Hesione sicula, Delle Chiaje, 1830

Salazar-Vallejo, Sergio I., 2018, Revision of Hesione Savigny in Lamarck, 1818 (Annelida, Errantia, Hesionidae), Zoosystema 40 (12), pp. 227-325 : 301-307

Hesione sicula delle Chiaje, 1830, reinstated

( Figs 48-51 )

Hesione sicula delle Chiaje, 1830: pl. 82, fig. 24; 1841a: 3: 95; 1841b, 5: 102; 1841c, 7: pl. 103, fig. 2; pl. 155, fig. 24 (same as 1830: pl. 82, fig. 24).

Telamone sicula – Claparède 1868: 541-545, pl. 18, fig. 4 (plate indicated, never published).

Fallacia sicula – Marion & Bobretzky 1875: 46-48, pl. 12, fig. 28.

Hesione steenstrupii Quatrefages, 1866: 96-98 , pl. 9, fig. 17. — Solís- Weiss et al. 2004: S5.

Hesione pantherina – Grube 1864: 83. — Saint-Joseph 1898: 329- 337, pl. 19, figs 131-144. — Rioja 1918: 36; 1925: 18. — Fauvel 1913: 56 (partim, Sta. 2096); 1953a: 18 (partim). — Fauvel & Rullier 1959a: 512; 1959b: 158 (non Risso, 1826).

Hesione picta – Rullier 1964: 155 (non Müller, 1858).

Hesione splendida – Hartmann-Schröder 1982: 8. — Kirkegaard 1983: 213. — Parapar et al. 2004: 216, fig. 76 (partim) (all non Savigny in Lamarck, 1818).

TYPE MATERIAL. — Mediterranean Sea, Italy. Hesione sicula delle Chiaje, 1830: Neotype, ZMB 7529 , and five specimens labelled paraneotypes, ZMB 11597 , Naples , X.1924, G. H. Heider coll. [paraneotypes complete, body cylindrical, variably dissected for observation of inner organs; body 45-76 mm long, 5 mm wide, 16 chatigers; antennae digitate 4-5 times as long as wide; eyes brownish, anterior ones slightly larger than posterior ones; posterior eyes with lenses directed posteriorly, better observed when pharynx is fully exposed; acicular lobe double, rounded; upper tine slightly longer than lower one; neuraciculae blackish, subdistally swollen, aristate; neurochaetal blades bidentate, guard approaching subdistal tooth]. Northeastern Atlantic, France. Holotype of Hesione steenstrupi Quatrefages, 1866 , MNHN-IA-TYPE0479, Guettary (43°25’36”N, 01°36’28”W), no further data, A. de Quatrefages coll .

