Pisione parapari Moreira, Quintas & Troncoso, 2000

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 : 17

Pisione parapari Moreira, Quintas & Troncoso, 2000

Material examined. MB29-000243, 1 specimen, site PC91; MB29-000244, 1 specimen, site PC132 ( Table 1 ). Additional material: 3 specimens, site R28; 13 specimens, site R39; 6 specimens, site R40; 9 specimens, site R48; 1 specimen, site PC87; 1 specimen, site PC90; 42 specimens, site PC91; 1 specimen, site PC92; 109 specimens, site PC132; 8 specimens, site PC133; 1 specimen, site PC137; 3 specimens, site PC138; 1 specimen, site PC222; 2 specimens, site PC229; 1 specimen, site G13(2); 3 specimens, site G21(1); 4 specimens, site ALG2; 14 specimens, site ALG9; 2 specimens, site ALG18; 6 specimens, site ALG19; 1 specimen, site ALG30; 1 specimen, site ALG34; 16 specimens, site ALG39; 1 specimen, site ALG42; 1 specimen, site ALG43; 3 specimens, site ALG49; 2 specimens, site ALG51; 3 specimens, site ALG59; 4 specimens, site ALG60; 1 specimen, site ALG62; 5 specimens, site ALG63; 10 specimens, site ALG66; 11 specimens, site ALG68; 2 specimens, site ALG71; 1 specimen, site ALG74 ( Table 1 ).

Brief description. Width of 10th chaetiger from 0.14 to 0.24 mm, total length from 2.24 to 7.60 mm, and total number of chaetigers ranging from 26 to 51. Buccal aciculae protrude obliquely the skin, not exceeding length of chaetiger 1, with a smooth distal margin. Prechaetal lobes entire. Dorsal cirri of chaetiger 2 is 1.3 to 1.6 times longer than the dorsal cirri of chaetiger 3 and following ones (cf. Table 2 ). All dorsal cirri globular-piriform, with a papilla with pilose tip, except on chaetiger 2 digitiform. Three types of chaetae: one long-bladed compound heterogomph chaeta with curved tip (blade length ranging from 21 to 28 µm; cf. Table 2 ), three short-bladed compound heterogomph chaetae and one supra-acicular simple chaeta distally bidentate. One stout notoaciculum embedded in all parapodia. Male genitalia with 2 to 3 pairs of copulatory organs appearing on chaetigers 11, 12, 21 (MB29-000243) or alternating on chaetigers 10, 18, 19, 20 in additional material (cf. Table 2 ). Female sexual organs not visible externally. Female gametes globular, with a diameter ranging from 38 µm to 64 µm, 49 µm in average, located in chaetigers 20–43 (MB29-000244) or earlier in additional material (19–28), depending on size of specimen. Pygidium with two long anal cirri.

Distribution and habitat. This species occurred in fine gravel (11%), very coarse (14%), coarse (63%) and medium sand (11%), with low total organic matter content, usually below 1% of total sediment dry weight and high biogenic content (5.9% in average). Specimens were recorded mainly in the near shore shelf of the western and southern Portuguese coast, between 3 and 80 m water depth, 24.6 m on average (cf. Table 3 ). The distribution depth range of this species is expanded since P. parapari was only previously recorded from 8 to 12 m ( Moreira et al. 2000). This species was only known in the northern Iberian Peninsula and this study extends its southern limit to the southern sector of the Portuguese continental shelf ( Fig. 1 ).

Remarks. In males, copulatory organs usually appeared in alternate parapodia, but in some cases they appeared in consecutive parapodia, which is not consistent with Moreira et al. (2000).

Figures

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