Paranaitis inflata, (HUTCHINGS & MURRAY, 1984)

Kato, Tetsuya & Pleijel, Fredrik, 2003, A revision of Paranaitis Southern, 1914 (Polychaeta: Phyllodocidae), Zoological Journal of the Linnean Society 138 (4), pp. 379-429 : 396-406

PARANAITIS INFLATA ( HUTCHINGS & MURRAY, 1984)

( FIGS 13–15 )

Compsanaitis inflata Hutchings & Murray, 1984: 24– 26 , fig. 9.1-9. Paranaitis inflata: Pleijel, 1991: 258 .

Material examined

Holotype ( AM W196585 ), Hawkesbury River , New South Wales, Australia, 2 August 1977; 1 paratype (USNM-81484), Hawkesbury River ; 1 specimen ( AM W196572 ), Hawkesbury River, 2 August 1979; 1 specimen ( AM W196569 ), Hawkesbury River, 3 August 1977.

Description

Holotype complete specimen with partly everted proboscis, 15 mm long, and 0.7 mm wide, for 117 segments. Up to 25 mm long, 1.0 mm wide, for 151 segments (paratype, USNM-81484). Live animals not observed. Body dorso-ventrally flattened, anteriorly and posteriorly tapered. Prostomium anteriorly rounded, with distinct deep ligula ( Fig. 13A ). Paired antennae and palps conical, c. one-third as long as prostomial width. Eyes large, rounded, with lenses, situated at posterior margin of prostomium, often partly covered by segment 1. Rounded nuchal papilla posteriorly in ligula. Nuchal organs retractile, rounded, ventro-laterally situated. Proboscis with distinct division separating proximal and distal part ( Fig. 14A ). Proximal part covered by numerous rounded chitinous papillae, 10–30 Mm in diameter ( Fig. 14B–E ), and with three pairs of large, pointed papillae. Distal part with five rows of tubercles. Terminal ring with c. ten poorly delineated papillae. Paired large papillae laterally inside ring. Segments 1 10. Segment 2 without neuropodial lobes and chaetae. Segment 3 with neuropodial lobes with c. five chaetae, and small ventral cirri. Aciculae in segments 2 and 3 unknown. Dorsal cirri of median segments oval, slightly longer than wide ( Fig. 13C–F ). Dorsal cirrophores distinct, short. Neuropodium with supra-acicular lobes longer than subacicular lobes, with 9–13 chaetae. Morphology of rostrum of chaetal shaft gradually changing from dorsal to ventral within single fascicle ( Fig. 15 ). Dorsal chaetae from part symmetrical, lacking main tooth; ventral chaetae asymmetrical, with single large main tooth on anterior side, smaller main tooth on posterior side. Ventral cirri with rounded ends, c. twice as long as wide, shorter than neuropodial lobes ( Fig. 13D,F ). Pygidial cirri cylindrical, with rounded ends, c. twice as long as wide ( Fig. 13B ). Pygidial papilla present.

and 2 fused. Cirri of segment 1, dorsal and ventral cirri of segment 2, and dorsal cirri of segment 3 cylindrical, long and tapered. Cirri of segment 1 reaching c. segment 6. Dorsal cirri of segment 2 reaching c. segment 10. Ventral cirri of segment 2 reaching c. segment 5. Dorsal cirri of segment 3 reaching c. segment Habitat

Muddy sand and sandy mud, 4–12 m.

Distribution

Known only from Hawkesbury River, Australia.