ADDITIONAL MATERIAL. — Mediterranean Sea. Italy. 3 specimens, MNHW unnumb., Broni (probably Genoa since it is the closest port), Kükhental coll. no further data [grayish, one with darker spots along body; acicular lobe double; neurochaetal handles colorless; 45-64 mm long, 5-6 mm wide]. Four specimens, MNHW unnumb., Naples, no further data [47-52 mm long, 5-6 mm wide, 3 specimens with transverse cuts along body, probably to improve preservation; two with pygidial gland ring reddish; acicular lobe double; neurochaetal handles brownish] . — 2 specimens, RMNH 281 , Naples , probably purchased, 1888, no further data (50- 72 mm long, 5-8 mm wide; larger specimen grayish, with pharynx everted, wider in posterior third of body, smaller specimen pale brownish, slightly wider in posterior third of body; posterior eyes with lenses centrally positioned; chaetal lobes invaginated; acicular lobe double) . — 2 specimens, SMF 8530 , Sherki Bank , off Sicily, RV Urania, Sta. 297, 45 m depth, 7.I.1997, H. Zibrowius coll. [31-43 mm long, 3-4 mm wide; partially dehydrated, with abundant salt particles adsorbed on body, both with pharynx partially exposed, larger one bent ventrally, right parapodia of chaetiger 9 removed for observation; anterior eyes twice larger than posterior ones, posterior eyes with lenses directed posteriorly; acicular lobe double, upper tine 3-4 times longer than lower one; about 25 neurochaetae per bundle, blades bidentate, guard approaching subdistal tooth] . — 2 specimens, USNM 5111 , purchased from the Zoological Station , Naples, 1893 [45-66 mm long, 5-8 mm wide; without pigmentation, well preserved; parapodial cirri macerated in 1 specimen, in the other dorsal cirri basally articulated, articles as wide as long, ventral cirri articulated, articles as long as wide; acicular lobe double, globose, upper tine slightly longer than lower one; blades with guard reaching subdistal tooth; posterior end tapered into a blunt cone; pygidium with six low, thick papillae] . — 1 specimen, ZMB 811 , Naples, A. Dohrn coll., plus 3 slides made by Dr Bergmann (44 mm long, 5 mm wide; body slightly bent ventrally, swollen, probably injected; left parapodium from chaetiger 8 removed for observation (kept in vial); antennae digitate, 4-5 times as long as wide; eyes colorless; neuraciculae blackish, capitate, mucronate; acicular lobe double; upper neurochaetae with blades unidentate, probably eroded; other chaetae with blades bidentate, guard approaching subdistal tooth]. — 1 specimen, ZMB 3800 , and one slide with gonad fragments (made by Dr Bergmann), Zoological Station, Naples , received 21.I.1903, W. Bergmann coll. [50 mm long, 6 mm wide; body with a longitudinal middorsal dissection throughout most of body, for observation of inner organs; antennae digitate, 4-5 times as long as wide; eyes brownish, anterior ones twice as large as posterior ones; chaetal lobes variably invaginated; neuraciculae blackish, subdistally swollen, capitate; acicular lobe double, digitate, upper one slightly longer than lower one; neurochaetal blades bidentate, guard approaching subdistal tooth]. — 1 specimen, ZMB 3804 , Bay of Naples, probably purchased from the Zoological Station , Dr Bergmann (author of the slides; 60 mm long, 6 mm wide; left parapodia of chaetigers 13-14 previously removed for permanent slides; antennae digitate, 4-5 times as long as wide; eyes brownish, anterior ones slightly larger than posterior ones; acicular lobe double, neuraciculae blackish, subdistally swollen, tapered; blades bidentate, guard approaching subdistal tooth]. — 1 specimen, ZMUC 2425, plus anterior and posterior fragments, probably purchased from the Stazione Zoologica Napoli, 1882, no further data (50 mm long, 5 mm wide; slightly dehydrated, distorted, most cirri broken, many chaetae without blades; several parapodia previously removed, left parapodium of chaetiger 9 removed for observation (kept in vial); acicular lobe double, blunt, upper tine 3 times longer than lower tine]. — 2 specimens, ZMH-P PE 314, Neapel Zoological Station , 1885 [53-58 mm long, 5 mm wide; complete, smaller one with pharynx slightly exposed, dorsal papilla blunt, as wide as long; eyes colorless; antennae digitate, 3-4 times as long as wide; acicular lobe double, upper tine slightly longer than lower one]. — 1 specimen, ZMH-P 1289, Naples, no further data [48 mm long, 6 mm wide; complete, colorless, dorsum darker than other body parts; eyes colorless; antennae about 3-4 times as long as wide; parapodia with chaetal lobes invaginated; acicular lobe double, upper tine slightly longer than lower one].

Croatia. 1 specimen, UCO HES 4 , Rovinj, no further data [25 mm long, 3 mm wide; no pigmentation; acicula blackish, subdistally swollen, mucronate; acicular lobe double] . — 2 specimens, ZMB 3809 , Collection Grube, Crivizza (Krivica), Dr Bergmann and Lussin Piccolo, Dr Bergmann made slide, no further data [15-26 mm long, 2.0- 2.5 mm wide; no pigmentation, eyes barely visible; parapodial features seen in permanent slide: acicular lobe double, blunt, upper one slightly longer than lower one; neuraciculae blackish tapered, not swollen subdistally; probably size-dependent] . — 3 specimens, ZMB 3811 , Collection Grube, Lesina ( Hvar Island ), Dr Bergmann coll. no further data [28-40 mm long, 3.5-5.0 mm wide; one without dorsal prostomial surface (in permanent slide), smaller one with pharynx exposed; antennae 2-3 times as long as wide, blunt; anterior eyes twice larger than posterior ones; dorsal cirrophore 2-3 times as long as wide; neuraciculae blackish, subdistally swollen, smooth (in permanent slides); neurochaetae with blades bidentate, guard approaching subdistal tooth] . — 3 specimens, ZMB 7567 , Saint Girolamo (Jerolim) island , SW Brijuni, Fažana Canal, 1933, G. K. Heider coll. [45-65 mm long, 6-8 mm wide; splendid specimens; two with pharynx exposed, dorsal papillae rounded, as long as wide; antennae longer than anterior eyes diameter; dorsal cirrophores 2-3 times as long as wide, cirrostyles basally cylindrical, reddish, smooth, medially annulated, distally articulated; neuraciculae blackish, subdistally swollen, mucronate; neurochaetal blades bidentate, anterior chaetigers with longer blades, with smaller teeth, shorter with larger teeth in median and posterior chaetigers; guard approaching subdistal tooth] .

