Levinsenia materi, Çinar & Dagli, 2013

Çinar, Melih Ertan & Dagli, Ertan, 2013, Polychaetes (Annelida: Polychaeta) from the Aegean and Levantine coasts of Turkey, with descriptions of two new species, Journal of Natural History 47 (13 - 14), pp. 911-947 : 941-945

Levinsenia materi sp. nov.

( Figures 11 , 12 )

Material examined

Holotype. ESFM-POL / 2011-130 , 1 September 2011, Aegean Sea, Menderes, station 35, 37 ◦ 56 ′ 58 ′′ N, 27 ◦ 15 ′ 35 ′′ E, 23 m, Posidonia oceanica .

Paratypes. ESFM-POL / 2011-80 , 25 August 2011, Aegean Sea, Baba Burnu, station 8, 39 ◦ 28 ′ 25 ′′ N, 26 ◦ 03 ′ 17 ′′ E, 23 m, P. oceanica , two specimens ; ESFM-POL / 2011- 179 , 3 September 2011, Aegean Sea, Bodrum, station 48, 37 ◦ 01 ′ 45 ′′ N, 27 ◦ 25 ′ 37 ′′ E, 19 m, P. oceanica , two specimens ; ESFM-POL / 2011-171 , 2 September 2011, Aegean Sea, Bodrum, station 47, 36 ◦ 59 ′ 30 ′′ N, 27 ◦ 21 ′ 45 ′′ E, 37 m, sand, one specimen ; ESFM-POL / 2011-180 , 28 August 2011, Aegean Sea, Aliağa, station 21, 38 ◦ 49 ′ 54 ′′ N, 26 ◦ 54 ′ 07 ′′ E, 36 m, P. oceanica , one specimen .

Description

Holotype incomplete, 9.8 mm long, 0.19 mm wide, with 92 chaetigers. Colour in alcohol opaque white. Body long, slender, wider anteriorly, filiform from midbody, gradually tapering to posterior end ( Figure 11A ). Anterior segments short, much wider than long (about three times). Prostomium long, conical, with truncated anterior margin, longer than wide (length: 183 µm; width: 95 µm), middle part slightly swollen; ending in a cylindrical sensory organ; a pair of nuchal organs as deep nuchal slits ( Figure 11A,B ). Posterior buccal lip with five or six longitudinal folds, extending to chaetiger 1 ( Figure 11B ). Eyes absent.

Notopodial postchaetal lobes (prebranchial) short (13 µm long), rounded on first seven chaetigers ( Figure 11A,B ); long (c. 35–43 µm long), thin, digitiform in branchial region (from chaetiger 8 to 19) ( Figures 11A , 12D ); short (c. 13 µm long), thick in middle part of body (postbranchial region) ( Figure 12C ); thin, short (c. 22 µm long), digitiform on posterior chaetigers ( Figure 12E ). Neuropodial postchaetal lobes absent. Branchiae always starting from chaetiger 8; 12 pairs (11 or 14 pairs in paratypes), c. 160 µm long, 45 µm wide (l / w mostly between 2.8–3.9); conical with rounded tip, with dense cilia emerging along a groove (slightly articulated) on ventral side of branchiae; first branchia shortest, c. 90 µm long.

Chaetigers 1–23 with only capillary chaetae; arranged in two rows in prebranchial region (first seven chaetigers), arranged in one row in branchial and postbranchial regions. Chaetiger 3: notopodium with 15 capillary chaetae (c. 125 µm long), neuropodium with 13 capillary chaetae (c. 132 µm long). Chaetiger 19: notopodium with nine capillary chaetae (c. 142 µm long), neuropodium with eight capillary chaetae (c. 135 µm long). Modified neurochaetae from chaetiger 24 (22–23 in paratypes) to end of body, up to four to nine per fascicle, arranged in a single row, slightly curved, unidentate, with thickened hood on convex side but not reaching tip of chaetae, a slight constriction at base; accompanied with three or six fine capillary chaetae ( Figure 12A ). Chaetiger 24: notopodium with five capillary chaetae (c. 125 µm long), neuropodium with three capillary chaetae (c. 120 µm long) and one modified chaeta (15 µm long; length from node to tip). Chaetiger 34: notopodium with five capillary chaetae (c. 102 µm long), neuropodium with four capillary chaetae (c. 115 µm long) and six modified chaeta (27 µm long; length from node to tip). In chaetiger 55, notopodium with four capillary chaetae (c. 127.5 µm long), neuropodium with three capillary chaetae (c. 115 µm long) and seven modified chaetae (27.5 µm long). Chaetiger 72: notopodium with four capillary chaetae (c. 97 µm long), neuropodium with six capillary chaetae (c. 117 µm long) and nine modified chaetae (30 µm long).