Remarks

Hutchings & Murray (1984) described the proboscis of Paranaitis inflata as lacking any macropapillae, but being entirely covered by minute micropapillae, based on a paratype specimen with everted proboscis ( AM W196598). Their interpretation is probably based on specimens which only had part of the proboscis everted. Re-examination and dissection of the proboscis of one of their specimens ( AM W196572) showed that the distal part of proboscis was covered by rows of large tubercles, and that c. three large pointed papillae are present on each side on the proximal-most part. Hutchings & Murray (1984) also recorded that the dorsal and ventral chaetae differed within a single fascicle, and that the rostrum of the ventral chaetae is less ornamented than that of the dorsal chaetae. Our examination confirmed the differences between the dorsal and the ventral chaetae; the dorsal chaetae are symmetrical and lack the main tooth, whereas the ventral chaetae are asymmetrical and provided with a single main tooth. The different degrees of ornamentation recognized by Hutchings & Murray may correspond to the absence/presence of a main tooth when examined at lower magnification. We could not confirm their reported difference of longer dorsal than ventral blades on segment 10. Paranaitis inflata is similar to P. kosteriensis , differing mainly in chaetal morphology, body size and pigmentation.

PARANAITIS KOSTERIENSIS ( MALMGREN, 1867)

( FIGS 16 , 17 , 37 )

Anaitis kosteriensis Malmgren, 1867: 142 ; Bergström, 1914: 156, textfig. 52, pl. 1, fig. 2.

Paranaitis kosteriensis: Fauvel, 1923: 157–158 , fig. 56; Hartman, 1959: 158; Eliason, 1962: 234–235; Pleijel & Dales, 1991: 94, fig. 26A–C; Pleijel 1993a: 24–25, figs 13, 14, map 7; Parapar et al., 1993: 415–417, fig. 3c.

Mystides lizziae McIntosh, 1908: 110–111 , pl. 58, fig. 11, pl. 69, figs 11 and 12, pl. 77, fig. 20.

Not Paranaitis kosteriensis: Pettibone, 1963: 77 , fig. 17d (= Paranaitis sp. ).

Material examined

SWEDEN: holotype (SMNH-Type-2402), Koster, Bohuslän , 237 m ; 3 specimens (SMNH-22547), Gullmaren, Bohuslän; c. 25 specimens (F.P. collection), various localities in northern Bohuslän. NORWAY : 1 specimen (SMNH-4786), Trondheim, Rødberg; 1 specimen (Akvaplan-niva), North Sea, Glitne Field ( UTM ED50 , Zone 31; N: E) 6510980.0: 423197.0, sand, c. 110 m ; 1 specimen (Akvaplan-niva), North Sea, Glitne Field ( UTM ED50 , Zone 31; N: E) 6508923.0: 423342.0, sand, c. 110 m ; 2 specimens, western Norway, Bergen area ( ZMB 34013, 34195 ) . UNITED KINGDOM: 1 specimen, holotype of Mystides lizziae ( BMNH 1921 : 5: 1: 1062), St Andrews, Scotland; Plymouth, The Sound, Duke Rock, 12 m, 9 June 1986 , coll. F.P.. SPAIN: 5 specimens (Julio Parapar collection), La Coruña and Ares Bay , Galicia . ITALY: 3 specimens (SMNH-22595, 22597), Brucoli, Sicily, Italy, 37∞17¢N, 15∞11¢E, 40 m .

Description

Holotype ovigerous female, lacking posterior end, 19.5 mm long, 2.1 mm wide, for 69 segments. Up to 80 mm long, for 155 segments ( Nelson-Smith et al. 1990); for further length-segment measurements, see fig. 14 of Pleijel (1993a). Live specimens white, with reddish brown transverse bands across dorsum. Proximal part of dorsal cirri with similar pigmentation. Eyes red. Preserved specimens similar to live ones, but eyes black. Body slender, dorso-ventrally flattened, anteriorly and posteriorly tapered. Prostomium rounded trapezoidal, with distinct deep ligula ( Fig. 16A ). Paired antennae and palps conical, laterally to postero-laterally directed. Eyes large, rounded, with lenses, situated at posterior margin of prostomium, often partly covered by segment 1. Nuchal papilla slightly longer than wide, with rounded tip, inserted posteriorly in ligula. Nuchal organs not observed. Proboscis with distinct division separating proximal and distal parts ( Fig. 17A ). Proximal part covered with minute chitinous papillae ( Fig. 17 B-E), and with 4–5 large papillae in transverse row basally each side ( Fig. 16B ). Distal part with rounded tubercles in five rows. Terminal ring with c. ten papillae; lateral papillae larger than dorsal and ventral ones. Paired large papillae present laterally inside ring.

