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Mastogloia calcarea

Lee, E.E.Gaiser, Van de Vijver, Edlund, and S.A.Spauld. 2014      Category: Symmetrical biraphid

REPORTED AS: Mastogloia smithii Morphotype I (Slate and Stevenson 2007) | Mastogloia smithii var. lacustris (Gaiser et al. 2010) 

Mastogloia albertii


Mastogloia elliptica

LM scalebar = 10 µm = 80 pixels.


Contributor: Sylvia Lee - February 2014
Length Range: 27-54 µm
Width Range: 7-9 µm
Striae in 10 µm: 19-20


Valves are linear-lanceolate (post-initial and small valves are elliptical-lanceolate) with rostrate ends (post-initial valves have round ends, small valves have subrostrate ends). Striae are punctate, radiate, weakly curved at the central area, and become parallel at the apices. The striation pattern on the valve face continues unchanged onto the mantle. The central area is elliptical to polygonal and is often asymmetric. Areolae are round and internally occluded by a cribrum, 16–20 areolae per 10 µm. The raphe is straight to weakly undulate with a kink near the central area. The proximal raphe ends are slightly expanded and deflect in the same direction. The distal raphe ends are slightly expanded, extend centrally over the mantle and hook to the same side. There is a small hyaline area where the curve of the distal raphe ends occurs.

Internally, the raphe is straight and encased in a thickened sternum. The internal proximal raphe ends are straight and the sternum fuses into the thickened central nodule. The internal distal raphe ends are occluded by pseudosepta. The partectal ring is closed, forming a complete band, and lacks a flange separating the ring from the valve margins. A pseudopartectum is present between the apex and each terminal partectum. There is a furrow opening into a pore-like cavity by each pseudopartectum. The apices of the partectal ring have a narrow cleft that expands into a pyriform lacuna. One pore is present between the center most pair of partecta on each side of the partectal ring. The partecta are distributed along both sides of the partectal ring, except near the apices. Partecta are clearly distinguishable and evenly sized, but they are slightly larger closest to the apices, 5-6 partecta in 10 µm. Thickened virgae are present throughout the valve interior. Cribral pores become highly irregular near the sternum and central nodule. There are five partectal pores located near both sides of the apices. Live specimens produce mucilage strands from the partectal pores. Live cells contain 2 H-shaped plastids at each pole.

Original Description

Author: Lee, E.E.Gaiser, Van de Vijver, Edlund, and S.A.Spauld. 2014
Length Range: 27-54 µm
Width Range: 7-9 µm
Striae in 10 µm: 19-20

Original Description

Original Images

Cite This Page:
Lee, S. (2014). Mastogloia calcarea. In Diatoms of the United States. Retrieved May 20, 2018, from

Species: Mastogloia calcarea

Contributor: Sylvia Lee

Reviewer: Sarah Spaulding


Gaiser, E.E., Childers, D.L., Jones, R.D., Richards, J.H., Scinto, L.J., and Trexler, J.C. (2006). Periphyton responses to eutrophication in the Florida Everglades: Cross–system patterns of structural and compositional change. Limnology and Oceanography 51: 617–630.

Gaiser, E., La Hée J.M., Tobias, F.A.C. and Wachnicka, A.H. (2010). Mastogloia smithii var lacustris Grun.: a structural engineer of calcareous mats in karstic subtropical wetlands. Proceedings of the Academy of Natural Sciences of Philadelphia 160(1):99-112. 10.1635/053.160.0111

La Hée, J.M. and Gaiser, E.E. (2012). Benthic diatom assemblages as indicators of water quality in the Everglades and three tropical karstic wetlands. Freshwater Science 31: 205–221. 10.1899/11-022.1

Lee S.S., Gaiser E.E., Van de Vijver, B., Edlund, M.B., and Spaulding, S.A. (2014). Morphology and typification of Mastogloia smithii and M. lacustris, with descriptions of two new species from the Florida Everglades and the Caribbean region. Diatom Research. doi:10.1080/0269249X.2014.889038

Slate, J.E. and Stevenson, R.J. (2007). The diatom flora of phosphorus-enriched and unenriched sites in an Everglades marsh. Diatom Research 22: 355–386. 10.1080/0269249X.2007.9705721

Links & ID's

Index Nominum Algarum (INA)

California Academy of Sciences (CAS)

North American Diatom Ecological Database (NADED)


Autecology Discussion

Lives embedded within microbial communities dominated by filamentous and coccoid cyanobacterial species that form extensive mats upon the sediment or bedrock surface and around the submersed stems of aquatic plants in shallow-water, limestone-based environments with seasonal desiccation. Weighted-averaging optima: water depth 52 cm, salinity 0.1, total phosphorus 225 μg/g, and pH 7.6.

Confirmed distribution records outside of the Florida Everglades include similar karstic wetlands in Jamaica, Belize, and Mexico.


Floating and epiphytic periphyton in the Everglades, Florida

Credit/Source: Florida International University Periphyton Lab

Mastogloia calcarea within periphyton mat

Credit/Source: Sylvia Lee and Franco Tobias

Recently divided frustules of Mastogloia calcarea within periphyton mat

Credit/Source: Sylvia Lee and Franco Tobias

Mastogloia calcarea with mucilage strands

Credit/Source: Sylvia Lee and Franco Tobias