Paradiopatra minuta Budaeva & Fauchald, 2011

Budaeva, Nataliya & Fauchald, Kristian, 2011, Phylogeny of the Diopatra generic complex with a revision of Paradiopatra Ehlres, 1887 (Polychaeta: Onuphidae), Zoological Journal of the Linnean Society 163 (2), pp. 319-436 : 382-388

PARADIOPATRA MINUTA ( MCINTOSH, 1885) COMB. NOV. ( FIG. 50)

Nothria minuta McIntosh, 1885: 334–335 , pl. XXIA, figs 17 and 18; pl. LX, fig. 4.

Nothria minuta Fauchald, 1982: 99 .

Notonuphis minuta Paxton, 1986a: 35–36 .

The type material was not available for reexamination. The following description is based on McIntosh’s (1885) original description, and on remarks provided by Paxton (1986a).

Type locality: New Zealand, off the North Island , 37.567°S, 179.367°E, 1280 m ( McIntosh, 1885) .

Diagnosis: Anterior several pairs of parapodia with simple bidentate falcigers with moderately long pointed hoods; branchiae absent; frontal lips globular; peristomial cirri absent.

Description: Type material was re-examined by Fauchald (1982) and Paxton (1986a). Both authors reported that the single known specimen lacked the head end; identification is thus only possible based on the original illustrations. McIntosh (1885) stated that the holotype was a small specimen about 20 mm long and 0.5 mm wide. According to his illustration ( McIntosh, 1885: pl. XL, fig. 4), the median antenna shorter than the lateral antennae, and reaching about chaetiger 3. Lateral antennae reaching about chaetiger 5. Frontal lips globular. Eyes absent. Nuchal organs were not described, and were not shown on the figure. Peristomial cirri absent.

The number of anterior modified parapodia is unknown. McIntosh’s drawing ( McIntosh, 1885: pl. XL, fig. 4) shows all anterior parapodia as not being enlarged and projected laterally. Anteriormost dorsal cirri relatively short and thick. Anterior falcigers simple and clearly bidentate, with moderately long pointed hoods. Paired subacicular hooks present, but chaetiger number of their first appearance remains unknown. Pectinate chaetae with oblique distal margins.

Branchiae absent. Maxillary formula ( McIntosh, 1885): Mx I = 1 + 1; Mx II = 6 + 8; Mx III = 8 + 0; Mx IV =? + 7; Mx V = 1 + 1. Mandibles were not described.

Pygidium and tubes unknown.

Remarks: Fauchald (1982) referred Nothria minuta ( McIntosh, 1885) to the genus Hyalinoecia based on the absence of peristomial cirri and the presence of simple falcigers on anterior parapodia. Paxton (1986a) referred the species to Notonuphis , indicating that the type specimen has pectinate chaetae with an oblique distal margin and subacicular hooks with short distal teeth.

We consider the absence or presence of peristomial cirri as an inappropriate diagnostic character at the generic level. Therefore, Notonuphis minuta sensu Paxton (1986a) is referred here to Paradiopatra , based on the original illustrations showing: the presence of moderately long pointed hoods on anterior falcigers; the lack of enlarged anterior parapodia; median antenna shorter than lateral antennae; and pectinate chaetae with oblique distal margins. Only one strongly damaged specimen is known for this species, and its validity remains uncertain.

Paradiopatra minuta comb. nov. differs from its congeners in having simple rather than pseudocompound anterior falcigers.

Distribution: Paradiopatra minuta comb. nov. is known only from its original record; New Zealand, off the North Island ( Fig. 50); depth 1280 m. ( McIntosh, 1885).

PARADIOPATRA OKAI IMAJIMA, 1999

( FIGS 51 AND 52)

Paradiopatra okai Imajima, 1999: 77–81 , figs 43–44; Imajima, 2001: 73.

Type material: NSMT Pol 402-2, Japan, Sagami Bay, September 1989, coll. Imajima, M. (one paratype) .

Type locality: Pacific Ocean , Japan, Sagami Bay 35.268°N, 139.208°E, 50 m.

Diagnosis: First three pairs of parapodia with pseudocompound bidentate falcigers with moderately long pointed hoods; ventral cirri subulate on first three chaetigers; subacicular hooks starting from chaetiger 9; branchiae absent; eyes present; perstomial cirri present.

