Levinsenia kosswigi, Çinar & Dagli & Açik, 2011

Çinar, Melih Ertan, Dagli, Ertan & Açik, Sermin, 2011, Annelids (Polychaeta and Oligochaeta) from the Sea of Marmara, with descriptions of five new species, Journal of Natural History 45 (33 - 34), pp. 2105-2143 : 2129-2132

Levinsenia kosswigi sp. nov.

( Figures 7 , 8 )

Material examined

Holotype. ESFM-POL / 2010-16 , 15 April 2010, Sea of Marmara , station G4, 40 ◦ 27 ′ 18 ′′ N, 27 ◦ 46 ′ 28 ′′ E, 66 m, mud.

Paratype. ESFM-POL / 2009-216 , 3 August 2009, Levantine Sea, Mersin Bay , station 10, 36 ◦ 37 ′ 16 ′′ N, 34 ◦ 41 ′ 34 ′′ E, 70 m, mud, one specimen .

Comparative material examined

Levinsenia gracilis japonica , Holotype, NSMT-Pol.H 98, off Koyahata , Sagami Bay, Japan, 145 m.

Description

Holotype incomplete, 15 mm long, 0.35 mm wide, with 70 chaetigers. Paratype incomplete 16 mm long, 0.40 mm wide, with 64 chaetigers. Colour pale brownish. Brown pigmentation present on anterior (bar-like) and posterior (sphaerical) parts of nuchal organs of prostomium ( Figure 7A ). Body long, slender, wider anteriorly, filiform from midbody. Anterior segments short, much wider than long (ca. three times). Prostomium conical, distally rounded, longer than width (length: 0.20 mm, wide: 0.18 mm), ending in a cylindrical sensory organ ( Figure 7A ). Pair of nuchal organs as deep nuchal slits. Posterior buccal lip with seven or eight longitudinal folds, extending to chaetiger 1 ( Figure 7B ).

First eight notopodial postchaetal lobes (prebranchial) short, rounded, ca. 20 µm long ( Figure 8B ); in branchial region longer, thin, digitiform, distally rounded, ca. 62.5–75 µm long ( Figure 8C ); in postbranchial region, between chaetigers 26 and 51, short, rounded, ca. 25 µm long ( Figure 8D ); after chaetiger 52, getting longer and digitiform, ca. 35–40 µm long ( Figure 8E ). Neuropodial postchaetal lobes absent. Branchiae 17 pairs (paratype with 21 pairs) commencing from chaetiger 9, conical with rounded tip, distinctly shorter than width of segments (ca. 250 µm long, 62 µm wide [l / w mostly between 3.7–4]), with dense cilia emerging along a groove (slightly articulated) on ventral side of branchiae ( Figure 8A ); last branchia shortest, ca. 187 µm long. Chaetigers 1–29 with only capillary chaetae; chaetiger 3: notopodium with 16 capillary chaetae (ca. 225 µm long), neuropodium with 18 capillary chaetae (ca. 250 µm long); chaetiger 13: notopodium with nine capillary chaetae (ca. 275 µm long), neuropodium with 14 capillary chaetae (ca. 312 µm long). Modified neurochaetae from chaetiger 30 to end of body, up to four to six per fascicle, arranged in a single row, slightly curved, unidentate, with thickened hood on convex side, a slight constriction at base; accompanied with three or four fine capillary chaetae ( Figures 7C , 8D,E ). In chaetiger 30, notopodium with five capillary chaetae (ca. 300 µm long), neuropodium with five capillary chaetae (ca. 275 µm long) and one modified chaeta (24 µm long; length from node to tip). In chaetiger 35, notopodium with five capillary chaetae (ca. 275 µm long), neuropodium with one capillary chaeta (ca. 275 µm long) and three modified chaetae (30 µm long) ( Figure 8D ). In chaetiger 50, notopodium with four capillary chaetae (ca. 250 µm long), neuropodium with three capillary chaetae (ca. 275 µm long) and four modified chaetae (34 µm long). In chaetiger 65, notopodium with four capillary chaetae (ca. 300 µm long), neuropodium with three capillary chaetae (ca. 300 µm long) and six modified chaetae (35 µm long) ( Figure 8E ). Pygidium missing.

Remarks

Levinsenia kosswigi sp. nov. is very similar to Levinsenia gracilis japonica , which was described from Sagami Bay (west Pacific Ocean) at 145 m depth by Imajima (1973). However, they differ from each other mainly because (1) L. kosswigi has two types of notopodial postchaetal lobes in the postbranchial region (small, rounded tubercle between chaetigers 26 and 51, and digitiform, long between 52 to the end of body), whereas L. gracilis japonica has one type of postbranchial notopodial lobe (digitiform); (2) L. kosswigi has one type of modified chaeta (slightly hooked with thickened hood) arranged in a row, whereas L. gracilis japonica has two types of modified chaetae somewhat arranged in a crescent shape (six or seven dorsalmost modified chaetae are long [60 µm long], thin [5 µm in diameter], straight with a bending tip, sometimes with a pubescent sheath on convex side of shaft; one ventralmost modified chaeta is thicker [6.25 µm in diameter], short [38 µm long], slightly hooked with thickened hood on convex side) ( Figure 7D ); (3) the prebranchial (max. 20 µm long) and postbranchial (max. 75 µm long) notopodial lobes of L. kosswigi are larger than those (max. 17 / 58 µm long) of L. gracilis japonica .

Levinsenia multibranchiata ( Hartman, 1957) , originally described from the coast of California (Pacific Ocean), is also similar to L. kosswigi sp. nov. in having many branchiae, but differs from the latter in having threadlike branchiae, much longer than the width of segments (max. l / w = 17), conical, distinctly shorter than width of segments in L. kosswigi (max l / w = 4), the first pair of branchiae commencing on chaetiger 6 (on chaetiger 9 in L. kosswigi ) and the modified chaetae commencing on chaetiger 58 (on chaetiger 30 in L. kosswigi ).

Etymology

This species is named in honour of the late Prof. Dr Curt Kosswig (1903–1982), who was one of the pioneers of marine biological studies in Turkey.

Distribution

Sea of Marmara and Mediterranean (Levantine Sea), between 66 and 70 m depth.

Figures

Figure 7. Levinsenia kosswigi sp. nov. (A) Anterior end, dorsal view, holotype (ESFM- POL/2010-16); (B) anterior end, ventral view, paratype (ESFM-POL/2009-216); (C) modified neurochaetae, chaetiger 60, holotype; (D) levinsenia gracilis japonica, modified neurochaetae, chaetiger 50, holotype (NSMT-Pol.H 98). Scale bars: (A) 500 µm, (B) 395 µm, (C) 33 µm, (D) 28 µm.

Figure 8. Levinsenia kosswigi sp. nov. (A) Branchia from chaetiger 27, paratype (ESFM- POL/2009-216); (B) right parapodium of chaetiger 4 (prebranchial region), paratype; (C) right parapodium of chaetiger 13 with branchia (branchial region), paratype; (D) right parapodium of chaetiger 35 (postbranchial region), paratype; (E) right parapodium of chaetiger 65 (postbranchial region), paratype. Scale bars: (A–C) 62 µm, (D,E) 25 µm.