Perinereis websteri sp. nov.

urn:lsid:zoobank.org:act: 1F30E930-AAA6-4F85-810A-76EEB08070C9

Figs 7–9, 13

Etymology

Named after Harrison Edwin Webster, as a tribute to his work on polychaete taxonomy and studying the nereidid species reviewed here.

Type material

Holotype BERMUDA • 1 spec.; Bermuda, Jews Bay, Public Wharf, near Waterlot Inn; 26 Nov. 1976; M.L. Jones leg.; intertidal sand; USNM 1490807.

Paratypes BERMUDA • 6 specs; same data as for holotype; USNM 1490808 • 2 specs; Bermuda, S side of Ferry Reach, ½ mile along Kindley Field Road; 23 Nov. 1976; intertidal, rock/mud; USNM 1490809.

Additional material

BERMUDA • 1 spec.; Bermuda, Bay E of BBS; 25 Sep. 1982; 0.75 m depth; M.L. Jones, GJ leg.; associated with red mangrove roots; 32 ppt; USNM 1490804 • 2 specs; Bermuda, ½ mile along Kindley Field Road, S side of Ferry Reach; 23 Nov. 1976; intertidal, rock/mud; USNM 1490805 • 8 specs; Bermuda, between Ferry Reach and St Georges Harbor, S of Stokes Pt; 21 Sep. 1982; 1 m depth; M.L. Jones, G.J. leg.; from gravel; 32 ppt; USNM 1490806 • 4 specs; Bermuda; 1876; G.B. Goode leg.; USNM 1660577 (syntypes of Nereis bairdii removed from USNM 4786).

Type locality

Jews Bay, Bermuda.

Description

BODY AND MEASUREMENTS. Holotype (USNM 1490807) complete, 35 mm long, 1.4 mm wide at chaetiger 10, 87 chaetigers (Fig. 8A). Two paratypes (USNM 1490809) in good conditions; one paratype complete, 75 mm long, 2.5 mm wide at chaetiger 10, 104 chaetigers; another paratype incomplete, 67 mm long, 2.5 mm wide at chaetiger 10, 83 chaetigers. Non-type material from syntypes of Nereis bairdii (USNM 1660577), one specimen dissected, 35 mm long, 1.6 mm wide at chaetiger 10, 90 chaetigers. Pigmentation not observed in all specimens (Figs 7–8).

PROSTOMIUM. Subpentagonal, as long as wide, anterior region distally entire, as long as posterior region, dorsal groove present (Figs 7A–B, 8F); anterolateral gap between antenna and palpophore as long as diameter of antennae (Figs 7A–B, 8F).

ANTENNAE. Cirriform, not passing palps, half as long as prostomium, gap between them as long as basal wide of antennae (Figs 7A–B, 8F).

PALPS. Palpophores subconical, swollen, 1.2× as long as wide, as long as prostomium, subdistal transverse groove present (Figs 7A–B, 8F). Palpostyles digitiform (Fig. 7A–B).

EYES. Rounded, anterior and posterior pairs subequal, in trapezoidal arrangement, posterior pair not covered by anterior margin of tentacular belt (Figs 7A–B, 8F).

TENTACULAR BELT. 1.5 × as long as chaetiger 1, covering posterior pair of eyes, anterior dorsal margin omega-shaped (Figs 7A–B, 8F).

TENTACULAR CIRRI. Smooth, longest cirri reaching end of chaetiger 7 (Figs 7A–B, 8F).

PHARYNX. Dissected in holotype, everted in paratypes and non-type specimens (Figs 7C–D, 8B–C, H) and in non-types (Fig. 8D–E); jaws brown, 10 teeth with truncate tips (Fig. 9I). Maxillary ring: I = 3 cones (3–11); II = 10–9 cones (8–19) in arc; III = 9 cones (8–13), 7 in a central ellipse and one cone at each lateral side of the ellipse; IV = 18–19 cones (18–27) in arc (Figs 7C–D, 8B–E). Oral ring: V = 1 cone (1– 1) displaced toward posterior margin of ring; VI = 1–1 smooth bar (1–1), rarely 4–6 paragnaths behind each bar; VII–VIII = 16 cones (10–16) in two bands: anterior band with one furrow row with 6 cones with 1 cone on the regions a–c; second band with one furrow row with 4 cones with 1 in each regions a–b, and one ridge row with 6 cones, 2 cones in region A and 1 cone in each regions B–C (Figs 7C–D, 8B–E, H, 13). Furrow pattern of areas VI–V–VI, λ-shaped (Figs 7D, 8B, D, 13).

DORSAL CIRRI. Digitiform in first chaetigers, subconical with blunt tip thereafter; attached basally to dorsal ligule in anteriormost chaetigers, medially in middle chaetigers, and subdistally in posterior chaetigers (Figs 7E–H, 9A–H); 1.2× as long as distal lobe of dorsal ligule in chaetiger 2, 1.4× in chaetigers 10–50, 1.8 × in chaetigers 70–75, 2.5× in chaetigers 82–100 (Figs 7E–H, 9A–H); 3.7× as long as proximal lobe of dorsal ligule in chaetiger 2, 5 × in chaetigers 10–31, 1.5× in chaetigers 50–75, 1.2× in chaetigers 82–100 (Figs 7E–H, 9A–H).

