Revision of Trigonostomum Schmidt, 1852 (Platyhelminthes, Typhloplanoida, Trigonostomidae) with the description of seven new species Author Willems, Wim R. Author Artois, Tom J. Author Vermin, Wouter A. Author Schockaert, Ernest R. text Zoological Journal of the Linnean Society 2004 2004-06-30 141 2 271 296 https://academic.oup.com/zoolinnean/article-lookup/doi/10.1111/j.1096-3642.2004.00124.x journal article 5407 10.1111/j.1096-3642.2004.00124.x d15c737e-c0cb-4f09-98dd-d707de72a43a 0024-4082 4634553 IDENTIFICATION KEY 1. Copulatory organ 106–121 Mm long and very complex, consisting of a gutter-shaped plate, enveloping a bundle of rods, of which one has a long thread-like distal tip; stylet funnel-shaped, ± 65 Mm long; bursal appendage with initial straight part (22–44 Mm long) and two heavily coiled distal tubes. (Figs 8E, 11A) .................................... T. denhartogi comb. nov. - Copulatory organ ± 60 Mm long; stylet bent over 90∞, surrounded by the mantle that has 8–10 small spines at the convex side and with broad distal plates and spines distally (Fig. 11B4); bursal appendage with two broad, highly coiled tubes (Figs 8F, H, 11B) ........................................................................................................................... T. spinigerum sp. nov. - Copulatory organ otherwise................................................................................................................................................2 2. Proximal part of the stylet curved over 90-270∞ and surrounded by the mantle only in its distal part. (Figs 4B, 6, 7)..........................................................................................................................................3 - Copulatory organ spirally coiled over 360∞ or more (except in T. franki , where it is coiled over 180∞); stylet surrounded over its whole length by the mantle, latter mostly wrinkled and split distally into two narrow, spiny plates with a terminal hook; bursal appendage consisting of two tubes (coiled over 270-360∞), with a straight distal part; animals with dorsal stripe or rostral spot or without pigmentation (Figs 4C, 5, 8A, B, G, I, 9, 10)..............................................................................................................................................7 3. Stylet long and narrow with a proximal turn of 270∞; mantle forming a narrow ring and carrying a long and slender spine; bursal appendage with two tubes, proximally with a ring (Fig. 6)...............................................................................................................................................................4 - Stylet broad, proximally curved over 90∞ or 180∞; mantle split into one, two or three plates (Fig. 7)........................................................................................................................................................................5 4. Copulatory organ consisting of a ± 225 Mm long slender stylet; mantle with flagelliform spine (± 75 Mm); bursal appendage ± 22 Mm long (Fig. 6B)................................................................... T. messoplanoides - Copulatory organ 74–130 Mm long; stylet 117–194 Mm long; mantle with a straight spine of 70–78 Mm; bursal appendage ± 54 Mm long (Fig. 6A)..................................................................... T. venenosum 5. Stylet bent over 90∞, mantle split into three pointed plates: * Copulatory organ 30–45 Mm long; stylet 44–53 Mm long; bursal appendage 60–70 Mm long, with a proximal barrel-like casing and ± 12 tubules, diverging distally (Fig. 7C)........................ T. penicillatum * Copulatory organ 28–36 Mm long; stylet 29–41 Mm; bursal appendage 62–78Mm long, consisting of a short funnel-shaped proximal part and two coiled (>360∞) tubes, all with a faint striation (Fig. 7B) ...................................................................................................... T. watsoni sp. nov. * Copulatory organ ± 44 Mm long; stylet ± 70 Mm long; bursal appendage ± 78 Mm long, with a proximal part, shaped like a clover leaf, and one to three distal bent tubes with a fine striation (Fig. 7A) ......................................................................................................................... T. coronatum - Stylet bent over 180∞; mantle with one or two plates.......................................................................................................6 6. Mantle split into two plates, stylet with spoon-like terminal opening (Fig. 7F1, 2, G1) (note that the copulatory organ of T. franki may easily be confused with this type): * Plates of the mantle blunt and shorter than the stylet; copulatory organ ± 78 Mm long; stylet ± 104 long, proximally with a crest; bursal appendage ± 65 Mm long, curved proximally over 270∞, with proximal barrel-like part and a bundle of very narrow, faint tubules, which form two bundles distally (Fig. 7G) .............................................. T. nataschae sp. nov. * Plates of the mantle pointed and at least as long as the stylet; copulatory organ slender, 72–74 Mm long; stylet 83–84 Mm long; bursal appendage ±66 Mm long, with a proximal barrel-like part and ± 10 distal tubules (Fig. 7F) ................................................................. T. mirabile - Mantle with only one plate (see Fig. 7D1, 3, E1): * Plate of the mantle as long as the stylet and ending in a little hook; copulatory organ 42–46 Mm long; stylet 40–57 Mm long; bursal appendage 95–98 Mm long consisting of a coiled tube, which distally splits into five to six tubules (Fig. 7D) .................................................................................................................................................................... T. lilliei * Plate of the mantle blunt and shorter than the stylet; copulatory organ ± 62 Mm long; stylet ± 64 Mm long, proximally with a crest; bursal appendage 20–24 Mm long with proximal barrel-like part and ±10 distal tubules (Fig. 7E) .............................................................................................................................................................. T. breitfussi 7. Copulatory organ 86–111 Mm long, proximally bent over 180∞ and continuing in a straighter part, where the two spiny plates are; bursal appendage 62–166 Mm long, coiled over 270∞; animals mostly with dorsal pigment stripe (Figs 5A, 9A, 10A)............................. T. franki sp. nov. - Copulatory organ with 1-5 complete spire(s) of 360∞, continuing in a straighter section, where the two spiny plates are situated (Fig. 5B- F): * Copulatory organ with one spire, 158–434 Mm long; bursal appendage 50–149 Mm long, coiled over 270∞ (Figs 5B, 9B, 10B) ..................................................................................... T. armatum * Copulatory organ with two spires, 284–498 Mm long; bursal appendage 64–161 Mm long, coiled over 360∞ (Figs 5C, 9C, 10C)......................................................................................................... T. setigerum * Copulatory organ with three spires, 414–445 Mm long; bursal appendage ± 34 Mm long, coiled over 270∞ (Figs 5D, 9D, 10D) ........................................................................................ T. australis sp. nov. * Copulatory organ with four spires (Figs 5E, 9E).................................................................. T. galapagoensis sp. nov. * Copulatory organ with five spires, 683–853 Mm long; bursal appendage 80–106 Mm long, coiled over 270∞ (Figs 5F, 9F, 10E).................................................................................................... T. tori sp. nov.