Paradoneis heterochaeta, Erdoğan-Dereli & Çinar, 2019

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 : 470-481

publication ID

https://doi.org/10.11646/zootaxa.4686.4.2

publication LSID

lsid:zoobank.org:pub:E4BE38CC-446C-421B-8146-95A711C26EDD

persistent identifier

https://treatment.plazi.org/id/038D87AE-FF9B-FF91-FF7B-FCAC05F3BF9C

treatment provided by

Plazi

scientific name

Paradoneis heterochaeta
status

n. sp.

Paradoneis heterochaeta n. sp.

urn:lsid:zoobank.org:act:42661073-8BD9-4DF6-B1A7-28A41CC6F261

Material examined. Holotype, ESFM-POL/2013-1060 , 08 June 2013, station Y15, 40°19’11’’N, 27°33’51’’E, 10 m, sandy mud. GoogleMaps

Paratypes. 224 specimens: ESFM-POL/2013-1361 , 07 June 2013, station Y7, 40°24’28’’N, 26°51’24’’E, 25 m, maerl bed, 29 specimens GoogleMaps ; ESFM-POL/2013-1078 , 07 June 2013, station Y10, 40°31’28’’N, 26°54’12’’E, 10 m, sand, 28 specimens GoogleMaps ; ESFM-POL/2013-1082 , 10 June 2013, station Y13, 40°45’00’’N, 27°20’29’’E, 25 m, muddy sand with shell fragments, 97 specimens GoogleMaps ; ESFM-POL/2013-1088 , 11 June 2013, station Y18, 40°58’01’’N, 27°31’26’’E, 10 m, mud with pebble, 70 specimens. GoogleMaps