Pygidium with a mid-dorsal lobe (c. 38 µm long, 30 µm wide) and two ventrolateral cirri (c. 33 µm long, 5 µm wide) in paratype ( Figure 11C ).

Remarks

Levinsenia materi sp. nov. is mainly characterized by having 11–14 pairs of branchiae between chaetigers 8 and 19–22. The same number of prebranchial chaetigers and branchiae, and the branchial morphology were previously reported in the following species: L. acutibranchiata ( Strelzov, 1973) , L. kirbyae Lovell, 2002 and L. reducta ( Hartman, 1965) .

Levinsenia acutibranchiata was originally described from the Uruguay shelf, in muddy sand at 90–175 m depths by Strelzov (1973). According to the original description, L. acutibranchiata is mainly characterized by having seven prebranchial chaetigers, 12 pairs of branchiae (relatively short with long cilia, the ratio of the length of fifth branchiae being 3.9–4.0), conical notopodial lobes in posterior chaetigers, and thick, curved modified chaetae with additional denticle and thickened membrane on convex side reaching to tip of chaetae. Levinsenia materi sp. nov. is mainly distinguished from L. acutibranchiata in having long prostomium, finger-like notopodial lobes in posterior chaetigers, and unidentate modified chaetae (without denticles) with thickened hood on convex side but not reaching tip of chaetae.

Levinsenia materi sp. nov. is closely related to L. kirbyae , which was originally described from the Andaman Sea between 42 and 63 m depths by Lovell (2002), but differs in some important characters; the shape of the postbranchial notopodial lobes in posterior part of the body (digitiform in L. materi sp. nov. versus more or less rounded in L. kirbyae ); the shape of the modified chaetae [one type (slightly curved) in L. materi sp. nov. versus two types (slender and nearly straight in the upper part of bundle, thicker and more recurved in the lower part of the bundle) in L. kirbyae ]; the arrangement of the modified chaetae (single row in L. materi sp. nov. versus double rows in L. kirbyae ); and the neuropodial postchaetal lobes (absent in L. materi sp. nov. versus reduced to a low mound in the anterior chaetigers in L. kirbyae ).

Levinsenia materi sp. nov. is also similar to L. reducta , which was originally described from the northeastern part of the South America between 520 and 1500 m depths by Hartman (1965). These two species differ considerably, however, in the shape of the notopodial lobes. The notopodial lobes of L. reducta is one type (tuberculate on all chaetigers), whereas those of L. materi sp. nov. are two types (tuberculate and digitiform). A transitional dorsal chaeta is present in L. reducta , whereas it was absent in L. materi sp. nov. The modified chaetae first occur on chaetigers 27–31 in L. reducta versus on chaetigers 22–24 in L. materi sp. nov. The shape of the modified chaetae represents another difference between these two species; strongly sickle-shaped with a marked hood in L. reducta , versus slightly curved with thickened hood in L. materi sp. nov. In addition, L. materi sp. nov. was found at depths ranging from 5 to 36 m, whereas L. reducta was previously reported at depths ranging from 520 to 1500 m ( Hartman 1965).

Levinsenia materi sp. nov. is also similar to L. antarctica ( Strelzov 1973) and L. brevibranchiata ( Strelzov 1973) in that the number of prebranchial chaetigers is seven. However, these species differ considerably from each other in the number of branchiae. Levinsenia antarctica and L. reducta have three and six pairs of short branchiae with blunt tip, respectively.

Reproduction

Specimens of Levinsenia materi sp. nov. collected in August and September had eggs in the coelomic cavities between chaetigers 21 and 35; egg diameter: 37.5– 80 µm (mean ± SE: 48.4 ± 3.45 µm, n = 19).

Distribution

Aegean Sea between 19 and 37 m depth.

Etymology

This species is named in honour of the late Prof. Dr Savaş Mater (1943–2007), who was one of the pioneers of marine biological studies (especially fish taxonomy and ecology) in Turkey.

Figures

Figure 11. Levinsenia materi sp. nov. (A) Anterior end, lateral view, holotype (ESFM- POL/2011-130); (B) anterior end, ventral view, paratype (ESFM-POL/2011-179); (C) posterior end, dorsal view, paratype (ESFM-POL/2011-179). Scale bars: (A) 250 µm, (B) 363 µm, (C) 159 µm.

Figure 12. Levinsenia materi sp. nov. (A) Modified neurochaetae, chaetiger 72, holotype (ESFMPOL/2011-130); (B) left parapodium of chaetiger 5 (prebranchial region), paratype (ESFMPOL/2011-80); (C) left parapodium of chaetiger 20 (postbranchial region), holotype; (D) right parapodium of chaetiger 12 with branchia (branchial region), paratype (ESFMPOL/2011-80); (E) right parapodium of chaetiger 85 (postbranchial region), paratype. Scale bars: (A) 10 µm, (B) 63 µm, (C) 48 µm, (D) 86 µm, (E) 49 µm.