Monaco. 1 specimen, MNHN-IA-PNT105 (formerly jar 404), Collection Prince de Monaco, Sta. 2029, off Monaco, III.1913, no further data [51 mm long, 7 mm wide (right parapodium of chaetiger 7 removed for observation, kept in vial); antennae digitate 3-4 times as long as wide; anterior eyes darker, slightly larger than posterior ones; pharynx exposed, dorsal papillae slightly as long as wide; acicular lobe double, blunt, upper tine 2-3 times longer than lower one; neurochaetae about 30 per bundle, blades bidentate, subdistal tooth smaller, guard approaching subdistal tooth] .

France. 1 specimen, MNHN-IA-PNT 91m (formerly jar 70-190a), Marseille , no further data, labelled in 1868, M. Barban coll. [32 mm long, 5 mm wide; damaged, anterior muscular digestive system fully exposed, as long as whole body; larger neuraciculae tapered, tip granulose, mucronate; acicular lobe double, upper tine twice as long as lower one. — 1 specimen, SMF 16084, Rade Sud de Marseille, Sta. A2 HC1( I), 20.X.1982, A. Willsie coll. [juvenile, 10 mm long, 2 mm wide; colorless, distorted, parapodia displaced ventrally, all dorsal and some tentacular cirri lost, right parapodium of chaetiger 9 removed for observation (kept in vial); antennae digitate, 2-3 times as long as wide; eyes colorless; acicular lobe double, upper tine twice longer than lower one; neurochaetal blades bidentate, teeth smaller in upper bundle chaete, larger medially and ventrally, subdistal tooth smaller, guards mostly broken, if entire, approaching distal tooth].

Spain. 1 specimen, MCZ 126440, Es Caials, Cadaqués (42.28919, 3.2757), Girona, 12.VIII.1997, C. Palacín & G. Giribet coll. [44 mm long, 4 mm wide; body bent ventrally, pharynx not exposed; eyes dark brown, anterior ones slightly larger than posterior ones (in lateral view look twice as large); antennae tapered, as long as interocular distance on the same prostomial side; acicular lobe digitate, double, mostly with an upper tine twice larger than lower one; chaetal blades long or short, with guard reaching subdistal tooth] . — 3 specimens, MCZ 134169, Catalunya, Blanes (41.676°N, 2.793°E), 31.VII.1997, C. Palacín & G. Giribet coll. [juveniles, 13-14 mm long, 1.5 mm wide; two complete; one without anterior region; body straight, stiff, with some pale red irregular bands dorsally, better retained over first few chaetigers; most cirri lost; pharynx completely invaginated; eyes reddish, anterior ones slightly larger than posterior ones (in lateral view look twice as large); antennae tapered, as long as interocular distance; acicular lobe double, mostly with upper tine digitate, twice larger than lower, round one; chaetal blades long or short, guards reaching subdistal tooth, most broken] . — 1 specimen, UF 4180 , Girona Province, Tossa de Mar , fixed dead, 2-4 m depth, 23.VI.2014, G. Paulay coll. [juvenile, 22 mm long, 4 mm wide, two left ones removed for molecular analysis; twisted specimen, with brownish longitudinal lines throughout body, especially dorsally, laterally lines shorter, becoming long spots in posterior segments, continued to anal tube; body pharynx exposed, basally constricted (distorted) with some pigmentation, margin ciliated band eroded, dorsal papilla low, as long as wide; prostomium slightly as wide as long, with a shallow anterior depression, lateral margins rounded, posterior margin deeply cleft, extended for about 1/5 prostomial length; eyes brownish, anterior ones slightly larger than posterior ones; antennae pale, tapered, longer than interocular distance; parapodia with cirrophores 3 times as long as wide; cirrostyles basally straight, annulated; chaetal lobe slightly tapered, blunt; acicular lobe double, digitate, upper tine slightly longer than ventral one; neurochaetal blades bidentate, teeth of similar size, guard usually reaching subdistal tooth, rarely passing it]. — 2 specimens, UF 4181 , Girona Province, Tossa de Mar (41.7226, 2.9396; 41°43’21.3600”N, 002°56’22.5600”E), 2 - 4 m depth, 23.VI.2014, G. Paulay coll. [43.0- 43.5 mm long, 4.0- 4.5 mm wide (1 specimen with two left parapodia removed for molecular analysis); excellent specimens; pigmentation less intense than in UF 4180 ; pharynx not exposed; prostomium fully relaxed, slightly as long as wide, with a shallow anterior depression, lateral margins slightly rounded, posterior margin deeply cleft, extended for about 1/8 prostomial length; nuchal organs exposed throughout their length; eyes brownish, anterior ones slightly larger than posterior ones; antennae pale, tapered, longer than interocular distance; parapodia with cirrophores three times as long as wide; cirrostyles basally straight, annulated; chaetal lobe slightly tapered, blunt; acicular lobe double, digitate, upper tine twice longer than ventral one; neurochaetal blades bidentate, teeth of similar size, guard reaching subdistal tooth] . — 1 specimen, MCZ 1158 , Adriatic Sea, Heller coll., no further data [24 mm long, 4 mm wide; colorless, laterally bent; eyes dark brown, anterior ones slightly larger than posterior ones (in lateral view twice as large); antennae smaller than interocular distance; dorsal cirri very long, markedly articulated throughout its length; ventral cirri smooth, markedly longer than chaetal lobe; acicular lobe double; neurochaetal blades long, guard mostly eroded, reaching subdistal tooth].

