Prionospio (Minuspio) pulchra Imajima, 1990

Dagli, Ertan & Çinar, Melih Ertan, 2011, Species of the subgenus Minuspio (Polychaeta: Spionidae: Prionospio) from the southern coast of Turkey (Levantine Sea, eastern Mediterranean), with the description of two new species, Zootaxa 3043, pp. 35-53 : 48-50

Prionospio (Minuspio) pulchra Imajima, 1990

( Figs 11 , 12 )

Prionospio (Minuspio) pulchra Imajima 1990: 68 –71, figs 6–7; Moreira et al. 2000: 233 –239, figs 2–4. Prionospio multibranchiata Çinar & Gönlügür –Demirci 2005: 255; Çinar et al. 2006: 233; Çinar et al. 2008: 5 (in part) (not Berkeley 1927).

Material examined. ESFM –POL/2005–263, 2 specimens, 9 September 2005, Iskenderun Bay, G2, 36º43ʹ19ʹ N– 36º09ʹ30ʹ E, 50 m, mud; ESFM –POL/2005–381, 77 specimens, 10 September 2005, Iskenderun Bay, G5, 36º43ʹ44ʹ N–35º43ʹ39ʹ E, 25 m, muddy sand; ESFM –POL/2005–1519, 5 specimens, 5 December 2005, Fethiye Bay, K50, 36º38ʹ40ʹ N–29º05ʹ30ʹ E, 5 m, muddy sand; ESFM –POL/2005–1548, 5 specimens, 6 December 2005, Fethiye Bay, K50, 36º37ʹ48ʹ N–29º06ʹ30ʹ E, 10 m, mud; ESFM –POL/2005–1730, 2 specimens, 6 December 2005, Fethiye Bay, G27, 36º37ʹ46ʹ N–29º06ʹ32ʹ E, 5 m, muddy sand; ESFM –POL/ 2005–2359, 2 specimens, 7 December 2005, Fethiye Bay, K53, 36º44ʹ20ʹ N–28º55ʹ43ʹ E, 3 m, Zostera marina ; ESFM –POL/ 2005–2682, 1 specimen, 2 December 2005, Beymelek Lagoon, BT5, 36º15ʹ57ʹ N–30º02ʹ59ʹ E, 2 m, mud. Additional material examined. Black Sea: ESFM –POL/2000–107, 15 specimens, 21 April 2000, Sinop Harbour, 42º00ʹ53ʹ N– 35º12ʹ36ʹ E, 5 m, Mytilus galloprovincialis ; ESFM –POL/2000–108, 3 specimens, 21 April 2000, Sinop Harbour, 42º01ʹ20ʹ N– 35º08ʹ49ʹ E, 5 m, Mytilus galloprovincialis . Aegean Sea: ESFM –POL/2003–153, 45 specimens, 2 July 2003, Alsancak Harbour, 38º24ʹ54ʹ N– 27º02ʹ24ʹ E, 9 m, muddy with shell fragments; ESFM –POL/2003–178, 20 specimens, 1 July 2003, Alsancak Harbour, 38º26ʹ55ʹ N– 27º08ʹ11ʹ E, 8 m, muddy with shell fragments. Pacific Ocean: NSMT –POL–P–303, Paratypes, 3 specimens, KT–75–2 cruise, Tokyo Bay, 35º19.0'N – 139º42.0'E, 47 m, coll. M. Imajima, March 1981; NSMT –POL– 90785–90789, Paratypes, 5 specimens, KT–71–19 cruise, Sta. B4–A, 35º35.0'N, 140º03.6'E, 10 m, attached on buoy, coll. M. Imajima, 1 December 1971.

Description. Largest specimen complete, 0.38 mm wide, 10.9 mm long, with 73 chaetigers. Body slender, enlarged anteriorly, gradually tapering to posterior end, pale yellowish. Prostomium subrectangular, rounded anteriorly, extending posteriorly as a narrow caruncle to posterior part of chaetiger 1, with five small anterior peaks ( Fig. 11 B). Two pairs of black crescent–shaped eyes present, similar in size ( Fig. 13A ). Peristomium fused to chaetiger 1, forming moderate wings ( Fig. 11 B).

Ten pairs of long, cylindrical, apinnate branchiae on chaetigers 2–11; first seven pairs longest, extending over 6–8 chaetigers; pairs eight and nine shorter than preceding ones, extending over 3–5 chaetigers; last pair shortest, extending over two chaetigers ( Fig. 11 A–B).

Chaetiger 1 reduced, lacking notopodial lamellae, with small, rounded neuropodial lamellae ( Fig. 11 A); noto– and neurochaetae present. Parapodia of chaetiger 2 with erect, subtriangular notopodial postchaetal lamellae and small, rounded neuropodial lamellae. Notopodial lamellae on branchial chaetigers large, subtriangular; united across dorsum, forming low crests on chaetigers 13–21 ( Fig. 11 B). Notopodial lamellae on middle chaetigers low, broadly rounded, becoming elongate finger–like lobes on posterior chaetigers ( Fig. 12 D). Neuropodial lamellae on branchial region well developed, ear–shaped, decreasing gradually in size, becoming more rounded on following chaetigers. Neuropodial lamellae on posterior chaetigers similar to notopodial lamellae.

