Branchiosyllis mayae, Álvarez-Campos & Martín & Aguado, 2012

Álvarez-Campos, Patricia, Martín, Guillermo San & Aguado, M. Teresa, 2012, The genus Branchiosyllis Ehlers, 1887 from Philippines Islands, with the description of two new species, Zootaxa 3542, pp. 49-68 : 59-66

Branchiosyllis mayae n. sp.

Figs 2B, 3A–G, 4A–H

Material examined. HOLOTYPE ( NMA 4434 ) and 23 paratypes fixed in ethanol ( NMA 4435 , MNCN 16.01 / 13182) and 708 in formaldehyde (4 mounted for SEM) ( NMA 4436 , MNCN 16.01 /13183). Philippines Islands: "Mainif point", between Balayan Bay and Batangas bay, Luzon Island , 13º40’48’’N – 120º51’20’’E, unidentified orange sponge, 20 m deep, 8 December 2010.

Comparative material: Syllis (Typosyllis) plessisi Rullier, 1972 ( Branchiosyllis plessisi Westheide, 1974 ), Holotype ( MNHN IRFA SYL Y14 ) coll. Rullier, New Caledonia, Pins Island , coral, 15 m deep, 21 August 1961.

Description. Holotype 1.42 mm long, 0.25 mm wide, 21 segments. Large paratype 1.5 mm long, 0.2 mm wide, 26 segments. Body cylindrical dorsally ( Fig. 4A), orange with black stripes in peristomiun and anterior four to seven segments more pigmented at bases of cirrophores ( Figs 2B, 3A). Prostomium ovate, with a less pigmented black band, joining the three antennae; four small and red eyes in open trapezoidal arrangement ( Figs 2B, 3A).

Three antennae similar in length slightly longer than combined length of prostomium and palps, with eight articles ( Fig. 4B). Median antenna inserted on middle of prostomium; lateral antennae inserted almost between anterior eyes. Palps triangular, fused at base, slightly shorter than prostomium. Nuchal organs as two ciliated pits on lateral base of prostomium ( Fig. 4B). Peristomiun shorter than subsequent segments. Dorsal tentacular cirri longer than median antenna with 11–15 articles, ventral tentacular cirri much shorter than dorsal ones, with 6 articles. Dorsal cirri from one to six chaetigers similar in length with about nine articles; subsequent dorsal cirri shorter, with five or six articles. Dorsal cirri of most posterior segments with three articles. Most distal article of antennae, tentacular cirri and dorsal cirri spindle-shaped. Parapodia blunt, without branchiae. Ventral cirri thick, digitiform, slightly shorter than parapodial lobes, proximally inserted. Typically two compound ungulae per parapodium (occasionally 3) ( Fig. 4E), bidentate (with distal teeth longer than proximal one) ( Fig. 4F, G). Compound chaetae in first four segments occasionally with blades rotated 180º ( Figs 3D, 4F); in medium parapodia most dorsal one bidentate, while ventral unidentate, most of them rotated 180º; unidentate chaetae more curved, shorter and slightly thicker than dorsal one ( Fig. 3E). Posterior segments with two unidentate ungulae with blades always rotated 180º, ventral one slightly bigger and more curved ( Figs 3F, 4H). Single slender aciculae per parapodia with slightly oblique tip ( Fig. 3G). Pygidium small, with two anal cirri shorter than dorsal cirri, lost in most specimens ( Fig. 4C). Pharynx almost as wide as proventricle, through five segments; pharyngeal tooth small, anteriorly located, surrounded by crown of 12 soft papillae ( Figs 3B, 4D). Proventricle through three segments ( Fig. 3A), with 30–36 muscle cell rows.

Remarks. Branchiosyllis mayae n. sp., differs from any other species of the genus in the presence of bidentate ungulae, its short dorsal cirri, and the striking colour pattern (Table 1). Branchiosyllis abranchiata Hartmann- Schröder, 1965 (synonymized by Westheide 1974, Licher 1999 and San Martín et al., 2008 with B. exilis ) has a similar small size but it has the typical anterior bidentate falcigers of the B. exilis species (see previous discussion) instead of bidentate ungulae. Although bidentate ungulae were illustrated in the original description of B. plessisi , the holotype of this species does not present this kind of chaetae and it is considered a synomy of B. exilis (see previous Discussion).

Etymology. The specific name refers to the cartoons “Maya the Bee” due to the colour pattern of the species.

Habitat. Inside orange, unidentified sponge, reaching high densities in a single, relatively small host individual.

