Syllis maganda, Martínez & Martín, 2020

Martínez, María José & Martín, Guillermo San, 2020, Syllidae (Annelida) from East Timor and the Philippines (Pacific Ocean), with the description of three new species of Syllis Savigny in Lamarck, 1818, Zootaxa 4834 (2), pp. 231-263 : 246-248

Syllis maganda n. sp.

Figures 2D , 7 , 8 , 9 , 10 , 11

LSID: urn:lsid:zoobank.org:act:A7D14743-8132-4A69-89A3-402ADF2FB1FA

Material examined. PHILIPPINES, Luzón, “Koala Point”, Balayan Bay, dead coral, 5–16 m depth, Dec 2010, coll. M.T. Aguado, P. Álvarez-Campos, C. Russell & G. San Martín, holotype ( MNCN 16.01 /18678) and 2 paratypes ( MNCN 16.01 /18679). Luzón, “House reef”, Balayan Bay , on hydrozoans, gorgonians ( Siphonogorgia sp.), ascidians ( Atriolum sp.) and dead coral, 2–4 m depth, Dec 2010, coll. M.T. Aguado, P. Álvarez-Campos, C. Russell & G. San Martín, 2 paratypes ( MNCN 16.01 /18680). Luzón, “House reef”, Balayan Bay , dead coral, 2–3 m depth, Dec 2010, coll. M.T. Aguado, P. Álvarez-Campos, C. Russell & G. San Martín, 1 paratype ( MNCN 16.01 /18681). “Sombrero Island”, Balayan Bay , dead coral, 2–3 m depth, Dec 2010, coll. M.T. Aguado, P. Álvarez-Campos, C. Russell & G. San Martín, 1 paratype ( MNCN 16.01 /18682). “Sombrero Island”, Balayan Bay , dead coral, 1–2 m depth, Dec 2010, coll. M.T. Aguado, P. Álvarez-Campos, C. Russell & G. San Martín, 1 paratype ( MNCN 16.01 /18683). “Mainif point”, between Balayan Bay and Batangas Bay, on dead coral and Halimeda sp., 1–2 m depth, Dec 2010, coll. M.T. Aguado, P. Álvarez-Campos, C. Russell & G. San Martín, 2 paratypes ( MNCN 16.01 /18684). “Beatrice Point”, Sombrero Island , blue sponge, 2–3 m depth, Dec 2010, coll. M.T. Aguado, P. Álvarez-Campos, C. Russell & G. San Martín, 2 paratypes ( MNCN 16.01 /18685). “Sepok Wall”, between Balayan Bay and Batangas Bay, dead coral, 6 m depth, Dec 2010, coll. M.T.Aguado, P. Álvarez-Campos, C. Russell & G. San Martín, 6 paratypes ( MNCN 16.01 /18686), one for SEM (16.01/18687). “Sepok Wall”, between Balayan Bay and Batangas Bay, dead coral, 2–3 m depth, Dec 2010, coll. M.T. Aguado, P. Álvarez-Campos, C. Russell & G. San Martín, 4 paratypes ( MNCN 18688 ) . EAST TIMOR, E of Atauro Island, 08°14’30”S 125°36’49”E, Inner reef, reef slope, branching coral matrix with epiphytic algae and sponges, 14 m depth, Sep 2012, coll. L.E. Hughes, 1 paratype ( AM W.45651) .

Additional material. PHILIPPINES. Luzón island, House reef, Balayan Bay , dead coral, 2-3 m depth, 7/12/2010, two specimens ( MNCN 16.01 /18689). Luzón Island , House reef, Balayan Bay , dead coral, 2-3 m depth, 12/2010, four specimens ( MNCN 16.01 /18690). Luzón Island , House reef, Balayan Bay , dead coral, 2-4 m depth, 4/12/2010, 1 specimen ( MNCN 16.01 /18691). Luzón Island , Koala Point, Balayan Bay , dead coral, 5-16 m depth, 5/12/2010, two specimens ( MNCN 16.01 /18692). Mainif point, between Balayan Bay and Batangas Bay, inside Xetospongia , 8/12/2010, 8/12/2010, 1 specimen ( MNCN 16.01 /18693) .

