Naineris uncinata Hartman, 1957

Blake, James A., 2020, New species and records of deep-water Orbiniidae (Annelida, Polychaeta) from the Eastern Pacific continental slope, abyssal Pacific Ocean, and the South China Sea, Zootaxa 4730 (1), pp. 1-61 : 26-28

Naineris uncinata Hartman, 1957

Figure 13

Naineris uncinata Hartman, 1957: 301–302 , Pl. 38, figs. 1–8; 1960: 107; 1961: 26; 1969: 32–33, 4 figs.

Naineris (Naineris) berkeleyorum Pettibone, 1957: 165–167 , Fig. 4 a–f.

Naineris cf. grubei: Blake 1996: 20–22 , fig. 1.8. Not Gravier 1908.

Material examined. Continental margin off Oregon, Cascadia Subduction Zone, Southern summit of Hydrate Ridge , R / V Sonne Cruise 143, coll. H. Sahling, Sta. 179, TV-multicore, 17 Aug 1999, 44°34.2′N, 125°08.8′W, 786

m, 29 specimens ( MCZ 153572 ); R / V Atlantis , coll. G. Rouse, HOV Alvin Dive 4629, 01 Aug 2010, 44º34.255′N, 125º09.289′W, 809 m, 1 specimen ( SIO-BIC A2069 ) ; HOV Alvin Dive 4631, 03 Aug 2010, 44º40.173′N, 125º05.899′W, 618 m, 1 specimen ( SIO-BIC A2082 ) ; HOV Alvin Dive 4633, 05 Aug 2010, 44º27.039′N, 125º01. 975′W, 643 m, 1 specimen ( SIO-BIC A2102 ) ; HOV Alvin Dive 4634, 06 Aug 2010, 44º40.185′N, 125º05.974′W, 603 m, 2, specimens ( SIO-BIC A2105 ) ; HOV Alvin Dive 4635, 07 Aug 2010, 44º34.118′N, 125º09.076′W, 795 m, 3 specimens ( SIO-BIC A2113 ) ; ROV Jason II Dive 593, 02 Sep 2011, 44°40.17212′N, 122°5.88719′W, 795 m, 1 specimen ( SIO-BIC A2659 ) ; ROV Jason II Dive 593, HR6, 06 Sep 2011, 44.67′N, 122.098′W, 795 m, 2 specimens ( SIO-BIC A2660 , A2661 ).— Seeps at Northern Hydrate Ridge , BSR-outcrop, R / V Sonne Cruise 143, coll. H.

Sahling, Sta. 167, TV-Grab, 16 Aug 1999, 44°50.550′N, 125°55.827′W, 567 m, 1 specimen ( MCZ 153573 ).

Description. A large species, recorded up to 180 mm long, 3 mm wide, with about 350 segments ( Pettibone 1957); largest specimen in current collection incomplete (SIO-BIC A2113), 18.5 mm long, 1.8 mm wide, with 50 segments. Complete juvenile 3.05 mm long with 36 setigers; larger incomplete juvenile 5.2 mm long with 44 setigers. Body with laterally expanded thoracic segments, dorsoventrally flattened, with narrow crowded segments, about ten times wider than long ( Fig. 13A ); abdominal segments oval in cross section with venter rounded, individual segments shorter, narrower, less crowded, about three times wider than long. Parapodia continuing across abdominal venter as broad annular ring, with intersegmental areas subdivided into two narrow rings, producing triannulate segments. Some specimens with oval-shaped protozoans attached to thoracic parapodia. Color in alcohol white to light tan.

Prostomium short, thick, rounded to truncate on anterior margin ( Fig. 13A ); eyespots absent; nuchal organs transverse grooves on posterior lateral margin ( Fig. 13B ). Peristomium a single ring, narrower than, but about same length as, setiger 1 ( Fig. 13A ); extending ventrally to form ventral lip of mouth.