Description: Paratype, an incomplete specimen consisting of 78 chaetigers, 0.4 mm wide. Imajima (1999) reported that the holotype, a complete specimen with 93 chaetigers was 0.5 mm wide (with parapodia) and 21 mm long. First four chaetigers cylindrical, later body becoming dorsally flattened. Examined paratype stored in alcohol light brown, lacking colour pattern.

Prostomium anteriorly rounded with paired ovoid frontal lips ( Fig. 51B ). Palps reaching chaetiger 1; lateral antennae reaching chaetiger 5; median antenna reaching chaetiger 3. Ceratophores of all antennae with four rings in examined paratype ( Fig. 51A, B ). Imajima (1999) reported five rings in ceratophores in holotype. Lateral projections of ceratophores absent. Two pairs of small eyespots located near the bases of lateral antennae and palps. Nuchal grooves short and almost straight. Peristomium as long as first chaetiger; peristomial cirri very small and tapering, significantly shorter than peristomium ( Fig. 51A ).

First three pairs of parapodia modified, projecting lateroventrally, directing anteriorly ( Fig. 51B ). Prechaetal lobes rounded; postchaetal lobes present on first five pairs of parapodia; triangular to digitiform, disappearing posteriorly. Dorsal cirri relatively short and subulate on all parapodia; ventral cirri subulate on first three chaetigers, later replaced by rounded to triangular glandular pads ( Fig. 51B ).

First three pairs of parapodia with single dorsal simple capillary chaeta and ventral fascicle of pseudocompound falcigers. As only a single specimen was available for the examination, parapodia were not dissected, and the detailed structure of chaetae described here follows that of Imajima (1999). All falcigers clearly bidentate with well-developed subdistal teeth and moderately long pointed hoods. Simple limbate chaetae in two fascicles, starting from chaetiger 4. Paired simple bidentate subacicular hooks, starting from chaetiger 9. Pectinate chaetae with slightly oblique distal margins with 15–20 equally sized teeth, starting from chaetiger 11.

Branchiae absent. Imajima (1999) reported fragile mandibles and maxillary formula: Mx I = 1 + 1; Mx II = 10 + 11; Mx III = 9 + 0; Mx IV = 6 + 7; Mx V = 1 + 1.

Description of pygidium and tubes is based on Imajima’s (1999) observations. Pygidium with two pairs of anal cirri; dorsal pair longer than ventral one. Tubes thin with an internal translucent layer and outer layer of sand particles.

Remarks: Paradiopatra okai resembles P. fragosa closely in having three pairs of modified parapodia with clearly bidentate pseudocompound falcigers, origin of subacicular hooks on chaetiger 9, and lack of branchiae. Imajima (1999) indicated that P. okai differs from P. fragosa in having three rather than four pairs of subulate ventral cirri. All examined specimens of P. fragosa , including type material, showed the presence of only three pairs of ventral cirri. Nevertheless, P. okai can be distinguished from the latter by having, rather than lacking, eyes and building sandy rather than muddy tubes.

Distribution: Pacific Ocean, off Japan, Sagami bay ( Fig. 52). Depth range 40–530 m ( Imajima, 1999).

PARADIOPATRA PAPILLATA (KUCHERUK, 1979B)

( FIGS 53 AND 54; TABLE 11)

Onuphis papillata Kucheruk, 1979b: 1227–1228 , fig. 1. Kucheruk, 1981: 42.

Sarsonuphis papillata Fauchald, 1982: 76 .

Paradiopatra papillata Paxton, 1986a: 38 .

Type material: ZIN 1 /43886, Akademik Kurchatov St. 255 (holotype) .

Non-type material examined: SIO RAS, Dmitry Mendeleev St. 1647-DO, Ocean grab (three); St. 1647-TG, Galathea trawl (four); SIO RAS Vityaz, St. 4534 (one); St. 6105 (one).

Type locality: Eastern Pacific , Peru – Chile Trench 21.15°S, 70.867°W, 3550 m .

Diagnosis: First three pairs of parapodia with pseudocompound bi- and tridentate falcigers with moderately long pointed hoods; ventral cirri subulate on first three chaetigers; subacicular hooks starting from chaetigers 11 or 12; branchiae absent; ceratophores with lateral projections; peristomial cirri present.

