Trophoniella fauveli, SALAzAR-Vallejo, 2012

SALAzAR-Vallejo, Sergio I., 2012, Revision of Trophoniella Hartman, 1959 (Polychaeta, Flabelligeridae), Zoosystema 34 (3), pp. 453-519 : 453-519

Trophoniella fauveli n. sp.

( Fig. 10 )

Stylarioides eruca – Fauvel 1937: 34 (non Claparède 1869).

TYPE MATERIAL. — Mediterranean Sea. Holotype ( MNHN 406 ), off Alexandria, Egypt, stn 61, 50 fathoms, mud, 30.X.1933, A. Steuer.

TYPE LOCALITY. — Off Alexandria, Egypt, in muddy bottoms at 100 m depth.

DISTRIBUTION. — Only known from the type locality in the eastern Mediterranean Sea, in muddy sediments at 100 m depth.

ETYMOLOGY. — This species is named to honor the late Dr Pierre Fauvel, who devoted his life to the study of polychaetes from all over the world, and especially for his relevant contributions to the Mediterranean fauna.

DESCRIPTION

Holotype (MNHN 406), cylindrical, tapering posteriorly ( Fig.10A ), without posterior end, soft, apparently fixed in alcohol, 29 mm long, 3 mm wide, cephalic cage 8 mm long, 49 chaetigers. Tunic papillated, with sparse sediment grains dorsally and ventrally ( Fig.10 B-D),slightly more densely covered in median and posterior chaetigers. Larger papillae forming longitudinal series, two dorsal and two ventral rows. Cephalic hood exposed, short, margin finely papillose. Anterior end everted, previously removed, not available. Cephalic cage chaetae about as long as 3 times body width. Chaetigers 1 - 2 involved in the cephalic cage; chaetae arranged in short series, each about the body corners, six noto- and four neurochaetae per bundle.

Anterior dorsal margin of first chaetiger with a large, bifid projection; chaetigers 1 - 4 with low notopodial lobes. Chaetigers 1 - 3 of about the same length.Chaetal transition from cephalic cage chaetae to body chaetae gradual; short bidentate neurohooks start in chaetiger 10. Gonopodial lobes not seen.

Parapodia better developed in anterior chaetigers; posterior ones reduced, placed over the body corners. Median neuropodia ventrolateral.Notopodia short, conical lobes, with mostly two large postchaetal papillae. Neuropodia low transverse lobe, with one postchaetal papilla.

Median notochaetae arranged in short transverse series, 5 - 6 per bundle, as long as body width; all multiarticulated capillaries, each with short articles basally, long medially and distally ( Fig. 10E , insert). Short bidentate multiarticulated neurohooks from chaetiger 10, arranged in a transverse or oblique series, 3 - 4 anteriorly, 4 - 5 in median chaetigers. Anchylosed bidentate neurohooks starting by chaetiger 30 ( Fig. 10F ); by chaetiger 40 multiarticulate neurohooks completely replaced by anchylosed ones. Multiarticulated neurohooks with short articles basally, longer medially, short subdistally. Anchylosed neurohooks bidentate, with short articles basally and medially, fading subdistally, subdistally slightly expanded; blade transparent, main fang curved, especially in multiarticulated hooks ( Fig. 10F , inserts), accessory tooth thin, widening distally.

Posterior end unknown.

REMARKS

Trophoniella fauveli n. sp. is closely allied to T. capitata n. comb. because both species have large, sparse sediment particles on dorsal and often lateral surfaces, and anchylosed neurohooks from median chaetigers. They especially differ regarding the presence of notopodial lobes and on the start of anchylosed neurohooks; thus, T. fauveli n. sp. has notopodial lobes and anchylosed neurohooks from chaetiger 40, whereas T. capitata n. comb. lacks notopodial lobes and its anchylosed neurohooks start by chaetiger 28.

On the other hand, because of the presence of large, scarce, sediment particles over the few anterior chaetigers, it resembles the illustrations made by Savigny (1822) for his Aristenia conspurcata . However, as it has been stated elsewhere (Salazar-Vallejo 2011a), the lack of chaetal details, especially for those present in posterior chaetigers, has resulted in it being regarded as indeterminable. It is noteworthy that this newly described species was also collected in Egypt, although perhaps in different depths. Without the critical missing information, the status of A. conspurcata cannot be modified.

Figures

FIG. 10. — Trophoniella fauveli n. sp., holotype (MNHN 406): A, dorsal view; B, anterior end, dorsal view; C, anterior end, ventral view; D, posterior region, lateral view; E, chaetiger 16, notopodium (insert: basal, medial and distal notochaetal regions); F, chaetiger 33, neurochaetae (inserts: tips of chaetae). Scale bars: A, 1.5 mm; B, C, 0.85 mm; D, 0.6 mm; E, 225 µm; F, 80 µm.