Paradoneis longifurcata, 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 : 481-495

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-FF8E-FF9F-FF7B-FBBE00FDBD14

treatment provided by

Plazi

scientific name

Paradoneis longifurcata
status

n. sp.

Paradoneis longifurcata n. sp.

urn:lsid:zoobank.org:act:CEAA1898-85A2-4786-860B-F95778394DDA

Material examined. Holotype, ESFM–POL/2013–1100 , 16 June 2013, station Y24, 41°03’08’’N, 28°08’44’’E, 25 m, maerl bed (muddy sand with Lithothamnion sp.) GoogleMaps

Paratypes. 167 specimens: ESFM-POL /2012-497, 21 October 2012, station K18, 40°50’26’’N, 29°07’33’’E 15-30 m, serpulid reef, 1 specimen; ESFM-POL /2013-1364, 08 June 2013, station Y9, 40°28’09’’N, 27°11’14’’E, 50 m, mud, 2 specimens; ESFM-POL /2013-1377, 09 June 2013, station Y17, 40°39’58’’N, 27°41’08’’E, 50 m, mud, 1 specimen; ESFM-POL /2013-1382, 10 June 2013, station Y18, 40°54’28’’N, 27°33’24’’E, 100 m, mud with shell fragments, 2 specimens; ESFM-POL /2013-1383, 12 June 2013, station Y19, 40°56’10’’N, 27°44’16’’E, 100 m, muddy sand, 4 specimens; ESFM-POL /2013-1101, 16 June 2013, station Y22, 40°23’22’’N, 27°59’46’’E, 50 m, mud, 1 specimen; ESFM-POL /2013-1103, 16 June 2013, station Y24, 41°03’08’’N, 28°08’44’’E, 25 m, maerl bed, 17 specimens; ESFM-POL /2013-1391, 16 June 2013, station Y24, 41°00’16’’N, 28°07’50’’E, 50 m, muddy sand with shell fragment, 92 specimens; ESFM-POL /2013-1392, 15 June 2013, station Y24, 40°57’20’’N, 28°07’21’’E, 100 m, muddy sand with shell fragments, 5 specimens; ESFM-POL /2013-1104, 16 June 2013, station Y25, 40°24’48’’N, 28°20’41’’E, 25 m, sandy mud with Amphiura filiformis , 1 specimen; ESFM-POL /2013-1112, 17 June 2013, station Y29, 40°32’39’’N, 28°46’42’’E, 50 m, muddy sand, 1 specimen; ESFM-POL /2013-1113, 17 June 2013, station Y29, 40°33’32’’N, 28°44’58’’E, 100 m, muddy sand, 17 specimens; ESFM-POL /2013-1408, 14 June 2013, station Y31, 40°56’40’’N, 28°25’15’’E, 100 m, sandy mud with shell fragments, 5 specimens; ESFM- POL/2013-1418, 20 June 2013, station Y41, 4043’18’’N, 2924’58’’E, 100 m, mud, 1 specimen; ESFM-POL /2013- 1116, 20 June 2013, station Y42, 40°45’43’’N, 29°29’39’’E, 50 m, mud, 17 specimens.

