Naineris setosa ( Verril, 1900 )

Álvarez, Ricardo & Budaeva, Nataliya, 2023, How complex is the Naineris setosa species complex? First integrative study of a presumed cosmopolitan and invasive annelid (Sedentaria: Orbiniidae), Zootaxa 5375 (3), pp. 349-378 : 362-365

Naineris setosa ( Verril, 1900) s. str.

( Figs 5–8 )

Aricia setosa Verrill, 1900: 651–653 . Anthostoma latacapitata Treadwell, 1901: 203–204 , figs 61–65. Nainereis latacapitata : Treadwell 1939: 264, fig. 81. Naineris setosa : Treadwell 1936: 55; Hartman 1957: 305, pl. 41, figs 1–6 (in part); Nonato 1981: 149–150, figs 177–179; SolisWeiss & Fauchald 1989: 774–778, figs 2a–j; Blake & Giangrande 2011: 20–26, figs 1–2; Khedhri et al. 2014: 83–88, fig.

2; Atzori et al. 2016: 1–6.

Material examined. Atlantic Ocean. Bermuda: YPM 001242 .AN (lectotype), YPM 1303 (1 spm), YPM 1384 (1 spm), USNM 34092 (1 spm), AMNH 1972 (4 spms), AMNH 2508 A (2 spms) . Panama, Caribbean Sea : USNM 181626 (1 spm), USNM 181660 (1 spm) . Puerto Rico: USNM 55607 (19 spms) . Bahamas. San Salvador Island, Oyster Pond: FM 5895 (1 spm), USNM 174087 (10 spms), Pigeon Creek Mangrove: FM 5898 (1 spm), Moon Rock Pond: FM 5904 (1 spm), Crescent Pond, FM 5902 (2 spms) . Brazil. Pernambuco, Cabo de Santo Agostino : MNRJP 007649 (DNA voucher Ns21), MNRJP 007650 (DNA voucher Ns22), MNRJP 007651 (DNA voucher Ns23), MNRJP 007652 (DNA voucher Ns24), MNRJP 007653 (DNA voucher Ns25), MNRJP 007625 (5 spms) . Rio de Janeiro, Cabo Frio : MNRJP 007639 (DNA voucher Ns11), MNRJP 007640 (DNA voucher Ns12), MNRJP 007641 (DNA voucher Ns13), MNRJP 007642 (DNA voucher Ns14), MNRJP 007643 (DNA voucher Ns15), MNRJP 007626 (13 spms) , Ilha Grande : ColBIO IG 166 (1 spm), ColBIO IG 168 (2 spms), ColBIO NS20 (7 spms) . Santa Catarina, Santa Catarina Island : MNRJP 007629 (DNA voucher Ns1), MNRJP 007630 (DNA voucher Ns2), MNRJP 007631 (DNA voucher Ns3), MNRJP 007632 (DNA voucher Ns4), MNRJP 007633 (DNA voucher Ns5), MNRJP 007628 (4 spms) . Bahia, Salvador: MNRJP 007644 (DNA voucher Ns16), MNRJP 007645 (DNA voucher Ns17), MNRJP 007646 (DNA voucher Ns18), MNRJP 007647 (DNA voucher Ns19), MNRJP 007648 (DNA voucher Ns20), MNRJP 007627 (8 spms) . Italy. Taranto : ZMBN 157797 (DNA voucher Ns43) . Livorno : ZMBN 157798 (DNA voucher Ns44) . Australia. Rozelle Bay, Sydney : AM W.22470 (4 spms) .

Type locality. Flatt’s Inlet Beach , Bermuda. Shell-sand, low intertidal .

Diagnosis. Thoracic neurochaetae only crenulated capillaries, thoracic segments without ventral groove and notches, paired dorsal sensory organs present, low dorsal crest from abdominal segments, thoracic neuropodial lobe with upper papilla, as wide flanges with well-delimited boundaries.

Description (based on the lectotype). Lectotype (YPM IZ 001242.AN) incomplete, 149 chaetigers, 57 mm long, 0.7 mm wide at chaetiger 50. Color in alcohol light tan (live Brazilian specimens pale yellow with reddish branchiae, bearing long fluorescent cilia along branchial axis and between them). Thorax and abdomen marked by dorsal displacement of parapodia in abdomen ( Figs 5A ; 7A ). Ventral surface smooth, ventral groove only present in abdominal segments ( Fig. 8A, B ), ventral notches absent.

Prostomium wider than long, more or less square and rounded in front and corners ( Figs 5B ; 7A ); eyespots along lateral margins; nuchal organs discernible ( Fig. 7A, B ). Peristomium with two annular rings, only weakly marked; mouth opening situated ventrally and surrounded by striated lips; proboscis, not everted, presumably broad and lobed as in topotype specimens.