Capillary notochaetae on anterior and middle chaetigers moderately granulated, with thin sheath, arranged in two rows; those of anterior row shorter, with wider sheaths than those of posterior row ( Fig. 12 A). Capillary chaetae becoming thinner in posterior chaetigers. Ventral sabre chaetae usually from chaetiger 13, sometimes from chaetiger 12, one or two per fascicle; each chaeta moderately granulated, with a short, distal filament ( Fig. 12 C). Neuropodial hooded hooks first present on chaetiger 16–17; numbering up to 9–10 per fascicle; three pairs of small teeth above main fang ( Fig. 12 B). Notopodial hooded hooks first present from chaetiger 29–31, numbering up to 4–5 per fascicle. Hooks accompained by capillary chaetae throughout.

Pygidium with one long dorso–medial and two short ventro–lateral anal cirri ( Fig. 12 D).

Remarks. The Mediterranean specimens of Prionospio (Minuspio) pulchra agree with the original description of the species from the coast of Japan ( Imajima 1990) and the subsequent description from the coast of north–west Spain ( Moreira et al. 2000). We also compared our specimens of P. (M.) pulchra with the paratypes of the species and observed some slight differences. These differences include: (1) sabre chaetae (usually first appeared on chaetiger 13 in the Mediterranean specimens, vs. on chaetigers 11 or 12 in the Japanese specimens); (2) number of neuropodial hooded hooks per fascicle (9–10 in the Mediterranean specimens vs. 7 in the Japanese specimens).

Habitat. The maximum population density (770 individuals.m–2) of this species was found on muddy sand substratum in 25 m depth at station G5 (Iskenderun Bay).

Distribution. This species was previously reported from the Japanese coast ( Imajima 1990), the Atlantic coast of Spain ( Moreira et al. 2000), the Aegean Sea ( Pancucci–Papadopoulou et al. 2005; Dagli et al. in press) and the Sea of Marmara ( Çinar et al. 2011a). This species is being newly reported from Levantine and the Black Sea coasts of Turkey.

The specimens that were previously identified as P. (M.) multibranchiata from the Black Sea (Çinar & Gönlügür–Demirci 2005) and Aegean Sea (Alsancak Harbour) ( Çinar et al. 2006, 2008) were re–examined and it was realized that the majority of the specimens in fact belonged to P. (M.) pulchra . The specimens that were collected from Lago di Sabaudia (Tyrrhenian Sea, Italy) and identified as Prionospio (Minuspio) cirrifera Wiren, 1883 by Giangrande and Gambi (1982) seem to be identical to P. (M.) pulchra [see Fig. 2 of the paper by Giangrande and Gambi (1982)]. This record indicates the first occurrence of this species in the Mediterranean Sea.Previous reports of P. (M.) cirrifera and P. (M.) multibranchiata from the Mediterranean Sea, especially in stressed environments, should be re–examined to find out their real distributional ranges and first arrival in the Mediterranean. Prionospio (Minuspio) pulchra is considered an invasive alien species in the Mediterranean Sea that was introduced to the region via ballast waters of ships ( Zenetos et al. 2010, Çinar et al. 2011b).

Figures

FIGURE 2. Prionospio (Minuspio) anatolica sp. nov.: A. Anterior end, dorsal view, paratype (ESFM – POL / 2005 – 267). B. Anterior end, lateral view, holotype (ESFM – POL / 2005 – 398). Scale bar: A – B 0.2 mm.

FIGURE 11. Prionospio (Minuspio) pulchra Imajima, 1990: A. Anterior end, lateral view (ESFM – POL / 2005 – 381). B. Anterior end, dorsal view. Scale bar: A – B 0.5 mm.

FIGURE 12. Prionospio (Minuspio) pulchra Imajima, 1990: A. Notopodial capillary chaeta on chaetiger 18 (ESFM – POL / 2005 – 1519). B. Neuropodial hooded hook on chaetiger 20 (ESFM – POL / 2005 – 1519). C. Ventral sabre chaeta on chaetiger 20 (ESFM – POL / 2005 – 1519). D. Posterior end, dorsal view (ESFM – POL / 2005 – 1519). Scale bar: A, C 22 µm, B 14.8 µm, D 0.2 mm.

FIGURE 13. A. Dorso – lateral view of anterior part of Prionospio (Minuspio) pulchra Imajima, 1990 (ESFM – POL / 2005 – 381). B. Lateral view of anterior part of P. (M.) anatolica sp. nov. (ESFM – POL / 2005 – 237). C. Lateral view of anterior part of P. (M.) maciolekae sp. nov. (ESFM – POL / 2005 – 3252). Scale bar: A 0.5 mm, B 0.3 mm, C 0.4 mm.