Description. Holotype ( Fig. 8A, B, H ) complete specimen, 36 mm long, 1.5 mm wide, with 93 chaetigers. Largest complete paratype, 37 mm long, 1.5 mm wide, with 131 chaetigers. Live specimens brightly coloured ( Figs 7 , 8 C–G, I–M, 9A, B); only red lines and spots retained in fixed specimens ( Fig. 8A, B, H ), losing the orange and blue colourations present in the dorsum and cirri. Body elongated, with orange dorsum, more intense in centre of segments, somewhat pale on anterior body quarter, more intense on next quarter, paler again on two posterior quarters, which become intense blue-violet ( Figs 7 , 9A ) due to intracoelomic oocytes ( Fig. 8G ); some midbody segments with middle orange colour and blue laterals ( Fig. 8F ); most anterior segments with two horizontal continuous red lines, one anterior and one posterior, and a discontinuous intermediate, central line ( Fig. 8C ); most anterior midbody segments with three continuous lines ( Fig. 8D ), anterior and posterior lines shorter than central one at midbody ( Fig. 8E ), becoming progressively smaller and less marked ( Fig. 8F ); posterior segments with only a continuous central line ( Fig. 8G ). Some specimens with Dicerous stolons ( Figs 9B , 10J , 11G ) still attached, either lacking red lines or only having pale ones on most anterior segments. Dark red rounded spots at bases of dorsal cirri ( Figs 8 C–G, 10A–C), on prostomium and on palps ( Fig. 8H, I ); usually four spots on prostomium, arranged regularly, anterior pair elongate and oblique, posterior pair round; sometimes with some smaller spots, particularly between eyes, two elongated spots on inner side of palps, and a small spot, sometimes very faint on peristomium ( Fig. 8H ). Antennae, tentacular cirri and dorsal cirri whitish to yellowish, with one reddish spot on a certain number of articles (5–8 articles in every long dorsal cirrus; 1–2 on short cirri) ( Fig. 8I ); anterior dorsal cirri ( Fig. 8J, K ) more pigmented than posterior ones ( Fig. 8L, M ); spots disappearing on most posterior short cirri ( Fig. 8M ). Long anterior cirri with eight or more spots ( Fig. 8J ), long posterior ones with 7–8 ( Fig. 8L ). Prostomium semicircular, with four red eyes in trapezoidal arrangement ( Fig. 8H ); eyespots not seen. Palps robust, elongated, somewhat longer than prostomium ( Fig. 8H, I ). Median antenna arising from posterior part of prostomium, between posterior eyes, approximately twice or twice and a half longer than combined length of prostomium and palps, with 25–50 articles ( Fig. 8I ); lateral antennae half or one third shorter than median antennae, with 23–30 articles ( Fig. 8I ). Peristomium somewhat shorter than subsequent segments, forming a small hood covering posterior part of prostomium ( Fig. 8H ). Dorsal tentacular cirri as long as median antenna, with 25-50 articles ( Fig. 8I ); ventral tentacular cirri as long as lateral antennae, with approximately same number of articles ( Fig. 8I ). Dorsal cirri somewhat thick at bases, becoming progressively thinner distally, with pointed tips ( Figs 8 J–M, 10A–C); distinct alternating long (more than three times longer than body width) ( Figs 7 , 9A ) and somewhat thinner short cirri ( Fig. 8K, M ); short dorsal cirri ( Fig. 8K, M ) less pigmented than long ones ( Fig. 8J, L ). Dorsal cirri of chaetigers 1, 4 and 6 longer than remaining ones; dorsal cirri of midbody long (60 articles) and short (30–40). Dorsal cirri of stolons all similar, short and thin ( Figs 9B , 10J , 11G ). Parapodial lobes conical, with two small lips, anterior digitiform and posterior round, shorter and a small round middorsal lobe ( Figs 10 A–C, 11A). Ventral cirri thin, digitiform, somewhat shorter than parapodial lobes ( Fig. 10 A–C). Compound chaetae heterogomph falcigers, with relatively short, bidentate blades; proximal teeth distinctly smaller and thinner than distal ones, with straight, short marginal spines, slightly longer and thinner on anterior chaetae; anterior chaetae have both teeth slightly more separated from each other than those of midbody chaetae, being even closer each other in posterior ones; blades gradually decreasing in length towards posterior segments ( Figs 10 D–F, 11B–D). Anterior parapodia ( Figs 10A , 11A ) with 13–14 compound chaetae with marked dorso-ventral gradation, blades about 60 µm long dorsally, 35 µm ventrally ( Figs 10D , 11B ); midbody parapodia ( Fig. 10B ) with about 10–11 compound chaetae; articles distinctly shorter and wider than those of anterior segments, with less marked dorsoventral gradation, 40- 30 µm long ( Figs 10E , 11C ); posterior parapodia ( Fig. 10C ) with 7–8 compound chaetae, similar in shape and size to those of midbody, with shorter marginal spines ( Figs 10F , 11D ). Dorsal simple capillary chaetae on posterior parapodia, thin, finely bidentate, both teeth small, equal in size, close each other, with a rounded tip, with very short marginal spines ( Fig. 11E ). Ventral simple capillary chaetae on most posterior parapodia, somewhat thicker than dorsal ones, bidentate, both teeth large, similar in size, well spaced each other, pointed, with short marginal spines ( Fig. 11F ). Anterior and midbody parapodia with four aciculae, three with blunt tips and one smaller with slightly oblique tip ( Fig. 10G, H ); number of aciculae per parapodium decreasing progressively posteriorly to one in posterior parapodia, with acute and distally blunt tips ( Fig. 10I ). Pharynx ( Fig. 11H , phx) extending along 12 segments ( Fig. 8A ); pharyngeal tooth on anterior margin, elongated, conical, sharp. Proventricle ( Fig. 11H , prv) somewhat shorter and wider than pharynx, extending along six segments, with about 33 muscle cell rows. Pygidium short, with two long anal cirri, with 33 articles, similar in colour to posterior dorsal cirri ( Figs 7 , 9A, B ).

