Levinsenia vulgaris, Erdoğan-Dereli & Çinar, 2021

Erdoğan-Dereli, Deniz & Çinar, Melih Ertan, 2021, Levinsenia species (Annelida: Polychaeta: Paraonidae) from the Sea of Marmara with descriptions of two new species, Zootaxa 4908 (2), pp. 151-180 : 174-178

Levinsenia vulgaris n. sp.

( Figures 19–22 )

Levinsenia vulgaris n. sp.: urn:lsid:zoobank.org:act:5BF49C1C-B5C6-4DA4-9F4C-39FA538E4B4E

Material examined. Holotype. ESFM-POL/2013-1380 , 20 June 2013, Y41, 40°42’42’’N, 29°25’20’’E, 50 m, mud with shell fragments.

Paratypes. ESFM-POL/2013-1181 , 12 June 2013, Y20, 40°57’09’’N, 27°54’46’’E, 50 m, mud with shell fragments, 1 specimen ; ESFM-POL/2013-1182 , 16 June 2013, Y24, 41°03’08’’N, 28°08’44’’E, 25 m, muddy sand with Lithothamnion sp., 4 specimens ; ESFM-POL/2013-633 , 23 June 2013, Y31, 40°53’30’’N, 28°27’32’’E, 500 m, mud, 2 specimens ; ESFM-POL/2013-1183 , 23 June 2013, Y33, 40°54’37’’N, 28°44’53’’E, 200 m, sandy mud with shell fragments, 1 specimen ; ESFM-POL/2013-1184 , 24 June 2013, 40°54’50’’N, 28°52’12’’E, Y 34, 100 m, sandy mud with shell fragments, 2 specimens ; ESFM-POL/2013-628 , 21 June 2013, Y37, 40°47’01’’N, 29°07’57’’E, 500 m, mud, 3 specimens ; ESFM-POL/2013-1185 , 19 June 2013, Y38, 40°47’42’’N, 29°18’22’’E, 50 m, muddy sand, 12 specimens ; ESFM-POL/2013-623 , 19 June 2013, Y40, 40°43’12’’N, 29°17’33’’E, 500 m, mud, 2 specimens ; ESFM-POL/2013-1186 , 20 June 2013, Y41, 40°42’42’’N, 29°25’20’’E, 50 m, mud, 6 specimens ; ESFM-POL/2013- 1187 , 20 June 2013, Y42, 40°45’43’’N, 29°29’39’’E, 50 m, mud, 6 specimens .

Additional material. ESFM-POL/2016-44 , 17 August 2016, Aegean Sea, Ildır Bay , 38º27’15”N, 26º26’38”E, 65 m, mud, 2 specimens ; ESFM-POL/2017-79 , 14 August 2017, Levantine Sea, Mersin Bay , 36°45’44”N, 34°39’03”E, 16 m, mud with shell fragments, 1 specimen .

Description. Holotype incomplete, 12.6 mm long, 0.22 mm wide for 67 chaetigers; all paratypes incomplete, 3.6–10.2 mm long, 0.14–0.22 mm wide for 30–59 chaetigers. Color in alcohol light yellow; red coloration present on dorsal body side of specimens with gametes ( Figs 20 A–C, H). Body slender, fragile; slightly wider and with antero-dorsal side swollen in prebranchial chaetigers, prebranchial and branchial chaetigers nearly of the same width, posterior part thin (weakly moniliform in gamete bearing specimens) ( Figs 19A ; 20 A–C, H).

Prostomium conical, longer than wide (ratio length / width: 1.5); anterior end somewhat rounded with an eversible palpode, without eyes ( Figs 19B ; 21A, C ). A pair of nuchal organs as narrow deep, short slits, vertically placed on dorso-lateral sides of posterior part of prostomium; with scarce internal cilia; without pigmentation ( Figs 19 A–B; 20B; 21A). Cilia patches and lateral organ absent. Cheek organ located on lateral sides of prostomium; retractile and rounded in shape ( Figs 19 A–B; 21A–D).

Peristomium indistinct on dorsal and lateral sides, only discernable in SEM picture, partly fused with anterior margin of chaetiger 1 on dorsal side. Mouth with two buccal lips; one placed anteriorly, and one placed posteriorly, extending to anterior margin of chaetiger 1 ( Fig. 20D ).

