Figure 2 - uploaded by Paul B Hamilton
Content may be subject to copyright.
-Neidium iridis: A & B, line drawing of original specimens; C & D, LM images of original specimens (C: lectotype specimen). Scale bars = 100 μm.
Source publication
Background and aims-Confusion over the taxonomic identity of Neidium iridis (Ehrenb.) Cleve (= Navicula iridis Ehrenb.) has persisted for more than 130 years with identifications of valve shapes varying from elliptical to linear and sizes from 100 to 300 µm. This confusion can be linked to the rarity of the species and poor attention to the origina...
Contexts in source publication
Context 1
... sample which contains original material of Navicula iridis is deposited in the Ehrenberg Collection, Institute of Paleontology, Museum für Naturkunde, Berlin (BHUPM). The following material was studied: 1. Reference: Ehrenberg (1843: 382, pl. IV: fig. 2: "New York, West-Point, 40°N 74°W, L. V. ...
Context 2
... is therefore uncertain. Four of the 60 micas did not have (or have lost) circles marking identified specimens. Twenty-one micas had one circle identifying specimens, 17 had two, 16 had three and three had four circles marking on the micas. For this study, mica strips 260109 and 260110 ( fig. 1), as noted above the specimens on the drawing sheet ( fig. 2A & B), were ...
Context 3
... original description presents only a few characters to ascribe to the species. However, Ehrenberg had an attention for detail in his drawings, which present additional character clues for the species. Ehrenberg (1843: pl. IV, fig. 2a, b, also on drawing sheet no 2074) presents a large linear diatom with cuneate apices ( fig. 2). Two black lines document the narrow axial area with a central area extending approximately 1/3 across the valve. Two small half circle lines within the central area document a central nodule. The striae are presented as linear (not radiate) ...
Context 4
... original description presents only a few characters to ascribe to the species. However, Ehrenberg had an attention for detail in his drawings, which present additional character clues for the species. Ehrenberg (1843: pl. IV, fig. 2a, b, also on drawing sheet no 2074) presents a large linear diatom with cuneate apices ( fig. 2). Two black lines document the narrow axial area with a central area extending approximately 1/3 across the valve. Two small half circle lines within the central area document a central nodule. The striae are presented as linear (not radiate) with individual dots suggesting that areolae could be observed within the striae. The original ...
Context 5
... he identified tentatively as Navicula columnaris Ehrenb. from Monticello (Fossil, New York, U.S.A.). Schmidt's comment "fraglich, aehnlich der viel kleineren" indicated that he recognized that this was much larger than Navicula columnaris s.str., and indeed the line drawing matches Schmidt's identification of another specimen as Neidium iridis ( fig. 49: 2) is not correct, but should be Neidium dilatatum (Ehrenb.) Cleve (see Cleve 1894: 70). Cleve (1894) identified a taxon Neidium affine [var. genuinum "genuina"] f. maximum "maxima" Cleve from the fossil deposit at Monticello, New York. Although he did not present a line drawing, the size (180-300 μm long, 40 μm wide, 12-17 striae in 10 ...
Context 6
... pl. 5:6). At that time Donkin noted an affinity to Navicula firma Kütz. (Kützing 1844: 92, pl. 21:10). Schmidt (1877: pl. 49:2) illustrated a more elliptic-linear valve with multiple canals, followed by Grunow in Van Heurck (1880, as "Navicula iridis var." [approaching Navicula iridis var. firma sensu Grunow, but larger]). Pelletan (1888: 272, fig. 209) and Van Heurck (1896: pl. 5: 212) copied the image of Grunow. Wolle (1890: pl. 18:4; 19:10) illustrated an even broader elliptical valve with rounded apices for Navicula iridis and a smaller similar valve for Navicula firma. Pantoscek (1902: 54, pl. 6:134) showed a small linear-elliptic valve (115 μm long, 21.6 μm wide) as Navicula ...
Citations
... AlgaeBase (M.D. Guiry in Guiry and Guiry 2020) presently includes some 250 species of Neidium. The early light microscopic (LM) investigations of North American species by Reimer (1959) helped to provide an initial foundation for the taxonomy that has since been enhanced by the use of scanning electron microscopy (SEM) and has led to descriptions of many more species (e.g., Lefebvre and Hamilton 2015;Hamilton et al. 2019). ...
Light and scanning electron microscopy were used to describe Neidium petersiveri sp. nov., a previously unnamed diatom found in the Canadian waters of Lake Superior. It had been reported previously as single cells of an unidentified Neidium species from four widely separated regions in North America: Michipicoten Island (Lake Superior, Ontario, Canada), Cape Cod (Massachusetts, United States), a Quebec river (Quebec, Canada), and the Back River (Nunavut, Canada). There are superficial resemblances to Neidium mirum Krasske and Neidium calvum Østrup, but there are significant differences in frustule size and shape as well as the pattern of striae on the valve face that render N. petersiveri unique. There was not a significant correlation between frustule lengths and widths in N. petersiveri, owing to a relatively small range within the width data that resulted in much higher width-to-length ratios among shorter cells than for longer cells (74 cells measured). Other significant aspects of morphologic variation include various shapes and configurations of the lacinial fissures and of the proximal raphe fissures, and the sporadic occurrence of pit-like depressions in the axial and central regions of the valves, which suggest that variations in these characters likely have limited value as discriminating characters at the species or subspecies levels.