Distribution. Philippines Islands.

Branchiosyllis tagalog n. sp.

Figs 2C–D, 5A–F, 6A–G

Material examined. Holotype ( NMA 4437 ) and 2 paratypes fixed in ethanol, 1 mounted for SEM ( MNCN 16.01 / 11625, 11626). Philippines Islands : Sombrero Island , Balayan Bay, Luzon Island, 13º41’52’’N – 120º49’47’’E, three different unidentified sponges, 2–8 m deep, coral rubble, 17 m deep, 6 December 2010.

Comparative material. Branchiosyllis baringabooreen , Holotype ( AM W30088) Western Australia: Bernouli Island , 15°00'S 124°47'E, sandy substrate with coral rubble, intertidal, coll. P.A. Hutchings, 12 July 1988 . Paratypes: 1 specimen ( AM W26511) W side of Cassini Island , 13°57'S – 125°37'E, coralline algae and rubble, low tide, 18 July 1988 ; 1 specimen ( AM W30089) Bernouli Island , 15°00'S – 124°47'E, 12 July 1988 ; 2 specimens ( AM W30090) Reef S of Lucas Island, Brunswick Bay, 15°16'S – 124°29'E, dead coral with Sargassum with heavy silt loading, 2 m deep, 24 July 1988 . One specimen mounted for SEM ( AM W41524), Long Reef, Stn 52/K10, Trans T 1, 13°48' 36"S – 125°49' 27"E, mid-littoral reef terrace, honeycombed reef flat with coral rubble and dead coral slabs, 0 m deep, Woodside Kimberley Survey, 23 October 2010 ; 1 specimen ( AM W41623), Queensland, Watson’s Bay, Lizard Island , 14º65’82”S– 145 º44’9”E, 9 m deep, 30 August 2010 .

Description. Longest complete specimen 8 mm long, 0.72 mm wide, 67 segments ( Fig. 2B). Body strongly dorsoventrally flattened, pigmented on each segment with dark central spot surrounded by two horizontal wide bands and less dense coloured circle on each parapodia. Cirri also with irregular traces of colour ( Figs 2C, 5A). Prostomiun ovate, slightly wider than long, with two pairs of small red eyes on trapezoidal arragment ( Figs 2C, 5A). Antennae inserted on anterior margin of prostomium; median antennae shorter than combined length of prostomium and palps, with 10–12 articles; lateral antennae longer, with 15–17 articles. Palps triangular, shorter than prostomium, fused at base. Peristomiun dorsally reduced ( Figs 5A, 6A). Nuchal organs not observed. Dorsal tentacular cirri much longer than median antenna with 52–54 articles, ventral tentacular cirri shorter than dorsal, with about 18–20 articles. Dorsal cirri of all chaetigers similar in length with about 55–60 articles, shorter than body width. Tentacular cirri and dorsal cirri spindle-shaped with minute pores irregularly distributed and small papillae organized in lines ( Fig. 6B, C). Parapodia with small post chaetal lobe and without branchiae ( Fig. 5C). Ventral cirri digitiform, as long as parapodial lobe, proximally inserted ( Fig. 5C). Typically two ungulae per parapodium, smooth, unidentate, most with blades rotated 180º ( Figs 5D, E, 6D–F). Ventral ungulae always larger than dorsal; shafts of chaetae thick, with small serration on distal part, ventral shafts thicker than dorsal ( Fig. 6E, F). Two slender and straight aciculae per parapodia, different in size ( Fig. 5F). Pygidium only observed in regenerating specimens, without anal cirri. Pharynx almost as wide as proventricle, through 5 segments; pharyngeal tooth small, anteriorly located surrounded by crown of 9–10 soft and small papillae. Proventricle through 6 segments, with 36–40 muscle cell rows ( Fig. 5B). Some specimens with acephalous stolon, pigmented with dark central spot surrounded by two horizontal lines and one red spot on each parapodia ( Figs 2D, 6G).

Remarks. The most similar species is B. baringabooreen with similar ungulae and body pigmentation. However, Branchiosyllis tagalog n. sp., differs in having only two curved ungulae per parapodia, ventral one larger than dorsal ( Fig. 4H), longer dorsal cirri with small pores and papillae organized in lines ( Figs 6B, C).

Etymology. The name refers to “Tagalog”, the Austronesian language spoken in the Philippines Islands.

Habitat. Shallow waters, on sponges and coral rubble.

Distribution. Philippines Islands.