Stenostomum tenuicauda Graff, 1911

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 : 49

publication ID	https://doi.org/10.1111/j.1096-3642.2005.00157.x
DOI	https://doi.org/10.5281/zenodo.5113622
persistent identifier	https://treatment.plazi.org/id/8C6887DA-3076-C474-FC39-A51ED3E3AC80
treatment provided by	Carolina (2021-03-24 20:42:53, last updated 2024-11-29 11:10:41)
scientific name	Stenostomum tenuicauda Graff, 1911
status

Treatment

Stenostomum tenuicauda Graff, 1911 View in CoL

( Fig. 3D View Figure 3 )

Description: Chains of up to eight zooids up to 5 mm long. Body cylindrical, slightly flattened ventrally. Anterior end blunt. Deep dorso-lateral ciliated pits. Body constriction at the level of the oral pore. Elongated intestine-lacking region at the posterior end (up to one-third of the body length). Caudal portion ventrally adhesive. Long, thin and dense epithelial cilia. Presence of long semi-rigid sensory cilia. Rhabdites grouped in packets placed vertically to the epidermis. Colour in life white.

Anterior brain lobe deeply dentate. Internal brain lobes associated with posterior lobes ( Marcus, 1945a). A pair of type 1 light-refracting bodies formed by numerous spheres (about 50) included into a large vesicle and associated with the posterior ganglia.

Oral pore semi-lunar, surrounded by longitudinal pharyngeal muscles. Pharynx almost as wide as it is long, with little circular musculature. Presence of radial muscles between the pharynx and the body wall. Regularly arranged glands (type a) along the entire pharynx. Intestinal walls smooth. Excretophores irregularly arranged, not very conspicuous. Nephridiopore ventrally placed in the intestinelacking region (subterminal).

Distribution: New York and Massachusetts ( Graff, 1911), Virginia ( Nuttycombe, 1932a; Nuttycombe & Waters, 1938), North Carolina, South Carolina, Tennessee and Georgia ( Nuttycombe & Waters, 1938), USA; São Paulo, Brazil ( Marcus, 1945b); Russia ( Beklemichev, 1917, 1921; Nassonov, 1926); Finland ( Nassonov, 1924); temporary pond near Zapata Stream and Route 11, Buenos Aires, Argentina, November 1999. This species has not been previously recorded in Argentina.

Stored material: Four sagittally sectioned specimens in the CHMLP. No. 5306.

Discussion: S. tenuicauda was synonymized with S. leucops ( Luther, 1960) . However, the differences found not only in the material studied here, but also in the specimens described by Marcus, support the validity of at least the South American populations as a species distinct from S. leucops .

References

Beklemichev W. 1917. Turbellaries, collectionnes dans les gouvernement de Kalouga, etc. Annuarie du Musee Zoologique Academie des Sciences 21: 347 - 368.

Beklemichev W. 1921. Turbellaria. Faune Petropolitanae Catalogus 2 (6): 1 - 9.

Graff L. 1911. Acoela, Rhabdocoela, Alloecoela des Ostens der Vereinigten Staaten von Amerika. Zeitschrift fur Wissenschaftliche Zoologie 99: 1 - 108, t. 1 - 4.

Luther A. 1960. Die Turbellarien Ostfennoskandiens. Fauna Fennica 7: 1 - 155.

Marcus E. 1945 a. Sobre Catenulida brasileiros. Boletins da Facultade de Filosofia, Ciencias e Letras Zoologia 10: 3 - 133.

Marcus E. 1945 b. Sobre Microturbelarios do Brasil. Comunicaciones Zoologicas del Museo de Historia Natural de Montevideo 1 (25): 1 - 74. Est I - XI.

Nassonov N. 1924. Les trats generaux de la distribution geographique des Turbellaria rhabdocoelida dans la Russie, etc. Bulletin de l'Academie des Sciences de Russie 1924: 327 - 352.

Nassonov N. 1926. Die Turbellarienfaunades Leningrader Gouvernements I. Bulletin de l'Academie des Sciences de l'Union des Republiques Sovietiques Socialistes 1926: 817 - 836.

Nuttycombe J. 1932 a. Observations on Stenostomum. Zoologischer Anzeiger 97: 123 - 131.

Nuttycombe J, Waters A. 1938. The American species of the genus Stenostomum. American Philosophical Society 79: 213 - 301.