Paraprionospio lamellibranchia, HARTMAN, 1975

Yokoyama, Hisashi, 2007, A revision of the genus Paraprionospio Caullery (Polychaeta: Spionidae), Zoological Journal of the Linnean Society 151 (2), pp. 253-284 : 270-279

publication ID	https://doi.org/ 10.1111/j.1096-3642.2007.00323.x
publication LSID	lsid:zoobank.org:pub:824A2B6D-5F84-4310-9524-76B0843871EB
persistent identifier	https://treatment.plazi.org/id/0A0A87A5-FFF8-E012-06EA-479EFBC1F8F2
treatment provided by	Felipe
scientific name	Paraprionospio lamellibranchia
status

Treatment

PARAPRIONOSPIO LAMELLIBRANCHIA HARTMAN, 1975 View in CoL

( FIG. 12 View Figure 12 )

Paraprionospio lamellibranchia Hartman, 1975 View in CoL

Material examined: Paraprionospio lamellibranchia , holotype: Station 363Q, 423 m deep, Mozambique Channel. Forty-two specimens used for the description of Paraprionospio lamellibranchia by Hartman (1975): Stations 251B, RH33 and RH51 (these specimens are not referred to Paraprionospio lamellibranchia ).

Description of holotype: Holotype mature male, incomplete with 63 setigers measuring 45 mm long and 1.85 mm wide (setiger 5, excluding parapodia). Posterior fragment with 59 setigers measuring 26 mm long enclosed. Prostomium fusiform with round anterior end ( Fig. 12A, B View Figure 12 ). Eyes not visible. Palpi missing. Peristomium with small marginal papilla on lateral sides. No pigmented patch on peristomium. Three pairs of branchiae on setigers 1–3. First and second branchiae missing. Third branchia (right side) bearing 54 lamellae; each lamella consisting of two plates on entire shaft ( Fig. 12A, B View Figure 12 ). A filament present at base of third branchiae. Notopodial postsetal lamellae elongate subtriangular on setigers 1–3, becoming low rounded back to setiger 15 reducing in size ( Fig. 12A View Figure 12 ); posteriorly, lamellae elevated, becoming lanceolate. Anterior neuropodial postsetal lamellae elongate and distally pointed, becoming low rounded posterior to setiger 4, thereafter reduced to a low ridge from setiger 11. Notopodial setae anteriorly bilimbate capillaries only, replaced gradually by long slender non-limbate capillaries posterior to about setiger 10. Neuropodial setae in anterior setigers bilimbate capillaries only, replaced by about 15 hooded hooks ( Fig. 12C View Figure 12 ) with alternating capillaries, and one or two punctate sabre setae from setiger 9. Alternating capillaries on setiger 9 limbate and short ( Fig. 12D View Figure 12 ), capillaries on setiger 10 and succeeding setigers nonlimbate and slender ( Fig. 12E View Figure 12 ). Notopodial hooded hooks appearing from setiger 35, numbering about four. Notopodial and neuropodial hooded hooks with three pairs of apical teeth above main fang. Dorsum of setigers 10–19 with slightly raised ridges: two ridges on setigers 10–12 and setigers 16–19, three ridges on setigers 13–15. Membranous dorsal crest connecting notopodial postsetal lamellae present on setigers 21– 30, accompanied by semi-transparent, dorsal cuticle. Ventral bilobed flap absent. Well developed interparapodial pouches on setigers 7–20. Pygidium with long median anal cirrus and two short, lateral cirri. Muscular gizzard present in setigers 8–9.

Remarks: Hartman (1975) described Paraprionospio lamellibranchia based on 168 specimens collected from the Mozambique Channel, Arabian Sea and Bay of Bengal. She reported that these specimens are identical in the possession of three vascular loops which penetrate in each branchial lamella. This structure, however, could not be confirmed from any specimen. Moreover, the material contains several distinct forms. For example, capillaries on the 9th neuropo- dium of the holotype (Stn. 363Q) and specimens collected from Stn. RH51 are short and bilimbate, whereas those of other specimens (Stns 251B, RH 33) are long, slender and non-limbate. The number of setigers bearing the membranous dorsal crest and semi-transparent dorsal cuticle is variable, i.e. setigers 21–30 (Stn. 363Q), setigers 21–29 (Stn. RH 33) and setigers 21–25 (Stn. 251B). Such differences found among specimens are taken as being of significance in relation to species differentiation; however, specimens except for those collected from Stns 363Q and RH33 ( Paraprionospio lamellibranchia and Paraprionospio inaequibranchia , respectively) remained as unidentified species due to being fragmentary.

