Nephtys hombergii Savigny

Ravara, Ascensão, Cunha, Marina R. & Pleijel, Fredrik, 2010, Nephtyidae (Annelida, Polychaeta) from southern Europe 2682, Zootaxa 2682 (1), pp. 1-68 : 45-48

Nephtys hombergii Savigny in Lamarck, 1818

Figures 11 , 17

Nephthys hombergii Savigny in Lamarck, 1818: 314; Savigny 1822: 34;? Ehlers 1868: 619, figs. 7 and 42 (partim); Théel

1879: 26; Langerhans 1880: 302; Saint-Joseph 1894: 3, pl. I, figs. 1–13 (partim); Charrier 1907: 297–306; McIntosh

1908: 17 (partim); Heinen 1911: 16, figs. 3–4 (partim); Fauvel 1923: 367, fig. 143A–D (partim); Fauvel 1936: 40;

Ditlevsen 1929: 20; Day 1953: 431; Tebble 1955: 102; Foret-Montardo 1969: 810, pl. I, figs. 6–7; Rullier and

Amoureux 1970: 124. Nereis scolopendroides Chiaje 1822 : pl. XXVII, figs. 8, 13 and 22–27; Chiaje 1825: 401, 424. Nephthys neapolitana Grube 1840: 71 . Nephthys macandrewi Baird 1873: 94 . Nephthys scolopendroides Audouin and Milne Edwards 1833: 260 ; Michaelsen 1896: 57 (partim). Nephthys hombergii var. kersivalensis McIntosh 1908: 20 (partim). Nephthys hombergii var. vasculosa McIntosh 1908: 21 (partim). Nephthys hombergi Augener 1913: 197 , 202, fig. 26 (partim). Nephtys hombergi Fauchald 1963: 3 , figs. 1G, 2D and 3E; Wolff 1968: 4, fig. 6; Kirkegaard 1992: 336, fig. 164 (partim). Nephtys hombergii Hartman 1950: 101 , pl. 17, fig. 2; Eliason 1962: 249; Gibbs 1969: 320 (juvenile stages); Hartmann-

Schröder 1971: 215, fig. 70A–B (partim); Hartmann-Schröder 1974: 88 (partim); Clay 1974; Hartmann-Schröder

1977: 88 (partim); not Hartmann-Schröder 1981: 31; not Hartmann-Schröder 1982 (= N. assimilis ): 10; Campoy

1982: 515; Laborda 1987: 132, figs. 2, 5, 10, 14, 16; Rainer 1991: 73, fig. 2B; Hartmann-Schröder 1996: 224, fig.

98; Böggemann 1997: 80, fig. 56; Dnestrovskaya and Jirkov 2001: 199, 1 fig; Laborda 2004: 402, fig. 147D–E. Nephtys (Nephtys) hombergii Day 1967: 344 , fig. 15.2G–I. not Nephtys hombergii var. kersivalensis Hartmann-Schröder 1971: 217 , fig. 70C.

Type locality. Le Havre, coast of France .

