Haplosyllis spongicola ( Grube, 1855 )

Lattig, Patricia & Martin, Daniel, 2009, A taxonomic revision of the genus Haplosyllis Langerhans, 1887 (Polychaeta: Syllidae: Syllinae), Zootaxa 2220, pp. 1-40 : 25-27

Haplosyllis spongicola ( Grube, 1855)

( Figs 17 A–C, 18A–D)

Syllis spongicola Grube, 1855: 104 –105.— Marion & Bobretzky, 1875: 24 –25, fig.7

Syllis setubalensis McIntosh, 1885: 195 –196, pl. 30,fig. 5; pl. 33, fig. 6; pl. 15a fig. 16–17.

Syllis spongicola tentaculata .— Marion, 1879: 19 –20, fig. 4 a–c.— Cognetti, 1955: 1 –3, fig. 1b.— Cognetti, 1957: 10 –14, fig. 2b.— Cognetti, 1961: 294.

? Syllis spongicola tentaculata .— Imajima, 1966: 221 –222, fig. 38 i –n.

? Haplosyllis spongicola .— Sun, 1996: 20 –21, fig. 3.

Haplosyllis spongicola .— Amoureux, 1977: 398.— Campoy, 1982: 363 –365, in part.— Hartmann-Schröder, 1981: 27, fig. 3–4.— San Martín, 2003: 323 –325, fig. 179 a, c, d y 180, in part.— Lattig et al. 2007: 554 –556, figs 1–2.

Geminosyllis sp. 1 Lattig et al. 2007: 564 –566, figs 7–8.

Non: Haplosyllis spongicola .— Fauvel, 1923: 257–258, fig. 95.— Imajima, 1966: 220–221 fig. 38, a–h.

Non: Syllis spongicola spongicola .— Cognetti, 1955: 1–3, Fig. 1 a.— Cognetti, 1957: 10–14, fig. 2a.— Cognetti, 1961: 294.

Examined material. Lesina, Adriatic Sea , Mediterranean. Syntype MPW 399. Coast of Portugal, Holotype of Syllis setubalensis BMNH, 850 m.

Additional material: Portugal, personal collection of Joao Gil ( CEAB – CSIC): SEPLAT 6: sta. 15 (1) 65 m; sta. 21 (1) 70 m; sta. 22 (4) 52 m; sta. 25 (1) 61 m; sta. 54 (3) 58 m; sta. 55 (1) 64 m; sta. 89 (1) 490 m. SEPLAT 7: sta.96 (1) 112 m; sta. 105 (1) 27 5m; sta. 149 (2) 113 m; sta. 175 (5) 202 m; sta. 179 (1) 120 m; sta. 212 (1) 147 m; sta. 220 (2) 28 m; sta. 223 (1) 38 m; sta. 231 (1) 32 m; sta. 289 (1) 338 m. Las Aguilas, Murcia, Spain, 28 m (2).

South of Ireland. 20 specimens MNHN, 40 specimens MNHN. Continental slope, 850–1000 m, Expedition Thalassa 1973.

W Mediterranean: 2 specimens MNCN 16.01/10591, Rhizomes of Posidonia oceanica , 5 m, October 1989; 2 specimens MNCN 16.01/10588, on Eunicella singularis , 9 m, August 1984; 6 specimens MNCN 16.01/10592, on algae Udotea petiolata , 12 m, April 1985; 2 specimens MNCN 16.01/10594, on Paramuricea clavata , 23 m, April 1983; 1 specimen 16.01/10593, 1 specimen 16.01/10587 on Paramuricea clavata , 15 m, August 1984. Cabo de Creus, coll. Carmen Alós.

E Atlantic, Cantabric Sea: 8 specimens MNCN 16.01/10550, 114– 116 m, 43º40’59’’N 7º04’35’’O. 3 specimens MNCN 16.01/ 10553, 146 m, 43º40’27’’N 5º13.36'0. Expedition Fauna Ibérica, June 1991.

Diagnosis. Body robust, variable in size, up to 60 mm long, for 35–110 chaetigers. Dorsal cirri long, whip-shaped. Chaetae all bidentate, anterior ones broad, US of MF with small denticles ( Fig. 18 A, C). Midbody chaetae variable, depending on size of specimens: in small worms (about 0.5 mm long), MJP straight and long; LMF similar than SW ( Fig. 18 D). In longer worms (> 1 cm long), MJP short and curved; LMF longer than SW ( Fig. 18 B).

Host. Found in association with different sponge species ( López et al. 2001), but more likely a specialized predator than a true sponge symbiont ( Martin & Britayev, 1998).

Distribution. Mediterranean and European Atlantic waters. Also reported from the Indo-Pacific ( Imajima 1966; Lee & Rho 1994; Sun 1996), but this material need to be rechecked. Recorded from 5 to 1000 m. Remarks. Observing the pharynx under SEM, we have found a variety of anterior margins ranging from those with smooth, to those with well defined trepans, either with small apparently eroded teeth ( Fig. 17 A), or with blunt, to triangular teeth ( Fig. 17 B). Sometimes, pharyngeal margins are impossible to distinguish due the presence of a densely ciliated ring ( Fig. 17 C). When present, teeth may occupy the whole pharyngeal margin or only a semicircle (usually opposite to the long anterior tooth).

Haplosyllis spongicola show different chaetal morphologies in anterior and midbody chaetae, as well as in small and large worms ( Fig. 18 A–D). Small worms (about 5 mm in length) have small denticles on US of MF, and LMF is similar to SW in all chaetae; long specimens (i.e. more than 10 mm length) have a long LMF. These variations may reflect the existence of an allometric variability. The same occurs with the shape of cirri, which may vary from long, broad to very long whip-shaped. Typically, the largest worms have more whipshaped cirri.

Haplosyllis spongicola has a variable ecological signal. Its bathymetric range is very wide (from shallow to very deep waters), and has been collected in different types of hard substrata, in association with gorgonian fields, algal mats, calcareous algae crusts or Posidonia meadows. Although it has been reported from inside sponges, the worm are found solitary or in low numbers and the sponges seem not to be hosts but a source of food. Contrary to other Haplosyllis species, which are strict endosymbionts found in large quantities inside their sponge hosts ( Martin & Britayev 1998).

The specimens reported as Geminosyllis sp. 1 in Lattig et al. (2007) fits within the morphological variability of H. spongicola and, thus, are here considered as the same species. Similarly, the examination of the holotype of H. setubalensis and additional material from Portugal (30–330 m) and the Thalassa 1973 expedition (Atlantic coast of France, 1000 m) allowed us to confirm the synonymy of this species with H. spongicola , as previously reported by Licher (1999).

Figures

FIGURE 1. Comparison between length of main fang (LMG) and chaetal width (SW). A—LMF is similar or shorter than SW, B—LMF is longer than SW.

FIGURE 17. SEM micrographs of the pharynx of Haplosyllis spongicola. A—trepan with small teeth arranged in semicircle around pharyngeal tooth; B—complete trepan, small and triangular teeth; C—pharynx covered by a dense ring of cilia, not visible if trepan is present. Arrows pointing to trepan tooth in A and B, the cilia in C. Scale bars: A = 300 Μm; B – C = 100 Μm.

FIGURE 18. Haplosyllis spongicola. Long specimen, 1.4 cm long: A—third chaetiger; B—midbody chaeta. Small specimen, 5 mm long: C—third chaetiger; D—midbody chaetae. Scale bars: A, C, D = 10 Μm; B = 30 Μm.