Trinema enchelys - 77 µm long

 

 

Trinema enchelys (Ehrenberg, 1838)

 

Diagnosis: shell ovoid and flattened slightly in the apertural region, composed of approximately fifty, large, circular, incompletely overlapping shell-plates and an unknown number of smaller, oval, shell-plates. Aperture circular, sub-terminal and invaginated, bordered by an inner circle of about forty denticulate apertural-plates, and two or three rows of small, oval, shell-plates. Each apertural-plate is circular, and carries a median, dorsal tooth. One to two contractile vacuoles; pseudopodia few, attenuate and long.

 

Dimensions: 30-100 um long; 15-60 µm wide; scales 4-12 µm in diameter.  diameter of large shell-plates 5.6-10.3, diameter of small shell-plates 1.9-4.3; diameter of apertural plates 0.9-1.8 µm. My measurements: up to 155 µm!

 

Ecology: very common in mosses and aquatic vegetation.

 

Remarks: Distinction between T. enchelys and the very similar T. lineare only by their size. Both Chardez (1956) and Thomas (1958) have shown the differences in shape and size of the shell of this species.

 

Trinema enchelys
Trinema enchelys
Trinema enchelys
Large shell, c. 155 µm, with several rows of teeth in its pseudostome - Ecuador
Trinema enchelys, 91 µm - Tirol,Austria
Trinema enchelys, living specimen
Living specimen
Trinema enchelys in division
Trinema enchelys, dividing
Trinema enchelys
Trinema enchelys, DIC
Trinema enchelys
Trinema enchelys
Pseudostome
Granules at the base of some filopodia
Trinema enchelys, after Lueftenegger et al, 1988
Trinema enchelys
Trinema enchelys
Very large shell from Ecuador, mosses, 155 µm; shell 104 µm
Trinema enchelys
Shell structure