Description. Holotype complete, 6.56 mm long (4.9–13.6 mm long in complete paratypes), 0.20 mm wide at chaetiger 10 (0.16-0.29 mm wide in paratypes), with 60 chaetigers (40–90 chaetigers in complete paratypes). Color of holotype in alcohol light yellowish (yellowish and dull white in paratypes) ( Fig. 15A View FIGURE 15 ). Body thin, cylindrical; prebranchial, branchial and postbranchial regions similar in width, gradually thinner towards posterior region ( Figs 13A View FIGURE 13 , 14A View FIGURE 14 ; 15A View FIGURE 15 ). Antero-dorsal side of body slightly swollen from chaetiger 1 to chaetiger 5 ( Figs 13A View FIGURE 13 ; 15A View FIGURE 15 ). A dense ciliary band on mid-dorsal transversal line of each prebranchial and branchial chaetigers ( Fig. 16A View FIGURE 16 ; 18A View FIGURE 18 ); ciliary bands absent on ventral side ( Figs 16B View FIGURE 16 ; 18B View FIGURE 18 ). Prostomium triangular; slightly longer than wide (length/ width: 1.08); anterior part rounded. A semicircular eversible palpode placed on anterior end of prostomium, bear- ing irregularly arranged pores with flexible cilia ( Figs 14A View FIGURE 14 ; 18A, B View FIGURE 18 ); eyes present on prostomium. An oval lateral organ present on lateral sides of prostomium and peristomuim, with about 60 irregular pores ( Figs 17 View FIGURE 17 A–C; 18A, C). 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. 18C View FIGURE 18 ). Peristomium fused with prostomium; starting point posterior to nuchal organs; highly reduced on dorsal view but much more developed on ventral side ( Fig. 18 View FIGURE 18 A–C). A short additional transversal ciliary band existing on dorsal side of prostomium, just anterior to nu- chal organs ( Fig. 18C View FIGURE 18 ). A pair of nuchal organs as deep slits placed dorso-laterally on posterior end of prostomium; cilia in nuchal organ well extending out of slits ( Figs 16C View FIGURE 16 ; 17C View FIGURE 17 ; 18C View FIGURE 18 ); without pigmentation in holotype, but with two brownish spots on posterior part in most paratypes ( Figs 14A View FIGURE 14 ; 15C View FIGURE 15 ). Mouth with eight buccal lips; two lips on anterior part, six lips on posterior part, extending to anterior margin of chaetiger 2 ( Fig. 18B View FIGURE 18 ). Proboscis without lobes, with dense ciliation ( Figs 15B View FIGURE 15 ; 16B View FIGURE 16 ). Lateral sense organs as an oval ridge located on ventral side of noto- podial postchaetal lobes in each chaetigers ( Figs 18A View FIGURE 18 ; 19C View FIGURE 19 ; 20A View FIGURE 20 ; 21 View FIGURE 21 A–C); with flexible cilia distinctly protruding from opening or embedded into pore ( Fig. 20A View FIGURE 20 ), showing its retractable character; lateral sense organs starting from chaetiger 1 to end of body; oval shaped with irregularly clustered pores; with ca. 8–9 pores (long axis: ca. 4 μm) in prebranchial region, with ca. 16–18 pores (long axis: 4–5 μm) in branchial region, with ca. 14–18 pores (long axis: 6–10 μm) in posterior region. Branchiae eight pairs in holotype, 6–11 pairs in paratypes (beginning on chaetiger 4). Branchiae cylindro-conical with a rounded tip; dense ciliary bands present on middle line ( Figs 16A View FIGURE 16 ; 19B, C View FIGURE 19 ); shorter than segment width, first pair slightly shorter than second one, last pair of branchiae shorter than the others ( Figs 13A View FIGURE 13 ; 15A View FIGURE 15 ; 16A View FIGURE 16 ); 159 μm long in anterior region, 177 μm long in middle region, 139 μm long in posterior region. Notopodial postchaetal lobes from chaetiger 1, short, cirriform, increasing in length to chaetiger 3 in pre- branchial region ( Figs 13A, B View FIGURE 13 ; 14A View FIGURE 14 ; 15C View FIGURE 15 ); longer and finger-like in branchial region, but shorter, with an enlarged base and weakly jointed on last 2–3 branchial ( Figs 13A View FIGURE 13 ; 14 View FIGURE 14 A–C; 15D, E); short, triangular and weakly jointed in postbranchial region ( Figs 13C View FIGURE 13 ; 14A, D, E View FIGURE 14 ; 15 View FIGURE 15 F–J); becoming longer and filiform, with weakly jointed base in preanal region ( Figs 14G View FIGURE 14 ; 15 View FIGURE 15 K–L). Neuropodial postchaetal lobes absent. Three types of chaetae: limbate, capillary and lyrate. Limbate chaetae hirsute, present on both notopodia of chaetigers 1–14 (chaetal length: 169-234 μm) and neuropodia (length: 167–270 μm). Notopodial and neuropodial capillary chaetae from chaetiger 15 to pygidium; 223–327 μm long in middle region; 225–278 μm long in posterior region. Lyrate chaetae from chaetiger 2 to end of branchial region, all of them of a single type (type I), with unequal branch lengths and equal branch thickness; num- bering 2–4 on anterior chaetigers, 41–54 μm long, bearing dense hairs on shaft and at conjunction between branches ( Figs 13B View FIGURE 13 ; 19 View FIGURE 19 A–C; 20A, B), long branch 2.5–3.5 times longer than short one, inner teeth discernible; numbering 1 in posterior chaetigers, 60–81 μm long, shaft without hairs long branch 4–4.5 times longer than short branch, inner teeth discernible ( Figs 13C View FIGURE 13 ; 15G View FIGURE 15 ; 20A, B, D View FIGURE 20 ).

