Orbiniella tumida, Blake, 2020

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 : 47-48

publication ID

https://doi.org/ 10.11646/zootaxa.4730.1.1

publication LSID

lsid:zoobank.org:pub:7F4CD129-9FF9-4593-A8A4-DB999B3E402F

persistent identifier

https://treatment.plazi.org/id/98DC0D6D-13A8-43B5-9F57-ACB41CE5C9A3

taxon LSID

lsid:zoobank.org:act:98DC0D6D-13A8-43B5-9F57-ACB41CE5C9A3

treatment provided by

Plazi

scientific name

Orbiniella tumida
status

sp. nov.

Orbiniella tumida View in CoL new species

Figure 24 View FIGURE 24

urn:lsid:zoobank.org:act:98DC0D6D-13A8-43B5-9F57-ACB41CE5C9A3

Orbiniella View in CoL sp. 1: Blake et al. 2009: 1797.

Material examined. Continental slope, off northern California, west of Farallon Islands, SF-DODS Benthic Monitoring Program, Sta. 23. 28 Sep 2017, 37°37.0012′N, 123°28.9813′ W, 2934 m, holotype ( LACM-AHF Poly 11662), 2 paratypes ( LACM-AHF Poly 11663) GoogleMaps ; Sta. 10, 22 Sep 2002, 37°40.00′N, 123°31.00′, 2739 m, 1 paratype ( CASIZ 234025 ) ; Sta. 64, 26 Sep 2003, 37°35.98′N, 123°32.96′, 3130 m, 2 paratypes ( CASIZ 234032 ) ; Sta. 64, 29 Aug 2016, 3221 m, 37°36.0068′N, 123°32.9960′W, 3221 m, 1 paratype ( MCZ 153581 About MCZ ) GoogleMaps .— Northern California off Half Moon Bay, US EPA 102 Site Selection Survey, R / V Point Sur , coll. J.A. Blake, south of Pioneer Canyon , Sta. 4-15. 9 Sep 1991, 37°12.42′N, 123°15.81′W, 1730 m, 1 specimen ( CASIZ 234046 ) GoogleMaps ; Pioneer Canon, Sta. C-7,19 Sep 1991, 37°17.57′N, 123°13.50′W, 1840 m, 1 specimen ( CASIZ 234052 ) GoogleMaps .— Off Central California, abyssal Plain , Sta. M, coll. 15 Aug 2006, HOV Alvin Dive 4227, B. Strickrott (Pilot), 34°39.105′N, 123°05.116′W, 4119 m (1, JAB) GoogleMaps

Description. A small species, holotype mostly complete but with damaged posterior end, 2.5 mm long, 0.8 mm wide with 21setigers; complete paratype (CASIZ 234032) 2.7 mm long, 0.36 mm wide, with 37 setigers; larger paratype (CZSIZ 234032) incomplete, 3.1 mm long, 0.25 mm wide, with 32 setigers. Body thick throughout, with no separate thorax and abdomen; all parapodia lateral, not shifted dorsally in posterior segments; individual segments crowded, about seven times wider than long ( Fig. 24A View FIGURE 24 ). Each segment with narrow intersegmental swelling along most of body producing superficial bi-annulate appearance ( Fig. 24A View FIGURE 24 ). Body with numerous subdermal glands appearing brown with Shirlastain A. Body somewhat dorsoventrally compressed, without dorsal or ventral longitudinal grooves. Holotype with eggs in setigers 7–11, each about 120–125 µm in diameter; individual eggs in notopodia forming large lobe, a possible brooding or discharge chamber. Color in alcohol: light tan.

Pre-setiger region short, narrower than following setigerous segments ( Fig. 24A View FIGURE 24 ). Prostomium broadly rounded anteriorly; eyespots absent; nuchal organs prominent lateral lobes, with numerous long cilia ( Fig. 24A View FIGURE 24 ). Peristomium with two narrow annular rings distinctly separated from one another dorsally and ventrally ( Fig. 24 View FIGURE 24 A–B). First annular ring forming ventral lip of mouth; dorsal lip with broad opening or vestibule ( Fig. 24B View FIGURE 24 ).

Branchiae entirely absent. Noto- and neuropodia formed as elongate lobes, more or less conical. Notopodia with short, clavate postsetal lamella ( Fig. 24D View FIGURE 24 ). Notopodia with 1–2 large, acicular spines and 3–5 long camerated capillaries; neuropodia with one large acicular spine and 5–6 long capillaries; ( Fig. 24D View FIGURE 24 ); furcate setae absent. Spines thick, smooth, tapering to narrow tip ( Fig. 24 View FIGURE 24 E–H), some with a distinct notch where spine narrows abruptly ( Fig. 24 View FIGURE 24 G–H). Capillaries all camerated with row of barbs along one edge.

Pygidium with four short anal cirri ( Fig. 24C View FIGURE 24 ).

Methyl Green stain. Prostomium not staining; rest of body staining uniformly green, de-staining rapidly.

Remarks. Among deep-sea species of Orbiniella , O. tumida n. sp. is most similar to O. abyssalis n. sp. from the abyssal Pacific Ocean, O. andeepia from Antarctica, and O. petersenae from the NE Atlantic Ocean in having smooth acicular spines in noto- and neuropodia and a notopodial postsetal lamella (see previous Remarks for O. abyssalis n. sp.). In having a short, clavate notopodial postsetal lamella O. tumida n. sp. is most similar to O. abyssalis n. sp., but differs in having two distinct peristomial rings instead of one. Another distinguishing feature of O. tumida n. sp. is the presence of a notch on some acicular spines that has not been observed previously on orbiniids. Spines with notches occur in both noto- and neuropodia and occur randomly with spines lacking this feature.

Etymology. The epithet is from the Latin, tumidus for swollen, in reference to short, thickened body of this species.

Distribution. Off northern California, lower continental slope and abyssal plain, 1730–4119 m.

R

Departamento de Geologia, Universidad de Chile

V

Royal British Columbia Museum - Herbarium

Kingdom

Animalia

Phylum

Annelida

Class

Polychaeta

Family

Orbiniidae

Genus

Orbiniella

Loc

Orbiniella tumida

Blake, James A. 2020
2020
Loc

Orbiniella

Blake, J. A. & Maciolek, N. J. & Ota, A. Y. & Williams, I. P. 2009: 1797
2009
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