Moralesonia frauenfeldii (Grunow) D. M. Williams, Ts. Georgiev, T. M. Schust. & C. E. Wetzel, 2024

Williams, David M., Georgiev, Tsvetoslav, Schuster, Tanja M. & Wetzel, Carlos E., 2024, The relationships of Eunotogramma frauenfeldii (Bacillariophyta) I. An account of its structure and description of the new genus Moralesonia, Plant Ecology and Evolution 157 (3), pp. 270-290 : 270-290

Moralesonia frauenfeldii (Grunow) D. M. Williams, Ts. Georgiev, T. M. Schust. & C. E. Wetzel comb. nov.

Figs 2 , 3 , 4 , 5 , 6

Euodia frauenfeldii Grunow (basionym), Verhandlungen der Kaiserlich-Königlichen Zoologisch-Botanischen Gesellschaft in Wien 13: 158, pl. 14, fig. 19 a – d (= our Fig. 2 A ) ( Grunow 1863). Also described in Grunow (1864: 119) and Grunow (1878: 24).

Eunotogramma frauenfeldii (Grunow) Grunow (in Van Heurck 1883: pl. 126, fig. 14, reproduced here as Fig. 4 J – K ).

Type locality.

South Africa, Kalk Bay [Kalkbaai] (“ Habitat ad litus Africae australioris [occurs on the South African coast] (Flugsand der Kalkbay am Cap der guten Hoffnung, von Herrn v. Frauenfeld auf der Novara-Expedition gesammelt [airborne sand from Kalkbay at the Cape of Good Hope, collected by Mr. von Frauenfeld during the Novara Expedition]) ”), ( Grunow 1863: 158; “ Im Flugsande der Kalkbai am Cap der guten Hoffnung, Frauenfeld [in airborne sand from Kalkbaai at the Cape of Good Hope, Frauenfeld]. ” “ Auch im Strandsande der Nikobaren-lnsel Kamortha beobachtete ich neuerdings diese Art [I have recently also observed this species in coastal sand from the Nicobar island Kamortha] (Sandstrand von Kamortha), (Sandstrand von Kamortha, Nicobaren I.) ”, ( Grunow 1867: 24; for the Nicobar Island specimens, these refer to two separate slides, see below); see Leuduger-Fortmorel 1898: 26, pl. V, fig. 7, [“ Congo ”] = our Fig. 2 D ), W: Grunow sample 790 ( W 0164898 !, W 0164899 !) [Grunow kept two slides, which still exist: “ Kalkbay ”, cream-coloured original label, round cover slip ( W 0164898 ) and “ Kalkbai ”, green original label, square cover slip ( W 0164899 ), see Fig. 3 B ].

Lectotype (designated here).

Slide “ Kalkbay ” of Grunow sample 790 ( W 0164898 !) lectotype designated here (= Fig. 2 B, C, E – G , Grunow’s drawings, catalogue notes, and slides: Fig. 3 A – C ); BR [VI- 41 - B 10 = Grunow sample 790 duplicate from W].

Isolectotypes (designated here).

SEM in Fig. 5 A from subsample of the Kalk Bay raw material (Grunow sample 790 in BR); BM 57572 ! (Wynne Baxter 2943 = Grunow sample 790, duplicate from W = Fig. 4 A – F ), W [ W 0164899 ! = Grunow sample 790 “ Kalkbai ”], BRM HB- 20 and BRM 24460, BM 10889 ! (“ Kalkbai Cap d. g. Hoffn. ”, L. H. [ardman] | 1132 ” (= Fig. 4 G – I ), BM 55989 ! (“ Kalkbay ”, ex Wynne Baxter 1361), BM 26220 ! (H. L. Smith, Diat. spec. typ. No. 659, “ Cape of Good Hope original ”; “ In mare ”), ANSP Febiger 3099, H. L. S. O A- 98, H. L. Sm. EX 659 ( Mahoney and Reimer 1997: 146).

Registration.

http://phycobank.org/104545

Analysed material.

MOZAMBIQUE • Lourenço Marques [Maputo]; BM Adams TS 751! (figured in Desikachary 1988: pl. 583, fig. 8).

SIERRA LEONE • ‘ Freetown’ (“ The site at Freetown was in Fura Bay, which is on the south side of the estuary at a point where it is about 10 km wide ”, Hendey 1957 [1958]: 29; one micrograph exists in the Hendey collection (specimen dimensions: 80 × 27 μm, Fig. 7 G ), slide not identified).

CONGO • Leuduger-Fortmorel (1898: 26, pl. V, fig. 7 = Fig. 2 D ; [“ Cette petite Diatomée, très commune de la côte du Congo, a été determinée et nommée par M. le professeur Brun ”, Leuduger-Fortmorel 1898: 24].

NICOBAR ISLANDS • Kamorta Island; “ Auch im Strandsande der Nikobaren-lnsel Kamortha beobachtete ich neuerdings diese Art [I have recently also observed this species in coastal sand from the Nicobar island Kamortha ”], W 0164901 ! (“ Sandstrand von Kamortha ”), W 0164902 ! (“ Sandstrand von Kamortha, Nicobaren I. ”), where the latter two designations in parentheses regarding locality refer to the two slides kept by Grunow for his sample 792 and are labeled as such; Grunow 1867: 24).