Mediterranean , locality not precised. 4 specimens, RMNH 280 , no further field data [32-75 mm long, 4-8 mm wide; colorless, two with glass bubbles for exhibition; body antennae broken in 3 specimens, smallest with antennae digitate, 4-5 times as long as wide; eyes visible in 2 specimens, anterior eyes twice as large as posterior ones, posterior eyes with lens centrally positioned; chaetal lobes invaginated, all with acicular lobe double, blunt, upper tine markedly longer than lower tine].

Northeastern Atlantic, France. 7 specimens, MNHNIA-PNT91n (formerly jar 70x), Saint-Jean-de-Luz, 1.II.1891 and 21.III.1892, A. Saint-Joseph coll. [47-62 mm long, 5-6 mm wide; splendid specimens, three with pharynx fully everted, several with eyes with pigmentation, one with a longitudinal dissection passing the body completely and used for details of pharynx muscles; body tapered, all with acicular lobe double, if small of the same size, if larger, upper tine longer] . — 3 specimens, MNHN-IA-PNT106 (formerly jar Coll. de Saint-Joseph , 20), Saint-Jean-de-Luz, 27.III.1892 [58- 63 mm long, 4.0- 5.5 mm wide; all with pharynx exposed and eyes pigmented] . — 5 specimens, MNHN-IA-PNT91o (formerly jar 70y), Saint-Jean-de-Luz, 1.VIII.1903, A. Saint-Joseph coll. (47-68 mm long, 6-8 mm wide; splendid specimens, three with pharynx fully everted, body fusiform, one with anteroventral dissection already made; parapodium of the smallest and largest specimens removed for acicular features (kept in same container); all with acicular lobe double, neuraciculae capitate]. — 4 specimens, MNHN-IA-PNT 91p (formerly jar 70z), Saint-Jean-de-Luz, 1.VIII.1903, A. Saint-Joseph coll. [16-22 mm long, 2-3 mm wide; acicular lobes double; largest specimen dissected middorsally, coelomic contents removed, stained with Carmin Red, anterior and posterior fragments from the same specimen, and two small complete specimens, laterally contracted] . — 8 specimens, MNHN-IA-PNT91q (formerly jar 70x), Saint-Jean-de-Luz, data unreadable in ancient label, A. Saint- Joseph coll. [54-63 mm long, 5-6 mm wide; colorless; 4 with pharynx variable everted; acicular lobes double; acicular tips capitate; 1 specimen with right antenna basally bifurcated] . — 3 specimens, MNHN-IA-PNT91r (formerly jar 70), Concarneau (47°52’31”N, 03°55’08”W), no further data [40-48 mm long, 5-7 mm wide; acicular tips become more spinulose in larger specimens].

Northwestern Africa. Cape Verde Islands. 5 specimens, ZMUC 2433, off São Pedro Bay , São Vicente Island, RV Atlantide Expedition, Sta. 40, 32 m (in publication) or 100 m (label), 11.XII.1945, J. B. Kirkegaard coll. [20-32 mm long, 3 mm wide; complete, two with prostomia invaginated, bent ventrally, two others ventrally bent with prostomia exposed, the last one with pharynx exposed; colorless, dorsal cirrostyle cylindrical, smooth; acicular lobe double, digitate, upper tine about twice longer than lower one; neurochaetal blades bidentate, upper chaetae with smaller teeth, lower ones with larger teeth; guard fragile, in a few chaetae approaching distal tooth] . — 1 specimen, MNHN-IA-PNT90d (formerly jar 372c), RV Calypso, Campagne aux îles du Cap Vert 1959, Sta. 34, 0.5 km SW off Santa Encarnação , 20-25 m depth, 20.XI.1959 [20 mm long, 3 mm wide; colorless, anteroventrally dissected, including a longitudinal cut throughout pharynx; several parapodia previously removed; antennae 3-4 times as long as wide; eyes brownish, anterior ones twice larger than posterior ones; acicular lobe double, upper tine slightly longer than lower one; neurochaetae about 20 per bundle, blades bidentate, many lost, distal tooth larger, guard mostly eroded, if complete, approaching distal tooth].

