Prionospio (Minuspio) maciolekae, Dagli, Ertan & Çinar, Melih Ertan, 2011

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 : 42-46

Prionospio (Minuspio) maciolekae sp. nov.

( Figs 6–8 , 13 C)

Material examined. Holotype. ESFM –POL/2005–1957, 6 October 2005, Fethiye Bay, G29, 36º39ʹ29ʹ N– 29º06ʹ0 2ʹ E, 25 m, sandy mud [salinity: 38.5 psu, temperature: 24°C, dissolved oxygen concentration: 5.58 mg/l]. Paratypes. ESFM –POL/ 2005–40, 1 specimen, 10 September 2005, Iskenderun Bay, D15, 36º31ʹ56ʹ N– 35º35ʹ16ʹ E, 50 m, mud; ESFM –POL/2005–177, 1 specimen, 10 September 2005, Iskenderun Bay, D21, 36º20ʹ43ʹ N–35º48ʹ0 8ʹ E, 25 m, muddy sand; ESFM –POL/2005–825, 1 specimen, 17 September 2005, Mersin Bay, D23, 36º40ʹ50ʹ N–34º35ʹ12ʹ E, 50 m, mud; ESFM –POL/2005–1405, 1 specimen, 17 September 2005, Mersin Bay, G11, 36º45ʹ47ʹ N–34º51ʹ54ʹ E, 5 m, mud; ESFM –POL/2005–1767, 1 specimen, 30 September 2005, Finike Bay, G15, 36º17ʹ34ʹ N–30º09ʹ33ʹ E, 10 m, Zostera marina ; ESFM –POL/2005–1957, 1 specimen, 6 October 2005, Fethiye Bay, G29, 36º39ʹ29ʹ N–29º06ʹ0 2ʹ E, 25 m, sandy mud; ESFM –POL/ 2005–2051, 7 specimens, 30 September 2005, Finike Bay, G17, 36º16ʹ48ʹ N– 30º10ʹ20ʹ E, 50 m, mud; ESFM –POL/2005–3249, 2 specimens, 6 October 2005, Fethiye Bay, G29, 36º39ʹ29ʹ N–29º06ʹ0 2ʹ E, 25 m, sandy mud; ESFM –POL/2005–3250, 1 specimen, 10 September 2005, Iskenderun Bay, D19, 36º21ʹ16ʹ N–35º44ʹ27ʹ E, 75 m, muddy sand with gravel; ESFM –POL/2005–3251, 2 specimens, 12 September 2005, Iskenderun Bay, K5, 36º08ʹ30ʹ N–35º54ʹ30ʹ E, 1 m, mud; ESFM –POL/2005–3252, 3 specimens, 6 October 2005, Fethiye Bay, G28, 36º37ʹ48ʹ N– 29º06ʹ30ʹ E, 10 m, mud. Additional material examined. ESFM –POL/2000–236, 3 specimens, 4 August 2000, Saroz Bay, Sta. A3, anchor dredge, 40º34ʹ45ʹ N– 26º09ʹ25ʹ E, 1 m, Posidonia oceanica ; ESFM –POL/2000–250, 3 specimens, 17 August 2000, Bozcaada, Sta. B10, anchor dredge, 39º34ʹ55ʹ N– 26º05ʹ13ʹ E, 41 m, mud; ESFM –POL/2000–278, 1 specimen, 30 September 2000, Kuşadası, Sta. E8, anchor dredge, 37º59ʹ0 0ʹ N–27º11ʹ15ʹ E, 32 m, muddy sand; ESFM –POL/2003–251, 1 specimen, 9 July 2003, Çeşme, Sta. 2, 38º23ʹ25ʹ N– 26º27ʹ11ʹ E, 45 m, mud; ESFM – POL/ 2005–2135, 5 specimens, 8 October 2005, Kuşadası, G39, 37º50ʹ25ʹ N– 27º12ʹ0 4ʹ E, 5 m, mudy sand; ESFM – POL/ 2005–2579, 1 specimen, 9 October 2005, Kalamaki, K55, 37º42ʹ32ʹ N–27º12ʹ21ʹ E, 1 m, Posidonia oceanica .

Description. Holotype complete, 0.29 mm wide, 9.74 mm long, with 67 chaetigers. Body slender, enlarged anteriorly, gradually tapering to posterior end, color in alcohol opaque, white to pale yellow. Prostomium subrectangular, broadly rounded anteriorly, extending posteriorly as a blunt caruncle reaching to base of chaetiger 1; posterior part of prostomium surrounded by nuchal organs ( Fig. 6 A). Anterior part of prostomium without peaks ( Fig. 6 A). Two pairs of small spherical eyes; anterior pair larger than posterior pair ( Fig. 6 A–B). Peristomium partly fused with chaetiger 1, forming moderate lateral wings ( Fig. 6 A–B). Palps missing in holotypes, short (ca. 232 µm), extending over two chaetigers in paratypes.

