Lamispina ammophila, Jimi & Kajihara, 2018

Jimi, Naoto & Kajihara, Hiroshi, 2018, A New Species, Lamispina ammophila sp. nov. (Annelida: Flabelligeridae), from Shimoda, Japan, Species Diversity 23 (1), pp. 39-42 : 39-41

Lamispina ammophila sp. nov.

[New Japanese name: suna-sasanoha-habouki]

( Figs 1 , 2 )

Material examined. Holotype: NMST-Pol H-663, anterior fragment, 4 mm long, 1 mm wide (widest chaetiger), 17 chaetigers, sex unknown, off Shimoda, 45–46m depth, 13 November 2015, collected by NJ; although the last two chaetigers were removed for observation and DNA extraction, any gene sequences could not be determined from those chaetigers. Paratypes: NSMT-Pol P-664, 10 specimens, anterior fragments, 2–6 mm long, 1 mm wide (widest chaetiger), 8–20 chaetigers, sex unknown, off Shimoda , 45–46 m depth, 13 November 2015, collected by NJ; the last two chaetigers and palps of one specimen were removed for DNA extraction.

Sequence. LC363891 , COI gene, 651 bp, determined from the paratype (NSMT-Pol P-664) .

Description. Holotype 4 mm long, 1 mm wide (widest chaetiger), 17 chaetigers (not complete). Body cylindrical, tapered in posterior region, greenish in life, yellowish aΠer fixation ( Fig. 1A ). Dorsal body surface with sparse sand particles ( Fig. 1B ), ventral side without sand particles ( Fig. 1A ). Body papillae long, thin, digitate, sediment particles attached on base, 1/2 times as long as parapodial papillae. Gonopodial lobes not seen. Gonopores not seen.

Prostomium low cone, red eyes present, caruncle developed, lateral lip expanded, dorsal and ventral lips not well developed ( Fig. 1C ). Palps short, thick, digitate, as long as branchiae ( Fig. 1D ). Branchiae arranged in a continuous dorsal series, eight in number, digitate, microcilia present on surface ( Fig. 1E ). Nephridial lobes present.

Cephalic cage well developed, 1.5–2.0 times as long as body width (widest chaetiger). Chaetigers 1–3 comprise cephalic cage, cephalic cage consisting of about 4 notochaetae and 8 neurochaetae (some chaetae broken). Chaetal transition from cephalic cage to body chaetae abrupt ( Fig. 1A ).

Parapodia poorly developed. Noto- and neuropodial low lobes, 1/3–3/4 times as long as neurochaetae, 2–4 times as long as body papillae, 5–7 internal papillae, 4–6 postchaetal papillae; 4–5 chaetae per notopodia, 3–4 chaetae per neuropodia. Notochaetae multiarticulated capillaries, brownish, with articles medium-sized basally, long medially and distally ( Fig. 2A ). Neurochaetae multiarticulated capillaries in chaetigers 1–3, brownish; anchylosed lamispines present in chaetiger 4 and succeeding posterior chaetigers, brownish, without accessory tooth, with articles medium-sized basally, slightly long medially ( Fig. 2B, C ).

Posterior end unknown.

Etymology. The specific name “ammophila” derives from ancient Greek α ˘ʹ’ μμoς ámmos (sand)+ φ ΄ ῐ λoς phílos (loving, friendly), referring to the new species having sand particles on its body.

Distribution. Only known from the type locality, Shimoda, Japan. 45–46 m in depth.

Remarks. Lamispina ammophila sp. nov. is different from the other known species by the following features: i) sediment particles are adhered only to the dorsal region of the body, ii) lamispines are present in chaetiger 4 and backward, lacking accessory tooth, and iii) the cephalic cage is 1.5–2.0 times as long as the body width. The species resembles L. amoureuxi Salazar-Vallejo, 2014 in having sediment particles and lamispines without accessory tooth. While lamispines in L. ammophila sp. nov. emerge from chaetiger 4 and backward, they occur from chaetiger 2 in L. amoureuxi . The cephalic cage is 1.5–2.0 times as long as body width in L. ammophila sp. nov., it is as long as body in L. amoureuxi . The species also resembles L. gymnopapillata (Hartmann- Schröder, 1965) in that lamispines occur from chaetiger 4, but it differs from the latter in that sand particles adhere dorsally in L. ammophila sp. nov., whereas L. gymnopapillata does not carry sand particles.

Figures

Fig. 1. Photographs of Lamispina ammophila sp. nov. in preserved state. A, B, D, E, Holotype, NSMT-Pol H-663; C, paratype, NSMT-Pol P-664. A, Anterior end, ventral view; B, anterior end, dorsal view; C, prostomium (BS, branchial scar; Ca, caruncle; LL, lateral lip; PS, palp scar; black arrows, nephridial lobe); D, palp; E, branchia. Scale bars: A–B, 1mm; C–E, 250µm.

Fig. 2. Photomicrographs of chaetae (chaetiger 17) in Lamispina ammophila sp. nov., holotype, NSMT-Pol H-663. A, Notochaetae; B, neurochaetae; C, tip of neurochaeta. Scale bars: A, B, 100µm; C, 50µm.