Segments 1 and 2 fused. Cirri of segment 1, dorsal and ventral cirri of segment 2, and dorsal cirri of segment 3 cylindrical, long and tapered. Cirri of segment 1 reaching c. segment 6. Dorsal cirri of segment 2 reaching segment 8–9. Ventral cirri of segment 2 short, reaching c. segment 5. Dorsal cirri of segment 3 Habitat

Muddy sand or mixed sediment with mud, sand, shell and stones, 10– 230 m.

Distribution

Sweden, Western Norway, Denmark, British Isles, Spain and Portugal; Gibraltar Strait; Sicily ( Pleijel, 1993a).

Remarks

Paranaitis kosteriensis is identified by the character combination presence of eyes, deep ligula, distinctly subdivided proboscis, dorsal cirrophores as wide as long, and absence of chaetae on segment 2. These features are also present in P. inflata , which, however, differs in having symmetrical chaetae in the dorsalmost part of the fascicles, and a smaller maximum body size. Paranaitis kosteriensis is also similar to P. misakiensis which differs in having indistinctly subdivided proboscis and chaetae with a long main tooth. The specimen (USNM-27029) from 2320 m off the US east coast which was recorded by Pettibone (1963) does not belong to P. kosteriensis , as seen from the circular dorsal cirri, and the chaetae on segment 2. In the absence of information on a series of characters, we prefer to leave this single specimen undescribed.

reaching c. segment 10. Segment 2 lacking neuropodia and chaetae. Segment 3 with neuropodia with c. six chaetae, and small ventral cirri. Dorsal aciculae of segment 2 and 3 absent.

Dorsal cirri of median segments oval, asymmetrical and slightly longer than wide ( Fig. 16D–G ). Dorsal cirrophores distinct, symmetrical. Neuropodium with supra-acicular lobes longer than subacicular lobes, with c. 20 chaetae. Morphology of rostrum of chaetal shaft gradually changing from dorsal to ventral within single fascicle. Chaetae from dorsal part asymmetrical, main tooth on anterior and posterior sides almost equal in size ( Fig. 37C ). Chaetae from ventral part asymmetrical, with tooth on anterior side distinctly larger than on posterior side ( Fig. 37D ). Ventral cirri elongated, with rounded end. Pygidial cirri cylindrical, 2–5 times as long as wide ( Fig. 16C ). Pygidial papillae present.

PARANAITIS MISAKIENSIS SP. NOV.

( FIGS 18–21 , 37 )

Material examined

Holotype (ZIHU-1380), 2 paratypes (ZIHU-1381), Moroiso Bay , Misaki , Kanagawa, Honshu , Japan, sand, 5 m, 35∞09.1¢N, 139∞36.5¢E, 21 May 1996, coll. T.K.; 1 paratype (ZIHU-1382), Aburatsubo , Misaki , intertidal, mud, 20 May 1996, coll. T.K.; 1 paratype (ZIHU-1977), Koajiro Bay , Misaki , mud, 8 m, 21 May 1996, coll. T.K.; 1 paratype ( MNHN POLY TYPE 1381 ), Moroiso Bay , sand, 9 m, 35∞09.1¢N, 139∞36.4¢E, 21 May 1996, coll. T.K.; 1 paratype ( MNHN POLY TYPE 1382 ), Koajiro Bay , sand, 15–20 m, 22 June 1994, coll. T.K.; 2 paratypes (ZIHU-1383), off U-ze, Amakusa, Kumamoto, Kyushu, Japan, shell sand, 30 m, 11 November 1994, coll. T.K.; 1 paratype ( MNHN POLY TYPE 1380 ), Odawa Bay , Kanagawa, 5 m, 22 April 1978, coll. H. Mukai; 1 paratype (ZIHU- 1384), Odawa Bay , 5 m, 17 June 1978, coll. H. Mukai; 1 paratype (ZIHU-1385), Odawa Bay , 3 m, 17 June 1978, coll. H. Mukai; 1 paratype ( AMNH z46-00015-1), Odawa Bay , 4 m, 22 July 1978, coll. H. Mukai; 1 paratype ( AMNH z46–00015–2), Odawa Bay , 3 m, October 1978, coll. H. Mukai; 1 paratype (CMNH-ZW- 836), off Manazuru Port, Sagami Bay , Kanagawa, Japan, sandy mud, 30–40 m, 17 July 2000, coll. Nishi; 1 specimen (ZIHU-1924), Tsukumo Bay, Noto, Ish- ikawa, Honshu, sandy mud, 30 m, 16 May 1995, coll. T.K.; 1 specimen (CMNH-ZW-1440), Odawa Bay, October 2001, coll. T. Kudo.