Branchiae apinnate, present from chaetigers 2 to 10, numbering 9 pairs (8–10 pairs in paratypes); densely ciliated ( Figs 7 A–C); cilia emerging along both sides of ventral groove ( Fig. 7 A–C). First pair longest, ca. 350 µm long, up to 1.3–1.5 times longer than other pairs; last pair shortest and narrowest, ca. 230 µm long ( Fig. 6 A–B); other pairs almost equal in length ( Figs 6 A–B; 13C). All branchiae almost 1.3–2.5 times longer than length of notopodial lamellae.

Notopodial lamellae lacking on chaetiger 1; notopodial lamellae short, triangular on chaetiger 2; largest on chaetiger 4, subtriangular ( Fig. 6 B); similar in size and shape between chaetigers 5 and 8; becoming shorter, broader and more triangular on chaetigers 9–10 (last pairs of branchiae) ( Figs 6 A–B, 7A–C). Notopodial lamellae united across dorsum on chaetigers 11 to 28 (10–25 in paratypes) ( Figs 6 A, 8A), forming low distinct crests; becoming evenly rounded. On remaining chaetigers, notopodial lamellae large, rounded; becoming finger–like on posterior chaetigers ( Figs 7 D, 8B–C).

Neuropodial lamellae small, fingerlike on chaetiger 1; becoming rectangular on chaetiger 2, not ventrally pointed; largest in branchial region; gradually decreasing in size on following chaetigers; becoming fingerlike on posterior chaetigers ( Figs 6 A–B, 7A–C, 8A–C). On all chaetigers, neuropodial lamellae smaller than notopodial lamellae. Genital pouches absent.

Anterior noto– and neuropodial lobes with only capillary chaetae, arranged in two rows in anterior chaetigers, with thin sheath; all capillaries moderately granulated ( Fig. 8 F). Ventral sabre chaetae from chaetiger 13 (14 on paratypes) to end of body; numbering one or two per fascicle; stout, curved, granulated, with a short distal filament ( Fig. 8 E). Neuropodial hooded hooks first emerging from chaetiger 14 (15 on paratypes), numbering up to 7–8 per fascicle; three pairs of small, thin teeth above main fang ( Fig. 8 D). Notopodial multidentate hooded hooks first present from chaetiger 33 (30–34 on paratypes); numbering up to 4–5 per fascicle. Hooks with obvious secondary hoods accompained by capillaries throughout.

Pygidium with one long dorso–medial cirri and two short ventro–lateral lobes, without pigmentations at tips ( Fig. 7 D).

Remarks. Prionospio (Minuspio) maciolekae sp. nov., is mainly characterized by short, thin and densely ciliated apinnate branchiae on chaetigers 2–10 (11). The same branchial morphology was reported in the following species; Prionospio (Minuspio) multibranchiata Berkeley, 1927 from the Pacific coast of Canada (Vancouver Island), Prionospio (Minuspio) cirrifera Wirén, 1883 from the Arctic Ocean (Kara Sea), and P. (M.) lighti Maciolek, 1985 from the coast of California.

Prionospio (M.) maciolekae sp. nov., is closely related to P. (M.) multibranchiata , which was first described from the Pacific coast of Canada (Vancouver Island) by Berkeley (1927), and subsequently reported from the western Atlantic and eastern Pacific (Florida, Gulf of Mexico and Washington) by Maciolek (1985), the eastern Atlantic ( United Kingdom, Norway, Sweden, France) and Mediterranean Sea (Venice, Adriatic) by Mackie (1984), and the western Pacific ( Japan) by Imajima (1990). We examined two specimens of P. (M.) multibranchiata collected from Bazan Bay (Pacific coast of Canada) at 10 m depth, a place very close to the type locality. The morphology of these specimens coincided with the original description of the species. We observed some important differences between these specimens and those of P. (M.) maciolekae sp. nov. These differences include (1) eyes (four large crescent– shaped eyes in the Canadian specimens vs. four (some specimens have six) small, spherical eyes in our specimens; (2) peaks on prostomium (five small peaks on the anterior part of the prostomium in the Canadian specimens vs.

absent in our specimens; (3) first neuropodial lamellae (rounded in the Canadian specimens vs. fingerlike in our specimens), (4) second neuropodial lamellae (subtriangular in the Canadian specimens vs. rectangular in our specimens); (5) first pair of branchiae (smaller than subsequent pairs in the Canadian specimens vs. longer than subsequent pairs in our specimens); (6) cilia on branchiae (absent in the Canadian specimens vs. dense in our specimens); (7) dorsal crests [indistinct, between chaetigers 13 and 20 in the Canadian specimens ( Berkeley (1927) did not mention this character) vs. distinct, between chaetigers 11 and 28 in our specimens], (8) notopodial hooded hooks (first present on chaetiger 44 in the Canadian specimens vs. chaetiger 30–34 in our specimens); (9) the morphology of hooks (teeth above above fang coarse and small in the Canadian specimens vs. thin and long in our specimens); (10) sabre chaetae (first appear on chaetiger 11, without distal filament in the Canadian specimens vs. first appear on chaetigers 13 or 14, with a distinct distal filament).