COUNTRY UNKNOWN • s. loc.; BM 59207 ! (I. [J.] D. Möller slide, Wynne Baxter 4591).

Description.

Valves lunate, occasionally fusiform, length 32–62 μm, width 20–22 μm [measurements of type specimens from Grunow sample 790 ( W 0164898 )], smaller valves tending towards ca 30 μm, width ± constant, forming less convex ventral margin. Each valve with two transapical ribs dividing valve into three ± equal parts. Ribs evident externally by clear area, extending through to entire mantle, indicating it as part of valve. Internally raised by 2–3 μm tapering towards mantle edge. Areolae ± round, radiating from eccentric hyaline centre, sometimes elongated. Rimoportulae absent. Few simple pores observed, randomly distributed on valve, notably near hyaline centre, absent elsewhere. Cribra with well-developed, complex volate structure, usually having 2–4 (– 6) pegs supporting complex (contorted) closing plate. External surface of valve finely ornamented. Girdle composed of few bands (3–4?), valvocopula and copulae, each with one curved row of areolae. Species synapomorphy: denser striation, less ornamented areolae.

Notes.

In Grunow’s later description he notes that aside from the Kalk Bay locality ( Grunow 1863: 158), “ Auch im Strandsande der Nikobaren-lnsel Kamortha beobachtete ich neuerdings diese Art ” ( Grunow 1867: 24). Those specimens have been examined and, for the moment, are considered Moralesonia frauenfeldii ( W 0164901 & W 0164902 , slides for Grunow sample 792, Fig. 6 A – F ). Although not examined in detail here, Euodia gibba var. africana M. Perag. (in Tempère and Peragallo 1908: 83, nos 152–153, sample from ‘ Algérie, Village-Négre, Oran, Terre fossile tertiaire’), the specimens are fragmented, but might possibly be interpreted as a species of Hemidiscus .

Figures

Figure 2. A. ‘ Euodia Frauenfeldii Grunow’ (= Moralesonia frauenfeldii) reproduced from Grunow (1863: pl. 14, fig. 19 a – d). B – C, E – G. Moralesonia frauenfeldii, specimens from Grunow sample 790 [2 slides, W 0164898 (lectotype), W 0164899, scale bar = 20 µm for all images]. D. ‘ Eunotogramma Frauenfeldii ’ (= Moralesonia frauenfeldii) reproduced from Leuduger-Fortmorel (1898: pl. V, fig. 7, “ Congo ”).

Figure 3. ‘ Eunotogramma Frauenfeldtii [sic] ’ (= Moralesonia frauenfeldii), reproductions from Grunow’s drawings (C), notes in his catalogue (A), and slides in W for his sample 790 (B).

Figure 4. A – F. Moralesonia frauenfeldii, specimens from BM 57572, isolectotype (scale bar = 20 µm); note that it is a slide made form Grunow sample 790. G – I. Moralesonia frauenfeldii, specimens from BM 10889 (“ Kalkbai Cap d. g. Hoffn. ”, L. H. [ardman] | 1132 ” (scale bar = 20 µm), isolectotype. J – K. Moralesonia frauenfeldii reproduced from Van Heurck (1883: pl. 126, fig. 14) and a reproduction in Grunow’s drawing collection for his sample 790 in W. L, M. specimens from BM Adams D 875 (“ Fundort? [locality?] ”).

Figure 5. Moralesonia frauenfeldii, specimens from isotype material, a subsample of the Kalk Bay raw material (Grunow sample 790) from BR (none available any longer at W). A. Whole external view of valve, arrows indicate ‘ unadorned’ holes, scale bar = 10 µm. B. Detail of external view of valve (as in Fig. 5 A), scale bar = 5 µm. C. External view of valve with ribs evident by clear area, extending through to entire mantle, indicating it as part of valve, dividing valve into three ± equal parts, scale bar = 20 µm. D. Detail of cribra with well-developed, complex volate structure, usually with 2–4 pegs supporting complex (contorted) closing plate, scale bar = 5 µm. E. Internal view showing ribs, with detail in Fig. 5 F, scale bar = 5 µm. G. Detail of valve surface with ‘ unadorned’ holes (arrows), scale bar = 4 µm.

Figure 6. Moralesonia frauenfeldii. A – D. Specimens from Kamorta Island, Nicobar Islands, W 0164902 (“ Sandstrand von Kamortha, Nicobaren I. ”). E. Slide W 0164902 from W. F. Grunow’s catalogue notes on slides W 0164901 & W 0164902 (Grunow sample 792).

Figure 7. Moralesonia australis. A – C. Moralesonia australis, BM 26837 (as “ Eunotogramma frauenfeldii Grun. | Australie. ”, Van Heurck 1885: 118, sér. XXII, no. 526), scale bar = 20 µm. D, H, I. Grunow’s drawings, catalogue notes on his sample 1484 (W 0164933), and slides. E, F. BM 12829 (Australia, Carpentaria Bay (Arafura Sea), holotype (= Cleve and Möller Diatoms [no.] 61, “ Carpentaria Bay ”, as Euodia Fraunfeldii Grun. )), scale bar = 20 µm. G. BM 6481 (“ Euodia Fraunfeldii Grun. | Australien | J. D. Möller ”), scale bar = 20 µm.