Remarks. Specimens photographed by Alexander Semenov and one Philippine paratype showed Chaetosyllis (Dicerous) stolons (i.e., with two dorsal and two ventral eyes, and two small articulated antennae) ( Figs 9B , 10J , 11G ). Stolons are relatively small relative to specimen’s size (13–16 chaetigerous segments). Additionally, a specimen had a regenerated head ( Fig. 2D , arrow).

Syllis maganda n. sp. is conspicuous because of its special and motley colour pattern, which differs from all other specie of Syllis having striking colourations, as well as for having a large size body, whip-shaped dorsal cirri composed of numerous small articles with a marked alternation in size and chaetae with relatively short and wide blades, except those of anterior-most chaetae, bidentate, with proximal tooth clearly smaller and thinner than distal one, both teeth becoming more separated from each other posteriorly. For instance, Syllis variegata Grube, 1860 , Syllis ferrani Alós & San Martín, 1987 and Syllis columbretensis Campoy, 1982 , from the Iberian Coast, show dorsal a ∞-shaped figure on each segment, but also more strongly bidentate chaetae ( San Martín 2003). Syllis alosae San Martín, 1992 , from Cuba, has a similar colour pattern than these aforementioned species, but more strongly bidentate chaetae, including some pseudospingers (chaeta with elongated article) on each fascicle ( San Martín 1992). Syllis unzima Simon, San Martín & Robinson, 2014 , from South Africa, has transversal segmental stripes but with a simpler pattern and, furthermore, it is viviparous ( S. maganda n. sp. reproduces by stolons), has almost unidentate chaetae and the pharyngeal tooth is located slightly behind the anterior margin of pharynx ( Simon et al. 2014). Syllis crassicirrata ( Treadwell, 1925) sharing a marked colour pattern and, partially, its geographical distribution (i.e., widely distributed in the Indo-Pacific). However, this species seemed to show a great variety of colourations which, in fact, could be an actually hiding a species-complex ( Ba-Akdah et al. 2018). Some pattern incude strong pigmentation, even with spots in dorsal cirri with, as in S. maganda n. sp. However, their dorsal cirri are relatively shorter and thicker and all similar in length, the chaetae are more strongly bidentate (especially the posterior ones), and the posterior aciculae are straight and extend out from the parapodial lobes ( Álvarez-Campos et al. 2015a; Ba-Akdah et al. 2018). Syllis ehlersioides Imajima, 1966 , from Japan, have similar long cirri and a noticeable colour pattern, although differs in consisting in wide transverse bands of chocolate colour, and the chaetae are almost unidentate and the aciculae tips are round ( Imajima 1966a).

