Phylo felix Kinberg, 1866

Blake, James A., 2021, New species and records of Orbiniidae (Annelida, Polychaeta) from continental shelf and slope depths of the Western North Atlantic Ocean, Zootaxa 4930 (1), pp. 1-123 : 80-83

Phylo felix Kinberg, 1866

Figure 40

Phylo felix Kinberg, 1866: 251–252 ; Hartman 1948: 105–106, pl. 15, fig. 10; 1953: 37–38; 1957: 262–265, pl. 23 (synonymy);

1966a: 10, pl. 2, fig. 4; Day 1973: 89; Maciolek-Blake et al. 1985: B-5; Blake 2017: 90–93, figs. 42–43 (synonymy). Aricia formosa Hansen, 1882: 18 , pl. 5, figs. 23–27; Augener 1934: 146–148. Fide Hartman 1957. Aricia michaelseni Ehlers, 1897: 88–91 , pl. 6, figs. 136–140; 1900: 12; 1901: 166. Fide Hartman 1948.—Not Monro 1930:

144–145, fig. 54; Okuda 1937: 101; Berkeley & Berkeley 1952: 96, figs. 194–196. Orbinia (Phylo) michaelseni: Pettibone 1963: 282 , fig. 75f. Orbinia felix: Hobson & Banse 1981: 29 . Phylo felix heterosetosa Hartmann-Schr ̂der, 1965: 192–194, figs. 176–177; Rozbaczylo 1985: 130. Fide Blake 2017.

Phylo kupfferi: Hartman 1967: 107–108 (in part); Rozbaczylo 1985: 130–131. Not Ehlers, 1874.

Phylo michaelseni: Rozbaczylo 1985: 131 .

Orbinia (Phylo) minima Hartmann-Schr ̂der & Rosenfeldt, 1990: 106–107, figs. 11–17. Fide Blake 2017.

Material examined. (17 specimens): Northeastern USA, off New England, Georges Bank, Benthic Infauna Monitoring Program (1981–1984), coll. G.W. Hampson, Chief Scientist. Sta. 7A: Cruise M-11, Rep. 5, 04 Feb 1984, 40°32.2′N, 67°44.2′W, 167 m (1, USNM 1622295 ) . Sta. 8: Cruise M-2, Rep. 3, 11 Nov 1981, 40°27.1′N, 67°37.4′W, 152 m (1, USNM 1622296 ) ; Cruise M-5, Rep. 2, 23 Jul 1982, 40°27.1′N, 67°37.4′W, 140 m (1, USNM 1622297 ) ; Rep. 6, (1, USNM 1622298 ) ; Cruise M-6, Rep. 5, 22 Nov. 1982, 40°27.1′N, 67°37.4′W, 145 m (1, USNM 1622299 ) ; Rep. 6 (1, USNM 1622300 ) ; Cruise M-8, Rep. 6, 16 May 1983, 40°27.1′N, 67°37.2′W, 146 m (1, USNM 1622301 ) ; Cruise M-9, Rep. 5, 15 Jul 1983, 40°27.1′N, 67°37.4′W, 152 m (1, USNM 1622302 ) ; Cruise M-11, Rep. 2, 03 Feb 1984, 40°27.1′N, 67°37.4′W, 152 m (1, USNM 1622303 ) ; Rep. 5 (1, USNM 1622304 ) ; Cruise M-12, Rep. 1, 05 Jun 1984, 40°27.1′N, 67°37.4′W, 140 m (1, USNM 1622305 ) . Sta. 9: Cruise M-8, Rep. 3, 19 May 1983, 40°26.7′N, 68°09.8′W, 143 m (1, USNM 1622306 ) ; Cruise M-12, Rep. 1, 08 Jun 1984, 40°26.7′N, 68°09.8′W, 144 m (1, USNM 1622307 ) . Sta. 16: Cruise M-6, Rep. 3, 21 Nov. 1982, 40°34.2′N, 67°12.3′W, 138 m (1, USNM 1622308 ) . Sta. 18: Cruise M-7, Rep., 09 Feb 1983, 40°33.5′N, 67°13.7′W, 147 m (1, USNM 1622309 ) ; Rep. 3 (1, USNM 1622310 ) ; Rep. 4 (1, juv. USNM 1622311 ) . Cruise M-8, Rep. 4, 16 May 1983, 40°33.5′N, 67°13.7′W, 141 m (1, USNM 1622312 ) .— US North Atlantic ACSAR program, coll. G.W. Hampson, Chief Scientist. Cruise NA-2, Sta. 7: Rep. 3, 28 Apr 1985, 40°27.44′N, 67°40.19′W, 558 m (1, USNM 1622313 ) .

Description. A moderate to large species, a complete specimen from Chile with up to 240 setigers, 80 mm long and 2.9 mm wide; incomplete specimens up to 92 mm long ( Blake 2017). Present specimens from Georges Bank smaller; complete specimen (USNM 1622309) with 87 setigers, 14 mm long and 1.0 mm wide; larger incomplete specimen (USNM 1622311) with 61 setigers, 21 mm long and 2.2 mm wide. Body elongate, with all segments short ( Fig. 40A ); thoracic segments about six times wider than long, flattened both dorsally and ventrally ( Fig. 40 B–C); abdominal segments strongly rounded on venter, flattened dorsally due to shift of parapodia to dorsum. Thoracic segments uniannulate; abdominal segments biannulate. No dorsal or ventral grooves along body. Branchiae from setiger 5. Present specimens light tan in alcohol.

