Luticola bandanensis M.Rybak & Peszek, 2024

Rybak, Mateusz, Peszek, Lukasz, Luthfi, Oktiyas Muzaky, Arsad, Sulastri, Kociolek, John Patrick & Witkowski, Andrzej, 2024, Description of five new Luticola D. G. Mann (Bacillariophyta, Diadesmidaceae) species from Indonesia with comments on the morphological boundaries of the genus, PhytoKeys 237, pp. 1-22 : 1

Luticola bandanensis M.Rybak & Peszek sp. nov.

Figs 1T -AC, 5A-H

Description.

LM observations (Fig. 1T -AC). Valves elliptic-lanceolate to rhombic-lanceolate with narrowly rounded apices in larger specimens becoming elliptic with broadly rounded apices in smaller specimens. Range of valve dimensions (n = 25): 6.8-21.5 μm long, 4.5-6.5 μm wide and 21-23 striae in 10 µm. Striae clearly punctate composed of 3-5 areolae. Central area bow-tie shaped, axial area linear and narrow. Isolated pore clearly visible in central area, shifted slightly to valve margin. Raphe filiform with proximal endings slightly bent away from isolated pore, distal raphe endings barely visible.

SEM observations (Fig. 5A-H ). External view: Striae composed of 3-5 round to slightly elongated areolae (Fig. 5A-F ). Single row of round areolae present on valve mantle uninterrupted at the apices (Fig. 5D, E ). Central area bordered by 2-4 areolae (Fig. 5A-F ). raphe straight and filiform with distal raphe endings hooked with irregular shallow grooves on valve face on isolated pore side (Fig. 5A-F ). Proximal raphe endings deflected finishing with varying in length shallow grooves extending to the first or second row of areolae on the opposite side of the isolated pore (Fig. 5A-F ). Distal raphe endings hooked with irregular shallow grooves on isolated pore side (Fig. 5A-F ). Small, transacially elongated opening of isolated pore shifted slightly to valve margin (Fig. 5A-F ). Girdle bands open with two rows of poroids (Fig. 5D ).

Internal view: Areolae occluded by hymenes forming a continuous strip (Fig. 5H ). Raphe slits straight (Fig. 5G, H ). Proximal raphe endings simple and straight (Fig. 5G, H ), distal raphe endings finishing on to weakly developed helictoglossae (Fig. 5G, H ). Isolated pore opening with small lipped structure (Fig. 5G, H ). Narrow longitudinal channels visible around valve (Fig. 5G, H ).

Type.

Indonesia, Banda Besar, 4°31'29.93"S, 129°56'51.69"E, 19 m a.s.l., coll. 23 June 2018, holotype slide no. SZCZ29103! and the unmounted material with the same number in the Szczecin Diatom Collection (University of Szczecin, Poland), isotype slide no. 2018/440 and the unmounted material with the same number at the University of Rzeszów , Poland. The type population is illustrated in Figs 1T -AC, 5A-H.

Etymology.

Name refers to type locality, the island of Banda Besar in the Banda Island archipelago in the Banda Sea.

Distribution.

So far, species observed only in the type locality.

Ecology and associated diatom flora.

The species was observed in a sample characterised by a slightly acidic pH (5.8) and conductivity was 1250 µS /cm. The species co-occurred with: Luticola insularis sp. nov., L. elliptica sp. nov., L. minima Levkov, Metzeltin & Pavlov, two unidentified small-celled Nitzschia sp., Nitzschia vitrea G.Norman and Tryblionella debilis Arnott ex O’Meara.

Figures

Figure 1. LM microphotographs of three new Luticola taxa in size diminution series. Luticola insularis sp. nov. (A-S), Luticola bandanensis sp. nov. (T-AC), Luticola eliptica sp. nov. (AD-AN). Scale bar: 10 µm.

Figure 5. SEM microphotographs of Luticola bandanensis sp. nov. external (A-F) and internal (G, H) views. Arrow indicate a longitudinal channel. Scale bars: 5 µm (A-G); 3 µm (H).