Description: All specimens incomplete, lacking posterior ends. Holotype, the most complete specimen, with 65 chaetigers, 1.3 mm wide. Width of all material studied varying from 1 to 1.9 mm. Specimens stored in alcohol yellowish, without colour pattern.

Prostomium rounded with a pair of ovoid frontal lips ( Fig. 53B ). Palps reaching chaetiger 1; lateral antennae reaching chaetiger 4 (chaetiger 3); median antenna reaching chaetiger 2 (chaetigers 3 or 4). Palpophores with two or three rings, without lateral projections. Lateral ceratophores consisting of four rings with lateral projections on two basal rings. Median ceratophore consisting of three rings with the basal ring bearing paired lateral projections ( Fig. 53A ). Nuchal organs slightly curved. Eyes absent. Peristomium as long as first chaetiger. Peristomial cirri present, slender, equal in length to peristomium ( Fig. 53A ).

First three pairs of parapodia modified, projecting laterally, directing anteriorly ( Fig. 53B ). Prechaetal lobes rounded on all chaetigers; postchaetal lobes triangular on first eight (nine) chaetigers, abruptly reducing from chaetiger 9 (chaetiger 10). Dorsal cirri long and slender on anterior chaetigers, becoming shorter towards posterior end of fragmentary specimens. Ventral cirri subulate on first three chaetigers, later replaced by rounded to slightly oval ventral glandular pads ( Fig. 53B, E, F ).

First three pairs of parapodia with two dorsal simple capillary chaetae and ventral fascicle of three or four pseudocompound falcigers ( Fig. 53E, F ). Falcigers indistinctly bi- or tridentate, with weakly developed subdistal teeth and moderately long pointer hoods ( Fig. 53I ). Simple limbate chaetae in both fascicles starting from chaetiger 4. Ventral fascicle of limbate chaetae replaced by paired subacicular hooks from chaetiger 11 (chaetiger 12) ( Fig. 53G, H ). Subacicular hooks relatively small, light coloured, and slender, becoming wider and stouter posteriorly ( Fig. 53J, K ). Pectinate chaetae with slightly oblique distal margins and about 20 small teeth ( Fig. 53L ). Neuroaciculae yellow with pointed tips, three or four per parapodium.

Branchiae absent. Mandibles weakly sclerotized. Calcareous cutting plates missing in all specimens examined ( Fig. 53D ). Maxillary formula (based on one specimen): Mx I = 1 + 1; Mx II = 9 + 10; Mx III = 11 + 0; Mx IV = 7 + 9; Mx V = 1 + 1 ( Fig. 53C ).

Pygidium unknown. Tubes cylindrical with a thin inner parchment-like layer and outer layer of mud.

Remarks: Kucheruk (1979b) reported only bidentate anterior falcigers with a weak subdistal tooth in the original decription of P. papillata . All known material including the holotype was examined: they all have both indistinctly bi- and tridentate falcigers with weakly developed subdistal teeth.

Paradiopatra papillata closely resembles P. capbretonensis and P. hartmanae in lacking branchiae and having lateral projections on the ceratophores. Paradiopatra papillata differs from P. capbretonensis in having subacicular hooks starting from chaetigers 11 or 12, rather than from chaetiger 9; P. papillata differs from P. hartmane by the presence of bi- and tridentate pseudocompound falcigers rather than indistinctly bidentate or unidentate falcigers or pseudocompound tapering chaetae.

Distribution: Paradiopatra papillata is widely distributed at abyssal depths in the Pacific and Indian oceans: Peru – Chile Trench, Gulf of Alaska, off Sumatra ( Fig. 54). Depth range 2980–3700 m.

PARADIOPATRA PARVA ( MOORE, 1911)

( FIGS 55–59 ; TABLE 12)

Onuphis parva Moore, 1911: 263–266 , pl. 17, figs 51– 57; pl. 18: figs 98 and 99. Hartman, 1944: 70–71. Fauchald, 1968: 37, pl. 9, figs a–e.

Sarsonuphis parva Fauchald, 1982: 76–77 , fig. 20f, table 25.

Paradiopatra parva Paxton, 1986a: 38 . Type material: USNM 17356 , Albatross St. 4446 (holotype); USNM 17359 , the same locality as holotype (11 paratypes).