Description

Holotype complete specimen, 14.7 mm long, 1.0 mm wide, for 82 segments. Largest examined specimen, from Amakusa, 33.2 mm long, 1.4 mm wide, with 110 of segments (ZIHU-1383) See Figure 21 for measurements of other specimens.

Live animals transparent white, with reddish brown transverse bands across dorsum on each segment. Eyes red. Preserved specimens similar to live ones; eyes blackish. Body dorso-ventrally flattened, anteriorly and posteriorly tapered. Prostomium anteriorly rounded, wider than long, with a distinct deep ligula ( Fig. 18A ). Paired antennae and palps conical, laterally to posteriorly directed. Eyes large, rounded, with lenses, situated at posterior margin of prostomium, often partly covered by segment 1. Nuchal papilla situated posteriorly in ligula. Nuchal organs small, ventro-laterally situated ( Fig. 18B ). Proximal part of proboscis lacking tubercles, with gradual transition to distal part with tubercles (examined by dissection, Fig. 19A ). Distal part with five rows of tubercles. Rounded chitinous papillae present on both proximal and distal parts ( Fig. 19B–E ). Papillae of terminal ring partly merged. Paired large papillae present laterally inside ring.

Segments 1 and 2 fused. Cirri of segment 1, dorsal and ventral cirri of segment 2, and dorsal cirri of segment 3 cylindrical, long and tapered ( Fig. 20 A-C). Cirri of segment 1 reaching c. segment 6. Dorsal cirri of segment 2 reaching c. segment 8. Ventral cirri of segment 2 reaching c. segment 6. Dorsal cirri of segment 3 reaching c. segment 9. Segment 2 with ventral aciculae, but lacking neuropodial lobes and chaetae ( Fig. 20B ). Segment 3 with small neuropodial lobes with aciculae, 1–3 chaetae, and ventral cirri ( Fig. 20C ). Dorsal aciculae of segments 2 and 3 absent.

Dorsal cirri of median segments oval, asymmetrical, longer than wide ( Fig. 20D–H ). Dorsal cirrophores short, distinct. Neuropodium with supra-acicular lobes longer than subacicular lobes, with c. 20 chaetae. Dorsal and ventral chaetae similar within single fascicle. Rostrum of chaetal shaft asymmetrical, with single large main tooth on anterior side ( Fig. 37E ). Ventral cirri with rounded ends, c. twice as long as wide, slightly shorter than neuropodial lobes ( Fig. 20F,H ). Pygidial cirri cylindrical, with rounded ends, 2–5 times as long as wide ( Fig. 18C ). Pygidial papilla present.

Habitat

Usually on bottoms with shell sand and sand, but also on mud, intertidally to 30 m.

Distribution

Known only from south Japan.

