Nephtys cirrosa Ehlers, 1868

Ravara, Ascensão, Cunha, Marina R. & Pleijel, Fredrik, 2010, Nephtyidae (Annelida, Polychaeta) from southern Europe 2682, Zootaxa 2682 (1), pp. 1-68 : 41-45

Nephtys cirrosa Ehlers, 1868

Figures 15 , 16

? Portelia rosea Quatrefages, 1865: 431 , pl. VII, fig. 12–15.

Nephthys cirrosa Ehlers, 1868: 624 , pl. XXIII, figs. 6–7, 37, 38; Saint-Joseph 1894: 20, pl. 1 fig. 19; McIntosh 1908: 36; Augener 1912: 199; Fauvel 1923: 369, fig. 144C–H; Fauvel 1936: 40; La Greca 1946: 277; Guille and Laubier 1966: 267; Gibbs 1969: 320 (juvenile stages); Foret-Montardo 1969: 812, pl. II, fig. 117; Hartmann-Schröder 1971: 214, fig. 69A–E; Hartmann-Schröder 1974: 208.

Nephtys cirrosa Wolff 1968: 4 , fig. 5; Kirkegaard 1969: 46, fig. 19; Campoy 1982: 512; Laborda 1987: 132, figs. 1, 3, 6, 11and12; Rainer 1991: 72, fig. 3F; Kirkegaard 1992: 334, fig. 163; Hartmann-Schröder 1996: 222, fig. 97; Dnestrovskaya and Jirkov 2001: 199, 1 fig; Laborda 2004: 400, fig. 147A–C.

Nephthys johnstoni McIntosh 1908: 34 (partim).

Nephtys ehlersi Heinen, 1911: 34 , pl. I, fig. 1 and 2.

Nephthys longisetosa Heinen 1911: 26 (partim).

Nephtys cf. cirrosa Böggemann 1997: 80 , fig. 55.

Type locality. England .

Material examined. Atlantic Ocean. North Sea, Scotland, St. Andrews: 2 complete and 1 incomplete spm ( NHM 1921.5.1.855/856); Fyfe , “Young Wom Area”: 1 complete spm ( NHM 1951.5 .2.59 as N. hombergii ). Irish Sea , Wales, Cemaes Bay : at low tide, Jul 1969, 1 incomplete spm ( NHM 1971.160 ) . Spain, Pontevedra, Alanzada beach: 42º27’03.61”N, 8º52’46.48”W, intertidal, Mar 2005, 1 complete spm ( DBUA 00843-01 ) ; Combarro : 42º26’01.47”N, 8º42’04.77”W, intertidal, Mar 2005, 2 incomplete spms ( DBUA 00843-02 ) ; Ensenada O Bao, O Grove : 42º27’24.49”N, 8º52’16.53”W, intertidal, Mar 2005, 4 complete spms ( DBUA 00843-03 ) , and 1 incomplete spm ( MB36000106 ) . Portugal, Vila Praia de Âncora : 41º49.26’N, 8º52.64’W, 12 m, grab, Aug 2001, 1 complete spm ( DBUA 00370-01 ) ; off Aveiro: cruise AVEIRO 94, RV Côte d’Aquitaine , 40º39.560’N’, 8º48.327’W, 22.3 m, grab, Jul–Aug 1994, 1 complete and 1 incomplete spms ( DBUA 00062- 01 ) ; 40º39.598’N, 8º49.561’W, 28.7 m, grab, Jul–Aug 1994, 1 incomplete spm ( DBUA 00062-02 ) ; 40º38.603’N, 8º50.038’W, 30.8 m, grab, Jul–Aug 1994, 2 incomplete spms ( DBUA 00062-03 ) ; cruise AVEIRO 95, RV Côte d’Aquitaine , 40º48.578’N, 8º44.192’W, 15.6 m, grab, 1 Aug 1995, 1 complete and 6 incomplete spms ( DBUA 00062-04 ) ; Ria de Aveiro: subtidal, grab, Mar 1993, 5 complete and 3 incomplete spms ( DBUA 00097-01 ) ; 1 complete and 7 incomplete spms ( DBUA 00097-02 ) ; 2 complete spms ( DBUA 00097-03 ) ; 1 incomplete spm ( DBUA 00097-04 ) ; Figueira da Foz, Mondego estuary: 40º08’43.352”N, 08º52’06.218”W, 8.5 m, Mar 2006 1 incomplete spm, (in collection of M. Pardal) ; 40º07’57.270”N, 08º51’07,744”W, 2.0 m, Nov 2005, 11 incomplete spms (in collection of M. Pardal), and Mar 2006, 2 complete spms (in collection of M. Pardal); 40º07’29.447”N, 08º50’47.313”W, 2.5 m, Nov 2005, 13 incomplete spms (in collection of M. Pardal); 5.2 m, Nov 2005, 2 incomplete spms (in collection of M. Pardal); 40º08’33.179”N, 08º49’38.073”W, 4.5 m, Nov 2005, 10 incomplete spms (in collection of M. Pardal), and Mar 2006, 4 complete spms (in collection of M. Pardal); 40º08’21,405”N, 08º48’55.126”W, 5.2 m, Nov 2005, 5 incomplete spms (in collection of M. Pardal), and Mar 2006, 2 complete spms (in collection of M. Pardal); Sado Estuary : 38º31.075’N, 8º54.056’W, 10 m, Jun 2005, 1 complete spm ( DBUA 00844-01 ) ; Lisboa, Trafaria : 38º40.31’N, 9º14.20’W, shallow water, Jul 2006, 1 complete spm ( MB36000107 ) ; Setúbal, Troia Peninsula : 38º26.25’N, 9º06.76’W, shallow water, Jul 2006, 12 complete and 11 incomplete spms ( DBUA 00846-01 ) , and 2 incomplete spms ( MB36000108 and MB36000109 ) ; Sines : 37º58.15’N, 8º52.29’W, shallow water, Jul 2006, 1 complete spm ( DBUA 00847-01 ) , and 2 incomplete spms ( MB36000110 and MB36000111 ) ; Vila Nova de Milfontes : 37º43.30’N, 8º47.25’W, shallow water, Jul 2006, 6 complete and 6 incomplete spms ( DBUA 00848-01 ) , and 1 incomplete spm ( MB36000112 ) ; Ria do Alvôr : 37º07.22’N, 8º37.14’W, shallow water, Jul 2006, 8 complete and 5 incomplete spms ( DBUA 00849-01 ) , and 3 incomplete spms ( MB36000113 , MB36000114 and MB36000115 ) ; Portinho de Ferragudo : 37º07.48’N, 8º31.24’W, shallow water, Jul 2006, 4 complete and 5 incomplete spms ( DBUA 00850-01 ) , and 2 incomplete spms ( MB36000116 and MB36000117 ) .