Non-type material examined: USNM 16963 , Albatross St. 4453 (three) ; USNM 16964 , Albatross St. 4485 (five) ; USNM 1695 , Albatross St. 4475 (31) ; USNM 17063 , Albatross St. 4480 (nine) ; USNM 17064 , Albatross St. 4457 (three) ; USNM, 17065 Albatross St. 4510 (five) ; USNM 17072 , Albatross St. 4445 (four) ; USNM, 17355 Albatross St. 4454 (two) ; USNM 17358 , Albatross St. 4464 (six) ; USNM 17430 , Albatross St. 4468 (one) ; USNM 17431 , Albatross St. 4467 (one) ; USNM 22432 , Albatross St. 3666 (one) ; USNM 123203 , MMS-CARP St. SB05, 41.51°N, 124.36°W, 95 m, 22 November 1987 (12) ; USNM, USA, California, Los Angeles Harbor, St. 10C, 33.669°N, 118.297°W, 61 m, 13 July 2004, coll. Zanol, J. (two) ; St. 9B, 33.682°N, 118.322°W, 151 m, 13 July 2004, coll. Zanol, J. (one) ; St. 7B 33.701°N, 118.352°W, 150 m, 14 July 2004, coll. Zanol, J. (one).

Type locality: Pacific Ocean, USA coast, off California, Point Piños Lighthouse , 36.633°N, 121.917°W, 95–108 m.

Diagnosis: First three pairs of parapodia with clearly bidentate pseudocompound falcigers with moderately long pointed hoods; ventral cirri subulate on first three chaetigers; subacicular hooks starting from chaetiger 9; branchiae pectinate with up to 14 (usually between five and ten) filaments, starting from chaetigers 3 or 4; peristomial cirri present.

Description: Holotype, a complete specimen consisting of 101 chaetigers, 0.8 mm wide and 33 mm long. Five more complete specimens, including two paratypes, with 60–99 chaetigers present among studied material. Width of all examined specimens varying from 0.6 to 0.8 mm; average width 0.77. All specimens stored in alcohol light brown, lacking distinct colour pattern.

Prostomium anteriorly rounded with paired ovoid frontal lips ( Fig. 55B ). Palps reaching chaetiger 1; lateral antennae reaching chaetiger 6 (chaetigers 3–9); median antenna reaching chaetiger 5 (chaetigers 2–7). Ceratophores of lateral antennae lacking lateral projections, consisting of five (four) rings ( Fig. 55A, B ). Nuchal grooves slightly curved. Eyes absent. Peristomium as long as first chaetiger. Peristomial cirri present, equal in length to peristomium ( Fig. 55A ).

First three pairs of parapodia modified, projecting lateroventrally, directing slightly anteriorly ( Fig. 55B–D ). Prechaetal lobes rounded; postchaetal lobes wide and triangular on first eight chaetigers, and abruptly reduced starting from chaetiger 9. Dorsal cirri digitiform on all parapodia, becoming more slender in posterior region. Ventral cirri

Figures

Figure 51. Paradiopatra okai (NSMT Pol-402-2): A, anterior end, dorsal view; B, anterior end, ventral view.

Figure 53. Paradiopatra papillata (SIO RAS, Dmitry Mendeleev St. 1647): A, anterior end, dorsal view; B, anterior end, ventral view; C, maxillae; D, mandibles (cutting plates are missing); E, parapodium of chaetiger 1, anterior view; F, parapodium of chaetiger 3, anterior view; G, parapodium of chaetiger 12, anterior view; H, parapodium of chaetiger 28, anterior view; I, bi- and tridentate pseudocompound falcigers from chaetiger 1; J, subacicular hook from chaetiger 12; K, subacicular hook from chaetiger 28; L, pectinate chaeta from chaetiger 28.

Figure 55. Paradiopatra parva (USNM 16964): A, anterior end, dorsal view; B, anterior end, ventral view; C, parapodium of chaetiger 2, anterior view; D, parapodium of chaetiger 3, anterior view; E, parapodium of chaetiger 4, anterior view; F, parapodium of chaetiger 9, anterior view; G, parapodium of chaetiger 29, anterior view; H, bidentate pseudocompound falciger from chaetiger 2; I, subacicular hook from chaetiger 20; J, pectinate chaeta from chaetiger 14.