Western Sahara ( Morocco). 1 specimen, ZMH-P 17727, RV Meteor, Cruise 36, Sta. 115 (21°17.1’N, 17°10.2’W), 50 m depth, 3.III.1975 [49 mm long, 5 mm wide; partially dried-out, pharynx exposed, integument annulated; most cirri and chaetal blades on site; antennae and eyes not visible due to integument foldings; right parapodia of chaetigers 2 and 9 removed for observation (kept in vial); parapodial lobes variably contracted; neuraciculae blackish, thick, tapered; acicular lobes double, massive, blunt, neurochaetal blades bidentate, guards mostly broken, a few blades with guards approaching distal tooth] . — 3 specimens, ZMH-P 17728, RV Meteor, Cruise 36, Sta. 118(?), 3.III.1975 [26-32 mm long, 3.0- 3.5 mm wide; partially dried-out, integument annulated; most cirri and chaetal blades on site; one with pharynx exposed, another one with most cirri and chaetae broken; antennae digitate 2-3 times as long as wide; eyes colorless, anterior ones twice larger than posterior ones; parapodial lobes variably contracted; neuraciculae blackish, thick; acicular lobes double, massive, blunt, upper tine twice as long as lower, rounded one; neurochaetal blades bidentate, guards mostly broken, a few blades with guards approaching distal tooth].

Gulf of Guinea. 12 specimens, MNHN-IA-PNT90f (formerly jar 372b), (plus one syllid ant. fragm.), RV Calypso, Campagne Golfe de Guinée, Sta. 1 (21°05’N, 17°14’W), off Cap Blanc Peninsula, sand, 43 -45 m depth, 10.V.1956 [20-41 mm long, 3-4 mm wide; variably distorted by compression, most with pharynx exposed; colorless; antennae 3-4 times as long as wide; eyes rounded, brownish, anterior ones slightly larger to twice as large as posterior ones; dorsal pharynx papilla rounded, slightly as wide as long; dorsal cirrophore 2-3 times as long as wide; cirrostyle basally cylindrical, smooth, medially annulated, distally articulated; acicular lobe double, blunt, upper tine slightly longer than lower one; neurochaetae about 30 per bundle, blades bidentate, subdistal tooth smaller, guard usually eroded, if complete, approaching distal tooth]. — 2 specimens, MNHN 372 b, RV Calypso, Campagne Golfe de Guinée, Sta. 1 (21°05’N, 17°14’W), off Cap Blanc Peninsula, sand, 43 - 45 m depth, 10.V.1956 [33-46 mm long, 4-5 mm wide; macerated, damaged, distorted by compression, most cirri and chaetae lost; one with pharynx exposed; colorless; anterior end features damaged; dorsal pharynx papilla rounded, as wide as long; neurochaetae about 25 per bundle, blades bidentate, subdistal tooth smaller, guard usually eroded, if complete, approaching distal tooth]. Southwestern Africa . Angola. 1 specimen, RBINS unnumb., Expédition océanographique belge dans les eaux côtières africaines de l’Atlantique Sud 1948 -1949, Sta. 116 (after label; Fauvel indicated it was from station 106; 09°20’S, 13°04’E), 13 km W Rio Cuanza, 17 m depth, 31.I.1949 [macerated, apparently fixed in ethanol; body pale, soft, cirri transparent; pharynx exposed, dorsal papilla as wide as long; antennae small, barely visible, right one lost, left one with tip eroded; eyes unpigmented, after methyl green staining, anterior eyes twice as large as posterior ones; dorsal cirrophores about twice as long as wide; parapodial lobes contracted; chaetal bundles barely visible; neuraciculae blackish, tapered; acicular lobe double; neurochaetal blades bidentate, guard approaching distal tooth] .

DISTRIBUTION. — From the Gulf of Vizcaya to the Northwestern African region, including the Mediterranean Sea. Records for more tropical localities like the Gulf of Guinea are dubious and the specimens might belong to another species. In mixed bottoms, from the intertidal to 50 m depth.

DIAGNOSIS. — Hesione with prostomium curved laterally; parapodia with dorsal cirri basally cylindrical, dorsal cirrophore three times as long as wide; larger acicula blackish; acicular lobe double, tines short, blunt, upper tine slightly longer than lower one; neurochaetal blades bidentate, 4-6 times as long as wide; subdistal tooth smaller than distal one, with guards approaching distal tooth.

DESCRIPTION

Neotype of H. sicula , ZMB 7529, complete, subcylindrical ( Fig. 48A ), tapered posteriorly, slightly bent ventrally, with a longitudinal dissection over lateral cushions along chaetigers 4-13. Body 45 mm long, 5 mm wide (left parapodium of chaetiger 9 removed for observation, kept in smaller container in same vial).

