Inermonephtys foretmontardoi, Ravara & Cunha & Pleijel, 2010

Ravara, Ascensão, Cunha, Marina R. & Pleijel, Fredrik, 2010, Nephtyidae (Annelida, Polychaeta) from southern Europe 2682, Zootaxa 2682 (1), pp. 1-68 : 21-23

Inermonephtys foretmontardoi sp. nov.

Figure 6

Nephthys (Aglaophamus) inermis McIntosh 1900b: 262 ; Foret-Montardo 1969: 820, pl. V, figs. 1–5; Bellan 1964b: 75 (not Ehlers, 1887).

Nephthys inermis Marenzeller 1904: 296 , 305; Fauvel 1923: 375, fig. 147 (partim); Bellan 1959: 326; Bellan 1960: 13; Bellan 1961: 169; Bellan 1964a: 275; Augener 1932: 679, fig. 3; not Fauvel 1933b: 47–50, fig. 3; Fauvel 1940: 11.

Nephtys (Aglaophamus) inermis Intes and Le Loeuff 1975: 303 .

Inermonephtys inermis? Campoy 1982: 504 ; Laborda 2004: 418, fig. 152D.

Etymology. The species is named for Dr. P. Foret-Montardo who provided the first accurate description of this species, although under the name of Nephthys (Aglaophamus) inermis Ehlers, 1887 ( Foret-Montardo 1969).

Type locality. Cape Finisterre (42º44’N, 9º23’W), NW Spain, 81 fms depth .

Material examined. Atlantic Ocean. England, Eddystone, Plymouth: 1 incomplete spm ( NHM 1969.301 as Nephtys longosetosa ). Spain , Cape Finisterre: coll. H. M. S. Porcupine, 42º44’N, 9º23’W, 81 fms, Jul 1870, 1 incomplete spm, holotype ( NHM 1921.5 .1.861, identified by McIntosh as Aglaophamus inermis ) ; 42º44’N, 9º23’W, 81 fms, Jul 1870, 3 incomplete spms, paratypes ( NHM 2009.143 – 144 , identified by McIntosh as Aglaophamus inermis ). SW Portugal : 37º14.1’N, 9º05.3’W, 145 m, May 1981, 1 incomplete spm (in collection of João Gil); 37º38.9’N, 8º53.1’W, 113 m, Oct 1981, 1 incomplete spm (in collection of João Gil); 37º38.9’N, 8º52.9’W, 113 m, Oct 1981, 1 incomplete spm (in collection of João Gil); 37º49.9’N, 8º56.8’W, 130 m, Dec 1981, 1 incomplete spm (in collection of João Gil).

Mediterranean Sea. Adriatic Sea: collection Pierre Fauvel (1948), 1 complete and 1 incomplete spm (MNHN A409).

Description. Holotype 28.8 mm long posteriorly incomplete specimen with 44 chaetigers. Body width including parapodia 3.6 mm, excluding parapodia 2.5 mm. Anterior segments poorly delineated. Colour in ethanol yellowish, without pigmentation; chaetae amber; aciculae brownish with dark tips. Eyes not visible. Pharynx smooth, without papillae. Jaws with spindle-shaped base and straight free margin. Prostomium subpentagonal, 0.58 mm long, 0.51 mm wide, anterior margin straight, posterior margin V-shaped and extending over first chaetiger ( Fig. 6A ); antennae absent; palps ovoid, very small (0.07 mm), inserted ventrolaterally on prostomium (not visible dorsally). Nuchal organs well developed, digitiform. Parapodia biramous; interramal space “U-shaped”, moderately ciliated. Parapodia of chaetiger 1 similar in size to subsequent ones, anteriorly directed, parallel to prostomium; notopodial acicular lobes rounded, prechaetal lamellae rudimentary, postchaetal lamellae extending beyond acicular lobes, rounded; neuropodial pre- and postchaetal lamellae forming a cylinder covering acicular lobe; dorsal and ventral cirri well developed, 0.24 mm long, conical. Anterior parapodial acicular lobes rounded, becoming conical in median parapodia and acutely pointed in posterior parapodia; prechaetal lamellae well developed but not extending beyond acicular lobes, rounded; postchaetal lamellae extending well beyond acicular lobes, rounded in notopodia of anterior chaetigers, becoming slender and leaf-like in median parapodia, slender in neuropodia; dorsal cirri conical in anterior parapodia (0.34 mm), cirriform in median parapodia (0.43 mm); ventral cirri conical, as long as neuropodial postchaetal lamellae (0.29 mm in anterior chaetigers, 0.34 mm in middle chaetigers) ( Fig. 6B–E ). Branchiae involute, thin and long, cirriform, moderately ciliated, with conspicuous conical basal projections; present from chaetiger 4; occupy half of interramal space when fully developed. Chaetae short (exposed length 1.2 mm), of three kinds: finely spinulated chaetae in pre- and postacicular position Fig. 6F–G ), lyriform chaetae with subequal rami in postacicular position ( Fig. 6H ) and capillary chaetae in the neuropodia of first chaetiger. Anteriormost parapodia with up to five aciculae in neuropodia and four in notopodia. Number of aciculae decreases gradually towards end of body. Single aciculae of posterior parapodia with curved tips. Smaller specimens have a lower number of aciculae ( Table 4).

