Naineris setosa ( Verrill, 1900 )

Blake, James A., 2017, Polychaeta Orbiniidae from Antarctica, the Southern Ocean, the Abyssal Pacific Ocean, and off South America, Zootaxa 4218 (1), pp. 1-145 : 95

Naineris setosa ( Verrill, 1900)

Figure 44

Aricia setosa Verrill, 1900: 651 –653.

Anthostoma latacapitata Treadwell, 1901: 203 –205, figs. 61–65.

Naineris latacapitata: Treadwell 1939: 254 , fig. 81.

Naineris setosa: Treadwell 1936: 55 ; Hartman 1942: 61, figs. 116–118; Hartman 1951: 67 –70, pl. 17, figs. 1–6; Hartman 1957: 305, pl. 41, figs. 1–6; Rioja 1960: 303; Solis-Weiss & Fauchald 1989: 774 –778, fig.2; Blake & Giangrande 2011: 20 –26, figs.1–2; Khedhri et al. 2014: 83 –88, fig. 2; Dean & Blake, 2015: 194 , fig. 5C–G; Atzori et al. 2016: 2016: 1–6.

Material examined. Galápagos Islands, Isla Santa Cruz, Puerto Nunez, intertidal in rocks, Anton Bruun Cruise 12, Sta. 66-120 (1, USNM 60628 ).

Description. Galápagos Island specimen incomplete, lacking pygidium and last few posterior setigers; 50 mm long and 3 mm wide for 160 setigers. Color in alcohol: light tan.

Prostomium short, blunt, slightly rounded on anterior margin ( Fig. 44 A); eyespots arranged in two groups of small pigment spots; everted proboscis large, saclike, multilobed ( Fig. 44 A). Peristomium a single achaetous ring appearing irregular in shape, fused dorsally to posterior margin of prostomium ( Fig. 44 A).

Branchiae from setiger 5, continuing to posterior end; each branchia short at first, flattened, cirriform, tapering to pointed tip ( Fig. 44 B); branchiae increasing in length, with those of posterior abdominal segments longest and least erect. Paired dorsal sensory organs anterior and medial to branchial bases of anterior segments. Low dorsal crests present between anterior abdominal branchiae.

Thoracic notopodia broad, triangular, tapering to narrow tip ( Fig. 44 B); abdominal notopodia digitiform, with blunted tip ( Fig. 44 C). Posterior thoracic setigers with interramal swelling between neuropodia and notopodia ( Fig. 44 B); distinct interramal cirrus lacking in thoracic and abdominal regions. Thoracic neuropodia elongate, thickened lobes, with posterior margin forming postsetal lobe, dorsally pointed ( Fig. 44 B); abdominal neuropodia reduced to short, blunted postsetal lobe ( Fig.44 ); ventral cirri lacking.

Thoracic neurosetae including dense fascicles of hundreds of capillaries arranged in 6–7 rows; capillaries of anteriormost row shorter, thicker, more strongly bent than those of subsequent rows; each capillary with minute teeth arranged in transverse rows on shaft ( Fig. 44 F); thoracic uncini absent. Abdominal neuropodia with few capillaries and 2–3 smooth, curved aciculae with narrow tip ( Fig. 44 D). Thoracic notopodia with 30–40 long, thin capillaries similar in structure to neurosetae; abdominal notosetae including capillaries and 1–2 furcate setae; each furcate seta with unequal tynes connected by webbing composed of fine needles; shaft with transverse rows of minute barbs ( Fig. 44 E).

Remarks. A more detailed description of Naineris setosa together with a review of its biology and ecology was presented by Blake & Giangrande (2011) who reported on an invasive occurrence of the species from a fish aquaculture facility in Brindisi, Italy . Naineris setosa is well-known from tropical and subtropical habitats in Bermuda, Florida and Gulf of Mexico, the Caribbean, and most recently from the Pacific coast of Costa Rica and Mexico ( Blake & Giangrande 2011; Dean & Blake 2015). The specimen reported here from the Galápagos Islands agrees very well with those from reported from the North American locations and thus the range extends well out into the Pacific.

Distribution. Atlantic Ocean, Bermuda; Florida; Mexico, Vera Cruz; Puerto Rico, Belize; eastern Pacific, Mexico, Acapulco, Costa Rica, Cocos Islands, Galápagos Islands; invasive in the Adriatic and Mediterranean Seas.

Figures

FIGURE 44. Naineris setosa (Verrill, 1900). Galápagos Islands, (USNM 60628). A, anterior end, dorsal view; B, thoracic parapodium, anterior view; C, abdominal parapodium, anterior view; D, abdominal neuropodial uncinus; E, furcate seta; F, thoracic neuropodial capillary seta.