Notopodia of anterior region bearing 3–4 lyrate chaeta and 10–16 limbate chaetae; those of middle region bear- ing 4–10 capillary chaetae and 1–2 lyrate chaetae; those of posterior region bearing 6–8 capillary chaetae and one lyrate chaetae. Neuropodia of anterior region bearing 12–18 limbate chaetae; those of middle region bearing capil- lary 4-9 capillary chaetae; those of posterior region bearing 6–9 capillary chaetae. Pygidium rounded with three anal cirri; two dorso-lateral cirri (thin, digitiform, 35–38 μm long) and one mid-ventral cirrus (thick, 20 μm long); anal aperture on dorsal side, with dense cilia ( Figs 14G View FIGURE 14 ; 15A View FIGURE 15 , K–L; 16D).

Reproduction. Some specimens have eggs or sperm packages in their coelomic cavities. Eggs usually present from chaetiger 24 onwards; each segment carries 4– 5 eggs. The diameter of eggs varies between 32 and 140 μm. Sperm packages as white masses, from chaetiger 15 onwards. No specific coloration exists on or around the nuchal organs of the male and female individuals of the species.

Remarks. Paradoneis longifurcata n. sp. is mainly characterized by having long notopodial postchaetal lobes in the post-branchial region that are enlarged and weakly jointed basally; and a high ratio between the lengths of long and short branches of the lyrate chaetae.

The main morphological differences between P. longifurcata n. sp. and the other Paradoneis species are summarized in Table 1 View TABLE 1 . The morphology of Paradoneis longifurcata n.sp. coincides to some extent with those of P. lyra and P. forticirrata , but differs from them in the following characters. (1) The number of the prebranchial chaetigers is always three in P. longifurcata n. sp. and P. lyra , but 3–4 in P. forticirrata ; (2) The number of branchial pairs is lower (7–11 pairs) in P. longifurcata n. sp. in comparison with P. lyra (8–14 pairs) or with P. forticirrata (15–17 pairs); (3) Notopodial postchaetal lobes are finger-shaped with an enlarged, jointed base in P. longifurcata n.sp., but without an enlarged, jointed base in P. lyra and P. forticirrata ; (4) The maximum ratio between long and short TABLE 1 View TABLE 1 . List of all described Paradoneis species with selected diagnostic features. branches of lyrate chaetae is up to 4.5 in P. longifurcata n. sp. and up to 2–3 in P. lyra ; there is no information about P. forticirrata .

Habitat and Distribution. This species was found in soft substrata and in serpulid reefs at depths ranging from 15 to 100 m in the Sea of Marmara.

Etymology. This species name refers to the morphology of the lyrate chaeta that has one branch that is 4–4.5 times longer than the other one.

Kingdom

Animalia

Phylum

Annelida

Class

Polychaeta

Family

Paraonidae

Genus

Paradoneis