Prionospio (M.) maciolekae sp. nov., is similar to P. (M.) cirrifera , which was first described from the Kara Sea (Arctic Ocean) by Wirén (1883) and subsequently from Arctic and north Atlantic Ocean by Maciolek (1985) and Mackie (1984). However, P. (M.) maciolekae sp. nov., differs from it in a number of characters which include (1) shape of the prostomium (subrectangular, broadly rounded anteriorly, extending posteriorly as a blunt caruncle reaching to base of chaetiger 1 in P. m a c i o l e k a e sp. nov., vs. bluntly triangular, truncate anteriorly, extending posteriorly as a narrow caruncle reaching to posterior margin of chaetiger 2 in P. (M.) cirrifera ), (2) the number of branchiae [9–10 pairs in P. (M.) maciolekae sp. nov., vs. 6–8 pairs in Prionospio (M.) cirrifera ], (3) first occurrence of sabre chaeta [chaetigers 13–14 in P. (M.) maciolekae sp. nov., vs. chaetiger 10 in P. (M.) cirrifera ]; (4) the morphology of hooded hooks [three pairs of small teeth above main fang in P. (M.) maciolekae sp. nov., vs. five or six pairs of small teeth above main fang in P. (M.) cirrifera ].

Prionospio (M.) maciolekae sp. nov., is also smilar to P. (M.) lighti , which was originally described from the coast of California by Maciolek (1985). However they differ from each other in a number of characters; (1) prostomium (broadly rounded in P. (M.) maciolekae sp. nov., vs. bluntly rounded in P. (M.) lighti ], (2) peaks on prostomium (absent in P. (M.) maciolekae sp. nov., vs. three large peaks in P. (M.) lighti ); (3) neuropodial lamellae on chaetiger 2 (rectangular in P. (M.) maciolekae sp. nov., vs. rounded in P. (M.) lighti ], (4) dorsal crests (present in P. (M.) maciolekae sp. nov. vs. absent in P. (M.) lighti ], (5) sabre chaetae (with distal filament in P. (M.) maciolekae sp. nov., vs. without distal filament in P. (M.) lighti ).

Ecology. The highest population density (70 individuals m–2) of this species was found on a muddy substratum in 50 m depth at station G17 (Finike Bay).

Distribution. This species was found in the eastern Mediterranea Sea. The re–examination of specimens collected along the Turkish coasts and identified as P. (M.) multibranchiata revealed that all specimens belong to P. (M.) maciolekae sp. nov. Therefore, the presence of P. (M.) multibranchiata in the Mediterranean Sea seems to be questionable and specimens from different basins of the Mediterranean requires a re–examination.

Etymology. This species is named for Dr. Nancy J. Maciolek (ENSR Marine and Coastal Center, Woods Hole, USA), who has made excellent contributions to the taxonomy of Spionidae .

Figures

FIGURE 6. Prionospio (Minuspio) maciolekae sp. nov.: A. Anterior end, dorsal view, holotype (ESFM – POL / 2005 – 1957). B. Anterior end, lateral view, holotype (ESFM – POL / 2005 – 1957). Scale bar: A – B 0.25 mm.

FIGURE 7. Prionospio (Minuspio) maciolekae sp. nov.: A. Parapodium of chaetiger 2 with branchia (first branchial segment), anterior view, paratype (ESFM – POL / 2005 – 2051). B. Parapodium of chaetiger 4 with branchia (third branchial segment), anterior view, paratype (ESFM – POL / 2005 – 2051). C. Parapodium of chaetiger 10, anterior with branchia (nineth branchial segment), anterior view, paratype (ESFM – POL / 2005 – 2051). D. Posterior end, dorsal view, holotype. Scale bar: A 0.1 mm, B – C 0.08 mm, D 0.07 mm.

FIGURE 8. Prionospio (Minuspio) maciolekae sp. nov.: A. Parapodium of chaetiger 12, anterior view, paratype (ESFM – POL / 2005 – 2051). B. Parapodium of chaetiger 33, anterior view, paratype (ESFM – POL / 2005 – 2051). C. Parapodium of chaetiger 60, anterior view, paratype (ESFM – POL / 2005 – 2051). D. Neuropodial hooded hook on chaetiger 20, paratype (ESFM – POL / 2005 – 2051). E. Sabre chaeta on chaetiger 15, paratype (ESFM – POL / 2005 – 2051). F. Capillary chaeta on chaetiger 8, paratype (ESFM – POL / 2005 – 2051). Scale bar: A 0.1 mm, B 0.07 mm, C 0.08 mm, D 18 µm, E – F 34.5 µm.

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.