Etymology. The specific name refers to its colouration, as maganda means “gorgeous and beautiful” in Tagalog. In addition to East Timor, this new species is also present in the Philippines where Tagalog is spoken. Therefore, it seems appropriate that the etymology of this new species has a meaning in this language.

Habitat. In amongst dead corals, with hydrozoans, gorgonians ( Siphonogorgia sp.), ascidians ( Atriolum sp.), and green algae ( Halimeda sp.) as epibionts; on a matrix of branched coral with epiphyte algae and sponges.

Distribution. Only known from the type locality of the Philippines, Australia (Lizard Island) and East Timor.

Figures

FIGURE 2. Syllis maganda n. sp. Paratypes (MNCN 16.01/18687). Scanning Electron Micrographs (A, B, D), digital camera (C). A), C) specimen of Haplosyllis sp. (arrows) which is feeding on a posterior dorsal cirrus of Syllis maganda n. sp. B) detail of simple chaeta of Haplosyllis sp. D) regeneration of the prostomium (arrow) of Syllis maganda n. sp., ventral view. No scale bar in digital camera photo.

FIGURE 7. Syllis maganda n. sp., complete live specimen, dorsal view. Photographed by Alexander Semenov in Lizard Island. No scale bars.

FIGURE 8. Syllis maganda n. sp. A), B), H) Holotype (MNCN 16.01/18678) photographed by Patricia Álvarez-Campos. C)– G), I)–M) live specimen photographed by Alexander Semenov in Lizard Island.A) anterior end, dorsal view. B) anterior end and midbody, dorsal view. C) anterior segments, dorsal view. D) the most anterior midbody segments, dorsal view. E) intermediate midbody segments, dorsal view. F) the most posterior midbody segments, dorsal view. G) posterior segments, dorsal view. H) detail of dark red spots on prostomium and peristomium, dorsal view. I) prostomium, lateral view. J) long anterior dorsal cirrus. K) short anterior dorsal cirrus. L) long posterior dorsal cirrus M) short posterior dorsal cirrus. No scale bars.

FIGURE 9. Syllis maganda n. sp., live specimen photographed by Alexander Semenov in Lizard Island. A) complete specimen, dorsal view. B) detail of stolon, dorsal view. No scale bars.

FIGURE 10. Syllis maganda n. sp. Paratype (MNCN16.01/18679), drawn from preserved specimen. A) anterior parapodium, lateral view. B) midbody parapodium, lateral view. C) posterior parapodium, lateral view. D) compound chaetae, anterior parapodium. E) compound chaetae, midbody parapodium. F) compound chaetae, posterior parapodium. G) aciculae, anterior parapodium. H) aciculae, midbody parapodium. I) acicula, posterior parapodium. J) stolon, dorsal view. Scale bars: 20µm.

FIGURE 11. Syllis maganda n. sp. Paratypes (MNCN 16.01/18687). Scanning Electron Micrographs. A) anterior parapodia, dorsal view. B) compound chaetae, anterior parapodium. C) compound chaetae, midbody parapodium. D) detail of compound chaeta, posterior parapodium. E) dorsal simple chaeta. F) ventral simple chaeta. G) posterior end with a developed stolon. H) pharynx (phx) and proventricle (prv), arrows.