Remarks

Paranaitis misakiensis sp. nov. is similar to P. kosteriensis in, e.g. presence of eyes, deep ligula, oval dorsal cirri with symmetrical cirrophores, and cylindrical pygidial cirri with rounded ends. It differs in proboscis and chaetal characters. In contrast to rostrum in P. misakiensis is distinctly larger than that of P. kosteriensis .

Paranaitis misakiensis instead resembles P. gardineri in proboscis and chaetal characters, but differs in parapodial and pygidial morphology and in pigmentation.The dorsal cirrophores of P. gardineri are large and very wide, and the dorsal cirri are wider than long in median segments. The dorsal cirrophores of P. misakiensis are thinner, and the dorsal cirri are longer than wide in median segments.The pygidial cirri of P. gardineri are about seven times as long as wide and have pointed ends, whereas those of P. misakiensis are shorter, 2–5 times as long as wide, and have rounded ends. The pigmentation is purple in P. gardineri , whereas in P. misakiensis it is reddish brown.

Etymology

This species is named for Misaki, the type locality.

PARANAITIS MORITAI SP. NOV.

( FIGS 22 , 23 )

Material examined

Holotype (ZIHU-1925), Otsuchi Bay , Iwate, Honshu , Japan, 39∞21.01¢N, 141∞58.51¢E, shell sand, 59 m, 7 May 1997, coll. T.K.; 1 paratype (ZIHU-2291), Shimoda, Shizuoka, Honshu, Japan, 34∞38.404¢N, 138∞56.915¢E, 39–45 m, 18 August 1999.

P. kosteriensis , which has a distinct proboscis division, the distal and proximal parts of P. misakiensis are separated by a gradual transition. Furthermore, the chitinous papillae appear on both the proximal and distal parts in P. misakiensis , whereas in P. kosteriensis the papillae occur only on the proximal part. As for differences in chaetal morphology, the main tooth on the Description

Holotype complete with regenerated caudal end, 31.8 mm long, 2.9 mm wide, for 99 segments. Paratype complete, 31 mm long, 2.7 mm wide, for 92 segments. Preserved specimen pale with brown pigmentation dorsally. Dorsal part of collar and following segments brown. Dorsal cirri with few to several brown spots, which frequently fuse to each other and form irregular-shaped pigmentation. Body dorso-ventrally flattened, anteriorly and posteriorly tapered. Prostomium anteriorly rounded, wider than long, posteriorly with distinct deep ligula ( Figs 22A , 23B ). Paired antennae and palps conical, laterally directed. Eyes large, rounded, with lenses, situated at posterior margin of prostomium. Nuchal papilla small, rounded, inserted posteriorly in ligula. Nuchal organs small, rounded, ventro-laterally situated. Proximal part of proboscis dorsally covered with small conical papillae, ventrally with larger conical papillae (examined by dissection; holotype and paratype; Fig. 22B ). Distal part with five rows of large tubercles, without chitinous papillae. Terminal ring with c. 12 papillae. Two large lateral papillae present inside ring.

Segments 1 and 2 fused. Cirri of segment 1, dorsal and ventral cirri of segment 2, and dorsal cirri of segment 3 cylindrical, long and tapered ( Figs 22C–E , 23C ). Cirri of segment 1 short, reaching c. segment 5. Dorsal cirri of segment 2 reaching c. segment 11. Ventral cirri of segment 2 reaching c. segment 5. Dorsal cirri of segment 3 reaching c. segment 10. Segment 2 with ventral aciculae and 0–5 chaetae, without neuropodia ( Figs 22D , 23C ). Segment 3 with small neuropodia with ventral aciculae and c. nine chaetae and ventral cirri. Dorsal aciculae of segment 2 and 3 absent.

Dorsal cirri of anterior segments cordate ( Figs 22F, G ); those of middle segments reniform, wider than long ( Figs 22H, I ). Dorsal cirrophores slightly prolonged dorsally. Neuropodium with supra-acicular lobes longer than subacicular lobes, with c. 30 chaetae. Dorsal and ventral chaetae similar within single fascicle. Rostrum of chaetal shaft asymmetrical, with single large main tooth on anterior side. Ventral cirri oval with rounded end, slightly shorter than neuropodia.

