Pisione guanche San Martín, López & Núñez, 1999

Martins, Roberto, Martín, Guillermo San, Rodrigues, Ana Maria & Quintino, Victor, 2012, On the diversity of the genus Pisione (Polychaeta, Pisionidae) along the Portuguese continental shelf, with a key to European species, Zootaxa 3450, pp. 12-22 : 16

Pisione guanche San Martín, López & Núñez, 1999

Material examined. MB29-000239, 1 specimen, site PC137; MB29-000240, 1 specimen, site PC138 ( Table 1 ). Additional material: 1 specimen, site PC90; 1 specimen, site PC92; 1 specimen, site PC132; 1 specimen, site PC133; 2 specimens, site PC138 ( Table 1 ).

Brief description. Body width (10th chaetiger) between 0.30 and 0.68 mm, total length between 9.80 and 20.40 mm and total number of chaetigers up to 74. Buccal acicula protruding obliquely, not exceeding chaetiger 1 backwards, with distal margin showing few irregular dentations at tip. All prechaetal lobes bilobed. Dorsal cirri of chaetiger 2, 2.3 to 3.3 times longer than dorsal cirri of chaetiger 3 and subsequent ones ( Table 2 ). All dorsal cirri globular, with a short, spherical distal papilla with a pilose tip, except that of chaetiger 2, which is digitiform. Two types of chaetae: four short-bladed compound heterogomph chaetae (blade length ranging from 18 to 26 µm; cf. Table 2 ) and one supra-acicular simple chaeta distally bidentate. One stout protruding notoaciculum, up to 0.049 mm. Male genitalia with 6 to 8 pairs of consecutive copulatory organs, in chaetigers 33–38, 34–41, 40–47 (MB29- 000240; cf. Table 2 ). Female sexual organs not visible externally (MB29-000239). Pygidium with two long anal cirri.

Distribution and habitat. This species occurred in fine gravel (33%), very coarse (33%), coarse (17%) and medium sand (17%), with low total organic matter content, usually below 1% of total sediment dry weight and high biogenic content (4.6% in average). Specimens were recorded mainly between 25 and 80 m deep (cf. Table 3 ). This work extends the distribution depth range of this species, previously recorded between 8 and 45 m ( San Martín et al. 1999). The northern distribution limit of P. guanche is now extended to off Peniche (south of the Nazaré Canyon; Fig. 1 ), being also present immediately south of the Setúbal Canyon, along the southwestern coastal shelf sector. This is the first record of P. guanche in the Lusitanian biogeographic province, increasing to five the number of species known for the European continental waters. Pisione guanche is presently known from three biogeographic provinces: the Macaronesia ( San Martín et al. 1999; Moreira et al. 2010), the Lusitanian (this study) and the Mediterranean Sea ( Çinar 2009 reported it as an alien species on the southern coast of Turkey).

Remarks. Dorsal cirri of chaetiger 2 is up to 3.3 times longer than the dorsal cirri of chaetiger 3 whilst San Martín et al. (1999) and Moreira et al. (2010) reported that the dorsal cirri of chaetiger 2 was only twice as long.

Figures

FIGURE 1. Distribution and relative abundance of Pisione species along the Portuguese continental shelf (northeastern Atlantic).