Dorsal ciliary bands (dcb) present, located on dorsal side of branchial chaetigers. Short dorsal ciliary bands (sdcb) present just ventral to each branchial base as a transversal line ( Fig. 22C ). Ciliary bands absent on ventral side of body. Dorso-lateral irregular pores (dlip) present, located on ventral side of each branchia and scattered on dorsal side of body ( Fig. 22D ).

Branchiae 14 pairs in holotype, 11–15 in paratypes, beginning on chaetiger 6; flattened dorso-ventrally, lanceolate, distal part with a rounded tip; first two pairs of branchiae relatively small and ciliary bands rudimentary; last pairs of branchiae shortest; dense ciliary bands located on both sides of outer margin of branchiae reaching subdistal region ( Figs 19 A–B; 20A; 22A, D); ca. 210 μm long in anterior part, ca. 248 μm long in middle region, ca. 216 μm long in posterior part of branchial region. Notopodium fused with branchiae, merging degree decreasing from anterior to posterior part of branchial region ( Fig 22A ).

Interramal lobes and notopodial papilla absent. Notopodial postchaetal lobes present, very short and cirriform on first five chaetigers (prebranchial chaetigers); emerging from branchiae, short and pyriform on chaetiger 6 and 7; long, digitiform, with more or less symmetrically enlarged base in the rest of the branchial region, length progressively increasing posteriorly; very short and cirriform on postbranchial chaetigers ( Figs 19 A–B; 22A–B, D–E). Neuropodial postchaetal lobes absent.

Lateral sense organs present on all chaetigers, located between notopodia and neuropodia, just posterior to notopodial postchaetal lobes; elliptical with irregularly clustered pores from prebranchial region to middle part of branchial region; ( Fig. 22B, E ); with 10–13 pores in prebranchial region (long axis of organ: 5–5.5 μm), with 13–15 pores (long axis: 6–6.5 μm) in branchial region; with flexible cilia distinctly protruding from opening or embedded into pore.

Three types of chaetae present on chaetigers: limbate, capillary and modified neurochaeta.

Limbate chaetae present on noto- and neuropodia of chaetigers 1–5; long, thin and straight with fibrils along edge (hirsute), positioning straight, colorless; in notopodia, numbering 6–15, arranged in two rows, ca. 204 µm long; in neuropodia, numbering 7–18, arranged in two rows, ca. 146 µm long.

Capillary chaetae commencing from noto- and neuropodia of chaetiger 6 to last posterior chaetiger; in notopodia, numbering 5–8 in each ramus, two rows and ca. 197 μm long in middle region, numbering 2–4 in each ramus, one row and ca. 114 μm long in posterior region; in neuropodia, numbering 6–10 in each ramus, two rows and ca. 177 μm long in middle region, numbering 3–4 in each ramus, one row and ca. 109 μm long in posterior region.

Modified neuropodial chaetae starting from chaetigers 23–32 to last posterior chaetiger, numbering 4–6, arranged in one row, superior chaetae relatively straight and long, inferior chaetae much shorter and curved, about 55 μm long, shape similar along in body regions, as a slender hook, weakly curved towards terminal region, with a rounded tip; with a distinct fibrillary hood on convex side ( Figs 19C ; 20 E–G).

Pygidium missing.

Reproduction. Eggs were present in some specimens of Levinsenia vulgaris n. sp. collected in June from the Sea of Marmara. Eggs usually first occurred at chaetiger 30, continued to the posterior end, and numbered 12 in each chaetiger. The egg diameter varied between 16 and 27 μm. The egg bearing specimens from the study area lacked coloration.

The male specimens collected in August from the Aegean Sea had specific red color patterns on the dorsal side of each chaetiger from chaetiger 24 to the end of the body ( Fig. 20C, H ).

Remarks. Levinsenia vulgaris n. sp. is mainly characterized by having five prebranchial chaetigers, mostly 14–15 pairs of branchiae, very short branchiae pairs on the first two branchial chaetigers, and the branchiae fused with notopodia and notopodial lobes, which have symmetrical enlargements at the base.

