Diatoms of North AmericaDiatoms of North America

Stauroneis staurolineata

Reimer 1961

Stauroneis Staurolineata Guide
  • Category
    Symmetric Biraphid
  • Length Range
    83-125 µm
  • Width Range
    13.5-16.1 µm
  • Striae in 10 µm
    16-17

Identification

Stauroneis staurolineata LM8 Stauroneis staurolineata LM10 Stauroneis staurolineata LM9 Stauroneis staurolineata LM5 Stauroneis staurolineata LM6 Stauroneis staurolineata LM4 Stauroneis staurolineata LM11
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Stauroneis staurolineata SEM2 Stauroneis staurolineata SEM1

Description

The valve is narrowly lanceolate with acute, narrowly rounded apices. The axial area is narrow and linear. The raphe is linear, with unilaterally hooked distal raphe ends. Proximal raphe ends are linear and not inflated. Striae are slightly radiate throughout. Longitudinal hyaline ribs run linear and parallel along the external side of the valve, 11-14 in 10 μ, creating a distinctive pixelated appearance in LM. Areolae are coarse and appear rectangular in LM. The stauros is rectangular, transected by longitudinal ribs.

Autecology

Stauroneis staurolineata is rare and occurs in low abundance throughout the northeast and southeast United States in low-alkalinity (Camburn and Charles 2000), acidic, and oligotrophic waters (Siver et al. 2005). It has been reported from lakes, streams, and wetlands.

Original Description

Valves lanceolate, tapering to narrow-rostrate ends. Axial area linear, broadening at the ends. Fascia narrow, linear, crossed by conspicuous longitudinal hyaline ribs. Raphe linear, slightly broadened between valve center and ends. Proximal raphe-ends close, distal ends forking about 3 to 4 μ from valve ends at a sub-terminal nodule. One raphe branch elongate, hooking into the end. Striae radiate except at the ends where they become single puncta due to the thick longitudinal ribs extending into the ends. Longitudinal ribs approximately parallel, not conspicuously undulate, not interrupted at the fascia. Length--90-115 μ; width--15-17 μ; striae--16-17/10 μ; longitudinal ribs--9-11/10 μ.

Illustration specimen: ANSP-H.L.Sm. 502 (holotype). Type locality: New Hampshire, Carroll Co., Wolfboro. Recorded U.S. distribution: NEW HAMPSHIRE, Carroll Co., Wolfboro (ANSP-H.L.Sm. 502, Febiger 4466); Bemis Lake, fresh water, recent (?) (ANSP-GC 42822, 42823). PENNSYLVANIA, Philadelphia Co., Gray's Ferry, clay (ANSP-GC 42665, 43542, 53543).

This species is very closely related to S. stodderi Lewis. The most conspicuous features of this species are: 1) the continuation of longitudinal lines through the stauros area, 2) the sub-terminal nodule. For a more complete discussion of this see S. stodderi.

Cleve (1984, p. 110) described a Navicula stodderi var. insignis Grun. Ms, which probably belongs here as a variety. The Cleve & Möller preparation (ANSP-Cl&Möll. 187) has Grunow's taxon listed but it is not present anywhere on the slide.

As described by Cleve, the variety insignis has coarser longitudinal ribs (7-8/10 μ) and is considerably broader (21 μ side) than S. staurolineata. The position of the terminal nodules and the character of the axial longitudinal ribs near the central area is not definite from Cleve's data. It is, nevertheless, quite clear that the stauros is crossed by the longitudinal ribs thus eliminating it from S. stodderi.

This taxon and also S. stodderi are most unusual for Stauroneis in that they have quite thick longitudinal ribs or partitions similar to the ribs described for the genus Neidium (Hustedt, 1939, pp. 17-20) (Reimer, 1959a, pp. 2-3). Further study may show the necessity of their being transferred to another genus or placed under a new genus. The latter would be more likely for they certainly would not fit in the genus Neidium. The only likely place at present seems to be in Stauroneis. In my opinion a stauros can be demonstrated thus warranting such a conclusion.

  • Basionym
    Stauroneis staurolineata
  • Author
    Reimer 1961
  • Length Range
    90-115 µm
  • Width
    15-17 µm
  • Striae in 10µm
    16-17

Original Images

Stauroneis Staurolineata Orig Illus
Stauroneis Staurolineata Orig Desc

Cite This Page

Polaskey, M. (2018). Stauroneis staurolineata. In Diatoms of North America. Retrieved October 30, 2024, from https://diatoms.org/species/stauroneis_staurolineata

Responses

The 15 response plots show an environmental variable (x axis) against the relative abundance (y axis) of Stauroneis staurolineata from all the stream reaches where it was present. Note that the relative abundance scale is the same on each plot. Explanation of each environmental variable and units are as follows:

ELEVATION = stream reach elevation (meters)
STRAHLER = distribution plot of the Strahler Stream Order
SLOPE = stream reach gradient (degrees)
W1_HALL = an index that is a measure of streamside (riparian) human activity that ranges from 0 - 10, with a value of 0 indicating of minimal disturbance to a value of 10 indicating severe disturbance.
PHSTVL = pH measured in a sealed syringe sample (pH units)
log_COND = log concentration of specific conductivity (µS/cm)
log_PTL = log concentration of total phosphorus (µg/L)
log_NO3 = log concentration of nitrate (µeq/L)
log_DOC = log concentration of dissolved organic carbon (mg/L)
log_SIO2 = log concentration of silicon (mg/L)
log_NA = log concentration of sodium (µeq/L)
log_HCO3 = log concentration of the bicarbonate ion (µeq/L)
EMBED = percent of the stream substrate that is embedded by sand and fine sediment
log_TURBIDITY = log of turbidity, a measure of cloudiness of water, in nephelometric turbidity units (NTU).
DISTOT = an index of total human disturbance in the watershed that ranges from 1 - 100, with a value of 0 indicating of minimal disturbance to a value of 100 indicating severe disturbance.