Stenostomum ciliatum Kepner & Carter, 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 : 43-44

Stenostomum ciliatum Kepner & Carter, 1931

( Fig. 1D )

Stenostomum agile Silliman, 1885

Description: Solitary individuals, 1 mm or less long. Chains with two zooids. Body robust, anterior end blunt. Ciliated pits lateral and superficial. Tapering posterior end with intestine-lacking region. Small epidermal cilia, uniformly distributed, longer at the posterior end. Rod-like rhabdites throughout the entire epidermis.

Anterior brain lobes deeply dentate. A pair of lightrefracting bodies associated with the posterior brain lobes; each one formed by one, two or three spheres, included in a colourless vesicle (type 2).

Oral pore oval, transversal and surrounded by glands. Wide pharynx. The glands on both sides of the pharynx (type b) open onto the anterior end, and smaller ones (type a) open onto the whole surface. Conspicuous pharyngeal sphincter. Intestinal wall with irregularly distributed excretophores. Nephridiopore ventral, subterminal and posterior to the intestine.

Distribution: Virginia, USA ( Kepner & Carter, 1931; Kolasa, 1991); São Paulo and Paraná State, Brazil ( Marcus, 1945b).

Discussion: Kepner & Carter (1931) described the ciliated pits as relatively small for the specimens from Virginia and Marcus (1945b) described them as long and extensive. This author states that this difference would not suffice to separate the species, because they share the rest of the diagnostic characters.

Figures

Figure 1. A, Stenostomum amphotum. B, S. arevaloi. C, S. bicaudatum. D, S. ciliatum. E, S. cryptops. Scale bars = 200 Mm.