DORSAL LIGULES. Subconical with blunt tip in anterior and middle chaetigers, becoming pennant-like toward posterior chaetigers, with distal lobes longer than proximal ones in first chaetigers, becoming as long as in anterior chaetigers, and shorter than in middle and posterior chaetigers (Figs 7E–H, 9A– H). Distal lobe of dorsal ligule subconical with blunt tip throughout; 2× as long as median ligule in chaetigers 10–31, 1.2 × in chaetiger 50, 2× in chaetigers 70–75, 1× in chaetiger 82, 2 × in chaetiger 100 (Figs 7E–H, 9A–H).

MEDIAN LIGULES. Digitiform in anterior chaetigers, becoming subconical with blunt tip thereafter (Figs 7E–H, 9A–H); 2.5 × as long as neuroacicular ligule in chaetiger 10, 1.8× in chaetiger 31, 2× in chaetigers 50–82, 1.3× in chaetiger 100 (Figs 7E–H, 9A–H).

NEUROACICULAR LIGULES. Subconical throughout (Figs 7E–H, 9A–H); 0.5 × length of ventral ligule in chaetiger 2, 1× in chaetigers 10–70, 1.5× in chaetiger 75–82, 2× in chaetiger 100 (Figs 7E–H, 9A–H).

NEUROPODIAL SUPERIOR AND INFERIOR LOBES. Present in anterior chaetigers, both rounded, inferior one wider than superior one throughout (Figs 7E–H, 9A–H).

NEUROPODIAL POSTCHAETAL LOBES. Rounded, half as long as neuroacicular ligule throughout.

VENTRAL LIGULES. Digitiform throughout (Figs 7E–H, 9A–H). Ventral cirrus subconical with blunt tips throughout (Figs 7E–H, 9A–H); 1× length of ventral ligule in chaetiger 2, 0.8 × in chaetiger 10, 0.6× in chaetigers 31–50, 1× in chaetigers 70–75, 1.2 × in chaetiger 82, 1.5× in chaetiger 100 (Figs 7E–H, 9A–H).

NOTOCHAETAE. All homogomph symmetrical spinigers. Blades of spinigers with pectinate, minute teeth, teeth decreasing in size toward distal end.

NEUROCHAETAE. Homogomph symmetrical spinigers and heterogomph falcigers in supra-acicular fascicles, heterogomph spinigers and falcigers in sub-acicular fascicles. Neuropodial homogomph and heterogomph spinigers with blades as notopodial ones. Heterogomph falcigers pectinate, narrow teeth, three quarter of inner edge of blade dentate, distal tips stout (Fig. 9J–N); shafts of supra-acicular falcigers stouter than in sub-acicular ones (Fig. 9J–N).

PYGIDIUM. Crenulated, funnel-shaped (Fig. 8G); anal cirri subulate, as long as last 10 chaetigers (Fig. 8G).

Remarks

Perinereis websteri sp. nov. is a sympatric species that co-occurs with P. bairdii in Bermuda.As discussed above, the type series of Nereis bairdii had two morphological patterns, and one of them belongs to P. websteri sp. nov.; the differences between them were discussed in the remarks of P. bairdii.

Perinereis websteri sp. nov. resembles P. floridana (Ehlers, 1868) by having long tentacular cirri, dorsal ligules with similar development along body, and the shape of neuropodial heterogomph falcigers, but there are relevant differences among their atokes: 1) in P. websteri sp. nov., the anterior and posterior regions of the prostomium are subequal, whereas in P. floridana the anterior region is 1.7× as long as the posterior one; 2) in P. websteri sp. nov., the anterior margin of tentacular belt is omega-shaped, whereas in P. floridana it is straight; 3) in P. websteri sp. nov., areas VI sometimes can have conical paragnaths, whereas in P. floridana there are smooth bars only; 4) in P. websteri sp. nov., there are no paragnaths in ridge regions D and furrow regions c–d of the posterior band in the areas VII–VIII, whereas in P. floridana they are present in regions D and sometimes present in regions c–d; 5) In P. websteri sp. nov., the dorsal cirri are 1.4× as long as distal lobes of dorsal ligules in middle chaetigers and 2.5× in posterior chaetigers, whereas in P. floridana they are 0.8–0.9× longer in middle and posterior chaetigers; 6) in P. websteri sp. nov., the dorsal cirri are 1.2 × as long as proximal lobes in posterior chaetigers, whereas in P. floridana they are 0.8–0.9x; 7) in P. websteri sp. nov., the dorsal ligules are 2 × as long as median ligules in posterior chaetigers, whereas in P. floridana they are 2.4× longer; 8) in P. websteri sp. nov., the neuroacicular ligules are 1.5–2.0 × as long as ventral ligules in posterior chaetigers; whereas in P. floridana they are 0.8 × as long; 9) in P. websteri sp. nov., the ventral cirri are 1.0–1.2 × as long as ventral ligules in posterior chaetigers, whereas in P. floridana they are 0.7× as long.

Distribution

Bermuda.