... f. 1). Hamilton et al. (2019) have recently shown, however, that N. iridis has much longer valves with protracted ends, and in addition, its proximal raphe endings are only shortly hooked, unlike our specimen. Fig. 73 is species is most similar to Nitzschia frustulum (Kützing) Grunow, but it has more rostrate valve ends than the type specimens of N. frustulum (ref. ...
We investigated the diatom flora of a wet grassland on mineral soil on the Ritsumeikan University Bi-wako-Kusatsu Campus (BKC) in Shiga Prefecture, central Japan. The wetland was originally present in the area, but other wetlands that had been present in other parts of the campus were also transplanted there; the wetland has been maintained by pumped-up ground water as well as by the original spring water. A field survey and sampling took place on 8 November 2013. e water was slightly acidic (pH 5.4-6.1) with variable electrical conductivities (4.8-17.5 mS m-1). Diatom samples were collected from the surfaces of Moliniopsis japonica and Sphagnum palusture. In total, 108 diatom species (including nine unidentified ones) belonging to 30 genera were found, and they were all listed and illustrated. In terms of species richness, the dominant genus was Pinnularia represented by 20 species followed by Eunotia with 12 species. While the generic diatom composition was similar to those in peaty moors in Lake Biwa basin, the species composition was much different. We found some diatoms that are unusual in wetlands around Lake Biwa such as Pinnularia osoresanensis, which has been reported only in strongly acidic waters.
... At present the prominent identifying morphological character for the genus is scattered renilimbia (Figs 16 & 42 this study, black arrows), which are internally positioned spathulate hooks associated with areolae on the valve face and on the longitudinal canal (e.g. Hamilton & Jahn 2005, Hamilton et al. 2019, Liu et al. 2010. Genetically, the genus Neidium forms a defined clade separated from Neidiomorpha Cantonati et al. (2010: 196), Luticola D.G. Mann (Round et al. 1990: 670), Biremis D.G. Mann (Round et al. 1990: 664) and Scoliopleura Grun. ...
... TABLE 4. Summary metrics for the Neidium taxa examined. Taxon N. affine N. amphigomphus N. beatyi N. bisulcatum N. collare N. dilatatum N. fossum N. hitchcockii N. iridis N. lavoieanum N. longiceps N. lowei N. potapovae N. productum N. promontorium N. sacoense N. tumescens N. vandusenense Length ( Neidium iridis has a large size range (length, 184-275 μm) in this population which is comparable to N. iridis from the type locality and another locality in eastern North America (Hamilton et al. 2019). N. iridis is comparable to N. beatyi but can be distinguished by the valve shape, valve size and number of longitudinal canals. ...
Five taxa in the genus Neidium, N. iridis, N. beatyi sp. nov., N. vandusenense sp. nov., N. collare sp. nov. and N. lavoieanum sp. nov. are documented from a pond and stream system in the VanDusen Botanical Garden, Vancouver, Canada. Neidium beatyi is a large linear species with multiple longitudinal canals and sagittate apices. The areolae are occluded by finger-like silica extensions on the external surface. This taxon is distinguished from Neidium iridis by the number of longitudinal canals (>5), shape of the valve apices, and smaller size. Neidium vandusenense is broadly linear with distinct rostrate apices. Two-three longitudinal canals are present along each margin. Plastid rbcL sequence data associates this taxon with N. amphigomphus. Neidium collare is an elliptic lanceolate taxon with one longitudinal canal. This taxon is genetically related to N. bisculatum sensu lato, but with a different shape form. Neidium lavoieanum has a valve shape form similar to Neidium potapovae, but is larger and genetically similar to N. productum sensu lato. The five Neidium taxa were observed in a small stream next to Lake Victoria (pond) in the VanDusen Botanical Garden Vancouver, Canada. The water was mildly alkaline with a pH of 7.86, a conductance of 163 µS/cm, higher nutrient loads and low metal content.
This monograph contains descriptions of taxa from the diatom genera Craticula, Aneumastus, Decussiphycus, Cavinula, Lacustriella, Luticola, Mastogloia, Geissleria, Placoneis, Petroplacus, Navicula, Hippodonta, Sellaphora, Prestauroneis, Fallacia, Stauroneis, Brachysira, Anomoeoneis, Neidium, Diploneis, Caloneis, Pinnularia, Capartogramma, Frustulia, Amphipleura, Krasskella, Gyrosigma and Plagiotropis from periphytic and surface sediment samples in the coastal ecosystems of the Laurentian Great Lakes. Light micrographs are provided for diatom taxa recorded in 207 samples from 106 wetlands, embayments, high-energy and deep, nearshore locales of the five Great Lakes. 148 taxa are characterized, and 2 previously undescribed taxa are named. For 36 of the more common species, lake and habitat specificity, modelled optima for phosphorus and chloride and tolerance to coastal anthropogenic stressors are described.