Material examined. Atlantic Ocean. North Sea, Sweden, Koster area , western coast of Sweden: 8 Aug 2001, 1 incomplete spm ( MB36000136 ) ; Kattegat, Anholt-Lysegrund : Jan 1873, 4 incomplete spms ( GNHM Polych. 1232, syntypes of N. emarginata ) . Scotland, St. Andrews, Fyfe , “Young Wom Area”: 1 complete spm ( NHM 1951.5.2.59) . England, off Northumberland: 48 m, Apr 2008, 2 incomplete spms ( DBUA 01056-01 ) , and 1 incomplete spm ( MB36000146 ) ; Blyth , Northumberland: intertidal, Nov 2008, 1 complete and 1 incomplete spm, ( MB36000147 and MB36000148 ) . SW Ireland, off Valentia Island : 1–160 fms, 6 spms ( NHM 1921.5.1.796-806, syntypes of N. kersivalensis ) . NW France, Bretagne, Roscoff : low tide, Sep 2001, 1 incomplete spm ( DBUA 01039-01 ) , and 1 incomplete spm ( MB36000134 ) ; Le Guillec Estuary : intertidal, 1 incomplete spm ( DBUA 00213-01 ) . Spain, Coruña : 1 complete spm ( NHM 1863.9 .19.12, holotype of N. macandrewi ) . Portugal, Vila Praia de Âncora : 41º48.83’N, 8º52.24’W, 10 m, Sep 2005, 3 complete spms ( DBUA 00851-01 ) ; Matosinhos : subtidal, Oct 2005, 3 incomplete spms ( DBUA 00852-01 , 02 ) ; Ria de Aveiro: intertidal, Apr 2005, 34 complete and 14 incomplete spms ( DBUA 00853-01 ) , and 1 incomplete spm ( MB36000118 ) ; Off Aveiro: cruise AVEIRO 94, RV Côte d’Aquitaine , 40º43.592’N, 8º45.580’W, 14.4 m, grab, Jul–Aug 1994, 2 complete spms ( DBUA 00059-02 ) ; 40º38.561’N, 9º02.683’W, 79.1 m, grab, Jul–Aug 1994, 2 incomplete spms ( DBUA 00059-07 ) ; 40º39.617’N, 8º52.265’W, 38.4 m, grab, Jul–Aug 1994, 1 incomplete spm ( DBUA 00059-08 ) ; 40º38.615’N, 8º45.985’W, 8.7 m, grab, Jul–Aug 1994, 1 complete spm ( DBUA 00059-09 ) ; 40º38.564’N, 8º47.293’W, 13.8 m, grab, Jul–Aug 1994, 1 incomplete spm ( DBUA 00059-010 ) ; 40º38.610’N, 8º45.618’W, 21.9 m, grab, Jul–Aug 1994, 2 complete spms ( DBUA 00059-011 ) ; 40º37.594’N, 8º47.574’W, 17.3 m, grab, Jul–Aug 1994, 1 incomplete spm ( DBUA 00059-012 ) ; cruise AVEIRO 95, RV Côte d’Aquitaine , 40º47.620’N, 9º04.853’W, 95.7 m, grab, 3 Aug 1995, 4 incomplete spms ( DBUA 00059-01 ) ; 40º43.673’N, 9º06.387’W, 98.6 m, grab, 29 Jul 1995, 1 complete spm ( DBUA 00059-03 ) ; 40º43.486’N, 9º11.955’W, 135.7 m, grab, 29 Jul 1995, 1 incomplete spm ( DBUA 00059-04 ) ; 40º33.514’N, 9º09.365’W, 96.3 m, grab, 28 Jul 1995, 1 incomplete spm ( DBUA 00059-05 ) ; 40º33.215’N, 9º14.179’W, 130.1 m, grab, 28 Jul 1995 ,1 incomplete spm ( DBUA 00059-06 ) ; Figueira da Foz, Mondego estuary: 40º08’43.352”N, 08º52’06.218”W, 8.5 m, Oct 2005, 1 incomplete spms (in collection of M. Pardal), and Mar 2006, 1 complete spm (in collection of M. Pardal) ; 40º08’36.600”N, 08º51’23.972”W, 7.5 m, Oct 2005, 2 incomplete spms (in collection of M. Pardal), and Mar 2006, 3 complete and 2 incomplete spms (in collection of M. Pardal); 40º07’57.270”N, 08º51’07.744”W, 2.0 m, Mar 2006, 3 complete spms (in collection of M. Pardal); Foz do Arelho : intertidal, Apr 2006, 6 complete and 7 incomplete spms, ( DBUA 00854-01 ) , and 2 incomplete spms ( MB36000119 and MB36000120 ) ; Off Cascais : 38º39’– 38º42’N, 9º25’– 9º30’W, 40 m, Jul 2005, 1 complete and 5 incomplete spms ( DBUA 00855 ) , and 2 incomplete spms ( MB36000121 and MB36000161 ) ; Jan 2006, 4 complete and 11 incomplete spms ( DBUA 01053 ) ; Sado Estuary : 38º31.075’N, 8º54.056' W, 10 m, Jun 2005, 1 complete spm ( DBUA 00856-01 ) ; 38º30.582’N, 8º51.993' W, 11 m, Jun 2005, 1 complete spm ( DBUA 00856-02 ) ; Vila Nova de Milfontes : 37º43.30’N, 8º47.25’W, shallow water, July 2006, 3 complete and 6 incomplete spms ( DBUA 00857-01 ) , and 1 incomplete spm ( MB36000122 ) ; Portinho de Ferragudo : 37º07.48’N, 8º31.24’W, shallow water, Jul 2006, 10 complete and 1 incomplete spms ( DBUA 00858-01 and 02), and 2 incomplete spms ( MB36000123 and MB36000124 ) ; Ria Formosa, Ilha da Armona : 37º01.55’N, 7º50.40’W, shallow water, July 2006, 3 complete spms ( DBUA 00859-01 ) , and 1 complete spm ( MB36000125 ) ; Ria Formosa, Faro beach: 37º00.481’N, 7º59.598’W, 0.7 m, Mar 2006, 1 complete spm ( DBUA 00860-01 ) , 1 incomplete spm ( DBUA 00860-02 ) , and 1 incomplete spm ( MB36000126 ) . Madeira Island, Machico : 15–32m, July 1999, 2 complete and 2 incomplete spms (in collection of A. Ravara) ; 10 m, grab, Jun 1992, 1 complete spm ( MMF.25182 as N. caeca ) .

