Hippodonta fujiannensis Zhao, Chen & Gao 2017, sp. nov.
Creators: name: Zhao, Long
name: Sun, Jiandong
name: Gao, Yahui
name: Liang, Junrong
name: Sun, Lin
name: Li, Xuesong
name: Chen, Changping
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy
Chromista
Ochrophyta
Bacillariophyceae
Naviculales
Naviculaceae
Hippodonta
Hippodonta fujiannensis

description: Hippodonta fujiannensis Zhao, Chen & Gao sp. nov. (Figs 2–36)   
Frustules rectangular, valves elliptic-lanceolate to rhombic-lanceolate, 11–44 μm long, 4–8 μm broad. Raphe filiform, weakly pronounced. Central area rectangular to panduriform. Striae uniseriate, dissymmetrical on the valve face, 12–20 in 10 μm. Girdle band broad and unornamented.  
 Type:— China, Fujian Province, Haitan Island, Longfengtou Beach, 25°31’18.41’’N, 119°48’16.26’’E, sand grain samples, 1 cm deep, collected by Long Zhao on April 18, 2015, School of Life Sciences, Xiamen University, Xiamen (holotype EMDPT1504! = Fig. 8, 17.8 mm south by 41.6 mm west from the benchmark spot on the slide; isotype EMDPT1504! = Fig. 9, 15.4 mm south by 40.0 mm west from the benchmark spot on the slide). Holotype and isotype slides are housed at Diatom Laboratory, School of Life Sciences, Xiamen University, China.   
 LM (Figs 2–13): Frustules rectangular with gently concave central nodule in girdle view. Cells solitary, valves elliptic-lanceolate to rhombic-lanceolate with broadly rounded ends in smaller frustules and acutely rounded ends in bigger frustules. Valve ends not protracted. Valve length 11–44 μm, width 4–8 μm. Axial area narrow-linear throughout, weakly expanding into a rectangular to panduriform central area. Central area well defined by continuous stria shortening, at both valve sides. Terminal areas clearly distinguishable in LM, lunate to semicircular and cap-like. Raphe filiform, weakly pronounced, with teardrop-shaped and closely spaced central endings. Terminal pores of raphe clearly discernible in LM, equally pronounced as the central endings, teardrop-shaped. Striae coarse, strongly radiate throughout valve length, or becoming moderately radiate at valve ends, evenly spaced throughout, 12–20 in 10 μm. Interstriae width equal to, or wider than, striae. Lineolae densely spaced within each stria, discernible in LM in longer valves.   
 SEM (Figs 14–32): Externally, valve face gently curved in transapical section merging gradually into valve mantle (Figs 14, 18). Raphe slits quite fine. Terminal endings of raphe distinct, strongly pronounced, teardrop-shaped depressions, positioned before terminal area, or weakly advancing into it, and slightly curved towards one valve side in smaller valves, or strongly curved in bigger valves (Figs 15, 18). Central endings of raphe small, teardrop-shaped, closely positioned depressions (Fig. 20). Central nodule clearly visible in girdle view (Fig. 23). Central area asymmetrical in bigger valves, with one side much bigger than the other (Figs 16, 20). Striae uniseriate throughout valve face and mantle (Figs 14, 17, 18). On one valve side, one column of lineolae, nearest to the raphe, is positioned perpendicular to remaining lineolae of the striae (Fig. 17). One the other valve side this column not as pronounced. Lineolae linear, 25–40 in 10 μm. Single rows of areolae surround valve apices. Prominent hyaline area present throughout valve mantle (Figs 21, 25). Internally, striae positioned on shallow linear depressions; thus, valve face not flat. Lineolae covered by hymens (Fig. 32). Central endings of raphe linear, closely positioned and gradually disappearing. Semicircular to rectangular hyaline area clearly developed in central area. Linear raphe slits distally terminated by weak, crescentshaped helictoglossae, weakly advancing into the terminal area. Terminal area strongly pronounced internally. Girdle band quite broad and unornamented (Fig. 24). Since the girdle is relatively broad, the frustules of H. fijiannensis often lie in girdle view or at an angle in valve view.   
 Etymology: The species name “ fujiannensis ” refers to Fujian Province.   
 Distribution and ecology: In our 25 sampling sites along the coast line of Fujian Province, H. fujiannensis was only found in the low intertidal zone of Haitan Island. The specimens of H. fujiannensis are infrequent in all of the samples from the Haitan Island; it is epipsammic (Figs 33–36) and inhabits the marine environment.
description: Published as part of Zhao, Long, Sun, Jiandong, Gao, Yahui, Liang, Junrong, Sun, Lin, Li, Xuesong & Chen, Changping, 2017, Hippodonta fujiannensis sp. nov. (Bacillariophyceae), a new epipsammic diatom from the low intertidal zone, Fujian Province, China, pp. 77-85 in Phytotaxa 295 (1) on pages 79-80, DOI: 10.11646/phytotaxa.295.1.7, http://zenodo.org/record/13695426