Chelonicola costaricensis Majewska, De Stefano & Van de Vijver 2015, sp. nov.
Creators: name: Majewska, Roksana
name: Kociolek, J. P.
name: Thomas, Evan W.
name: Stefano, Mario De
name: Santoro, Mario
name: Bolaños, Federico
name: Vijver, Bart Van De
Publisher: name: Zenodo
Year: 2015
Subjects: Biodiversity
Taxonomy
Chromista
Ochrophyta
Bacillariophyceae
Cymbellales
Rhoicospheniaceae
Chelonicola
Chelonicola costaricensis

description: Chelonicola costaricensis Majewska, De Stefano & Van de Vijver, sp. nov. (Figs 1–12)   
Frustules wedge-shaped in girdle view showing conspicuous septa at both poles. Valves small, heteropolar, typically clavate with a broadly rounded, non-protracted headpole and an acutely terminating footpole. Septa visible in LM and SEM on both poles. Valve dimensions (n=50): length 6.0–17.5 μm, width 1.7–3.1 μm. Axial area very narrow, not discernible in LM. Central area very small. Raphe filiform, straight with simple, indistinct proximal raphe endings. Distal raphe endings not discernible in LM. Striae almost parallel throughout the entire valve, very faintly visible in LM, 36–47 in 10 μm.  
 Type:— COSTA RICA. Olive ridley sea turtle, 9º 59’ 23.7” N, 85º 41’ 52.6” W, M. De Stefano, 27 October 2013 (holotype BR! stub 4420).   
 Scanning Electron Microscopy:—(Figs 1–12) Frustules isovalvar, clavate in girdle view, attached by the footpole on short mucilaginous stalks (Fig. 3). Valve face flat in both valves with a clear angle to the very shallow mantle (Figs 3, 7). The mantle is equally high in its distal and proximal part but larger in the central part (Fig. 7). Pseudosepta absent (Figs 9, 10, 12). Axial area very narrow, linear (Figs 4–6). Central area very small, bordered on one or both sides by one slightly shortened central stria (Figs 4–7). Fascia never present (Fig. 5). External raphe branches almost straight to very weakly curving (Figs 4–6). External proximal raphe endings slightly expanded, unilaterally weakly deflected (Fig. 5). External distal raphe fissures elongated, weakly deflected, continuing shortly onto the mantle on both poles (Figs 6, 7). Striae uniseriate, equally spaced throughout the entire valve, composed of a series of 3–5 slightly transapically elongated areolae (Figs 4–7). Areolae bordering the axial area being the largest (Fig. 6). Striae continuing without interruption onto the shallow mantle (Figs 4–7). Apical pore field absent on both poles (Figs 4, 6, 8). Internally, raphe straight to weakly curved, positioned asymmetrically in a raised raphe sternum (Figs 9–12). Primary side of the sternum thickened, opening the raphe in a lateral position (Figs 9–12). Proximal raphe endings covered by a silica flap and distal raphe endings straight, terminating on weakly developed helictoglossae (Figs 9–12). Areolae internally slightly sunken between thickened interstriae, covered by hymenes (Figs 11, 12). Cingulum composed of a large number (up to 12) of open copulae, each with one row of apically elongated, slit-like poroids in the advalvar position (Figs 3, 4 & 7). First band, the valvocopula, with a small, but distinct septum at the head pole (Fig. 9). Second copula with a small septum at the footpole (Fig. 10). Other copulae lacking a septum.   
 Etymology:—The specific epithet refers to the geographical locality, Costa Rica, where the species was first observed.
description: Published as part of Majewska, Roksana, Kociolek, J. P., Thomas, Evan W., Stefano, Mario De, Santoro, Mario, Bolaños, Federico & Vijver, Bart Van De, 2015, Chelonicola and Poulinea, two new gomphonemoid diatom genera (Bacillariophyta) living on marine turtles from Costa Rica, pp. 236-250 in Phytotaxa 233 (3) on pages 242-243, DOI: 10.11646/phytotaxa.233.3.2, http://zenodo.org/record/13633146