Paradoneis ilvana Castelli, 1985

Erdoğan-Dereli, Deniz & Çinar, Melih Ertan, 2019, The genus Paradoneis (Annelida: Paraonidae) from the Sea of Marmara, with descriptions of two new species, Zootaxa 4686 (4), pp. 465-496 : 468-470

Paradoneis ilvana Castelli, 1985

Paradoneis ilvana Castelli, 1985: 273–275 , Figs 3 B–E, 4A–D; Tena et al. 1991: 36, Figs 4 A–E; Aguirrezabalaga & Gil 2008: 39–41, Figs 2 A–C, 3A–D, 6A–B; Aguirrezabalaga 2012: 257–259, Figs 117 A–G, 118 A–D.

Material examined. 74 specimens: ESFM-POL /2013-1151, 06 June 2013, station Y3, 40°13’10’’N, 26°25’45’’E, 50 m, sand, 3 specimens; ESFM-POL /2013-1355, 07 June 2013, station Y5, 40°20’55’’N, 26°40’38’’E, 25 m, mud, 9 specimens; ESFM-POL /2013-1152, 07 June 2013, station Y5, 40°21’21’’N, 26°39’59’’E, 50 m, mud, 3 specimens; ESFM-POL /2013-1358, 07 June 2013, station Y6, 40°26’03’’N, 26°41’59’’E, 25 m, mud, 4 specimens; ESFM-POL /2013-1154, 07 June 2013, station Y7, 40°24’28’’N, 26°51’24’’E, 25 m, maerl bed, 1 specimen; ESFM- POL/2013-1153, 07 June 2013, station Y7, 40°25’09’’N, 26°51’18’’E, 50 m, mud, 1 specimen; ESFM-POL /2013- 1155, 07 June 2013, station Y8, 40°25’27’’N, 27°03’34’’E, 25 m, mud, 3 specimens; ESFM-POL /2013-1156, 07 June 2013, station Y10, 40°31’28’’N, 26°54’12’’E, 10 m, sand, 1 specimen; ESFM-POL /2013-1157, 08 June 2013, station Y12, 40°40’23’’N, 27°16’31’’E, 25 m, mud, 2 specimens; ESFM-POL /2013-1158, 09 June 2013, station Y16, 40°18’35’’N, 27°45’46’’E, 10 m, fine sand, 2 specimens; ESFM-POL /2013-1159, 09 June 2013, station Y16, 40°18’39’’N, 27°45’43’’E, 25 m, mud with Amphiura filiformis , 8 specimens; ESFM-POL /2013-1161, 09 June 2013, station Y16, 40°24’13’’N, 27°39’47’’E, 41 m, mud, 3 specimens; ESFM-POL /2013-1162, 09 June 2013, station Y17, 40°39’58’’N, 27°41’08’’E, 50 m, mud, 17 specimens; ESFM-POL /2013-1164, 16 June 2013, station Y24, 41°03’08’’N, 28°08’44’’E, 25 m, maerl bed, 2 specimens; ESFM-POL /2013-1165, 16 June 2013, station Y24, 41°00’16’’N, 28°07’50’’E, 50 m, muddy sand with shell fragment, 1 specimen; ESFM-POL /2013-1166, 16 June 2013, station Y25, 40°24’48’’N, 28°20’41’’E, 25 m, sandy mud with Amphiura filiformis , 2 specimens; ESFM- POL/2013-517, 17 June 2013, station Y28, 40°29’15’’N, 28°51’09’’E, 50 m, mud, 7 specimens; ESFM-POL /2013- 1167, 24 June 2013, station Y35, 4057’22’’N, 2858’21’’E, 50 m, mud, 5 specimens.

