Luticola vancampiana Chattová & Van de Vijver, 2017

Chattová, Barbora, Lebouvier, Marc, Haan, Myriam De & Vijver, Bart Van De, 2017, The genus Luticola (Bacillariophyta) on Ile Amsterdam and Ile Saint-Paul (Southern Indian Ocean) with the description of two new species, European Journal of Taxonomy 387, pp. 1-17 : 8-10

Luticola vancampiana Chattová & Van de Vijver sp. nov.

Figs 44‒71

Etymology

The species is named after Prof. Dr. Karel Van Camp (University of Antwerp, Belgium), to thank him for his efforts in conserving the Van Heurck Collection and his broad interest in diatom research.

Type

ILE SAINT-PAUL: Conserverie, TAAF, sub-Antarctica , 38°42′52.0″ S, 77°31′55.5″ W, 24 Nov. 2016, B. Van de Vijver sample S029 (holo-: slide no. BR‒4496 , Fig. 47 ; iso-: slide PLP‒331; University of Antwerp, Belgium) .

Description

Light microscopy ( Figs 44–67 )

Valves linear-lanceolate to elliptic-lanceolate, elliptic in the smallest specimens, with protracted, subcapitate to rostrate apices. In smaller specimens, valve ends not as protracted, only subrostrate or obtusely rounded. Initial cells rhombic-lanceolate. Valve dimensions (n = 35): length 10.0‒26.0 μm, width 5.0‒8.5 μm. Axial area linear, narrow. Single, rounded isolated pore present in the central area, located halfway between the valve centre and margin, sometimes attached to a stria. Central area wide, bow–tie shaped, bordered on both sides with a series of 3–5 round areolae. Raphe branches straight,

deflected away from the isolated pore at both proximal and distal ends. Transapical striae radiate throughout, 16‒19 in 10 µm.

Scanning electron microscopy ( Figs 68–71 )

Valve mantle with a single row of round areolae ( Fig. 71 ), interrupted at the apices. Striae composed of 3–4 areolae, 1–2 areolae at the apices. Areolae round to elongated, clearly enlarged and prolonged close to the valve margins ( Fig. 68 ). Internally, areolae occluded by hymens, forming a continuous strip across the valve ( Fig. 70 ). Isolated pore showing an elliptic external opening. Internally, central nodule thickened, expanding into stauros. Isolated pore with semi-lunar opening formed by tonguelike structure. Raphe branches straight. Proximal raphe endings short, deflected to side opposite to the isolated pore. Terminal raphe fissures deflected to the same side as the proximal endings, not extending onto the mantle ( Fig. 69 ). Internally, proximal raphe endings straight, while distally, raphe branches terminating on small helictoglossae.

Ecology and distribution

So far L. vancampiana sp. nov. was found on both IleAmsterdam and Ile Saint-Paul.The largest population was found in a wet soil covered by green algae close to the ocean on Ile Saint-Paul. The sampling site is frequently visited by fur seals and penguins, as was visible in the macroremains (feathers, excrements). The sample was almost entirely dominated by the new Luticola species. Other (smaller) populations were found in soil samples collected near penguin rookeries where similar conditions (considerable biotic influence, considerable salinity input) prevailed.

Figures

Figs44–71.Luticola vancampianaChattová&VandeVijversp. nov.Light(LM) andscanning electron micrographs (SEM) from the type population from Conserverie on Ile Saint-Paul, B. Van de Vijver sample S029. 44–67. LM showing the variation in size and shape of the valve apices. 68–69. SEM of valveexterior.70. SEM of valveinterior.71. SEM girdle view.Scalebars:44–67 10µm; 68‒71=5µm.