anterior to posterior chaetigers according to specimen size.

Remarks. Inermonephtys foretmontardoi sp. nov. is here erected based on European specimens previously identified as I. inermis . Inermonephtys inermis was originally described as Nephtys (Aglaophamus) inermis by Ehlers (1887) from specimens found in Florida, and has up to now been considered to have a cosmopolitan distribution in temperate, tropical and subtropical seas (including Atlantic, Pacific and Indian Oceans) (e.g. Hartman 1940, 1950; Fauchald 1968; Day 1973; Taylor 1984; Kirkegaard 1995). We compared specimens previously identified as I. inermis from Europe with the holotype of I. inermis from Florida (MCZ 1088), and the observed differences justify the erection of a new species ( I. foretmontardoi sp. nov.). The main difference is the presence of well-developed neuropodial postchaetal lamellae (extending well beyond acicular lobes) in I. foretmontardoi sp. nov., while they are rudimentary in I. inermis . Also the prechaetal lamellae of both rami are more developed, although not extending beyond acicular lobes in the former, but rudimentary or poorly developed in the latter. Records of Inermonephtys inermis from European waters include specimens from Cape Finisterre and the Adriatic Sea ( McIntosh 1900b; Quatrefages 1904; Fauvel 1923), Alboran Sea (Mediterranean) and S Portugal ( Bellan 1959, 1960), and Marseille (Mediterranean) ( Foret-Montardo 1969). Campoy (1982) and Laborda (2004) also refer to Inermonephtys inermis as a member of the Iberian fauna. In some cases the descriptions and drawings provided by these authors were taken from the original description of I. inermis ( Ehlers 1887) but morphological differences in European specimens were already noticed by some authors. The brief description provided by Fauvel (1923), in Faune de France, matches the original description of I. inermis , although with some doubts regarding the presence of antennae, absence of eyes, and the rudimentary condition of the neuropodial postchaetal lamellae. The drawings were taken from the original description. The detailed description and drawings by Foret-Montardo (1969) as well as the brief description and a parapodium drawing by Laborda (2004) match the characters herein assigned to I. foretmontardoi . Although not confirmed from specimens, we assume that all European records of I. inermis belong to I. foretmontardoi sp. nov.. There are five more species described in the genus Inermonephtys , all from the Pacific ( Thailand, Viet Nam, Japan and Australia). The new species is distinguished from all these species by the chaetiger were branchiae start and the morphology of the parapodia.

Distribution. Atlantic Ocean (S England, Spain, Portugal); Mediterranean Sea (from Alboran Sea to Aegean Sea, and Adriatic Sea).

Habitat. Muddy and sandy sediments, 0–450 m depth ( Foret-Montardo 1969; Laborda 2004).

Figures

FIGURE 6. Inermonephtys foretmontardoi n. sp. A. Prostomium and anterior chaetigers, dorsal view. B. Right parapodium of chaetiger 10, anterior view. C. Same, posterior view. D. Right parapodium of chaetiger 30, anterior view. E. Same, posterior view. F. Preacicular chaeta from a posterior chaetiger. G. Postacicular chaetae from a posterior chaetiger. H. Lyriform chaeta from a posterior chaetiger.