Additional material: 1022 specimens: ESFM-POL/2013-57 , 06 June 2013, station Y2, 40°06’32’’N, 26°22’31’’E, 25 m, mud with pebble, 2 specimens GoogleMaps ; ESFM-POL/2013-72 , 06 June 2013, station Y3, 40°12’15’’N, 26°26’12’’E, 25 m, mud, 5 specimens GoogleMaps ; ESFM-POL/2013-75 , 06 June 2013, station Y3, 40°13’10’’N, 26°25’45’’E, 50 m, sand, 3 specimens GoogleMaps ; ESFM-POL/2013-67 , 06 June 2013, station Y3, 40°12’052’’N, 26°26’350’’E, 10 m, mud with shell fragments, 1 specimen ; ESFM-POL/2013-1062 , 07 June 2013, station Y4, 40°17’36’’N, 26°35’51’’E, 10 m, mud, 1 specimen GoogleMaps ; ESFM-POL/2013-83 , 07 June 2013, station Y4, 40°17’49’’N, 26°35’44’’E, 25 m, maerl bed, 11 specimens GoogleMaps ; ESFM-POL/2013-1065 , 07 June 2013, station Y4, 40°18’09’’N, 26°35’15’’E, 50 m, sand, 2 specimens GoogleMaps ; ESFM-POL/2013-91 , 07 June 2013, station Y5, 40°20’55’’N, 26°40’38’’E, 25 m, mud, 11 specimens GoogleMaps ; ESFM-POL/2013-99 , 07 June 2013, station Y6, 40°26’03’’N, 26°41’59’’E, 25 m, mud, 10 specimens GoogleMaps ; ESFM- POL/2013-101, 07 June 2013, station Y6, 40°25’23’’N, 26°44’03’’E, 50 m, mud with Amphiura filiformis , 2 specimens ; ESFM-POL/2013-1069 , 07 June 2013, station Y8, 40°25’15’’N, 27°03’49’’E, 10 m, mud, 1 specimen GoogleMaps ; ESFM-POL/2013-1363 , 08 June 2013, station Y9, 40°26’20’’N, 27°11’32’’E, 10 m, mud with gravel and shell fragments, 1 specimen GoogleMaps ; ESFM-POL/2013-1422 , 08 June 2013, station Y9, 40°26’25’’N, 27°11’29’’E, 25 m, mud, 1 specimen GoogleMaps ; ESFM-POL/2013-1365 , 08 June 2013, station Y9, 40°28’09’’N, 27°11’14’’E, 50 m, mud, 2 specimens GoogleMaps ; ESFM-POL/2013-1366 , 07 June 2013, station Y10, 40°30’38’’N, 26°54’58’’E, 25 m, maerl bed, 4 specimens GoogleMaps ; ESFM-POL/2013-1368 , 08 June 2013, station Y11, 40°36’12’’N, 27°05’20’’E, 10 m, mud, 1 specimen GoogleMaps ; ESFM- POL/2013-1369, 08 June 2013, station Y11, 40°35’55’’N, 27°05’25’’E, 25 m, mud with Turritella communis , 1 specimen ; ESFM-POL/2013-1370 , 08 June 2013, station Y11, 40°34’50’’N, 27°05’59’’E, 50 m, mud, 1 specimen GoogleMaps ; ESFM-POL/2013-1371 , 08 June 2013, station Y12, 40°40’38’’N, 27°16’25’’E, 10 m, sand, 1 specimen GoogleMaps ; ESFM- POL/2013-1372, 08 June 2013, station Y12, 40°40’23’’N, 27°16’31’’E, 25 m, mud, 1 specimen ; ESFM-POL/2013- 1080 , 10 June 2013, station Y13, 40°44’59’’N, 27°20’16’’E, 10 m, muddy sand with shell fragments, 4 specimens GoogleMaps ; ESFM-POL/2013-1084 , 08 June 2013, station Y15, 40°19’11’’N, 27°33’51’’E, 10 m, sandy mud, 42 specimens GoogleMaps ; ESFM-POL/2013-1373 , 08 June 2013, station Y15, 40°25’41’’N, 27°27’57’’E, 50 m, mud, 1 specimen GoogleMaps ; ESFM- POL/2013-1374, 09 June 2013, station Y16, 40°24’13’’N, 27°39’47’’E, 41 m, mud, 1 specimen ; ESFM-POL/2013- 1375 , 09 June 2013, station Y17, 40°39’58’’N, 27°41’08’’E, 50 m, mud, 7 specimens GoogleMaps ; ESFM-POL/2013-1378 , 09 June 2013, station Y17, 40°41’03’’N, 27°39’52’’E, 100 m, mud, 1 specimen GoogleMaps ; ESFM-POL/2013-1379 , 10 June 2013, station Y18, 40°54’28’’N, 27°33’24’’E, 25 m, maerl bed, 16 specimens GoogleMaps ; ESFM-POL/2013-1087 , 12 June 2013, station Y19, 40°59’52’’N, 27°41’59’’E, 10 m, maerl bed, 10 specimens GoogleMaps ; ESFM-POL/2013-1091 , 12 June 2013, station Y19, 40°58’36’’N, 27°42’29’’E, 25 m, maerl bed, 125 specimens GoogleMaps ; ESFM-POL/2013-1385 , 16 June 2013, station Y22, 40°23’22’’N, 27°59’46’’E, 50 m, mud, 11 specimens GoogleMaps ; ESFM-POL/2013-1095 , 13 June 2013, station Y24, 41°03’55’’N, 28°09’12’’E, 10 m, sandy mud with shell fragments, 1 specimen GoogleMaps ; ESFM-POL/2013-1386 , 15 June 2013, station Y24, 41°03’08’’N, 28°08’44’’E, 25 m, maerl bed, 154 specimens GoogleMaps ; ESFM-POL/2013-1389 , 16 June 2013, station Y24, 41°00’16’’N, 28°07’50’’E, 50 m, muddy sand with shell fragment, 13 specimens GoogleMaps ; ESFM- POL/2013-1395, 16 June 2013, station Y25, 40°24’48’’N, 28°20’41’’E, 25 m, sandy mud with Amphiura filiformis , 2 specimens ; ESFM-POL/2013-1397 , 16 June 2013, station Y26, 40°22’36’’N, 28°39’41’’E, 25 m, muddy sand with shell fragments, 20 specimens GoogleMaps ; ESFM-POL/2013-1398 , 17 June 2013, station Y28, 40°29’54’’N, 28°51’29’’E, 25 m, mud, 81 specimens GoogleMaps ; ESFM-POL/2013-1405 , 17 June 2013, station Y29, 40°34’01’’N, 28°44’45’’E, 200 m, muddy sand with shell fragments, 1 specimen GoogleMaps ; ESFM-POL/2013-1400 , 17 June 2013, station Y29, 4032’34’’N, 2846’53’’E, 25 m, maerl bed, 2 specimens ; ESFM-POL/2013-1423 , 17 June 2013, station Y29, 40°32’39’’N, 28°46’42’’E, 50 m, muddy sand, 20 specimens GoogleMaps ; ESFM-POL/2013-1402 , 17 June 2013, station Y29, 40°33’32’’N, 28°44’58’’E, 100 m, muddy sand, 29 specimens GoogleMaps ; ESFM-POL/2013-1098 , 14 June 2013, station Y31, 40°01’44’’N, 28°26’31’’E, 10 m, sand, 2 specimens GoogleMaps ; ESFM-POL/2013-1406 , 14 June 2013, station Y31, 41°01’25’’N, 28°26’23’’E, 25 m, maerl bed, 210 specimens GoogleMaps ; ESFM-POL/2013-1409 , 24 June 2013, station Y34, 40°56’58’’N, 28°51’39’’E, 25 m, sandy mud with shell fragments, 56 specimens GoogleMaps . ESFM-POL/2013-1412 , 22 June 2013, station Y36, 40°57’57’’N, 29°01’14’’E, 10 m, mud, 1 specimen GoogleMaps ; ESFM-POL/2013-1413 , 19 June 2013, station Y38, 40°47’42’’N, 29°18’22’’E, 50 m, muddy sand, 9 specimens GoogleMaps ; ESFM-POL/2013-1415 , 19 June 2013, station Y39, 40°39’36’’N, 29°09’18’’E, 10 m, sandy mud, 1 specimen GoogleMaps ; ESFM-POL/2013-1416 , 19 June 2013, station Y40, 40°41’22’’N, 29°20’58’’E, 10 m, mudy sand, 61 specimens GoogleMaps ; ESFM-POL/2013-1417 , 20 June 2013, station Y41, 40°41’52’’N, 29°25’08’’E, 25 m, mud with shell fragments, 7 specimens GoogleMaps ; ESFM-POL/2013-1419 , 20 June 2013, station Y42, 40°45’43’’N, 29°29’39’’E, 50 m, mud, 71 specimens GoogleMaps .

