SPECIES OF TEREBELLIDES ( POLYCHAETA , TEREBELLIDAE , TRICHOBRANCHINAE ) FROM THE BRAZILIAN COAST

Terebellides sepultura sp. nov. is described from the continental shelf bottoms off southern Brazil. Terebellides carmenensis Solis-Weiss, Fauchald & Blankensteyn, 1991 is newly recorded for the Brazilian coast and notes on T. anguicomus F. Müller, 1858 and T. klemani Kinberg, 1867 are provided. A key to 28 species of Terebellides is given.

The genus is poorly known in Brazilian waters.NONATO & LUNA (1970) and SOLIS-WEISS et al. (1991) recorded only three species for the region: T. anguicomus F. Müller, 1858, T. klemani Kinberg, 1867 andT. lanai Solis-Weiss, Fauchald &Blankensteyn, 1991.The aim is to present a taxonomic survey of Terebellides species which occur along the Brazilian coast, and a key to the species of the genus.
Terebellides sepultura sp.nov.Etimology.The species is named to honour Sepultura, the best Brazilian heavy metal band.
Diagnosis.Eighteen thoracic segments with notopodia, first notopodia on segment 3. Branchial lobes free for 2/3 of their length.Branchiae four-lobed, with numerous tentacles of similar width.
Buccal tentacles of one type, with expanded tips.Prostomium compact, fused to the peristomial free frontal edge, tentacular membrane compact.Peristomial upper lip hidden, expanded lower lip as an elongate rectangular structure (fig.1).Eyespots absent.Lateral lappets present on segment 3, distinctly reduced on segments 4 to 7. Nephridial papillae not visible.
Branchiae as a single mid-dorsal stalked structure on segment 3, with four lobes, two large and two small ones, fused basally, made up of loosely fused flat lamellae (fig.2).
Notopodia 18 pairs, present on segment 3-20.First pair (on segment 3) less developed than posterior ones, with small capillary notosetae.Anterior notopodia laterally inserted, at same level of those from subsequent chaetigers.Neuropodia present from segment 8 to segment before pygidium.
Notochaetae on segment 3 small, reduced in length and number in comparison to notochaetae of the posterior notopodia.Notochaetae similar in structure belonging to two kinds: with single or double wings (fig.3).
Segments crowded towards posterior end of the body.Pygidium short and conical.Anus terminal; without blunt papillae.No tube was observed.
Variation.One examined specimen (MCEM 1630) has only one branchial lobe.As previously suggested by HUTCHINGS & PEART (2000) for other trichobranchin species, this variation may be a result of lobes being damaged and becoming detached.
Remarks.Terebellides sepultura resembles T. klemani in having branchiae lobes free for 2/3 of their length (figs.1, 3).Terebellides sepultura can be distinguished by the presence of lateral lappets on segments 3-7, four branchiae lobes, a lower number of thoracic uncini per segment, and a single mid-dorsal branchial stalked structure (length up to 1.5 -2 segments) much larger than in congeneric species (length up to 0.5 -1 segment) (tabs.I, II).
Biological data.Occurs in continental shelf bottoms, between 163 and 350 m in depth, on muddy sediments.Remarks.The specimens analyzed in this study closely resemble the original description provided by SOLIS-WEISS et al. (1991).Their main diagnostic features are the presence of a dorsal hump on segment 9, notopodia of segment 3 smaller than posterior ones, acicular uncini on segment 8 (chaetiger 6) sharply bent and with a pointed tip, and branchial lobes fused for most of their length.Specimens from the Brazilian coast differ from the original description of Terebellides carmenensis only in number of thoracic and abdominal neurochaetae.SOLIS-WEISS et al. (1991) described 12 thoracic long-handled neurochaetae and 45-48 abdominal neurochaetae in the holotype (39-54 in the paratypes), whereas specimens from the northeastern Brazilian coast have 10-12 thoracic neurochaetae with long-handled hooks and 25-35 abdominal neurochaetae (figs.9, 10), most probably as a result of intraspecific variation.This species is new to the Brazilian marine fauna.
Biological data.In shallow waters associated with mangrove vegetation (SOLIS-WEISS et al., 1991), and coral reefs.GARRAFFONI & LANA misunderstanding of the numbering of anterior segments, which then modifies the notation of all subsequent segments.We had the opportunity to examine live specimens and to check that the size of this dorsal hump can vary between live and fixed specimens (figs. 11,12).The three species that present the dorsal hump, Terebellides anguicomus, T. carmenensis and T. totae, have this structure on segment 9 (chaetiger 7).SOLIS-WEISS et al. (1991) also stated that "the nephridial papillae are in a groove medial to rudimentary parapodia of segment 2, close to branchial base".The specimens studied herein have nephridial papillae on segment 3, the same segment of the branchial base.
Biological data.In shallow waters on silty and sandy sediments and coral reefs.
Distribution.Brazil: from Sergipe to Santa Catarina states.
Remarks.Terebellides klemani was synonymized with T. anguicomus by HESSLE (1917).The two species are currently considered valid (SOLIS-WEISS et al., 1991).Terebellides klemani differs from T. anguicomus by the absence of a dorsal hump on segment 9, notopodia on segment 3, and free branchial lobes.The animals collected in this study closely agree with the description provided by SOLIS-WEISS et al. (1991).