Holotype of H. steenstrupi , MNHN-IA-TYPE0479 (indicated as holotype below) without pigmentation ( Fig. 49A ) in ethanol; body 43 mm long, 4 mm wide (left parapodia of chatigers 6 and 10 removed for observation, now kept in plastic vial with the holotype).

Prostomium as wide as long, anterior margin barely projected, covered by basal pharynx ring corrugations, lateral margins rounded, widest in anterior eyes region, posterior margin with a shallow depression, partially covered by anterior margin of tentacular segment, reaching slightly behind posterior eyes ( Fig. 48B ). Antennae digitate, three times as long as wide, as long as interocular distance. Eyes brownish, anterior ones twice larger than posterior ones, posterior eyes with lenses directed posteriorly (holotype with antennae fusiform, 3 times as long as wide; eyes colorless [ Fig. 49B ]).

Tentacular cirri long, with tips eroded, longest ones reaching chaetiger 5. Lateral cushions low, slightly projected, smooth, separated into three (anteriorly) or two sections.

Parapodia with chaetal lobes truncated, as long as wide; dorsal cirri with cirrophores 3 times as long as wide; cirrostyles basally cylindrical, annulated, articulated medially and distally, tips lost ( Fig. 48C ), probably longer than body width including parapodia (length confirmed in holotype Fig. 49C ). Ventral cirri smooth, slightly rugose medially and distally, surpassing chaetal lobes.

Neuraciculae blackish, cylindrical, tapered, larger one often subdistally swollen, mucronate; thinner one tapered. Acicular lobe double, tines blunt, short, upper one slightly longer than lower one ( Fig. 48C [inset]) (confirmed in holotype Fig. 49C [inset]).

Neurochaetae about 30 per bundle (about 20 in holotype), handles honey-colored, blades bidentate (many lost), blades at a certain angle from handle, 4-5 times as long as wide, slightly decreasing in size ventrally, each with smaller to equal-sized subdistal tooth, guards delicate, most broken ( Fig. 48D [insets]), approaching subdistal tooth, if complete, approaching subdistal one (confirmed in holotype Fig. 49D [insets], or Fig. 51C [insets]).

Posterior end tapered into a blunt cone; pygydium smooth ( Fig. 48E ; slightly depressed in holotype, Fig. 49E ), anus with seven low, rounded anal papillae.

Pharynx exposed, divided into three rings; basal ring corrugated, shortest; medial and distal rings of similar length, distal ring with a thick glandular margin, cilia mostly eroded; dorsal papilla rounded, distorted by ring foldings ( Fig 48A, B ). Whitish, anastomosing gonadal tubules visible through previously made dissection; a small fragment removed from chaetiger 14, without mature oocytes.

Pigmentation

Pigmentation pattern observed in a recently collected specimen, UF 4180: dorsal surface with irregular, thin, solid longitudinal bands, barely interrupted intersegmentally ( Fig. 50A ), better defined along anterior region, more irregular in posterior region ( Fig. 50D ), extended into lateral cushions. Middorsal surface with irregular pale spots, rounded, less defined in posterior region. Prostomium with anterior marginal brownish band, projected posteriorly medially and to anterior eyes, with some pale spots just ahead of anterior eyes ( Fig. 50B ); posterior prostomial half pale. Brownish pigmentation extended into basal pharynx half, progressively paler, dorsal papillae pale, rounded. Tentacular segment, tentacular and dorsal cirri pale. Neuropodia extended, blunt, about twice as wide as long ( Fig. 50C ).

Among the Saint-Joseph collection in the Paris museum, one specimen preserved over 100 years ago, surprisingly retained its pigmentation pattern ( Fig. 51A ): dorsal surface markedly annulated, with brownish longitudinal bands interrupted by integument foldings into spots, round to polygonal, usually with a central paler thin band, more or less arranged into longitudinal, discontinuous series ( Fig. 51B ), continued to the end of body ( Fig. 51E ); these longitudinal irregular bands are extended into lateral cushions, but segmentally interrupted by irregular, as wide as long pale middorsal spots, on parapodial lobes level, sometimes another pale area basal to parapodial lobes. Prostomium ( Fig. 51C ), tentacular segment, tentacular and dorsal cirri without pigmentation.

Variation

Among the same splendid specimens referred to above, MNHN IA-PNT 106 (formerly de Saint-Joseph 20), three variations must be indicated. First, the left antenna diverges into two tines ( Fig. 51C ), and this separation is from a common base. Second, in another specimen, the right posterior eye is duplicated, but coalescent, such that it looks twice as large as the left posterior eye ( Fig. 51D ). Third, the dorsal papillae can be low, as wide as long ( Fig. 51C , asterisk) or markedly projected as a blunt, twice as long as wide lobe ( Fig. 51D [asterisk]). On the other hand, a small specimen, MNHN-IA-PNT91s (formerly 70-190a), 32 mm long, 5 mm wide has acicular lobe double, upper tine twice as long as lower one.

