Lecythium spinosum
Lecythium spinosum, 68 µm long, excl. spines – Laegieskamp

 

Lecythium spinosum (Penard, 1890)

Diagnosis: test membranous, ovoid or pyriform, in dorsal view circular or a little compressed, with numerous short curved spines, which are modifications of the membrane; aperture sub-terminal, oblique and pliable; nucleus granular, placed posteriorly; cytoplasm filling the test; filopodia numerous, simple or branched, sometimes anastomosing.

Ecology: aquatic vegetation (Hopkinson), sediments (Lauterborn). I have found one specimen in the sediments of a forest pond at Groeneveld, Baarn, the Netherlands, in 1981. I found some specimens again in the ooze of ditches in Den Treek (2012), Laegieskamp (2013) and Naardermeer (2015).

Dimensions: Lauterborn, Penard and Hopkinson: 45-70 µm long; my measurements: 37-68 µm long (n=11).

Remarks: This species has been described by Penard (1890) as Trinema spinosum and by Lauterborn (1901) as Plagiophrys armatus. Later Penard (1902) accepted the name Pamphagus armatus. Penard (1902) described this species as follows: ‘Body pocket-shaped. Membranous test with curved spines all over its surface. 45-70 µm.

Lecythium spinosum with filopodia
Lecythium spinosum, 51 µm – Den Treek
Lecythium spinosum
Lecythium spinosum, 68 µm long, excl. spines; some filopodia are visible to the left; note the large granules.
Lecythium spinosum
Lecythium spinosum, apertural view; the cell hangs on the cover glass.
Lecythium spinosum, from the Naardermeer, 57 µm
Lecythium spinosum, with detail showing that spines are modifications of the membrane
Lecythium spinosum
Lecythium spinosum
Lecythium spinosum, mouth (arrow) – both specimens from Den Treek, Amersfoort
Lecythium spinosum
Lecythium spinosum with large food vacuole, body 58 µm long; in the fundus region the nucleus is visible, but without distinct visible structure. It looks if the nucleolar material is fragmented and saucage shaped – Den Treek, Amersfoort
Specimen from the Naardermeer
Specimen from the Naardermeer
Lecythium spinosum
Lecythium spinosum, filopodia – Phase Contrast
Lecythium spinosum
Lecythium spinosum, filopodia – DIC
Lecythium spinosum
Lecythium spinosum
The original description with original drawings, Penard, 1890.
Pamphagus armatus
Lecythium spinosum Lauterborn
Left: Drawing of L. spinosum by Penard (1902), He considered this specimen as a Trinema-species in 1890, but corrected his identification later in Pamphagus armatus, giving the credit to Lauterborn.
Right: Drawing of L. spinosum by Lauterborn (1901). He described this species as Plagiophrys armatus.
Lecythium spinosum
Drawing in Cash, Wailes and Hopkinson (1915)
Lecythium spinosum
Lecythium spinosum
Lecythium spinosum – Photo: Eckhard Voelcker, Berlin, and L. spinosum, apical view
Lecythium spinosum
Lecythium spinosum – Photomicrograph: Eckhard Voelcker, Berlin
Lecythium spinosum
Lecythium spinosum – drawing Ferry Siemensma

 

The photomicrographs below were made by Francisco Pujente, Spain, and might represent L. spinosum:

According to Francisco, his sample comes from Parque La Albufera in Valencia in Spain, freshwater with moderate pollution. Water temperature approx. 18 º Celsius. The lake is fed by the river Turia and is in contact with the Mediterranean Sea through various channels. All around the lake are rice fields flooded with water for several months a year.

Plagiophrys spec.
Plagiophrys spec.
Plagiophrys spec.
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