Paraprionospio lamellibranchia can be separated from Paraprionospio pinnata and Paraprionospio alata by the possession of small papilla on the posterior margin of the peristomium, bifoliate lamellae of the branchiae, a filament at the base of the 3rd branchia, limbate capillaries in the 9th neuropodium, interparapodial pouches on setigers 7–20, and a dorsal membranous crest and semi-transparent dorsal cuticle on setigers 21–30. Paraprionospio lamellibranchia is similar to Paraprionospio africana in having bifoli- ate lamellae of branchiae and limbate capillaries in the 9th neuropodium. However, the former is distinguished from the latter by the presence of a ridge between branchial bases on setigers 2–3.

Distribution: Mozambique Channel.

PARAPRIONOSPIO OCEANENSIS SP. NOV.

( FIG. 13 View Figure 13 )

Paraprionospio sp. form CII, Yokoyama & Tamai, 1981: 313–315, fig. 6.

Material examined: Holotype (OMNH-Iv 4889), entire specimen, 80 setigers, 32 mm long, 1.0 mm wide at setiger 3: Tosa Bay (33°23′N, 133°26′E), 49 m deep, sand, ii.1977, collected by K. Tamai. Nine paratypes (OMNH-Iv 4890–4898): Tosa Bay (33°23–28′N, 133°26–39′E), 35–70 m, coll. K. Tamai. Six specimens (OMNH-Iv 4899, 4900) collected from the following localities: off Takahama (35°33–35′N, 135°29–30′E), Wakasa Bay, 37–61 m, coll. H. Yokoyama.; Tanabe Bay (33°43′N, 135°17′E), 59 m, coll. H. Yokoyama. GoogleMaps

Description: Body up to 65 mm long, 1.8 mm wide (excluding parapodia) with 98 setigers. Prostomium fusiform with round or truncate anterior end ( Fig. 13A View Figure 13 ), extending posteriorly as a faintly raised ridge to the first setiger. Two pairs of dark-brown, small eyes in trapezoidal arrangement usually visible. Brown pigment patch usually present on lateral side of peristomium. Faint groove just posterior to pigmented area on peristomium. Small papilla on posterior margin of peristomium. Three pairs of branchiae on setigers 1–3 ( Fig. 13A View Figure 13 ). First branchiae usually longest, third pair shortest. In basal region of first branchial shaft, 1–5 conic processes placed along anterior face. All branchiae bearing lamellae; in proximal region, 2–4 lamellae consisting of single triangular plate; succeeding lamellae consisting two plates; thereafter two plates connecting at their basis; in middle and distal regions two plates uniting completely, showing flabellate-shape. A slender filament present at base of third branchia ( Fig. 13A View Figure 13 ). On setigers 1–3, notopodial postsetal lamellae long, foliaceous and distally pointed; posterior to setiger 4, lamellae becoming rounded and low; posterior to about setiger 13, lamellae elevated increasingly and becoming triangular to lanceolate ( Fig. 13A, B View Figure 13 ). Neuropodial postsetal lamellae of setigers 1–2 lanceolate; posterior to setiger 3, lamellae becoming rounded; posterior to setiger 9, lamellae reduced to a low ridge. Anterior setae all limbate capillaries bearing granules. Posterior to about setiger 16, notopodial limbate capillaries replaced by slender, non-limbate capillaries. Neuropodial hooded hooks ( Fig. 13C View Figure 13 ) from setiger 9, accompanied by alternating non-limbate slender capillaries and one to two granulated sabre setae. Notopodial hooded hooks ( Fig. 13D View Figure 13 ) appearing from setiger 34–42. Notopodial and neuropodial hooks with 3–4 pairs of teeth above main fang and striate secondary internal hoods. No ventral bilobed flap on setiger 8. Striated interparapodial pouches present in some specimens, appearing between setigers 4 and 15 and disappearing between setigers 14 and 39 ( Fig. 13A, E View Figure 13 ). Dorsum of setigers 6–11 faintly biannulated with two ciliated bands ( Fig. 13A View Figure 13 ). Dorsum of setigers 12–17 transverse series of lighter coloured slightly raised ridges, 3 ridges per setiger. Semi-transparent dorsal cuticle bearing circular convexities on setigers 21–31 ( Fig. 13E View Figure 13 ). Dorsal crests absent. Pygidium with a long median cirrus only ( Fig. 13F View Figure 13 ). Muscular gizzard present in setigers 6.