Thorax recorded with 17–26 setigers by Hartman (1957) and Pettibone (1957) and 13–14 setigers by Blake (1996); largest specimens in present collection with 14–15 thoracic setigers and 1–2 transitional setigers. Branchiae from setiger 4–6, short at first ( Fig. 13A ), becoming longer over thoracic segments and longest in middle and abdominal segments, continuing to posterior end; individual branchiae erect, tapering to narrow rounded apex, with dense lateral ciliation.

Thoracic notopodia with a narrow, tapering postsetal lamella and dense fascicles of long, camerated capillaries ( Fig. 13D ). Abdominal notopodia with a long, narrow postsetal lobe and a fascicle of long, thin camerated capillaries and 1–3 furcate setae with unequal, blunt-tipped tynes and a row of thin needles between tynes. Thoracic neuropodia thickened basally with an elongated postsetal lamella; a second lamella beginning ventral to the first at about setiger 10 ( Fig. 13 B–D), continuing on a few abdominal segments before disappearing. Juveniles of about 5 mm or less lacking second neuropodial postsetal lamella. Neurosetae of thoracic segments include 2–4 rows of thick uncini with transverse ribs along their length, terminating in a flattened, weakly notched tip surrounded by thin transparent hood ( Fig. 13 E–F). Uncini accompanied by long, thin camerated capillaries ( Fig. 13 E–F), both interspersed and as 1–2 separate posterior rows. Abdominal neuropodia narrow, ending in bilobed tip with short inner, rounded lobe and longer narrow outer lobe. Setae include a few thin, capillaries and 1–2 thicker, blunt-tipped projecting aciculae.

Pygidium with four lobes surrounding anus, each bearing a short cirrus.

Methyl Green stain. No pattern; prostomium not staining; body stains uniformly, de-stains rapidly.

GenBank accession numbers: SIO-BIC A2069: MN816166 ; SIO-BIC A2659: MN816167 ; SIO-BIC A2660: MN816168 ; SIO-BIC A2661: MN816169 .

Remarks. Naineris uncinata is characterized by having a short, blunt prostomium, a mixture of thoracic neuropodial capillaries and uncini with transverse ribs along the shaft and a notched tip, branchiae from setigers 4–6, and most importantly a second neuropodial postsetal lamella in posterior thoracic and some transitional segments. However, in the present study, juveniles ranging in size from 3–5 mm long and with 36–44 setigers that are clearly Naineris uncinata have all characteristics of the adults except for the second neuropodial lamella of posterior thoracic segments. Evidently, the extra cirrus does not develop until later in development. This discovery suggests that the small specimens identified as N. cf. grubei by Blake (1996) are in fact N. uncinata .

The range and depths recorded for Naineris uncinata are unusual, ranging from the intertidal and low water to middle slope depths down to about 600 m. However, the majority of historical records are from about 70–150 m with relatively few specimens recorded from any one location ( Hartman 1957; Pettibone 1957). In the present study, larger numbers of specimens have been recorded from gas hydrate seeps off Oregon in 786 m suggesting that the preferred habitat for the species might be in such locations.

Distribution. Alaska to southern California, shallow subtidal to ca. 620 m ( Hartman 1957; Pettibone 1957). Upper slope depths of 567–795 m off Oregon in gas hydrate and seep sediments on the Cascadia Subduction Zone (this study).

Figures

FIGURE 4. Leitoscoloplos gordaensis n. sp. Holotype (MCZ 153564):A, anterior end, left lateral view; B, posterior thoracic and anterior abdominal setigers, left lateral view, setigers numbered; C, middle abdominal setigers, left lateral view, arrows denote tri-annular rings on venter. Paratype (MCZ 153565): D, posterior abdominal setiger, anterior view. Stained with Shirlastain A.

FIGURE 13. Naineris uncinata Hartman, 1957. (MCZ 153572): A, anterior end, dorsal view; B, anterior end, right lateral view; C, posterior thoracic segments, right lateral view; D, posterior thoracic parapodium, anterior view; E, fascicle of thoracic neurosetae; F, detail of thoracic neuropodial uncini and capillaries. Stained with Shirlastain A.