Trigonostomum, 2004

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 : 288

TRIGONOSTOMUM FRANKI SP. NOV.

( FIGS 2 , 3 , 5A , 8G, I , 9A , 10A; TABLE 1)

Alternative species name: trigonostomum-franki sp. nov.

Holotype: Whole mount, Curaçao (Dutch Antilles), Dam di Cabicuchi (‘Spaanse water’), on Turbinaria - like algae from exposed rocks at the side of ‘Caracasbaai’, 14 December 1998 ( LUC no. 225).

Paratype: Whole mount, same data as for the holotype ( LUC no. 226) .

Other material: Observations on live material. Two whole mounts and one serially sectioned specimen from Curaçao ( Dutch Antilles ), ‘ Spaanse water’, mixed sample of algae containing mainly Caulerpa sp. and Halimedia gantia, 30 December 1998 . One whole mount from Florida ( USA), Fort Pierce, in fine detritus-rich sand between rocks, 16 November 1994 . Three whole mounts - Kenya, Mombasa area, Mc-Kenzie Point - on algae and seagrasses, 4 and 15 June 1987 and 27 September and 1 October 1991 . One whole mount from Tanzania, Zanzibar, Pete, on seagrasses, 16 August 1995 . Three whole mounts, New Caledonia, Nouméa, Nouville, on algae in a lagoon south of the asylum, 3 and 10 August 2003 . One whole mount, New Caledonia, Nouméa, Baie des Citrons, on algae in a lagoon, 8 August 2003 . Live observations from New Caledonia, Nouméa , Nouville, on algae covered with shells and sand on a reef in the western part of the Kuendu Bay, 16 August 2003 .

Etymology: Dedicated to Mr Frank Van Belleghem, who helped to collect the material on Curaçao.

Diagnosis: Trigonostomum species with moderately coiled copulatory organ, with 1 / 2 spire. Stylet 86– 111 Mm long, enveloped by the mantle over its entire length. Mantle distally split into two spiny plates with terminal hook. Bursal appendage 61–166 Mm long, with two tubules, proximally curved over 270∞ and with straight distal part.

Figures

Figure 2. Reconstruction on sagittal sections of the rostral body end from the left hand side (T. franki sp. nov.). Abbreviations: cbm, circular body muscles; dil1–2, dilators of opening of antero-ventral invagination; e, eye; ecm, external circular pharyngeal muscles; elm, external longitudinal pharyngeal muscles; i, antero-ventral invagination; icm, internal circular pharyngeal muscles; ig, invagination glands; ilm, internal longitudinal pharyngeal muscles; ir, integument retractors; lbm, longitudinal body muscles; m, mouth; pc, prepharyngeal cavity; pg, pharynx glands; ppt, pharynx protractors; prt, pharynx retractors; ps, pigment stripe; rm, radial pharyngeal muscles; rr, retractors of antero-ventral invagination.

Figure 3. Reconstruction on sagittal sections of the genital system from the left hand side (T. franki sp. nov.). Abbreviations: ba, bursal appendage; bs, bursal stalk; bu, bursa; cga, common genital atrium; cop, copulatory organ; ds, spermatic duct; fd, female duct; fg, female glands; gp, common genital pore; n, nucleus; od, oviduct; ov, ovary; rh, rhabdite; sd, seminal duct; vg, prostate vesicle; vit, vitellary; vs, seminal vesicle.

Figure 5. Schematic representation of the copulatory organ of the representatives of group 2, showing the different number of spires (dashed lines indicate the location of the mantle plates). A, T. franki sp. nov. (1/ spire). B, T. armatum. (11/ 2 2 spires). C, T. setigerum. (21/ spires). D, T. australis sp. nov. (31/ spires). E, T. galapagoensis sp. nov. (41/ spires). F, 2 2 2 T. tori sp. nov. (51/ spires).

Figure 8. A, rostral spot in T. armatum (whole mounted specimen from Curaçao). B, dorsal stripe in T. setigerum (whole mounted specimen from Greece). C, bursal appendage of T. tori sp. nov. (from the paratype). D, constricted distal tubes of bursal appendage (arrow indicates constriction) in T. setigerum (specimen from Bermuda). E, copulatory organ of T. denhartogi comb. nov. (specimen from New Caledonia). F, copulatory organ of T. spinigerum sp. nov. (from the holotype). G, habitus of T. franki sp. nov. (live specimen from New Caledonia). H, bursal appendage of T. spinigerum sp. nov. (from the holotype). I, head region of T. franki sp. nov. showing both epidermal and subepidermal pigment (live specimen from New Caledonia). Scale bars: A, B = 200 Mm. C-F = 20 Mm. H = 10 Mm.

Figure 9. Copulatory organ of the representatives of group 2. A, T. franki sp. nov. (specimen from Curaçao) B, T. armatum (specimen from Curaçao). C, T. setigerum (from the neotype). D, T. australis sp. nov. (from the holotype). E, T. galapagoensis sp. nov. (from the holotype; after Ehlers and Ax, 1974: fig. 13C). F, T. tori sp. nov. (from the holotype). Scale bars: A-D, F = 20 Mm.

Figure 10. Copulatory organs and bursal appendages of the representatives of group 2. A, T. franki sp. nov. A1, 3 copulatory organ; A2, 4 bursal appendage (A1, 2 from the holotype; A3, 4 from a specimen from Kenya). B, T. armatum sp. nov. B1, 3 copulatory organ; B2, 4 bursal appendage (B1, 2 specimen from France; B3, 4 specimen from Curaçao). C, T. setigerum: C1 copulatory organ; C2 bursal appendage (specimen from Kenya). D, T. australis sp. nov. D1 copulatory organ; D2 bursal appendage (from the holotype). E, T. tori sp. nov. E1 copulatory organ; E2 bursal appendage (from the holotype).