Morphologically, Levinsenia vulgaris n. sp. is similar to L. kantauriensis Aguirrezabalaga & Gil 2009 , L. kirbyae Lovell 2002 , L. materi Çinar & Dagli 2013 and L. gracilis ( Tauber 1879) . The latter was re-described by Lovell and Fitzhugh 2020 based on syntypes and topotypes. However, these species differ from each other in terms of the following diagnostic features: (1) Fusion of notopodia with branchiae: fused in L. vulgaris n. sp.; not fused in L. gracilis , L. kantauriensis , L. kirbyae and L. materi . (2) The number of prebranchial chaetiger: five in L. vulgaris n. sp.; 5–7 in L. gracilis , five in L. kantauriensis , and seven in L. kirbyae and L. materi . (3) Branchiae: lanceolate with a rounded tip, 11–15 pairs in L. vulgaris n. sp.; digitiform, with a blunt tip, 7–16 pairs in L. gracilis ; cirriform with a rounded tip, 5–6 pairs in L. kantauriensis ; conical, gradually tapering to tip, 13–14 pairs in L. kirbyae ; conical with a rounded tip, 11–14 pairs in L. materi . (4) Notopodial postchaetal lobes: very short and cirriform in the prebranchial region, pyriform in the first two branchial chaetigers, long, digitiform with a symmetrical basal enlargement in the branchial region, short and cirriform in the posterior part of the body in L. vulgaris n. sp.; as low mounds in the prebranchial region, digitiform without a basal enlargement in the branchial region and shorter in the posterior region of the body in L. gracilis ; short and rounded in the prebranchial region, long, digitiform, distally rounded without a basal enlargement in the branchial region and short, thin, rounded in the posterior part of the body in L. kantauriensis ; papilla-shaped in the prebranchial region, digitiform without a basal enlargement in branchial region and short in the post-branchial region in L. kirbyae ; short and rounded in the prebranchial region, long and digitiform without a basal enlargement in the branchial region, short and thick in the postbranchial region in L. materi .

Etymology. The specific epithet means “common, usual”.

Habitat and Distribution. The specimens of Levinsenia vulgaris n. sp. were found on soft substrata between 25 and 500 m in the Sea of Marmara, Aegean and Levantine Seas. This species might have been reported as L. gracilis on the coasts of Turkey and in the Mediterranean Sea.

Figures

FIGURE 19. Levinsenia vulgaris n. sp. A, General view of body, holotype (ESFM-POL/2013-1380); B, Anterio-dorsal view of body, paratype (ESFM-POL/2013-1186); C, Modified neurochaeta from posterior chaetiger, holotype (ESFM-POL/2013-1186). Scale bar: A, 272 µm; B, 125 µm; C, 17 µm.

FIGURE 20. Levinsenia vulgaris n. sp. A, General view of body (ESFM-POL/2013-1185, paratype); B, Dorsal view of anterior end of body (ESFM-POL/2013-1186, paratype); C, General view of body, male specimen with red colour patterns on dorsal side of body (ESFM-POL/2016-44, paratype); D, Ventral view of prostomium and first two chaetigers (ESFM-POL/2013-1186); E, Modified neurochaetae from chaetiger 58, paratype (ESFM-POL/2013-1186); F, Modified neurochaeta from chaetiger 62, ho- lotype; G, Modified neurochaetae from chaetiger 60, paratype (ESFM-POL/2013-1186); H, Posterior chaetigers in moniliform shape with sperm masses and red colour patterns (ESFM-POL/2016-44). Scale bar: A, 735 µm; B, 267 µm; C, 378 µm; D, 87 µm; E, 38 µm; F, 37 µm; G, 60 µm; H, 186 µm. Abbreviation: ntpcl, notopodial postchaetal lobe.

FIGURE 21. Levinsenia vulgaris n. sp. (ESFM-POL/2013-1181, paratype). A, Dorso-lateral side of prostomuim with a cheek organ; B, Cheek organ in retracted position; C, D, Lateral view of prostomuim with a cheek organ and nuchal organ. Scale bar: A, 79 µm; B, 7 µm; C, 70 µm; D, 23 µm. Abbreviations: cho, cheek organ; ep, eversible palpode; no, nuchal organ.

FIGURE 22. Levinsenia vulgaris n. sp. (ESFM-POL/2013-1185, paratype). A, Dorso-lateral view of middle branchial region; B, First notopodium with notopodial postchaetal lobe and lateral sense organ; C, Dorsal view of branchial chaetigers, dorsal ciliary band and second dorsal ciliary band; D, Second branchial pair with notopodial postchaetal lobe emerging on branchia; E, Parapodium from middle branchial region with notopodial postchaetal lobe and lateral sense organ. Scale bar: A, 56 µm; B, 6 µm; C, 57 µm; D, 36 µm; E, 1 µm. Abbreviations: ant; anterior region; bran, branchiae; dcb, dorsal ciliary band; dlip, dorsolateral irregular pores; lso, lateral sense organ; ntpcl, notopodial postchaetal lobe; post, posterior region; sdcb, second dorsal ciliary band.