Mediterranean Sea. Naples: 3 complete spms ( NHM 1919.11.6.31-33); 2 complete spms ( NHM 1890.6.7.8); 3 incomplete spms ( NHM 1951.5.1.4); Israel, off Caesarea: 1 complete spm ( NHM 1955.10.12.40 as Aglaophamus inermis ).

Atlantic/Indian Ocean. South Africa, South African Collection of Prof. J. H. Day, Nov 1960, 3 complete and 6 incomplete spms ( NHM 1961.9.71/79); 1 incomplete spm ( NHM 1961.19.76/81) .

Description. Examined specimens up to 160 mm long for up to 147 chaetigers. See Fig. 11 for length and width measurements. Body slightly wider anteriorly, gradually tapering from median region to pygidium. Poor dorsal delineation between anterior segments. Colour cream in ethanol or with brownish-reddish pigment dorsaly on anterior and median setigers of larger specimens; prostomium with brown pigment spot in anterior region; chaetae amber in anterior chaetigers, darker in posterior ones; aciculae amber, sometimes with reddish pigment around tip. One pair of eyes visible only in small specimens at level of chaetiger 2. Pharynx distal region with 10 pairs of terminal bifid papillae, separated by small dorsal and ventral elevation; middorsal papilla cirriform, long ( Fig. 11D ); midventral papilla normally absent (if present equal in length to distalmost subterminal papillae); subdistal region with 22 rows of 2–5 conical subterminal papillae (papillae of lateral rows slightly longer than dorsal or ventral ones), extending over 1/3 length of pharynx ( Fig. 17A ); proximal region smooth. Jaws conical, deeply incised at base ( Fig. 17B ). Prostomium subrectangular, anterior margin slightly convex, posterior margin V-shaped extending over first chaetiger (not very well deliniated; Fig. 17C ); antennae and palps conical; palps slightly longer than antennae, inserted ventrolaterally on median region of prostomium. Nuchal organs rounded, conspicuous. Parapodia biramous; interramal space “Ushaped”, with ciliated patches. Parapodia of chaetiger 1 ( Fig. 17D ) smaller than subsequent ones, directed anteriorly, parallel to prostomium; notopodial acicular lobes conical, pre- and postchaetal lamellae well developed but not extending beyond acicular lobes, prechaetal lamellae slightly bilobed, postchaetal lamellae rounded; neuropodial pre- and postchaetal lamellae forming a cylinder covering acicular lobes; dorsal cirri poorly developed, rounded, lamelliform ( Fig. 11C ); ventral cirri conical, with broad base and tapering distally. Acicular lobes of following parapodia conical to rounded, with a distinct papilliform outgrowth on interramal side of aciculae; prechaetal lamellae well developed but not extending much beyond acicular lobes, bilobed (in neuropodium, dorsal lobe much larger than ventral one); postchaetal lamellae extending beyond acicular lobes, truncated in notopodium, rounded and much larger in neuropodium; dorsal cirri digitiform; ventral cirri conical ( Fig. 17E–H ). Branchiae recurved, long and cirriform, moderately ciliated, with papilliform basal projection; present from chaetigers 4 or 5 (rarely 6) to near posterior end; occupy half of interramal space when fully developed. Chaetae of three kinds: distally barred chaetae in preacicular position ( Fig. 17I ), spinulated chaetae in postacicular position ( Fig. 17J ), and capillary chaetae in neuropodia of chaetiger 1. One acicula per ramus, posterior ones with curved tips.