Remarks: Paraprionospio oceanensis is closely related to Paraprionospio inaequibranchia ; however, the former differs from the latter in having a small papilla on the peristomium and processes on the basal region of the first branchia and in the absence of membranous dorsal crests. Paraprionospio oceanensis also resembles Paraprionospio coora , but differs from the latter in having a filament at the base of the third branchia, semi-transparent dorsal cuticles and single anal cirrus.

Etymology: The species name (= oceanic) is derived from the fact that the species is distributed on continental shelf areas facing open waters ( Tamai, 1981).

Distribution: Continental shelf areas off western Japan, more southern than 36°N.

PARAPRIONOSPIO PATIENS SP. NOV.

( FIGS 14 View Figure 14 , 15 View Figure 15 )

Paraprionospio pinnata Yokoyama, 1981 Paraprionospio sp. form A, Yokoyama & Tamai, 1981:

304–309, figs 2, 3.

Material examined: Holotype (OMNH-Iv 4901), entire specimen, female, 95 setigers, 41 mm long, 1.1 mm wide at setiger 5: Station 6 (34°39′N, 135°22′E), Osaka Bay, 14 m deep, mud, 27.viii.1984, collected by H. Yokoyama. Seven paratypes (OMNH-Iv 4902–4908): Stations 5–9 (34°37–40′N, 135°20–23′E), Osaka Bay, 12–15 m, 27–29.viii.1984, collected by H. Yokoyama [see Yokoyama, Tsuchinaga & Oda (1985) for the sampling station of the type specimens and environmental factors]. One hundred and fifty-four specimens (OMNH-Iv 4909–4919) collected from the following localities in Japan: Hitachi Harbor (36°27′N, 140°37′E), Ibaraki Pref., coll. Ibaraki Fisheries Experimental Station; Tsuruga Bay (35°43–44′N, 136°5–6′E), 11–20 m, coll. I. Hayashi; Obama Bay (35°29–30′N, 135°42–44′E), 3–13 m, coll. I. Hayashi; off the mouth of Yura River (35°31–32′N, 135°17– 18′E), Wakasa Bay , 10–20 m, coll. H. Yokoyama; Kumihama Bay (35°37′N, 134°54′E), 7 m, coll. H. Yokoyama; off the mouth of Sendai River (35°32–33′N, 134°12–13′E), Tottori Pref., 9–15 m, coll. H. Yokoyama; Nagoya Harbor (35°5′N, 136°53′E), Ise Bay , coll. H. Yokoyama; Gokasho Bay (34°19′N, 136°39′E), 12 m, coll. H. Yokoyama; Tanabe Bay (33°42–43′N, 135°20– 22′E), 6–13 m, coll. H. Yokoyama; off the mouth of Kinokawa River (34°13′N, 135°8′E), Kii Channel, 9 m, coll. H. Yokoyama; Higashi-Harima Harbor (34°43′N, 134°50′E), Hyogo Pref., coll. H. Yokoyama. Thirty- eight specimens (OMNH-Iv 4920) collected from Jakarta Bay , Indonesia, 18.ix.1993. GoogleMaps

