Ardissoneopsis gracilis Lobban, 2022
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publication ID |
https://dx.doi.org/10.3897/phytokeys.208.89913 |
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persistent identifier |
https://treatment.plazi.org/id/BD9DE006-3FAD-5C0E-A316-49B6E2078499 |
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treatment provided by |
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scientific name |
Ardissoneopsis gracilis Lobban |
| status |
sp. nov. |
Ardissoneopsis gracilis Lobban sp. nov.
Fig. 18 View Figure 18
Diagnosis.
Differing from A. fulgicans in valves being more slender, slightly wavy outline, lower stria density, and markedly heteropolar frustule in girdle view and from A. undosa by lack of central inflation.
Description.
Frustules cuneate in girdle view (Fig. 18C, D, N, O View Figure 18 ), both valve mantle and width of girdle bands decreasing from apical pole to basal pole; hypothesized to be attached to mucilage pads at the basal pole, but not observed in live or raw material. Valves slender, weakly undulating, slightly inflated in the middle and at poles, slightly heteropolar but poles not consistently distinguishable except for mantle depth (Fig. 18A, B, G, E View Figure 18 ). Dimensions: 206-431 µm long, 5 µm wide except 7 µm across the middle and poles (Fig. 18A-G View Figure 18 ). Striae parallel, 10-12 in 10 µm, except radiating at poles, areolae small, circular. The annulus near valve-mantle junction, indicated only in places where striae on mantle are offset from those on valve face (oval on Fig. 18I View Figure 18 ). There is often also an offset across the midline but no sternum. Several spines occur on both poles. (Fig. 18H, K, N, O View Figure 18 ). Internally, interstriae are barely thickened, not forming costae, and there are no longitudinal costae on the annulus (Fig. 18L, M View Figure 18 ). Three girdle bands were present (Fig. 18N-R View Figure 18 ): valvocopula with a row of pores along the edge of the pars interior and a fimbriate internal margin (Fig. 18Q View Figure 18 ); two rows of pores occur around basal pole, but become one within 10 µm from base, further out becoming two and then three or more rows (Fig. 18N, O View Figure 18 ). In the copula, also bearing a fimbriate flange (Fig. 18P, R View Figure 18 ), pars exterior has numerous pores arranged in a generally decussate pattern but becoming looser near basal pole (Fig. 18N, O View Figure 18 ). The pleura is very narrow even at the poles (Fig. 18N, O, P View Figure 18 ).
Holotype
(designated here). Specimen at 11.0 mm E, 2.5 mm S of the mark on slide 1831, deposited at ANSP accession # ANSP-GC20087. Fig. 18E, F View Figure 18 .
Registration.
Phycobank http://phycobank.org/103243.
Type locality.
Guam: Apra Harbor: GabGab reef, 13.443°N, 144.643°E, sparse filamentous algal turf on farmer fish territory ( Plectroglyphidodon lacrymans ), associated with A. gigantea and Toxarium undulatum , depth ca. 8 m., collection number GU44BJ-4, 8 Feb. 2015. C.S. Lobban and M. Schefter leg.
Other materials examined.
Guam: Apra Harbor: GU52P-7!, GU52AI-1!. Federated States of Micronesia: Chuuk: TK28 !; Yap: Y36-2!. Marshall Islands: Majuro: M1!, Jaluit, J1 !.
Etymology.
Adjective (Latin), slender.
Taxonomic comments.
Most similar to Ardissoneopsis fulgicans but differing in the wavy margin, width only half that of A. fulgicans , and in having only 10-12 striae vs. 19-20 in 10 µm. Its shape resembles some Toxarium hennedeyanum , which can sometimes be slightly wavy and only weakly inflated in the middle (e.g., Suppl. material 4: Fig. S2A-C) but always has a random pattern of areolae on the valve face. Much less inflated in the middle, much less strongly undulate, and more coarsely striated than Synedra undosa .
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.