REMARKS

Hesione sicula delle Chiaje, 1830 has a complex, confusing taxonomic perspective (see below); together with H. pantherina , they live in the Mediterranean and adjacent regions, and despite being regarded as synonyms, they are different. As indicated above, a neotype was proposed for H. pantherina , and it was restricted; a similar approach is needed for H. sicula in order to clarify its taxonomic status ( ICZN 1999: art. 75.3.1). The neotype of H. sicula was described above and the differences to other species are listed below ( ICZN 1999: art. 75.3.2, 75.3.3). There were no type specimens deposited by delle Chiaje ( ICZN 1999: art. 75.3.4), and the neotype and additional specimens have the same set of diagnostic features ( ICZN 1999: art. 75.3.5). Further, the neotype was collected in the same region in the Gulf of Naples ( ICZN 1999: art. 75.3.6), and it is now deposited in the Berlin museum ( ICZN 1999: art. 75.3.7).

Hesione pantherina , and H. sicula together with H. steenstrupi Quatrefages, 1866 were all described from the Northeastern Atlantic and Mediterranean region having a colorful, reddish-brown pattern on their bodies. As indicated above, parapodial features, especially the type of acicular lobes, were not included in the original description of any of these three species. The observations on a small specimen of H. sicula (MNHN-IA-PNT91s, formerly 70-190a, 32 mm long, 5 mm wide) confirm that acicular lobes are double, with upper tine twice longer than lower one. Consequently, the development of acicular lobe is not size-dependent; further, in H. pantherina acicular lobes are single and its specimens do not reach the same large size as those of H. sicula (incl. H. steenstrupi ).

Saint-Joseph (1898) provided a detailed illustration of parapodia for what he regarded as H. pantherina and illustrated acicular tips. The main diagnostic features in his plate 19 were that antennae are shorter than interocular distance (Fig. 131), acicular lobes are double and blunt (Fig. 135), neuraciculae are slightly capitate with tiny spines on its tip (Fig. 137), chaetal blades are bidentate with subdistal tooth larger than distal tooth, and guard approaches subdistal tooth (Fig. 136). As indicated below, these features match H. steenstrupi and his material was collected in Saint-Jean-de-Luz, close to the type locality (Guethary), in the Gulf of Vizcaya. Further, Saint-Joseph (1898) compared specimens from Naples and concluded that they were identical with his materials from the Atlantic French coast, leading him to conclude that the three species were synonyms. It is true that H. sicula and H. steenstrupi have acicular lobes double, and there are subtle differences in the color of neurochaetal handles, being honey-color in H. steenstrupi and chocolate-color in H. sicula , besides the pigmentation differences in body and neurochaetal handles. Consequently, it is difficult to regard them as distinct species, and H. sicula has priority over H. steenstrupi . On the other hand, as indicated above, H. pantherina has acicular lobes single, and this difference is enough to separate it from the two other ones. Pleijel (1998: 159) indicated that H. sicula could be a junior synonym of H. pantherina ; after the comparision of specimen originating from area close to the type locality and additional material of both species, it is herein concluded they are different species.

As indicated above, Fauvel (1923a: 234) followed the Saint- Joseph conclusion on synonymy and regarding acicular lobes, he indicated that “au-dessus des soies une ou deux petites languettes coniques, souvent rétractées” (Transl.: over the chaetae there is one or two small conical lobes, often retracted). Fauvel was actually reiterating something he had concluded before ( Fauvel 1911: 375) when he recorded H. pantherina for the Persian Gulf, rejected the use of the acicular lobe as a diagnostic feature, and indicated that “j’observe à cet égard une grande variabilité, non seulement d’un individu à l’autre mais encore d’un parapode à l’autre sur un même animal”. (Transl.: I observe about this a large variability, not only from one specimen to the other but even from one parapodium to another in the same specimen). This is incorrect and by taking a look at the corresponding illustrations ( Fauvel 1911: 375; fig. IV), it is clear that the parapodia were mounted differently by the relative position of the ventral cirri, such that if these parapodia came from the same specimen they were probably drawn from different perspectives, or worse, they belong to different specimens.