Description. Holotype complete, 15 mm long (5.37–17.16 mm long in paratypes), 0.47 mm wide (0.20–0.55 mm wide in paratypes) with 84 chaetigers (53–100 chaetigers in paratypes). Color in alcohol pale brownish in large specimens (pale yellowish in small ones), with dark brown speckles scattered along body ( Fig. 6 View FIGURE 6 A–D). Body stout, somewhat cylindrical; widths of prebranchial and branchial regions nearly same; body significantly thicker at beginning of postbranchial region; gradually thinner towards posterior end ( Figs 4A View FIGURE 4 ; 5A View FIGURE 5 ; 6A, B View FIGURE 6 ; 7A View FIGURE 7 ). A dense cili- ary band on mid-dorsal transversal line of each prebranchial and branchial chaetigers ( Figs 7A, B View FIGURE 7 ; 10A, B View FIGURE 10 ); ciliary bands absent from ventral side ( Fig. 8A View FIGURE 8 ). Prostomium triangular; longer than wide (length/width: 1.2), anterior part somewhat or distinctly conical, with an eversible palpode without pores ( Figs 5A View FIGURE 5 ; 6B, C View FIGURE 6 ; 7A View FIGURE 7 ; 8B View FIGURE 8 ); eyes present. Lat- eral organs not observed on prostomium and peristomium. One complete ciliated band, termed as nuchal associated ciliary band (nacb), connecting ventrally one nuchal organ to another and leaving a gap between them in dorsal side ( Fig. 9 View FIGURE 9 A–D). Peristomium highly reduced on dorsal view ( Figs 6B, C View FIGURE 6 ; 8B View FIGURE 8 ; 9A, C View FIGURE 9 ). A pair of nuchal organ as deep, broad slits placed dorso-laterally on posterior part of prostomium; cilia in nuchal organ well extending out of margin of slits; dense brown pigment present on each side of nuchal organ in many paratypes ( Figs 6B, C View FIGURE 6 ; 8B, C View FIGURE 8 ). Mouth with eight buccal lips; two placed anteriorly; six lips placed posterior part, extending to anterior margin of chaetiger 2 ( Figs 8A View FIGURE 8 ; 9B View FIGURE 9 ). Proboscis without lobes, with dense cilia ( Fig. 8A View FIGURE 8 ). Branchiae numbering 12 pairs in holotype, 8 12 pairs in paratypes, beginning on chaetiger 4 in all specimens; flattened, thin, cylindro-conically shaped, with a rounded tip; dense ciliary bands on both side on outer margin of branchiae ( Fig. 7B View FIGURE 7 ); shorter than segment width, first and last pair of branchiae shorter than others ( Figs 4A View FIGURE 4 ; 7A, B View FIGURE 7 ); 164 μm long in anterior region, 231 μm long in middle region, 125 μm long in posterior region. Notopodial postchaetal lobes short, thick, cirriform on chaetigers 1 and 2; longer and much more stouter than others on chaetiger 3 ( Figs 5A View FIGURE 5 ; 10A View FIGURE 10 ); short, digitiform on branchial region ( Figs 5A, B View FIGURE 5 ; 7B View FIGURE 7 ; 10B View FIGURE 10 ); very short, triangular with irregular dense pores on posterior region ( Figs 5C View FIGURE 5 ; 6F View FIGURE 6 ; 10C View FIGURE 10 ; 12A, C View FIGURE 12 ); longer, thin, filiform on pre-anal region ( Figs 4A, F View FIGURE 4 ; 6D View FIGURE 6 ; 10D View FIGURE 10 ). Neuropodial postchaetal lobes absent ( Figs 5B, C View FIGURE 5 ; 8A View FIGURE 8 ). Lateral sense organs located between notopodium and neuropodium, below notopodial postchaetal lobes in each chaetiger ( Figs 9C View FIGURE 9 ; 12 View FIGURE 12 A–C); with flexible cilia distinctly protruding from opening or embedded into pore; one cilia present in each pore ( Fig. 10 C View FIGURE 10 ; 12B, C View FIGURE 12 ), showing its retractable character; lateral sense organs starting from chaetiger 1 to end of body; oval shaped with irregularly clustered pores; with ca. 10 pores in prebranchial region (long axis: ca. 10 μm), with ca. 20–22 pores (long axis: 7–10 μm) in branchial region, with ca. 17–28 pores (long axis: 8 μm) in posterior region. Five types of chaeta present on chaetigers; limbate, capillary and two types of lyrate chaetae. Limbate chaetae hirsute ( Figs 4C View FIGURE 4 , 6E View FIGURE 6 ), present both on notopodia (only on chaetigers 1–13) and neuropodia (pres- ent on chaetigers from 1 to pygidium), 228 μm long in anterior region, 412 μm long in middle region, 333 μm long in posterior region. Notopodial capillary chaetae starting from chaetiger 15 to pygidium; 218 μm long in middle region; 196 μm long in posterior region. Lyrate chaeta with unequal branches, long and short branches; two types based on thickness of branches; thickness of two branches equal (Type I) and thickness of two branches unequal (short branch thicker than long one) (Type II). Type I present from chaetiger 2 to pygidium, those on prebranchial and branchial chaetigers with dense hairs on one side of shaft, numbering 2–4, 68 μm long, long branch 1.5-2 times longer than short branch ( Figs 4B View FIGURE 4 ; 11 View FIGURE 11 A–C); chaetae in postbranchial region numbering 1–2, 40 μm long, long branch 1.5 times longer than short branch, teeth discernible, without hair ( Figs 4D View FIGURE 4 ; 11D View FIGURE 11 ). Type II lyrate chaeta pres- ent from chaetiger 19 to pygidium; numbering 1–3 on posterior chaetigers, 38 μm long; long branch 2–2.5 times longer than short branch; teeth discernible ( Fig. 4E View FIGURE 4 , 11D View FIGURE 11 ). Notopodia of anterior region bearing 2– 4 type I lyrate chaeta and 22–34 limbate chaetae; those of middle region bearing 9–16 capillary chaetae and 2–4 lyrate chaetae (type I and II); those of posterior region bearing 4–7 capillary chaetae and 2–4 lyrate chaetae (type I and II). Neuro- podia of anterior region bearing 20–30 limbate chaeta; neuropodia of middle region bearing 12–24 limbate chaeta; neuropodia of posterior region bearing 11–16 limbate chaetae. Pygidium rounded with three anal cirri; two cirri placed dorso-laterally (thin, digitiform, 45–48 μm long), one cirrus placed mid-ventrally (thick, 47 μm long); anal aperture on dorsal side, with dense cilia ( Figs 4A, F View FIGURE 4 ; 6D View FIGURE 6 ; 10D View FIGURE 10 ).

