Stenostomum leucops (Dugès, 1828) O. Schmidt, 1848

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 : 46-47

publication ID	https://doi.org/10.1111/j.1096-3642.2005.00157.x
DOI	https://doi.org/10.5281/zenodo.5113612
persistent identifier	https://treatment.plazi.org/id/8C6887DA-3073-C472-FC25-A05FD5D6AE6B
treatment provided by	Carolina (2021-03-24 20:42:53, last updated 2024-11-29 11:10:41)
scientific name	Stenostomum leucops (Dugès, 1828) O. Schmidt, 1848
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Stenostomum leucops (Dugès, 1828) O. Schmidt, 1848 View in CoL

( Fig. 2D View Figure 2 )

Fasciola composita Schrank, 1776

Derostoma leucops Dugès, 1828

Stylacium isabellinum Corda, 1838

Microstomum leucops Ørsted, 1844

Stenostomum torneense Schmidt, 1852 View in CoL

S. neoborecense Girard, 1893

S. tenuicaudatum Nuttycombe & Waters, 1938 View in CoL

S. sthenum Borkott, 1970 View in CoL

S. platycaudatum Borkott, 1970

S. plebejum Borkott, 1970

Description: Length variable. Two-zooid chain 1– 1.75 mm. Cylindrical body. Rounded or pointed anterior end. Posterior end of the body with intestinelacking region forming a tail. Ciliated epithelium with small rhabdites. Epidermic cilia with rigid sensitive cilia at anterior and occasionally at the posterior end. Colour in life yellowish white.

Anterior brain lobes deeply dentate. A pair of type 1 light-refracting bodies associated with the posterior brain lobes.

Oral pore shape variable, rounded, triangular or elongated. Simple muscular pharynx. Two types of pharyngeal glands: type a, abundant at the distal end, opening onto the posterior region of the pharynx; and type b, arranged in bunches lateral to the pharynx, opening onto the anterior end. Excretophores present. Nephridiopore subterminal, in the intestine-lacking region.

Distribution: Cosmopolitan. In South America, margins of the Surinam River, near Paramaribo, Surinam ( Van der Land, 1970); Paraná River, Argentina ( Noreña-Janssen, 1995).

Discussion: Nuttycombe & Waters (1938) consider the validity of this species questionable. This criterion has been followed by Marcus (1945b). These authors consider that the descriptions of this species are so broad and ambiguous as to make its recognition difficult. By contrast, Borkott (1970) in an exhaustive study of Stenostomum leucops subdivides this species into three new species: S. sthenum , S. platycaudatum and S. plebejum . The results of this research did not confirm the existence of these species in South America ( Noreña-Janssen, 1995). Young & Kolasa (1974b) identified specimens from Africa as S. leucops leucops , on the basis of Luther’s (1960) description, ascribing the differences described by Borkott (1970) to those originated in the cultures or not visible in animals captured in natural environments.

In the 1990s, Reuter ( Reuter, 1988, 1991, 1994; Reuter & Palmberg, 1990; Reuter & Eriksson, 1991; Reuter & Kuusisto, 1992; Reuter, Joffe & Palmberg, 1993; Reuter et al., 1995) as well as Wikgren & Thorndyke (1990), Lindroos & Reuter (1991), Palmberg & Reuter (1992) and Grahn et al. (1995) carried out ultrastructural studies of stenostomids, mainly S. leucops . S. sthenum was not mentioned in any of them.

References

Borkott H. 1970. Geschlechtliche Organisation, Fortpflanzungsverhalten und Ursachen der sexuellen Vermehrung von Stenum sthenum nov. spec. (Turbellaria, Catenulida). Zeitschrift fur Morphologie und Oekologie der Tiere 67: 183 - 262.

Grahn M, Maule AG, Elo 1 Shaw C, Reuter M, Halton DW. 1995. Antigenicity to neuropeptide f (NPF) in Stenostomum leucops and Microstomum lineare. Hydrobiologia 305: 307 - 308.

Kolasa J, Young JO. 1974 b. Studies on the genus Stenostomum O. Schmidt (Turbellaria; Catenulida). II. A new subspecies and records of two species new to Poland. Freshwater Biology 4: 157 - 161.

Lindroos P, Reuter M. 1991. Extracellular matrix in some microturbellarians. Hydrobiologia 227: 283 - 290.

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

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

Norena-Janssen C. 1995. Studies on the taxonomy and ecology of the Turbellaria (Plathelminthes) in the floodplain of the Parana River (Argentina). II. Taxonomy and ecology of the Turbellaria. Archiv fur Hidrobiologie / Supplement Band 107: 211 - 262.

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

Palmberg I, Reuter M. 1992. Sensory receptors in the head of Stenostomum leucops. 1. Presumptive photoreceptors. Acta Biologica Hungarica 43 (1 - 4): 259 - 267.

Reuter M. 1988. Development and organization of nervous system visualized by immunocytochemistry in three flatworm species. Fortschritte der Zoologie 36: 181 - 184.

Reuter M, Palmberg I. 1990. Synaptic and nonsynaptic release in Stenostomum leucops. A study of the nervous system and sensory receptors. Acta Academiae Abonensis Series B. Mathematica et Physica Matematik Naturvetenskaper Teknik 50: 121 - 136.

Reuter M, Eriksson K. 1991. Catecholamines demostrated by glyoxylic-acid-induced fluorescence and HPLC in some microturbellarians. Hydrobiologia 227: 209 - 219.

Reuter M, Kuusisto A. 1992. Growth factors in asexually reproducing Catenulida and Macrostomida (Plathelminthes)? A confocal, immunocytochemical and experimental study. Zoomorphology 112: 155 - 165.

Reuter M, Joffe B, Palmberg I. 1993. Sensory receptors in the head of Stenostomum leucops. 2. Localization of catecholaminergic histofluorescence-ultrastructure of surface receptors. Acta Biologica Hungarica 44: 125 - 131.

Reuter M, Maule AG, Halton DW, Gustafsson MKS, Shaw C. 1995. The organization of the nervous system in Platyhelminthes. The neuropeptide F-immunoreactive pattern in Catenulida, Macrostomida, Proseriata. Zoomorphology 115: 83 - 97.

Schmidt EO. 1848. Die rhabdocoelen Strudelwurmer des sussen Wassers. Jena: Fr. Mauke.

Van der Land J. 1970. Kleine Dieren Uit Het Zoete Water Van Suriname Verslag Van Een Onderzoek In 1967. Zoologische Bijdragen 12: 1 - 46.

Wikgren MC, Thorndyke MC. 1990. An echinoderm neuropeptide in flatworms? Acta Academiae Abonensis Series B. Mathematica et Physica Matematik Naturvetenskaper Teknik 50: 45 - 52.