Trigonostomum penicillatum, (Schmidt, 1857)

Willems, Wim R., Artois, Tom J., Vermin, Wouter A. & Schockaert, Ernest R., 2004, Revision of Trigonostomum Schmidt, 1852 (Platyhelminthes, Typhloplanoida, Trigonostomidae) with the description of seven new species, Zoological Journal of the Linnean Society 141 (2), pp. 271-296 : 290

TRIGONOSTOMUM PENICILLATUM ( SCHMIDT, 1857)

MICOLETZKY, 1910

( FIG. 7C )

Alternative species name: trigonostomumpenicillatum

Vortex penicillatus Schmidt, 1857: 352 , t. 1, fig. 3.

Hyporhynchus penicillatus Diesing, 1862: 227 ; Graff, 1882: 341, t. 9, figs 15–20; Gamble, 1893: 467; Fuhrmann, 1898: 459; Gamble, 1900: 813; Meixner, 1925: 256; 1926: 577.

Trigonostomum intermedium n.n. Graff 1910: 4.

Trigonostomum penicillatum Micoletzky, 1910: 174 ; Graff, 1913: 308–309, figs 268–270; Southern, 1912: 3, 9; 1915: 34; Meixner, 1924a: 202–203; 1924b: 89, 92, 94, 96, 98, 99, 105; Southern, 1936: 45, 58; Westblad, 1954: 8; Den Hartog, 1964: 378; Ax, 1971: 216– 217, fig. 45.

Trigonostomum marki Graff, 1911b: 60 , t.4, figs 44, 45; 1913: 309–310, fig. 271; Meixner, 1924b: 96, 99.

Known distribution: North American Atlantic coast ( Graff, 1911b), French Atlantic coast ( Ax, 1971), English Channel ( Gamble, 1893), North Sea ( Graff, 1913; Meixner, 1924b), Ireland ( Southern, 1912, 1936), Norway ( Westblad, 1954), Mediterranean Sea ( Schmidt, 1857; Graff, 1913; Meixner, 1925, 1926) and Adriatic Sea ( Meixner, 1925, 1926).

New localities: Great Britain, Plymouth, 5 July 1949, Westblad (coll. SMNH) . France, Corsica, Ocellutia , large sandflat with coarse sand, 10–12 m deep, 19 October 1982 and 18 September 1983 . Italy, Sardinia, Porticciolo , on algae at ± 10 m deep, 14 August 1994 (type locality) . France, Banyuls, Ile Gros , on green algae near the jetty behind the station, 20, 22 and 23 June 2000 . Yugoslavia, Adriatic Sea, Dubrovnik , 24 June 1952, Westblad (coll. SMNH) . Bulgaria, Varna ( Black Sea ), on algae, 21 December 1953, Valkanov (coll. SMNH) .

Material examined: Observations on live material from Corsica, Sardinia and Banyuls. Neotype ( LUC no. 229) from Sardinia. One whole mount from Bulgaria ( SMNH, no. 47485) and serially sectioned specimens from Great Britain ( SMNH, nos. 47480–3) and Yugoslavia ( SMNH, nos. 47484). Seven whole mounts from Banyuls and three from Corsica.

Diagnosis: Trigonostomum species with copulatory organ 30–45 Mm long. Stylet 44–53 Mm long, proximally bent over 90∞. Mantle with three spiny plates, surrounds only the distal part of the stylet. Bursal appendage 60–70 Mm long, with a barrel-like casing and ± 12 distal tubules.

Remarks: According to Meixner (1924b), the bursal appendage of T. penicillatum partially consists of ± 26 fine rods. However, our observations on serially sectioned material of T. penicillatum (SMNH) revealed only 12 fine, slightly bent rods in the bursal appendage of a specimen from Plymouth, though more in the individuals in the whole mounts.

In 1897, T. intermedium was described by Attems, but the same name was used by Graff as a nomen nudum in 1910 for a species he later ( Graff, 1911b) described as T. marki . The structure of the bursal appendage of T. marki is identical to that of T. penicillatum ( Graff, 1911b, 1913). According to Graff (1913) the species differ in the structure of the copulatory organ. In T. penicillatum the organ has a stylet, enclosed by a mantle, which carries three plates; the same structure is described and drawn by Graff (1911b: 61, table 4, figs 44, 45; 1913: 309, fig. 271) for T. marki . T. marki is therefore synonymized with T. penicillatum .

Figures

Figure 7. Copulatory organs and bursal appendages of the representatives of group 1B, A, T. coronatum: A1 copulatory organ; A2 bursal appendage. (from the neotype). B, T. watsoni sp. nov. B1, 2 copulatory organ; B3 bursal appendage (B1 from the holotype; B2, 3 from the paratype). C, T. penicillatum: C1 copulatory organ; C2 bursal appendage (from the neotype). D, T. lilliei: D1, 3 copulatory organ; D2, 4 bursal appendage. [D1, 2 specimen from Australia; D3, 4 specimen from the USA (neotype = holotype of T. prytherchi)]. E, T. breitfussi: E1 copulatory organ; E2 bursal appendage; E3 section through the bursa and the bursal appendage (different specimens from Sweden; E2, 3 freehand drawings). F, T. mirabile: F1, 2 copulatory organ; F3 bursal appendage (F1, 3 from the neotype; F2 from another specimen from the Black Sea). G, T. nataschae sp. nov. G1 Copulatory organ; G2 Bursal appendage (from the holotype).