Lamispina falcata (Støp-Bowitz, 1948), Salazar-Vallejo, 2014

Salazar-Vallejo, Sergio I., 2014, Revision of Pherusa Oken, 1807 (Polychaeta: Flabelligeridae), Zootaxa 3886 (1), pp. 1-61 : 45-47

Lamispina falcata (Støp-Bowitz, 1948) n. comb.

Figure 19

Pherusa falcata Støp-Bowitz, 1948a:22–24 , Fig. 5 .— Hartmann-Schröder, 1971:372, 1996:419.—Jirkov & Philippova, 2001:363, Figs 4–6 (repr. from original).

Type material. Northeastern Atlantic Ocean, Norway. Seven syntypes ( ZMUB 41784 ), Ideosen, Herdla, 11 Sep. 1924, Grieg, coll.

Description. Syntypes (ZMUB 41784) three anterior fragments (one without cephalic cage region), and four posterior fragments, tapered posteriorly, macerated ( Fig. 19A ); largest syntype a mature female ( Fig. 19B, C ). Body pale, almost without sediment cover, integument shiny; 4–6 mm long, 1.0– 1.3 mm wide, cephalic cage 2–3 mm long, 9–10 chaetigers. Tunic thin, free from sediment. Body papillae digitate, fine sediment particles adhering basally and medially, fusiform, arranged in 8–10 transverse alternating series per segment, most eroded over anterior dorsal surface; better preserved close to chaetal lobes, posteriorly or ventrally.

Anterior end not exposed; dissection avoided due to condition of specimens. Cephalic cage chaetae 2–3 x longer than body width. Chaetigers 1–2 forming cephalic cage, chaetigers 3–4 with notochaetae as long as following ones. Cephalic cage chaetae arranged in short series, chaetiger 1 with notochaetae dorsal, neurochaetae lateral, chaetiger 2 with chaetae lateral. Chaetigers 1 and 2 with about 10 noto- and 6 neurochaetae.

Anterior dorsal margin of first chaetiger papillated, some central papillae longer. Chaetigers 1–3 increasing in length posteriorly. Chaetal transition from cephalic cage to body chaetae abrupt; lamispines from chaetiger 4. Gonopodial lobes not seen.

Parapodia poorly developed; chaetae emerge from body wall ( Fig. 19D ). Parapodia lateral; medial neuropodia ventrolateral. Notopodia 1–3 better developed, low rounded chaetal lobes, with longer papillae. Neuropodia low rounded lobes, with longer papillae. Noto- and neuropodia close to each other.

Notochaetae arranged in short transverse series (up to chaetiger 10); afterwards unknown; all multiarticulated capillaries, articles medium-sized basally, long medially and distally ( Fig. 19E ), about 10 notochaetae per ramus, 1.3x longer than body width. Neurochaetae multiarticulated capillaries in chaetigers 1–3; lamispines from chaetiger 4, arranged in transverse series, 4–5 per bundle; tips with a blunt, round tooth ( Fig. 19F ).

Posterior end unknown; largest syntype a mature female, developing oocytes about 50 µm in diameter ( Fig. 19B, C ).

Remarks. Lamispina falcata (Støp-Bowitz, 1948) n. comb., L. milligani n. sp., and L. schmidtii (Annenkova- Chlopina, 1924) n. comb. resemble each other by having body papillae delicate, filiform, which are easily eroded and leave bare surfaces.

As stated above, L. milligani can be separated from the other species by its very short notochaetae, not longer, than body width. Then, L. falcata and L. schmidtii differ due to the number and size of notochaetae, type and number of lamispines, and number of transverse series of papillae per segment. In L. falcata there are 4–5 lamispines and their tips are entire, not hooded, and 8–10 transverse series of papillae per segment, whereas L. schmidtii has slightly more lamispines (5–7) with tips hooded, and fewer transverse series of papillae (5–6).

Regarding the type material, Støp-Bowitz (1948a:24) indicated: “La côte oust jusqu’a Stad (62° N): Au milieu du Karmøsound, devant Kopervik (104 m; 4 ex., 3 juillet 1908; “Michael Sars” st. 115; B. [l’un d’entre eux est le holotypus]). This means that he had regarded one out of the four specimens as the holotype but it was apparently not separated; what is being regarded as the type series differs, but chaetal features agree despite the differences in localities and number of specimens.

Distribution. Originally described from Southwestern Norway, it has been recorded in the North Sea (Skagerrak), and has been regarded as being present in the Arctic Ocean. Probably subtidal to deep water (100–180 m).

Figures

FIGURE 4. Pherusa aspera (Stimpson, 1854). A. Neotype (USNM 8889), anterior region, dorsal view. B. Same, ventral view. C. Another specimen (USNM 8957), head, frontal view (branchiae and palps removed; BS: branchial scar, LL: lateral lip, PS: palp scar). D. Neotype, chaetiger 10, right notopodium (inset: chaetal tips). E. Same, chaetiger 9, neurochaetae (two smaller neurochaetae not shown). Scale bars: A, C: 0.7 mm, B: 0.9 mm, D: 225 µm, E: 112 µm.

FIGURE 5. Pherusa hobsonae n. sp. A. Holotype (USNM 43803), lateral view. B. Anterior end, dorsal view. C. Same, right side, ventral view. D. Paratype (USNM 1131565), anterior end, dorsal view, tunic removed. E. Same, head, frontal view (branchiae and palps removed; BS: branchial scar, NL: nephridial lobe, PS: palp scar). F. Paratype, chaetiger 12, right parapodium, notochaetae (inset: basal and distal regions). G. Same, chaetiger 12, right parapodium, neurochaetae (one not shown). Scale bars: A: 3 mm, B: 2.2 mm, C: 1.7 mm, D: 1 mm, E: 0.5 mm, F: 0.25 mm, G: 45 µm.

FIGURE 6. Pherusa incrustata de Quatrefages, 1866, reinstated. A. Syntype (MNHN 382), dorsal view (inset: posterior region of dried syntype with large dorsal sediment particles). B. Anterior end, dorsal view (body wall damaged by removal of sediment particles). C. Anterior end, ventral view. D. Non-type specimen (MNHN 507), anterior end, dorsal view. E. Another non-type specimen (MNHN 183), head, frontal view (branchiae and palps removed; BS: branchial scar, LL: lateral lip, PS: palp scar; *: nephridial lobes base). F. Syntype (MNHN 381), chaetiger 10, basal, medial and distal notochaetal regions. G. Same, chaetiger 10, neurochaetae (2 broken). Scale bars: A: 3 mm, B: 2 mm, C: 1.9 mm, D: 1.4 mm, E: 0.8 mm, F: 0.3 mm, G: 0.4 mm.

FIGURE 19. Lamispina falcata (Støp-Bowitz, 1948) n. comb. A. Syntypes (ZMUB 41784). B. Same, anterior fragments, dorsal view. C. Largest syntype, ventral view. D. Posterior fragment, right parapodium, posterior view (neuropodium at right). E. Same, notochaetal basal, medial and distal regions. F. Same, lamispine basal, medial and distal regions. Scale bars: A: 1.3 mm, B: 0.9 mm, C: 1 mm, D: 140 µm, E: 25 µm, F: 20 µm.