Trypanosyllis leivai, Álvarez-Campos & Giribet & San Martín & Rouse & Riesgo, 2017

Álvarez-Campos, Patricia, Giribet, Gonzalo, San Martín, Guillermo, Rouse, Greg W. & Riesgo, Ana, 2017, Straightening the striped chaos: systematics and evolution of Trypanosyllis and the case of its pseudocryptic type species Trypanosyllis krohnii (Annelida, Syllidae), Zoological Journal of the Linnean Society 179 (3), pp. 492-540 : 530-531

TRYPANOSYLLIS LEIVAI

ALLVAREZ- CAMPOS, RIESGO & SAN MARTIN SP. NOV.

FIGS 10G , 15G – I

Type material examined

Holotype. Philippines: specimen in 96% EtOH ( MNCN 16.01 /16082), Luzon Island, between Balayan Bay and Batangas Bay , ‘ Mainif Point’ , (13.68, 120.855556), coral rubble, 2 m, 8 December 2010, leg. G. San Martın Project CGL2009-12292 BOS collecting team.

Paratypes. Philippines: three specimens in 96% EtOH ( MNCN 16.01 /16062, 16063, 16081), collection data as for the holotype ; one specimen mounted for SEM ( MNCN 16.01 /16073) and one anterior part in 96% EtOH ( MNCN 16.01 /16077), Luzon Island, Balayan Bay (13.740556, 120.892778), coral rubble, 2 – 4 m, 7 December 2010, leg. G. San Martın Project CGL2009-12292 BOS collecting team ; one specimen in 96% EtOH ( MNCN / ADN 85680 ), Sombrero Island (Luzon), Balayan Bay , ‘ Beatrice Point’ , (13.697778, 120.829722), unidentified sponge, 2 m, 9 December 2010, leg. G. San Martın Project CGL2009-12292 BOS collecting team ; one specimen in 96% EtOH ( MNCN 16.01 /16075), Sombrero Island (Luzon), Balayan Bay (13.697778, 120.829722), unidentified sponges, 2 m, 6 December 2010, leg. G. San Martın Project CGL2009-12292 BOS collecting team ; one specimen in 96% EtOH ( MNCN 16.01 /16074), Luzon Island, Balayan Bay, ‘ Koala Point’ (13.798889, 120.869444), coral rubble, 2 m, 5 December 2010, leg. G. San Martın Project CGL2009-12292 BOS collecting team ; 1 specimen in 96% EtOH ( MNCN ADN 85683 , 16.01 /16061), Palawan Island, El Nido (11.197222 119.317222), unidentified sponge, 12 m, 18 December 2010, leg. G. San Martın Project CGL2009-12292 BOS collecting team .

Diagnosis

Similar to Trypanosyllis krohnii except for pigmentation, body size, and length of appendages ( Fig. 9G ). Red-brown transverse stripes across anterior segments, two per segment, one wider than the other. Stripes do not reach end of segments ( Fig. 10G ). Specimens considerably (0.3 – 0.4 mm; n = 10) with slender and shorter anterior cirri (14 – 19 articles). Dorsal cirri alternating in anterior and midbody segments: Segments 1 and 3 presenting longer cirri (30 – 32 articles) and segments 2 and 4 with shorter ones (16 – 18 articles). Midbody segments with an alternation pattern less evident: long cirri with 16 – 18 articles and short cirri with 12 – 14 articles; posterior dorsal cirri all short (7 – 9 articles).

Description

Holotype incomplete: 15 mm long, 0.4 mm wide, 144 chaetigers. Well-preserved specimens white in colour with brown transverse stripes across anterior and midbody segments; one stripe slightly thicker, in middle of each segment, and the other two stripes thinner, in both anterior and posterior ends of segment ( Fig. 10G ). Only these two lines are similar in length, reaching the parapodia ( Fig. 10G ). Appendages also white. Oval prostomium with two pairs of red eyes in trapezoidal arrangement ( Fig. 10G ). Oval palps shorter than prostomium, completely separate. Nuchal organs not seen. Segment 1 slightly smaller than subsequent segments; antennae originating on anterior margin of prostomium, median antenna with about 22 articles; lateral antennae slightly shorter, with 15 – 17 articles. Dorsal enlarged anterior cirri longer than antennae, with about 19 articles, longer than ventral cirri, with about 14 articles. Dorsal cirri alternating long (16 – 18 articles) and short (12 – 14 articles). Dorsal cirri of the first and third segment longer than remaining cirri, with 32 articles; those from the second and fourth segment much shorter with 14 articles. Ventral digitiform cirri, shorter than parapodia. Compound bidentate heterogomph falciger chaetae with spines on margin. Between ten and 12 chaetae on anterior parapodia ( Fig. 15G ), between nine and 11 chaetae on midbody parapodia ( Fig. 15H ), and between six and eight chaetae in posterior parapodia ( Fig. 15I ). Blades similar throughout body, with ventral blades shorter both in midbody and posterior chaetae ( Fig. 15H, I ). Three aciculae in anterior parapodia, two thick, straight, acutely pointed and one slightly thinner, distally blended; only two thick, straight, acutely pointed aciculae in midbody parapodia and one in posterior parapodia. Dorsal and ventral simple chaetae not seen. Pharynx through about 14 segments, proventricle through 15 segments, with about 45 muscle cell rows.

