Polycirrus abrolhensis, Garraffoni, André R. S. & Costa, Elisa M., 2003

Garraffoni, André R. S. & Costa, Elisa M., 2003, Two new species of Polycirrus (Polychaeta, Terebellidae) from Abrolhos Archipelago, Brazil, Zootaxa 297, pp. 1-7 : 3-5

Polycirrus abrolhensis sp. nov. (figs. 1–4)

Holotype: Abrolhos Archipelago, 17° 58’44’’ S, 038° 42’41’’ W, 1 complete specimen, 2,805 mm in length, 0,55 mm in width, approximately 25 segments, IBUFRJ­0481.

Paratypes: all from Abrolhos Archipelago, IBUFRJ­0482 (16 specimens), IBUFRJ­ 0 483 (5 specimens), MCEM­1303 (1 specimen).

Description. Dorsum faintly annulated on first segments. Prostomium, laterally expanded and difficult to distinguish dorsally and laterally from the peristomium with only one type of bucal tentacles attached along the distal margin. Tentacular membrane or peristomial upper lips trilobate with convoluted lateral lobes. Peristomial lower lips form small ventral conical projection. Mid ventral groove shallow, which extends along the entire body ( Fig. 1 ).

Notopodia from segment 2, 15 pairs, elongate slightly tapered ( Fig. 2 ). All notochaetae pinnate capillaries, similars in size ( Fig. 3 ). Neurochaeta from segment 7 and then continuing to the last segment before the pygidium. Neuropodial uncini with a concave base and long narrow neck ( Fig. 4 ), 6 to 8 in a single row, number consistent for all segment.

Abdominal uncini are more or less 3 times larger than the thoracic ones.

Nephridial papillae at the ventral base of the notopodia present on segments 3–11.

Discussion. Polycirrus abrolhensis is within the group of Polycirrus species which have first notopodia beginning on segment 2: P. albicans (Malmgren, 1866) , P. arenivorus Caullery, 1915 , P. aurantiacus Grube, 1860 , P. caliendrum Claparède, 1868 , P. carolinensis Day, 1973 P. denticulatus Saint­Joseph, 1894 , P. haematodes (Claparède, 1864) , P. hamiltoni Benham, 1921 , P. hesslei Monro, 1930 , P. latidens Eliason, 1962 , P. pallidus (Claparède, 1864) P. plumosus (Wolllebaek, 1912) , Polycirrus paivai . Polycirrus abrolhensis also resembles to P. boholensis Grube, 1878 in having nephridial papillae on segments 2­11 and P. aquila Caullery, 1944 by having pinnate notochaetae. However, P. abrolhensis can be distinguished from any other species of Polycirrus by the presence of the first neurochaetae on segment 7.

Distribution. Abrolhos Archipelago, Bahia State, Eastern Brazilian coast, 10 m, associated to calcareous algae.

Etymology. The specific name derived from the area in which the specimens were collected, Abrolhos Archipelago.

Figures

FIGURES 1 – 4. Polycirrus abrolhensis n sp.: 1, ventral view of head end; 2, notochaeta from anterior thorax; 3, anterior view of notopodium from anterior thorax; 4, lateral view of anterior uncinus. Scale bars 90 m (1), 9. 9 m (2,4), 22. 2 m (3).