Remarks. Nephtys hombergii has a wide latitudinal distribution in the eastern Atlantic (from the Barents Sea to South Africa). We suggest that the northernmost as well as the southernmost records should be considered with caution. We examined one specimen from Iceland identified as N. hombergii (NHM 1954.1.1.198) that was in fact N. ciliata , and probably exist other misidentifications. Nephtys hombergii was one of the earlier described species and there are many old references that included several other species under this designation. Also the references from deeper locations (below 150 m depth) were not confirmed and should be considered with caution, since this species appears to be typical of shallower waters and is very abundant in coastal and estuarine habitats. Among all the specimens examined (from Sweden to South Africa, and Mediterranean Sea), some morphological differences between the northernmost and the southernmost specimens became apparent. Specimens from northern regions ( Sweden to N Portugal) are all very similar with same parapodial morphology, whereas specimens from southern regions (S Portugal, Madeira Island and Mediterranean Sea) present some minor variation in parapodial morphology. In these later specimens the neuropodial postchaetal lamellae are broader (more like N. assimilis but without vascularization), the notopodial postchaetal lamellae are also broader and some times slightly bilobed, the branchiae are shorter and thicker, and for some specimens the papilliform outgrowth of the acicular lobes is larger, giving the acicular lobes an almost bilobed appearance. The specimens from South Africa are even more distinct, with much longer postchaetal lamellae and very reduced papilliform outgrowth on acicular lobes. Apart from this small variation in parapodial morphology all specimens examined are in agreement with the above description and we could find no obvious reasons to separate them into different species. Nevertheless we consider that further investigation, specially using molecular analyses, is required to clarify this subject, with particular attention to the South African specimens.

Distribution. Atlantic Ocean (from Barents Sea to South Africa, including outer Baltic, Skagerrak, Kattegat, North Sea and the coast of France, Spain and Portugal); Mediterranean Sea ( Rainer 1991; Laborda 2004).

Habitat. Muddy or gravely sand, from the intertidal to continental shelf depths, also cited until 1000 m depth; tolerant to a wide range of salinity and temperature ( Rainer 1991; Laborda 2004).

Figures

FIGURE 11. Relationships between: A. Number of segments and body length. B. Body length and body width. C. Length of ventral cirri (VC) and dorsal cirri (DC) of chaetiger 1. D. Length of pharynx distalmost subterminal papillae and middorsal papilla. Nephtys assimilis. × N. hombergii. N. kersivalensis.

FIGURE 17. Nephtys hombergii. A. Pharynx, dorsal view. B. Jaw. C. Prostomium and anteriormost chaetigers, dorsal view. D. Right parapodium of chaetiger 1, posterior view. E. Left parapodium of chaetiger 10, anterior view. F. Left parapodium of chaetiger 20, anterior view. G. Left parapodium of chaetiger 40, anterior view. H. Left parapodium of chaetiger 80, anterior view. I. Preacicular chaeta from chaetiger 40. J. Postacicular chaeta from chaetiger 40.