Reproduction. Some specimens had eggs or sperm packages in their coelomic cavities. Eggs usually appeared from chaetiger 30 onwards; each segment carried 4– 6 eggs. The diameter of eggs varied between 77 and 96 μm. Sperm packages started from chaetiger 31 onwards; each segment carried two sperm packages. The female speci- mens did not have any pigmentation around the nuchal organs, while the male specimens had dense brownish pig- mentation near the nuchal organs ( Fig. 6C View FIGURE 6 ). It seems that this species could be sexually dimorphic.

Remarks. Paradoneis heterochaeta n. sp. is mainly characterized by having dark brownish speckles irregularly scattered along the body; anterior part of prostomium distinctly conical; large-sized body (especially after the bran- chial region); very short notopodial postchaetal lobes (especially getting indistinct in post-branchial region, except for the preanal region) onwards); neuropodial limbate chaetae along the body; and two types of lyrate chaetae based on the thickness of the branches.

The main morphological differences between P. heterochaeta n. sp. and the other Paradoneis species are summarized in Table 1 View TABLE 1 . Paradoneis heterochaeta n. sp. is most similar to P. ilvana and P. brunnea . However, P. heterochaeta n. sp. differs from them in terms of the following characters: (1) Lyrate chaetae are of two types (type I, thickness of branches equal; type II, thickness of branches unequal) in P. heterochaeta n. sp. and P. ilvana , but P. brunnea only has one type (type I). However, both types of lyrate chaetae (types I and II) are simultaneously present in the postbranchial region of P. heterochaeta , whereas in the postbranchial region of P. ilvana only type II of lyrate chaeta occurs. (2) P. heterochaeta n. sp. has a large body size (especially after the branchial region) and dark brown speckles irregularly scattered along the body. On the other side, P. brunnea has a shorter body size and dark brown pigments densely covering the anterior part of the prostomium, and P. ilvana has longer but thinner body lacking pigmentation. (3) Prostomium triangular, with the anterior end distinctly conical in P. heterochaeta n. sp., but conical in P. brunnea and triangular with the anterior end weakly conical in P. ilvana . (4) The notopodial postchaetal lobes are short and cirriform in the prebranchial region, indistinctly digitiform in the branchial region, short and triangular in the postbranchial region of P. heterochaeta n. sp. In P. brunnea , they are small and oval in the prebranchial region, longer and finger-shaped in the branchial region, and finger-shaped or spindle-shaped in the postbranchial region. In P. ilvana , they are short and rounded in the prebranchial region, rudimentary in the branchial region and long and triangular in the postbranchial region.

Habitat and Distribution. This species was found on maerl beds and sandy-muddy bottoms at 10–200 m depths in the Sea of Marmara.

Etymology. This species name refers to the character of possessing two types of lyrate chaetae.

Kingdom

Animalia

Phylum

Annelida

Class

Polychaeta

Family

Paraonidae

Genus

Paradoneis