Description. Largest specimen complete, 6.74 mm long, 0.20 mm wide, with 69 chaetigers. Color in alcohol usually dull white. Body thin, long; middle part relatively stouter; posterior part gradually thinner ( Fig. 3A ). Pro- stomium conical; longer than wide (length/width: 2.12); anterior part rounded ( Fig. 3A, B ); without eyes. A pair of nuchal organ as deep slits placed dorso-laterally on posterior part of prostomium. Peristomium located posterior to nuchal organs on dorsal side. Mouth with three buccal lips; two placed anteriorly; one placed posteriorly; extending to anterior margin of chaetiger 1; a Y-shaped gap between anterior lips. Branchiae numbering 10–11 pairs, beginning on chaetiger 4; somewhat flattened, cylindro-conically shaped, with a rounded tip; shorter than segment width, last pairs much shorter than the others; 150 μm long in anterior region, 166 μm long in middle region, 140 μm long in posterior region. Notopodial postchaetal lobes short, cirriform on first three chaetigers; short, cirriform on branchial region; short, triangular on posterior chaetigers. Neuropodial postchaetal lobes absent. Two types of chaetae present on chaetigers; capillary and lyrate chaetae. Capillary chaetae, present on both neuropodium and notopodium; occurring on chaetigers all along body; 946 μm long in anterior region, 828 μm long in middle region, 645 μm long in posterior region. Notopodia of anterior region bearing 20–22 capillary chaetae and two lyrate chaeta; those of middle region bearing 9–10 capillary chaetae and one lyrate chaeta; those of posterior region bearing 10–11 capillary chaeta and one lyrate chaeta. Neuropodia of anterior region bearing 18–20 capillary chaetae; those of middle region bearing 17–18 capillary chaetae; those of posterior region bearing 12–13 capillary chaetae. Lyrate chaetae typical, branches with unequal lengths (long branch 1.5–2 times longer than short one), 33 μm long in an- terior chaetigers, 39 μm long in middle and posterior chaetigers; teeth discernible; thickness of branches equal on chaetigers 2–13, unequal on chaetigers from 14 to pygidium ( Fig. 3D, E ). Pygidium triangular with three anal cirri; two cirri placed dorso-laterally (slender, digitiform, 55–60 μm long) and one cirrus placed mid-ventrally (thick, short, length: 27 μm) ( Fig. 3C ).

Remarks. The specimens of Paradoneis ilvana collected from the Sea of Marmara differ from the original de- scription of the species by Castelli (1985) in having a relatively shorter body (max. of 6.74 mm in total body length in specimens from the Sea of Marmara vs. max. 2 cm in the original description) and by the presence of notopodial lobes on the first three chaetigers (absent in the original description). However, Aguirrezabalaga & Gil (2008) reexamined the Castelli’s specimens and realized that the types of P. ilvana actually bear notopodial lobes on the first three chaetigers. According to this, the morphology of the Sea of Marmara’s specimens is quite similar to the description made by Aguirrezabalaga & Gil (2008).

Habitat and Distribution. This species was found in soft substrata at depths ranging from 10 to 50 m in the Sea of Marmara. It was previously reported on the same habitat between 0 and 50 m depths in the eastern Atlantic Ocean ( Aguirrezabalaga & Gil 2008), and the eastern ( Çinar et al. 2014) and western ( Castelli 1985, Tena et al. 1991) Mediterranean Sea.

Figures

FIGURE 2. Paradoneis armata Glémarec, 1966. A, Complete specimen (ESFM-POL/2013-1298), stained with ShirlastainA; B, Antero-dorsal view (ESFM-POL/2013-1298), stained with Shirlastain A; C, Lyrate chaeta from chaetiger 9 (ESFM-POL/2013- 1298); D, Pygidium (ESFM-POL/2013-1298); E, Modified notochaeta from a posterior chaetiger (ESFM-POL/2013-1298); F, Modified neurochaeta of holotype from chaetiger 42; G, Modified neurochaeta of holotype from posterior chaetigers; H, Modi- fied neurochaeta of holotype from preanal chaetigers. Scale bars: A, 1304 µm; B, 500 µm; C, 26 µm; D, 92 µm; E, 18 µm; F, 22 µm; G, 32 µm; H, 31 µm.

FIGURE 3. Paradoneis ilvana Castelli, 1985.A, complete specimen (ESFM-POL/2013-1158); B, Antero-lateral view (ESFM- POL/2013-1151), stained with Shirlastain A; C, Preanal chaetigers and pygidium (ESFM-POL/2013-1158); D, Lyrate chaetae from posterior chaetiger (ESFM-POL/2013-1151); E, Lyrate chaetae from posterior chaetiger (ESFM-POL/2013-1151). Ab- breviation: ac, anal cirri. Scale bars: A, 935 µm; B, 486 µm; C, 176 µm; D, 18 µm; E, 20 µm.

FIGURE 4. Paradoneis heterochaeta n.sp. A, line drawing of holotype (ESFM-POL/2013-1060); B, Lyrate chaeta from pre- branchial chaetigers (ESFM-POL/2013-1078); C, Limbate chaeta (ESFM-POL/2013-1082); D, Lyrate chaeta (thickness of branches equal) from posterior chaetigers (ESFM-POL/2013-1084); E, Lyrate chaeta from posterior chaetigers (thickness of branches unequal) (ESFM-POL/2013-1078); F, Pygidium. Scale bars: A, 955 µm; B, 11 µm; C, 30 µm; D, 13 µm; E, 15 µm; F, 92 µm.