrow and mostly seamless craticular bars are unlike the massive septum with complex unions in the bars reported for C. moniligera ( Peragallo and Peragallo 1897-1908; Hustedt 1931-1959; Round 1982).

Figures

Figure 31. Climacosphenia soulonalis sp. nov. All TK 4 A-C holotype valve with valvocopula, entire, basal pole and apical pole, respectively, showing seamless craticular bars except near basal pole; arrowheads on B show complex unions D external valve apical pole showing irregular patch of areolae (arrow), spines, and narrowing of the annulus at apical pole E internal aspects of basal and apical poles, showing lack of costae (contrast costae in the piece of Synedrosphenia crystallina to the right) F, G valvocopula with two complex unions at the basal pole (arrowheads, F) and showing the row of pores on the pars interior around the basal pole (arrow). Scale bars: 100 µm (A); 10 µm (B-G).