Stenostomum virginianum Nuttycombe, 1931

Noreña, Carolina, Damborenea, Cristina & Brusa, Francisco, 2005, A taxonomic revision of South American species of the genus Stenostomum O. Schmidt (Platyhelminthes: Catenulida) based on morphological characters, Zoological Journal of the Linnean Society 144 (1), pp. 37-58 : 50

Stenostomum virginianum Nuttycombe, 1931

( Fig. 3F )

Stenostomum carnivorum Jones, 1932

Description: Individuals with 1–4 zooids up to 5 mm long, solitary individuals 0.4–1 mm long. Mobile tapering anterior end. Small, rounded ciliated pits lateral or latero-ventrally placed. Truncate caudal end without intestine-lacking region. Vacuolar epidermic cells and short rhabdites. Long semi-rigid cilia concentrated in the anterior and posterior ends of the body. Vacuolar epidermal cells. Colour in life whitish.

Anterior brain lobes forming small independent masses (‘metameric’). A pair of light-refracting bodies, with fewer than ten spheres (type 2), associated with an extension of the posterior brain lobes.

Small rounded oral pore. Long tubular pharynx (1/4 body length) with isolated pharyngeal glands (type a) distributed along the entire pharynx. Excretophores regularly arranged in two lateral bands, or irregularly in the North American specimens. Nephridiopore subterminal.

Distribution: Virginia ( Nuttycombe, 1931; Nuttycombe & Waters, 1938), Georgia, North Carolina ( Nuttycombe & Waters, 1938; Kolasa, 1991), USA; Nova Scotia, Canada ( Jones, 1932); São Paulo State and Paraná State, Brazil ( Marcus, 1945b); Los Talas, Berisso, Buenos Aires, Argentina, July 1999. This species has not been previously recorded in Argentina.

Stored material: One sagittally sectioned specimen in the CHMLP No. 5307.

Discussion: Marcus (1945b) and Luther (1960) refer to the similarity between this species and Stenostomum unicolor O. Schmidt, 1848 .

The largest sized specimens correspond to those mentioned by Marcus (1945b)

Figures

Figure 3. A, Stenostomum paraguayense. B, S. rosulatum. C, S. simplex. D, S. tenuicauda. E, S. uronephrium. F, S. virginianum. Scale bars = 200 Mm.