Nephtys squamosa Ehlers, 1887

Figure 7 (A −D); Figure 9 (G −I)

Nephtys squamosa Ehlers 1887: 128 −131, pl. 37, Figures 7 −10; Hartman 1940: 237–238, pl. 41, Figures 98–99; Hartman 1950: 110 –111; Fauchald 1976: 18; Taylor 1984: 35 -11, Figures 35−7, 8a-e; Lana 1986: 139, Figures 4–5; Ohwada 1989: 124 −130, Figures 1−3; Rizzo & Amaral 2007: 261 −262, Figure 4.

Material examined. 8 specimens: HABITATS: Paraíba do Sul River Mount: UERJ 3208 (1 spec., 21º23’1.498’’S and 040º42’46.825”W, HAB.17 17 R1, 28 m), UERJ 3251 (2 spec., 21º17’47.436”S and 040º31’5.328”W, HAB.13 27 R1, 29 m), UERJ 3226 (1 spec., 21º44’57.624’’S and 040º25’51.384’’W, HAB.13 R1, 26 m), UERJ 3218 (1 spec., 21º34’8.184’’S and 040º25’38.544’’W, HAB.13 30 R2, 29 m). Continental Shelf: UERJ 3250 (1 spec., 22º8’4.667’’S and 040º27’33.828’’W, HAB.11 E3R2, 65 m), UERJ 3276 (2 spec., 21º10’56.708’’S and 040º28’34.966’’W, HAB. 17 I1 R3, 26 m).

Type locality. Florida, United States of America.

Diagnosis. Posterior edge of prostomium “V-shaped” with purplish spot projection; notopodial and neuropodial lobes well developed, with translucent imbricate expansion on following parapodium.

Description. Examined specimen complete, 68.3 long and 3 mm wide (excluding chaetae) and 142 chaetigers (UERJ 3250). Other specimens (some incomplete) ranging from 3−63 mm long, 0.5−4.8 mm wide, with 21–122 chaetigers. Body cylindrical in anterior region and rectangular in posterior. Prostomium pentagonal and spatulate, posterior edge V-shaped and bearing purplish spot extending to near posterior border of chaetiger 1 (juvenile with a pair of these purplish spots; Figure 7 B); some anterior and posterior furrows on anterior and posterior portions (Figure 7 A −B). Dorsal pair of conical antennae and ventral pair of palps, these larger than antennae. First pair of dorsal cirri positioned laterodorsally and well developed, easily confused with antennae (Figure 7 A −B). Nuchal organs rounded and small, located between prostomium and chaetiger 1. Mouth ventral, occupying chaetigers 1 to 3. Interramal branchiae curved outward (Figure 7 C −D), some apparently straight (without clear bending); starting on second parapodia. Notopodial and neuropodial with translucent imbricate laterodorsal and lateroventral expansions over the following parapodia. Notopodial lobes well developed; preacicular lobe rounded and small; acicular lobe conical and longer than preacicular lobe; postacicular lobe well developed, with foliaceous translucent expansion (Figure 7 C −D). Neuropodial lobes well developed; preacicular lobe rounded; acicular lobe conical; postacicular lobe longer than other lobes (Figure 7 C −D). Dorsal cirri foliaceous to digitiform; ventral cirri foliaceous with thin tips (Figure 7 C −D). Anterior region with notopodial and neuropodial preacicular chaetae short and barred (Figure 9 H), and a few serrulate and flattened chaetae; postacicular chaetae capillary (Figure 9 G), serrulate, and more flattened than preacicular chaetae. Posterior region with notopodial and neuropodial preacicular chaetae of two types: one short and barred, others serrulate, short and flattened (Figure 9 I); postacicular chaetae of two types: one serrulate, others long and flattened. Pygidium rounded, without appendix and with dorsal anal opening.

Remarks. Nephtys squamosa has a characteristic prostomium that makes it easy to distinguish from other species. The purplish spot on the posterior edge of the prostomium distinguishes N. squamosa from other species such as N. californiensis Hartman, 1938 and N. simoni Perkins, 1980 (both recorded in Brazil), which have a reddish spot in the central region of the prostomium. Nephtys imbricata Grube, 1857 is also closely related to N. squamosa, since both have notopodial and neuropodial lobes with translucent, well developed and imbricate laterodorsal and lateroventral expansions over the following parapodium; but the spur-like chaetae and the irregular neuropodial postacicular lobe found in N. imbricata, but not in N. squamosa, distinguish the two species. In specimens of N. squamosa from southeastern Brazil, Rizzo & Amaral (2007) found this type of chaetae elongated and flattened, serrulate and basally cleft on one margin, and slightly segmented on the other margin (though some chaetae were not cleft) on the notopodial and neuropodial lobes. However, in the specimens examined here, these spur-like chaetae were not found, as they also were not found in the redescription of N. squamosa by Ohwada (1989).

Distribution. California (Gulf of California and Catalina Island), Florida, USA; Cuba, Ecuador (Gorgona Island), Colombia, Brazil (states of Alagoas, Sergipe, Rio de Janeiro, São Paulo, Paraná, and Rio Grande do Sul) (Hartman 1950; Fauchald 1976; Taylor 1984; Lana 1986). It is probable that the record from West Africa (Morocco) from Fauvel (1936) could refer to Aglaophamus agilis (Langerhans, 1880) (see Ravara et al. 2010).