Description. Examined specimens up to 84 mm long for up to 99 chaetigers. See Fig. 16 for length and width measurements. Body slender, slightly wider anteriorly, gradually tapering from median region to pygidium. Poor dorsal delineation between anterior segments. Colour in ethanol yellowish-white; prostomium of some specimens with median pigment spot on anterior region and some orange pigmentation posteriorly; chaetae and aciculae amber. One pair of eyes visible only in small specimens at the level of chaetigers 1–2. Pharynx distal region with 10 pairs of terminal bifid papillae, separated by dorsal and ventral gap; middorsal papilla cirriform, similar in size or longer than distalmost subterminal papillae ( Fig. 16D ); midventral papillae absent. Subdistal region with 22 rows of 4–9 long, cirriform subterminal papillae, extending to base of pharynx (proximal ones may be very small) ( Fig. 15A ); proximal region smooth. Jaws conical ( Fig. 15B ). Prostomium subpentagonal; anterior and lateral margins convex, giving prostomium a rounded appearance; posterior margin V-shaped, extending over first chaetiger; antennae and palps long, conical; palps longer than antennae, inserted ventrolaterally on median region of prostomium. Nuchal organs rounded. Parapodia biramous; interramal space “U-shaped”, heavily ciliated. Parapodia of chaetiger 1 smaller than subsequent ones, directed anteriorly, parallel to prostomium; notopodial acicular lobes conical, pre- and postchaetal lamella well developed but not extending beyond acicular lobes, rounded; neuropodial pre- and postchaetal lamellae forming a cylinder covering acicular lobes; dorsal cirri poorly developed ( Fig. 16C ); ventral cirri cirriform with slightly broad base. Notopodial acicular lobes of following parapodia rounded or slightly bilobed (with acicula in the ventral lobe) in anterior and median parapodia, conical in posterior parapodia; neuropodial acicular lobe conical; notopodial prechaetal lamellae rudimentary and rounded or well developed and bilobed, postchaetal lamellae extending beyond acicular lobes, rounded; neuropodial prechaetal lamellae well developed but not extending beyond acicular lobes, rounded or slightly bilobed, directed dorsaly and surrounding the dorsal part of the acicular lobe, rudimentary in posterior parapodia; postchaetal lamellae extending beyond acicular lobes, rounded; dorsal cirri conical to cirriform, equal in length or longer than branchiae on the last chaetigers; ventral cirri conical, lamelliform ( Fig. 15C–G, K–M ). Branchiae recurved, cirriform, thick in anterior and posterior parapodia, heavily ciliated, with small rounded papillae-like basal projection; present from chaetiger 4 to near posterior end; occupy all interramal space when fully developed; strongly decreases in size posteriorly, reaching the same length as dorsal cirri in posteriormost chaetigers. Chaetae of three kinds: barred chaetae in preacicular position ( Fig. 15H ), very finely spinulated chaetae in postacicular position ( Fig. 15I ), and capillary chaetae in neuropodia of chaetiger 1. One acicula per ramus, posterior ones with curved tips (very dificult to see; Fig. 15J ).