Regarding pigmentation, delle Chiaje (1841a: 95) indicated: “Corpo […] roseo tigrato di ovali macchiette rosso-fosche, giù cerulescente con duplice filiera mediana di macchie rossastre; testa rosso-iridea[…]” [Transl.: Body banded as a tiger with oval reddish spots, pale grayish with double medial reddish series, head iridescent red…]. Some additional details were given by de Quatrefages (1866: 96, 97, as H. steenstrupi ): “bruneo longitudinaliter striatum” [Transl.: brownish striated longitudinal lines], or “Le dessus du corps est strié de blanc jaunatre et de brun. La separation des 7-8 premiers anneaux est nettement indiquée par une bande transversale tirant sur le jaune. Vers le 7 e anneau, une ligne blanche nait sur le côté, se pronounce de plus en plus en arrière, et s’élargit en un point blanc diffus à chaque séparation.” [Transl.: The back of the body is streaked by yellowish white and brown. The separation of the first 7-8 rings is clearly indicated by a transverse yellowish band. Over the 7th ring, a white line starts over the side, is progressively more defined posteriorly, and enlarges into a diffuse white point on each separation]. Saint-Joseph (1898: 330) confirmed this pattern: “Le côté dorsal d’un brun rougeâtre est parcouru par 8 à 10 raies longitudinales blanches qui sont coupées à angle droit par de nombreuses raies blanches transversales, de sorte que le corps paraît moucheté de brun et réticulé de blanc… Quatre bandes blanches transversales assez larges relient l’un à l’autre les pieds des segments 2 à 5, et quelquefois ceux de presque tous les autres… Enfin, quelques exemplaires ont une grosse tache blanche au milieu du dos de chaque segment.” [Transl.: The brown reddish dorsal side is browsed by 8-10 longitudinal stripes that are cut in right angles by numerous transverse stripes, such that the body appears with brownish spots and reticulated by white […] Four large transverse white bands connect the parapodia in segments 2-5, and sometimes those of nearly all others […] Finally, some specimens have a large white spot middorsally in every segment]. The record by Fauvel (1953a: 18, Sta. 122) indicated the body had dark brown transverse bands, subdivided by thin white lines, approaching H. picta . However, this specimen is a Leocrates cf. diplognathus ; it differs from the China Sea specimens by having longer palpophores, and double J-shaped nuchal organs, which rather corresponds with an undescribed species. Further, the record of H. picta for the Cape Verde islands by Rullier (1964: 155) cannot be confirmed because his specimen was without pigmentation when he studied it, and its neurochaetal blades do not match the H. picta pattern as illustrated above, and it is being regarded as belonging to H. sicula . The records for the Gulf of Guinea by Fauvel & Rullier (1959a: 512; b: 158) are included here with hesitation because they indicated there were transverse bands (“quelques rayures transversales”), instead of the typical longitudinal, discontinuous lines. Further, the specimen was somehow distorted preventing separating them into another species.Better specimens are needed to clarify this point. Likewise, the specimen from Angola ( Fauvel 1953a) is very poorly preserved as to be confidently included with this species, and is listed above with hesitation.

Figures

FIG. 48. — Hesione sicula delle Chiaje, 1830, reinst., neotype,ZMB 7529: A, anterior region, dorsal view; B, prostomium and everted pharynx, dorsal view (arrow points to right lateral antenna); C, chaetiger 9, left parapodium, anterior view (inset: acicular lobe); D, same, lower half of neurochaetal bundle (insets: blades); E, posterior region, dorsal view. Scale bars: A, E, 1.8 mm; B, 0.9 mm; C, 0.5 mm; D, 80 µm.

FIG. 49. — Hesione sicula delle Chiaje, 1830, reinst., holotype of H. steenstrupi Quatrefages, 1866, MNHN-IA-TYPE0479: A, anterior region, dorsal view; B, prostomium; C, chaetiger 10, left parapodium, anterior view (inset:acicular lobe); D, same, neurochaetae (insets: blades); E, posterior region, dorsal view.Scale bars: A, 1.5 mm; B, D, 0.3 mm; C, 0.5 mm; E, 1.9 mm.

FIG. 50. — Hesione sicula delle Chiaje, 1830, reinst., non-type specimen, UF 4180: A, anterior region, dorsal view; B, prostomium and everted pharynx, dorsal view; C, chaetiger 9, left parapodium, anterior view (insets: acicular lobe, upper and lower chaetal blades); D, posterior region, oblique dorsal view. Scale bars: A, 0.7 mm; B, 0.8 mm; C, 0.4 mm; D, 0.9 mm.

FIG. 51. — Hesione sicula delle Chiaje,1830,reinst., non-type specimens, MNHN IA-PNT-106 (formerly jar de Saint-Joseph 20): A, complete, oblique dorsal view; B, anterior region, pharynx exposed, dorsal view; C, prostomium and base of pharynx, dorsal view (arrows point to left lateral antennae, asterisk indicates dorsal papilla);D, another specimen,prostomium and base of pharynx, dorsal view (asterisk indicates dorsal papilla);E, another specimen,posterior region, dorsal view. Scale bars: A, 4 mm; B, 2.4 mm; C, 0.5 mm; D, 0.4 mm; E, 1.8 mm.