Malmgreniella castanea (McIntosh, 1876)

Barnich, R. & Fiege, D., 2001, Mediterranean species of Malmgreniella Hartman, 1967 Polychaeta: Polynoidae: Polynoinae), including the description of a species, Journal of Natural History 35, pp. 1119-1142 : 1133-1135

Malmgreniella castanea (McIntosh, 1876)

(®gure 5A±J)

Malmgrenia castanea McIntosh, 1876: 376 , plate 67 ®gures 15±19; McIntosh, 1900: 379, plate 28 ®gure 15, plate 30 ®gure 5, plate 33 ®gure 10, plate 40 ®gures 23±26; Fauvel, 1923: 48, ®gure 17h±m; Campoy, 1982: 80 [part]; Chambers and Muir, 1997: 124, ®gure 36.

Harmothoe lunulata : PeÂreÁs, 1954: 92; Bellan, 1964: 27 [part]. [not Delle Chiaje, 1830]

Harmothoe castanea: Tebble and Chambers, 1982: 47 , ®gures 15, 44, 45.

Malmgreniella castanea: Pettibone, 1993: 30 , ®gure 20; Hartmann-SchroÈder, 1996: 63, ®gure 19.

Type material. Malmgrenia castanea , SYNTYPES: Six specimens, Shetland Islands , 25 mi NNE of North Unst, 155 m, shell and sand, 1868, on Spatangus purpureus O. F. MuÈller , leg. G. JeOEreys, BMNH 1921.5 .1.507, ZMB 1162, USNM 54714 . Two specimens, SW Ireland, 50 mi W Valentia, 146±201 m, leg. G. JeOEreys, BMNH 1921.5 .1.509. One specimen, Channel Islands, oOE St. Peter Port, Guernsey, ± 13 m, 1868, BMNH 1921.5 .1.508. (Type material not checked for this study) .

Material examined. Two specimens, St. 430, 25 February 1954, sur Spatangus purpureus , 100 m au large de Cassis, sable vaseux, det. J. M. PeÂreÁs (1954) as Harmothoe lunulata (Delle Chiaje) , Coll. PeÂreÁs. One specimen, Mediterranean: sand with Amphioxus de Jarre (island near Marseille), 8 m, on oral surface of heart urchin Spatangus purpureus , leg. and don. G. Bellan, det. M. Pettibone, USNM 59929.

Diagnosis. Elytral surface with patch of microtubercles in anterior part, elytral margin smooth. Short and long notochaetae stout with pointed tips and faint rows

spines; upper and middle neurochaetae bidentate with minute secondary tooth, lower neurochaetae unidentate. Antennae and cirri smooth, not pigmented basally in preserved material).

Description. Prostomium bilobed, without cephalic peaks; median antenna with ceratophore in anterior notch, style smooth, tapering to ®liform tip; lateral antennae with ceratophores inserted terminoventrally and with short, smooth, tapering styles; 1134 IG. 5. Malmgreniella castanea ( USNM 59929): (A) anterior end; dorsal view; (B) left anterior elytron; (C) detail of anterior margin of same; (D) middle right cirrigerous parapodium; style of dorsal cirrus unusually coiled; posterior view; (E) notochaeta; (F) tip of same; (G) middle neurochaeta; (H) tip of upper neurochaeta; (I) tip of middle neurochaeta; (J) tip of lower neurochaeta (scales 5 1 mm for A, B; 100 m m for C; 500 m m for D; 250 m m for E, G; 50 m m for F, H, I, J).

median and lateral antennae not distinctly pigmented basally; palps smooth, stout, tapering; anterior pair of eyes dorsolaterally in front of widest part of prostomium, posterior pair dorsally near hind margin (®gure 5A). Tentaculophores inserted laterally to prostomium, without chaetae on inner side, each with a pair of smooth dorsal and ventral tentacular cirri, tapering to ®liform tip; tentacular cirri not distinctly pigmented basally (®gure 5A). Second segment with ®rst pair of elytra, biramous parapodia, and long ventral buccal cirri, similar to tentacular cirri.

Fifteen pairs of elytra; elytral surface with patch of conical microtubercles in anterior part and few scattered, dark papillae in posterior part, elytral margin smooth; with or without slightly visible C-shaped pigmentation (®gure 5B, C). Styles

dorsal cirri smooth, tapering to ®liform tip, not distinctly pigmented basally, extending to tips of neurochaetae; styles of ventral cirri smooth, tapering, shorter than neuropodia (®gure 5A, D).

Parapodia biramous, both rami with single aciculum penetrating epidermis; notopodia with short, rounded prechaetal and longer, pointed postchaetal acicular lobe, neuropodia with subconical prechaetal acicular lobe with thick, digitiform supra-acicular process and shorter rounded postchaetal lobe (®gure 5D). Short and long notochaetae stout with pointed tips and faint rows of spines (®gure 5E, F); neurochaetae with rows of spines only in distal part and with pointed tips, upper and middle neurochaetae bidentate with minute secondary tooth, lower neurochaetae unidentate (®gure 5G±J).

Remarks. Malmgreniella castanea shows similar characters to M. lunulata (Delle Chiaje, 1830) and M. andreapolis (McIntosh, 1874) , but the chaetal characteristics and the smooth, non-papillate and non-pigmente d cirri and antennae clearly separate

from these species (see also Remarks for M. lunulata and M. andreapolis ).

Measurements. Specimen ®gured ( USNM 59929): L 16 mm, W 3.5 mm for 39 chaetigers.

Distribution. Mediterranean Sea: western Mediterranean. Elsewhere: northeast Atlantic (see also Pettibone, 1993; Chambers and Muir, 1997). Due to confusion with M. lunulata , all other literature records need to be checked.

Habitat. On sandy substrata, commensal with burrowing heart-urchin Spatangus purpureus O. F. MuÈller ; known from 8 to 100 m depth; elsewhere recorded from up to 878 m depth (cf. Pettibone, 1993).