Nitzschia haloserbica Vidaković, Ector, C.E.Wetzel & Krizmanić, 2022

Vidaković, Danijela, Ector, Luc, Wetzel, Carlos E., Krizmanić, Jelena, Gavrilović, Bojan, Dojčinović, Biljana & Ćirić, Miloš, 2022, A new Nitzschia Hassall species (Bacillariaceae, Bacillariophyta) from saline ponds in Serbia, Cryptogamie, Algologie 20 (4), pp. 85-94 : 87-89

Nitzschia haloserbica Vidaković, Ector, C.E.Wetzel & Krizmanić , sp. nov.

( Figs 2; 3 )

Nitzschia sp. 2 – Stenger-Kovács & Lengyel 2015: 144-145, pl. 68, figs 1-24.

Nitzschia haloserbica Vidaković, Ector, C.E.Wetzel & Krizmanić , sp. nov. can be distinguished from other sigmoid Nitzschia species, in particular N. austriaca by stria density, and central fibulae. In N. austriaca the transapical striae are visible in LM, and central fibulae are more widely spaced reflecting the presence of central raphe endings, which are absent in N. haloserbica sp. nov.

HOLOTYPE. — Serbia. Bela Bara saline pond, 45°56’50.6796”N, 19°5’25.7676”E, 08.V.2019, Leg. D. Vidaković, (accession no. DCSR 000062 ) (holo-, ICTM [slide DCSR 000062 /A]; iso-, BR [slide BR 4599 Meise Botanic Garden, Meise, Belgium ]). The holotype is marked drawing an ink ring with a fine waterproof felt pen on the cover slip and is illustrated in Fig. 2 BI.

ETYMOLOGY. — The specific epithet “halo” indicates that the species is characteristic for saline habitat and “serbica” that is found in Serbia.

DISTRIBUTION. — Nitzschia haloserbica Vidaković, Ector, C.E.Wetzel & Krizmanić , sp. nov. was recorded in four saline ponds in Serbia ( Fig. 1 ). The species was found in epipelic (Bela Bara, Čoka Kopovo, and Slatina ponds) and epiphytic communities (Čoka Kopovo, Velika Rusanda, and Slatina ponds). The higher relative abundance of this species was on mud (epipelic material), at the type locality of Bela Bara pond (94.93 %). In Čoka Kopovo, Velika Rusanda, and Slatina ponds the relative abundance was lower (8.98 %, 0.99 %, 0.65 %, respectively). In Hungary, this species was named as Nitzschia sp. 2 and was recored in 7 saline lakes (Böddi-szék, Büdös-szék, Fehérszék, Kardoskúti Fehér-tó, Kele- men-szék, Kisréti-tó, Zab-szék) with mean/max. abundance 22.7%/72.2 % ( Stenger-Kovács & Lengyel 2015).

ECOLOGY. — The investigated saline ponds are shallow water bodies with high pH, except for the Slatina which is a degraded saline pond ( Table 1). According to Hammer’s (1986) salinity classification, Velika Rusanda pond can be characterized as hyposaline, while Čoka Kopovo pond fitted into the subsaline category. Depending on the different combinations and order of dominant anions existed in water Velika Rusanda pond can be classified as Na-HCO 3 -SO 4 -Cl and Čoka Kopovo pond as sodic base type (Na-HCO 3). Data found in previous papers as well as determined by subsequent surveys of Bela Bara and Slatina ponds have been shown that Slatina pond fitted into the subsaline category white dominance of sodium and magnesium (Na-Mg-HCO 3) (Ćirić et al. 2021), while Bela Bara can be classified as sodic base type (Na-HCO 3) ( Boros et al. 2014).

DESCRIPTION

Light microscope ( Fig. 2)

Valve linear, strongly curved towards opposite sides (sigmoid), progressively tapering at some distance from the slightly protracted and sometimes subcapitate ends. Frustules are sigmoid in valve and girdle view. Valve length 14.3-46.4 µm, width 3.1-3.6 µm (dimensions of population in Bela Bara: length

A B C D E F G H I J K L M N O P R S

T U V W X Y Z AA AB AC AD AE AF AG AH AI AJ AK AL AM AV AW AX BI BJ BK

16.8-34 µm, width 3.1-3.5). Fibulae quite regularly distributed along the raphe canal, the central pair not more widely separated, 12-18 in 10 µm. Transapical striae not visible in LM.

Scanning electron microscope ( Fig. 3 )

The striae are uniseriate, 54-75 in 10 µm. Areole circular, slightly domed hymenes close to the external apertures of the areolae ( Fig. 3E ).Two single rows of areolae surround the keel, and never doubled on the raphe keel. An inner valve view details tubular to rectangular fibulae quite regularly distributed along the raphe canal. The raphe is eccentric. The distal raphe endings straight. No central nodule. A small helictoglossa is present internally at distal raphe endings. On the mantle, the striae are very short, comprising one areola ( Fig. 3B ).

Figures

FIG. 3. — Nitzschia haloserbica Vidaković, Ector,C.E.Wetzel & Krizmanić,sp. nov.,SEM images taken from the type material (Bela Bara saline pond):A, C, E, SEM views of a frustule in valve view; B, SEM internal view of two valves from the same frustule; D, SEM internal view of the center of the valve with fibulae regularly distributed; F, SEM internal view of valve apex with helictoglossa and raphe;G, SEM internal detail view of valve apex with helictoglossa. Scale bars: A-C, 5 µm; D, G, 1 µm; E, 3 µm; F, 2 µm.

FIG. 1. — Location of the four study saline ponds in the Vojvodina Region, Serbia. A, Bela Bara; B, Čoka Kopovo; C, Velika Rusanda; D, Slatina.