Branchiae first present from chaetiger 5–6, cirriform, tapering to sharp tip, with dense cilia, first branchiae long, reaching ⅓ of abdominal branchiae ( Fig. 5B ). Conspicuous dorsal sensory organs from chaetiger 7, oval-shaped and paired, with dense cilia ( Fig. 7C ). Dorsal crest present from abdominal segments; straight, supported by thick base; low, approximately ¼ diameter of branchiae, ciliated.

Thorax comprises 20 chaetigers, moderately flattened ( Fig. 5A ). Parapodia biramous; interramal papilla absent. Notopodial lobes lanceolate. Neuropodial lobes represented by wide flanges ending above digitate papillae, with well-delimited boundaries ( Figs 5A, C ; 6A ). Abdominal notopodial and neuropodial lobes cirriform ( Figs 5D ; 6B ); abdominal notopodial lobes longer or equal to thoracic notopodial lobes, shorter than branchiae ( Figs 5D ; 6B ).

Thoracic notochaetae with two bundles of about 20–30 crenulated capillaries at different levels ( Figs 5C ; 6A ). Abdominal notochaetae arranged in two groups of 10–15 crenulated capillaries and furcate chaetae ( Figs 6B ; 7F ); furcate chaetae with unequal tines and tiny needles at different levels ( Fig. 7F ), placed in a lower position, difficult to observe; shaft bearing numerous crowded transversal rows of about 10–12 small barbs ( Fig. 7F ). Thoracic neurochaetae with around seven rows of numerous capillaries ( Figs 5C ; 6A, E ) separated into two groups by oblique gap ( Fig. 5C ). Abdominal neurochaetae with 5–10 capillaries and three acicular spines ( Figs 6B ; 7D ). Pygidium missing.

Remarks. Hartman (1951) examined specimens from the Gulf of Mexico and synonymized Anthostoma lacapitata Treadwell, 1901 with Naineris setosa . Solis-Weiss & Fauchald (1989) redescribed the syntype of N. setosa retaining its wide distribution in the tropical Northwest Atlantic, herein designated as the lectotype (ICZN 1999, Art. 74). Subsequently, Blake & Giangrande (2011) reported the species as invasive in the Mediterranean Sea. The species was also reported from the Adriatic and the Tyrrhenian Seas expanding its distribution to Tunisia and Taranto ( Arduini et al. 2022, Rebai et al. 2022). The records from the Pacific, such as those from Galapagos and Australia, require further revision. We examined the specimen from Galapagos studied by Blake, but it was in poor condition preventing accurate identification.

Pygidium was not observed in the lectotype, but in the examined Brazilian specimens it agreed with Solís-Weiss & Fauchald’s (1989) description, stating that N. setosa bears four anal cirri. Morphological variation of Brazilian populations of N. setosa s. str. is shown in Table 7 .

Habitat. Shell-sand, intertidal.

Distribution. Intertidal and shallow subtidal (down to 1 m deep) zone of the Atlantic. Western Atlantic: Bermuda, Bahamas, Gulf of Mexico, Caribbean Sea, Panamá, Belize, Puerto Rico, and Brazilian coast. Presumably invasive in the Mediterranean Sea ( Blake & Giangrande 2011; Khedhri et al. 2014; Dean & Blake 2015; Atzori et al. 2016).

Figures

FIGURE 5. Naineris setosa, lectotype (YPM IZ 001242.AN): (A) Lateral view; (B) Anterior end, dorsal view; (C) Thoracic parapodia; (D) Abdominal parapodia. bq—branchia, cc—crenulate capillaries, NeL—neuropodial lobe, NoL—notopodial lobe, pr—prostomium. Scale bars; (A–B): 0.7 mm; (C–D): 0.35 mm.

FIGURE 6. Naineris setosa, lectotype (YPM IZ 001242.AN): (A) Thoracic parapodium (ch. 11); (B) Abdominal parapodium (ch. 91). bq—branchia (displaced), NeL—neuropodial lobe, NoL—notopodial lobe. Scale bars; (A–B): 1 mm.

FIGURE 7. Naineris setosa from Pernambuco, Brazil (MNRJP 007720) examined under SEM: (A) Anterior end, dorsal view; (B) Nuchal organ; (C) Dorsal organ; (D) Acicular spines; (F) Furcate chaetae. Naineris setosa from Bahamas under SEM (FM 5898): (E) Thoracic neurochaetae. ac—acicular spines, bq—branchia, cc—crenulated capillaries, do—dorsal organ, fc—furcate chaeta, no—nuchal organ, pr—prostomium. Scale bars; (A): 500 μm; (B): 50 μm; (C): 20 μm; (D): 5 μm; (E–F): 10 μm.

FIGURE 8. Naineris setosa from Taranto, Mediterranean Sea (ZMBN 157797): (A) Anterior end, ventral view; (B) Smooth, thoracic ventral surface. Scale bars; (A): 1 mm; (B): 500 μm.