Figures

Figure 13. Paranaitis inflata. A, paratype (USNM-81484). B, holotype. C–F, specimen from Hawkesbury River, Australia (AM W196572). A, anterior end, dorsal view. B, posterior end, ventral view. C, parapodium of segment 11, anterior view. D, same, posterior view. E, parapodium of segment 87, anterior view. F, same, posterior view.

Figure 14. Paranaitis inflata, specimen from Hawkesbury River, Australia (AM W196572). A, dissected proboscis, ventral view (median area corresponds to dorsal part). B–E, chitinous papillae.

Figure 15. Paranaitis inflata, specimens from Australia (AM W196572). Chaetae from a single fascicle of right parapodium of segment 87. Top to bottom correspond to dorsal to ventral.

Figure 16. Paranaitis kosteriensis. A, holotype; B, D–G specimens from Sweden (SMNH-22547). C, specimen from Norway. A, anterior end, dorsal view. B, same with partly everted and damaged proboscis, dorsal view; C, posterior end, ventral view. D, parapodium of segment 9, posterior view. E, parapodium of segment 41, posterior view. F, parapodium of segment 60, anterior view. G, same, posterior view.

Figure 17. Paranaitis kosteriensis. A, specimen from Sicily, Italy (SMNH-22595). B–E, specimen from Sweden (SMNH-22547). A, dissected proboscis, ventral view (median area corresponds to dorsal part). B–E, chitinous papillae.

Figure 18. Paranaitis misakiensis sp. nov., holotype. A, anterior end, dorsal view. B, same, ventral view. C, posterior end, ventral view.

Figure 19. Paranaitis misakiensis sp. nov., paratype (ZIHU-1381). A, dissected proboscis, ventral view (median area corresponds to dorsal part). B–E, chitinous papillae.

Figure 20. Paranaitis misakiensis sp. nov., paratype (ZIHU-1381). A, cirri of segment 1, anterior view. B, parapodium of segment 2, anterior view. C, parapodium of segment 3, anterior view. D, parapodium of segment 5, anterior view. E, parapodium of segment 33, anterior view. F, same, posterior view. G, parapodium of segment 75, anterior view. H, same, posterior view.

Figure 21. Paranaitis misakiensis sp. nov., specimens from Japan. Relationships between A, number of segments and body length, B, number of segments and body width, and C, body length and body width.

Figure 22. Paranaitis moritai sp. nov., holotype (ZIHU-1925). A, anterior end, dorso-lateral view. B, proximal part of dissected proboscis, ventral view. C, cirri of segment 1, anterior view. D, parapodium of segment 2, anterior view. E, parapodium of segment 3, anterior view. F, parapodium of segment 4, anterior view. G, parapodium of segment 5, anterior view. H, parapodium of segment 43, anterior view. I, same, posterior view.

Figure 23. Paranaitis moritai sp. nov. A, holotype (ZIHU-1925). B, paratype (ZIHU-2291). A, posterior end, ventral view. B, anterior end, dorsal view. C, parapodium of segment 2, anterior view.

Figure 37. Chaetae of species of Paranaitis. A, P. wahlbergi, specimen from Sweden, ZIHU-2014. B, P. caeca, specimen from Japan, ZIHU-1919. C, P. kosteriensis, specimen from Sweden, SMNH-22547, dorsal chaetae. D, P. kosteriensis, same specimen, ventral chaetae. E, P. misakiensis sp. nov., paratype, ZIHU-1381. F, P. polynoides, ZIHU-2016. G, P. pumila sp. nov., paratype, ZIHU-1379. H, P. speciosa, syntype USNM 380. I, P. speciosa, specimen from Japan, ZIHU-1921. J, P. uschakovi, specimen from Japan, ZIHU-1923.