Description: Body up to 66 mm in length and 1.8 mm in width, with 112 setigers. Prostomium fusiform with bluntly pointed, round or truncate anterior end ( Fig. 14A View Figure 14 ). Two pairs of black eyes in trapezoidal arrangement. A raised, narrow ridge on posterior part of prostomium. Small papilla on posterior margin of peristomial wing. No pigment patch on peristomium. A pair of grooved palpi with dark brown pigment patches along lateral sides and membranous basal sheath ( Fig. 14B View Figure 14 ). Three pairs of branchiae on setigers 1–3. First branchiae longest, third branchiae shortest ( Fig. 14A View Figure 14 ). All branchiae bearing lamellae on branchial shaft except in base and distal tip. Lamellae consisting of two plates except in most proximal region of branchial shaft, where 1–2 lamellae consisting of single subtriangular plate ( Fig. 14C View Figure 14 ); in proximal region, each plate lanceolate ( Fig. 14D View Figure 14 ); in the middle region lamellar plates becoming broader, but keeping separate each other, showing bifoliate-shape ( Fig. 14E View Figure 14 ); in distal region, each plates connecting at its base, but not fusing completely ( Fig. 14F View Figure 14 ). A slen- der filament at base of third pair of branchiae ( Fig. 14A View Figure 14 ). Notopodial lamellae anteriorly lanceolate, distally pointed, longest on setiger 3, becoming rounded and reducing in size posteriorly to about setiger 20 ( Figs 14A View Figure 14 , 15A View Figure 15 ); succeeding lamellae elevated, becoming triangular to lanceolate gradually ( Fig. 15B View Figure 15 ). Neuropodial lamellae lanceolate in setigers 1–3; posterior to setiger 4, lamellae becoming rounded and reduced to a low postsetal ridge in middle and posterior setigers ( Figs 14A View Figure 14 , 15A, B View Figure 15 ). Ventral bilobed flap on setiger 8 absent. Interparapodial pouches absent. Dorsum of setigers 6–12 faintly biannulated. Dorsum of setigers 13–20 with transverse series of slightly coloured slightly raised ridges, 2 or 3 ridges per setiger. Notopodial postsetal lamellae united across dorsum, forming dorsal crests on setigers 21–35 (most specimens including type specimens) or setigers 21–36 (a specimen collected from Hitachi Harbor) ( Fig. 14G View Figure 14 ). Anterior setae all limbate capillaries bearing granules. Notopodial limbate capillaries replaced by slender, non-limbate capillaries posterior to middle body region. Neuropodial hooded hooks with 3–4 apical teeth above main fang ( Fig. 15C View Figure 15 ) from setiger 9, numbering 12–15 per fascicle, accompanied by alternating capillaries and 1–2 granulated sabre setae. Neuropodial capillaries short and limbate on setiger 9 ( Fig. 15D View Figure 15 ), replaced by long, fine, non-limbate capillaries from setiger 10 ( Fig. 15E View Figure 15 ). Notopodial hooded hooks with 2–3 apical teeth ( Fig. 15F View Figure 15 ) from setiger 31–36. Neuropodial and notopodial hooks with striate secondary internal hoods. Pygidium with a long median anal cirrus and two short, lateral cirri ( Fig. 14H View Figure 14 ). Muscular gizzard present in setigers 9–10.

Remarks: Paraprionospio patiens is closely allied to Paraprionospio africana and P. lamellibranchia in having bifoliate branchial lamellae, a filament at the base of the third branchia, and limbate capillaries in the 9th neuropodium. However, Paraprionospio patiens differs from Paraprionospio africana in the absence of a ridge between branchia bases on setigers 2–3. Paraprionospio patiens can also be separated from Paraprionospio lamellibranchia based on the absence of interparapodial pouches and the number of dorsal crests (on setigers 21–35 rarely on setigers 21– 36 vs. on setigers 21–30).

Etymology: The new species has been found frequently in organically polluted areas suffering from depleted oxygen concentration in Japanese coastal waters ( Tamai, 1981). Yokoyama (1995) reported that larvae of this species were distributed exclusively in water layers with oxygen levels below 1 mg L −1. The specific name (= patient) is derived from the ability to endure such severe environments.

Distribution: Western Japan, more southern than 37°N; Indonesia.

PARAPRIONOSPIO PINNATA ( EHLERS, 1901) View in CoL

( FIGS 16–18 View Figure 16 View Figure 17 View Figure 18 )

Prionospio pinnata Ehlers, 1901 View in CoL

Paraprionospio pinnata Wilson, 1990 View in CoL

Material examined: In total, 1046 specimens (OMNH- Iv 4921), off Concepciòn, 27 m deep, mud, collected by F. D. Carrasco.