Remarks. Nephtys cirrosa was erected by Ehlers (1868) for specimens having acicular lobes rounded to bilobed and notopodial prechaetal lamellae rudimentary, apart from the other diagnostic features that separate it from other species. Later, Heinen (1911) described N. ehlersi from specimens having clearly bilobed notopodial prechaetal lamellae. Nephtys ehlersi was synonymized several times with other species such as N. hombergii and N. kersivalensis and was most recently synonymized with N. cirrosa by Rainer (1991), who presents a complete synonymy history for N. ehlersi . Rainer (1991) examined the type material of N. ehlersi and concluded that it conformed to the descriptions of N. cirrosa except for having bilobed prechaetal lamellae and lacking elongated dorsal cirri in posterior chaetigers. However, he also noted that the posterior chaetigers of the type specimen appeared to be in the process of regeneration. Thus, the elongated dorsal cirri, typical of N. cirrosa , might not be completely developed in that specimen. As for the bilobed prechaetal lamellae, Rainer also found this feature in at least some specimens of N. cirrosa from the North Sea. Foret- Montardo (1969) and Böggemann (1997) also found specimens with bilobed prechaetal lamellae in Marseille (Mediterranean Sea) and Germany, respectively. The specimens from Portugal examined in this study also have this type of lamellae. We thus consider the existence of two forms of N. cirrosa (A and B). Form A (originally described by Ehlers, 1868) with acicular lobes rounded to bilobed, notopodial prechaetal lamellae rudimentary and pharynx middorsal papilla subequal in size to the other subterminal papillae ( Fig. 15C–G ). Form B (described as N. ehlersi by Heinen 1911) has acicular lobes rounded to conical, notopodial prechaetal lamellae well developed and bilobed, and pharynx middorsal papilla longer than the other subterminal papillae ( Fig. 15K–M ). Furthermore, form B specimens usually have larger postchaetal lamellae and orange pigmentation in prostomium. In both forms the branchiae of posteriormost chaetigers are of same length as dorsal cirri, a consistent and diagnostic feature for the species N. cirrosa . Between these two extremes there are intermediate forms that make the distinction difficult between the two potentially different species. Although we have examined only a few specimens from northern regions, the northernmost specimens (from Scotland, Wales, North Sea and NW Spain) are mostly form A while southernmost specimens (from North Sea, Germany, Portugal and Marseille) match mostly form B. Further investigation and, possibly, molecular analyses are required to resolve this problem. If future research provides the evidence to consider two distinct species then the name N. ehlersi may be reinstated to designate the specimens ascribed presently to form B.

Distribution. Atlantic Ocean (Irish Sea; from North Sea to Côte d’Ivoire); Mediterranean Sea; Black Sea ( Foret-Montardo 1969; Rainer 1991; Laborda 2004).

Habitat. Clean to muddy, coarse and fine sands, from shallow waters to 45 m depth. Most common in clean, fine sand in the lower intertidal ( Rainer 1991; Laborda 2004).

Figures

FIGURE 15. Nephtys cirrosa (form A). A. Pharynx, prostomium and anteriormost chaetigers, dorsal view. B. Jaw. C. Right parapodium of chaetiger 10, anterior view. D. Right parapodium of chaetiger 21, anterior view. E. Right parapodium of chaetiger 40, anterior view. F. Right parapodium of chaetiger 80, anterior view. G. Right parapodium of chaetiger 88, anterior view. H. Preacicular chaeta from chaetiger 40. I. Postacicular chaeta from chaetiger 40. J. Acicula from chaetiger 88. Nephtys cirrosa (form B). K. Right parapodium of chaetiger 10, anterior view. L. Right parapodium of chaetiger 40, anterior view. M. Right parapodium of chaetiger 90, anterior view.

FIGURE 16. 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 cirrosa. N. paradoxa. Minute dorsal cirri were scored as 0.01.