Remarks

The general aspect of specimens from the Philippines is more slender and smaller than specimens of the type species of the genus, although they both share a similar coloration pattern ( Fig. 10G ). Trypanosyllis leivai sp. nov. is the second species of the genus described in the Philippines, together with Trypanosyllis luzonensis comb. nov., although our results showed that there are probably two other species inhabiting these waters (see Fig. 1 , Trypanosyllis sp. 1 and specimens Tz39 – Tz43). Within the Philippines, the most similar species that also presents stripes on the body is Trypanosyllis luzonensis comb. nov.; however, it clearly differs from Trypanosyllis leivai sp.nov in coloration pattern, size of body, and length of the dorsal cirri (see description above).

Type locality

‘Mainif Point’, between Balayan Bay and Batangas Bay, Luzon Island, Philippines (Indo-Pacific Ocean).

Distribution

Known from the type locality and from El Nido (Palawan Island), in the Philippines .

Etymology

Named after Carlos Leiva, colleague and friend of P.A.-C. and A.R., for his help collecting and sorting some of the analysed material.

Figures

Figure 1. Maximum clade credibility tree from concatenated, partitioned Bayesian analysis of all genetic data (28S rRNA, 18S rRNA, 16S rRNA, and COI) showing the phylogenetic relationships between Eurysyllis, Xenosyllis, Plakosyllis, and Trypanosyllis s.l. Numbers over branches indicate posterior probability (PP) support values (only PP> 0.90 are indicated); red circles indicate a PP value of 1.00. The 23 specimens of Trypanosyllis luzonensis comb. nov. are abbreviated as Tluzo1–Tluzo23. The 46 specimens of Trypanosyllis krohnii s.l. are abbreviated as Tk1–Tk46.

Figure 9. Scanning electron micrographs of Trypanedenta gigantea comb. nov.: A, anterior part (MNCN 16.01/ 16505); B, prostomium (MNCN 16.01/16505), arrow points to the nuchal organs (no); C, detail of dorsal cirri (MNCN 16.01/16506); D, detail of the trepan pharynx in apical view, arrow points to the trepan (t) (MNCN 16.01/16501); E, pharynx and proventricle (MNCN 16.01/165052); F, anterior chaetae (MNCN 16.01/16505); G, midbody chaetae, arrow points to four protruding aciculae (a; MNCN 16.01/16506); H, posterior chaetae, arrow points to two protruding aciculae (a; MNCN 16.01/16508).

Figure 10. Light microscopy images of the anterior of Trypanosyllis s.s. species: A, Trypanosyllis krohnii neotype (MNCN/ADN 9623); B, Trypanosyllis aeolis (MNCN 16.01/16039); C, Trypanosyllis zebra (ZMB Q4428); D, Trypanosyllis luzonensis comb. nov. (AM W.47275); E, Trypanosyllis taboadai sp. nov. holotype (MNCN 16.01/16087); F, Trypanosyllis luquei sp. nov. holotype (SIO A5005); G, Trypanosyllis leivai sp. nov. holotype (MNCN 16.01/16082); H, Trypanosyllis californiensis sp. nov. holotype, live specimen (SIO A5008); I, Trypanosyllis sp. 2 (MNCN 16.01/ 16065); J, Trypanosyllis kalkin sp. nov. holotype (MNCN 16.01/16058).

Figure 15. Scanning electron micrographs of new species from the Trypanosyllis krohnii species complex: A–C, Trypanosyllis taboadai sp. nov. (MNCN 16.01/16078); D–F, Trypanosyllis californiensis sp. nov. (SIO 5007); G–I, Trypanosyllis leivai sp. nov. (MNCN 16.01/16073). A, D, G, anterior chaetae. B, E, H, midbody chaetae. C, F, I, posterior chaetae.