Description: Body up to 34 mm in length and 1.3 mm in width (excluding parapodia), with 79 setigers. Prostomium fusiform with round ( Fig. 16A, B View Figure 16 ) anterior end. Two pairs of dark-brown eyes in trapezoidal arrangement on prostomium. Palpi with basal sheath. Brown pigment patch occasionally found on lateral side of peristomium. Peristomium without marginal papilla. Three pairs of branchiae on setigers 1–3 ( Fig. 16A View Figure 16 ). Each pair of branchiae of approximately equal length, bearing 50–60 lamellae on branchial shaft except on its base and distal tip. In proximal region of branchial shaft, one or two lamellae consisting of single triangular plate ( Fig. 17A View Figure 17 ); succeeding lamellae consisting of two plates ( Fig. 17B View Figure 17 ); in middle and distal regions two plates connected, showing crescent or fan in shape ( Fig. 17C–F View Figure 17 ). First pair of branchiae without protuberances on anterior face in basal region of branchial shaft. Filament absent from base of third pair of branchiae. Notopodial postsetal lamellae elongate subtriangular on setigers 1–3 ( Fig. 17G, H View Figure 17 ), becoming low rounded posteriorly to about setiger 11 reducing in size ( Figs 16A View Figure 16 , 17I–K View Figure 17 ). Notopodial postsetal lamellae posteriorly elevated ( Fig. 17L View Figure 17 ), becoming triangular to lanceolate in middle to posterior setigers ( Fig. 17M, N View Figure 17 ). Anterior neuropodial postsetal lamellae ovate, distally pointed ( Fig. 17G, H View Figure 17 ), becoming low rounded from setiger 4 ( Figs 16A View Figure 16 , 15I View Figure 15 ); lamellae reduced to a low ridge from setiger 9 ( Fig. 17K–N View Figure 17 ). Notopodial setae anteriorly bilimbate capillaries ( Fig. 18A View Figure 18 ) only, posteriorly replaced gradually by long slender non-limbate capillaries. Neuropodial setae in anterior setigers bilimbate capillaries only, replaced by hooded hooks with 3–4 pairs of apical teeth above main fang ( Fig. 18B View Figure 18 ), slender non-limbate capillaries ( Fig. 18C View Figure 18 ), and sabre setae ( Fig. 18D View Figure 18 ) from setiger 9. Neuropodial hooded hooks, attaining 10–13 per fascicle. Sabre setae, usually 1, occasionally 2 per fascicle; each moderately granulated and with slight limbation. Notopodial hooded hooks ( Fig. 18E View Figure 18 ) from setiger 32–34, numbering 2–4 per fascicle; each hook with three pairs of teeth above main fang. Neuropodial and notopodial hooded hooks with 3–4 pairs of apical teeth above main fang. Dorsum of setigers c. 12–17 transverse series of lighter coloured slightly raised ridges, 3 ridges per set- iger. A faint ridge between notopodial postsetal lamellae, not forming a membranous dorsal crest, present on setigers 21–26, accompanied by semi-transparent cuticle on dorsum ( Fig. 16C View Figure 16 ). Ventral bilobed flap absent. Interparapodial pouches absent. Pygidium with a long medial cirrus and two short lateral cirri ( Fig. 16D View Figure 16 ). Muscular gizzard present in setigers 7–8.

Remarks: Paraprionospio pinnata was originally described by Ehlers (1901) based on specimens collected from shallow water (water depth = c. 9 m) off Talcahuano, Chile. Wilson (1990) redescribed Paraprionospio pinnata based on the lectotype and paralectoypes, which were all fragments, by referring to the characters used by Yokoyama & Tamai (1981). He noted that branchial lamellae are bifoliate. The term ‘bifoliate’ means that each lamella consists of two plates, as in Yokoyama & Tamai (1981); however, Wilson (1990: fig. 89) shows that the two plates are connected to each other at their bases showing a boomerang-like shape. Lamellae of the specimens examined in the present study were bifoliate in the proximal region of each branchia and crescent-shaped or flabellate in the middle and distal regions. Wilson (1990) did not find eyes, obvious pigment patterns or dorsal crests. Two pairs of darkbrown eyes on the prostomium were found in all specimens and brown pigment patches were found in some of specimens examined in this study, which were collected from Concepciòn, which is located close to Talcahuano (type locality of Paraprionospio pinnata ). Such pigments may progressively fade during the long period of preservation. Wilson (1990) found semi-transparent dorsal cuticle on setigers 21–35, but he did not find any dorsal crests. In the specimens examined in the present study, a faint ridge but not a membranous dorsal crest was found on setigers 21–26, accompanying the semi-transparent dorsal cuticle. Wilson (1990) found only a single anal cirrus in the posterior fragment specimens, whereas the present specimens have a median anal cirrus and two small lateral cirri. Taking account of the deterioration of the type specimens and that some of the properties of the diagnostic characters are indiscernible, discrepancies between Wilson’s description and the present observation seem to refer to a single species.

Distribution: Chile.