Pre-setiger region short, wider than long ( Fig. 40 B–C). Prostomium triangular, narrow, tapering to pointed tip ( Fig. 40 A–C). eyespots absent; nuchal organs narrow paired slits at border of prostomium and peristomium. Peristomium a narrow ring, about as long as setiger 1 dorsally ( Fig. 40 A–B) but extending onto setiger 1 ventrally due to posterior lip of mouth. Mouth an elongate opening with two large lobes forming upper lip and numerous narrow lobes forming lower lip extending on to setiger 1 ( Fig. 40C ). Proboscis with 2–3 large inflated lobes when fully everted.

Thorax of present specimens with 15–18 setigers; one juvenile with 13 setigers. Thorax divided into anterior and posterior sections: anterior thorax consistently with 10 setigers; posterior thorax with large spines beginning on setiger 11 and continuing up to setiger 18 depending on specimen. Thoracic notopodia digitate, shortest in setigers 1–2, becoming long over subsequent thoracic setigers. Abdominal notopodia similarly elongate digitiform lobes. Interramal cirrus present between noto- and neuropodia of posterior thoracic setigers, continuing over abdominal setigers ( Fig. 40I ). Thoracic neuropodia thick, elongate, bearing up to five rows of uncini and capillaries ( Fig. 40D ). Setiger 1 with single neuropodial postsetal lobe, increasing up to 10 lobes by about setiger 12 ( Fig. 40A, D ), thereafter gradually decreasing to about 6–8 lobes by setiger 15. All neuropodial postsetal lobes short, conical, arranged in a row posterior to rows of neurosetae. Subpodial lobes or stomach papillae from about setiger 14, numbering 6–8 at first, then extending to ventral midline on both sides on setigers 16–18 ( Fig. 40E ); continuing on at least one anterior abdominal setiger, then entirely absent. Abdominal neuropodia elevated, divided apically into rounded inner lobe and narrow digitiform lateral lobe. First 1–2 abdominal segments with 2–3 extra lobes or ventral cirri ventral to neuropodium; these reduced to single ventral cirrus in all subsequent abdominal neuropodia.

Branchiae from setiger 5. Branchiae more medial in thoracic setigers and closer to notopodia in abdominal segments. Each branchia triangular in shape, narrowing to conical tip; all branchiae heavily ciliated ( Fig. 40E, I ).

Notosetae of anterior thoracic setigers in fascicles of 30–40 crenulated capillaries; posterior thoracic segments with capillaries reduced to about 15–20 per fascicle. Abdominal notosetae including 15–20 long thin capillaries with barbs or crenulations along one edge and 1–2 furcate setae; furcate setae with unequal blunt-tipped tynes connected by a web of numerous fine needles; shaft with transverse rows of ribs.

Anterior thoracic neuropodial setigers 1–10 with 4–6 rows of uncini of two types: (1) 3–5 rows of large, heavy uncini, each with curved apex with transverse rows of ribs on convex side; tip of spine with a closely adhering sheath and (2) a posterior row of narrower crenulated spines. Posterior row of crenulated capillary setae accompanying uncini. Posterior thoracic setigers 11–18 with an anterior row of 5–6 large heavy smooth spines with a curved tip ( Fig. 40G ) and a single long hastate or spear-like spine in the uppermost position of first row ( Fig. 40E, H ); a few crenulated uncini also present together with crenulated capillaries. Abdominal neurosetae including 5–10 long capillaries, each with mostly smooth shafts and with short barbs along on edge; 1–2 minute imbedded aciculae also present. Flail setae absent.

Pygidium enlarged, swollen, turned dorsally, with a pair of long anal cirri ( Fig. 40J ).

Remarks. Phylo felix is a widely distributed species and the present specimens agree well with previous accounts ( Blake 2017). One difference noted in the present collection is the presence of the emergent tips of a few thick relatively smooth, blunt-tipped spines accompanying the hastate spears in posterior thoracic setigers. Hartman (1957) illustrated these spines, mostly imbedded in the same location, ventral to the hastate spines; Blake (2017) illustrated these as entirely imbedded. Neither author provided details of these spines, however.

Biology. Some specimens had guts filled with large sand grains ( Fig. 40J ). Males with numerous sperm packets were observed; individual sperm have a short head and long tail.

Distribution. A widely reported species: Western North Atlantic, off New England, along outer shelf and shelf break on Georges Bank, 138–167 m and upper continental slope, 558 m; off North Carolina, 120– 200 m. Southern Atlantic and SE Pacific: Brazil (type-locality), Uruguay, Argentina, Patagonia, Southern Chile, Straits of Magellan, intertidal to 424 m; Falkland Islands, intertidal to 361 m; Antarctic Peninsula and off Elephant Island, intertidal to 430 m. Eastern Pacific, southern California to Mexico, shallow subtidal.

Figures

FIGURE 40. Phylo felix (Kinberg, 1866): A, anterior end, right lateral view (arrows denote spear-like notopodial spines); B, anterior end, dorsal view; C, anterior end, ventral view; D, thoracic setiger 9, anterior view; E, thoracic setiger 16, anterior view; F, thoracic neuropodial uncini, setiger 8; G, heavy curved neuropodial spine from first row on setiger 16; H, hastate or spear-like spine from uppermost position in neuropodium of setiger 16; I, abdominal setiger, anterior view; J, posterior end and pygidium (arrows denote sand grains in gut), left lateral view. A–G, H (USNM 1622307); J (USNM 1622309); I (USNM 1622301). Most stained with Shirlastain A.