Laubieriopsis arenicola ( Riser, 1987 )

Salazar-Vallejo, Sergio I., Zhadan, Anna E. & Rizzo, Alexandra E., 2019, Revision of Fauveliopsidae Hartman, 1971 (Annelida, Sedentaria), Zootaxa 4637 (1), pp. 1-67 : 40-41

Laubieriopsis arenicola ( Riser, 1987)

Figure 23

Fauveliopsis arenicola Riser, 1987: 211 – Figs 5–11 ; Petersen 2000: 510 (n. comb.).

TL: New Zealand, North Island, Leigh, Amphioxus sand, Sponge Flats, off Goat Island, 22 m. D: Only known from the type locality.

Type material: Southwestern Pacific Ocean, New Zealand. Holotype ( USNM 97494 ) and one paratype ( USNM 97495 ), Leigh , Goat Island, Sponge Flats (36°15’55” S, 174°47’34” E), 22 m, Amphioxus sand, 8 Oct. 1982, N.W. Riser, coll. (paratype twisted over itself, about 5.5. mm long, 0.3 mm wide, 26 chaetigers).

Diagnosis. Laubieriopsis with 25 chaetigers. Anterior segments with 3 or 4 annulations ( Fig. 23A ); posterior segments smooth ( Fig. 23B, C ). First 4 anterior chaetigers with two aciculars and two capillaries per bundle, tips apparently entire. Median and posterior parapodia with one acicular and one capillary per ramus. Last chaetiger with short aciculars, not reaching pygidium limit. Genital papillae paired, on chaetigers 6/7.

Remarks. Laubieriopsis arenicola resembles L. fauchaldi because both species have more than 21 chaetigers and have aciculars with tips entire along the first few chaetigers. The differ, however, as indicated in the key above in the number of chaetigers in the body, in the presence of genital papillae (GP), and in the segment surface along body. In L. arenicola the body has 25 chaetigers, the integument is 3–4 annulated, and GP are present in chaetiger 6–7, whereas in L. fauchaldi the body has 47 chaetigers, segment surface is smooth, not annulated, and there are no GP recorded.

The description is nearly complete in Riser (1987) including the chaetigers count (25). Because of its body wall being smooth, and especially because the body ends and chaetiger size matches with the body pattern in Laubieriopsis , the species is being referred to this genus after the study of the type material.

Figures

FIGURE 5. Fauveliopsis challengeriae McIntosh, 1922, non-type specimens. A. Complete specimen from scaphopod shell (USNM 55546a), dorsal view. B. Same, anterior region, dorsal view. C. Same, posterior region, right lateral view. D. Other specimens (USNM 56662), smaller specimen within foram tube, and larger foram tube. Scale bars: A: 360 µm, B: 260 µm, C: 280 µm, D: 1 mm.

FIGURE 6. Fauveliopsis challengeriae McIntosh, 1922, non-type specimens (SIORAS AK242). A. Four specimens from scaphopod shells (one inside shell with exposed posterior end). B. Better preserved specimen, dorsal view (irregular masses in midbody are sperm). C. Same, ventral view (oocytes visible by transparency). D. Same, after staining with acidic methylene blue, lateral view (*: genital papilla). Scale bars: A: 1 mm, B–D: 0.4 mm.

FIGURE 7. Fauveliopsis glabra (Hartman in Hartman & Barnard, 1960), non-type specimens (LACM 7610).A. Largest specimen, dorsal view (arrow points to genital papilla). B. Same, close-up of chaetigers 9–13, right lateral view showing genital papilla (GP) over posterior margin of chaetiger 10. C. Three specimens of different size, larger ones in ventral view, smallest one in oblique dorsal view; largest specimen has a ventral region distorted (‘shield’). D. Anterior region of another specimen, left lateral view, exposed after fracture of scaphopod shell. E.Another specimen, in dorsal view, after shell was broken and sediment removed. Scale bars: A: 1.3 mm, B: 0.3 mm, C: 0.8 mm, D: 0.4 mm, E: 0.7 mm.

FIGURE 8. Fauveliopsis glabra (Hartman in Hartman & Barnard, 1960), non-types (LACM 7613), tubes. A. Tube fragments and one transverse section. B. Eight-shaped tube, opening directed upwards. C. Medial and basal fragments showing complex inner features, worms surrounded by fine sediment. D. Cross section of a medial fragment, inner cover is mucous with fine particles, median brownish core of variable width, outer tube regions more homogeneous. E. Basal fragment, outer cover darker than outer layer, inner with fine sediment particles (broken for figure 10). F. Basal fragment with darker cover inside, fine sediment particles covering tube lumen. Scale bars: A, B: 2 mm, C: 1.3 mm, D: 0.3 mm, E, F: 0.7 mm.

FIGURE 9. Fauveliopsis glabra (Hartman in Hartman & Barnard, 1960), non-types (LACM Sta. 6850), tubes 2. A. Piece broken longitudinally to show tube wall structure. B. Close-up of fragment in lower left part of A. C. Close-up of fragment in lower right part of A. D. Same, close-up of basal region. Scale bars: A: 0.9 mm, B: 0.6 mm, C: 0.5 mm, D: 0.3 mm.

FIGURE 10. Fauveliopsis levensteinae n. sp., holotype (SIORAS Vi 6142).A. Dorsal view (arrow points to genital papilla). B. Anterior end, dorsal view. C. Dorsal view of chaetigers 10–15 (asterisk indicates genital papilla). D. Same, lateral view, after temporary staining with methyl green (arrow points to genital papilla). E. Anterior abdominal region, chaetigers 21–22, with oocytes. F. Posterior region, dorsal view. Scale bars: A: 0.9 mm, B: 0.6 mm, C, E: 0.3 mm, D: 110 µm, F: 0.2 mm.

FIGURE 11. Fauveliopsis levensteinae n. sp., holotype (SIORAS Vi 6142). A. Anterior region, ventral view. B. Chaetigers 10–17, ventral view (arrow points to genital papilla). C. Transition thorax-anterior abdomen (chaetigers 17–18), ventral view. D. Chaetigers 19–20, full of oocytes (diameter 90–100 µm), ventral view. E. Chaetigers 20–21, with oocytes and irregular pale masses (sperm?), ventral view. F. Posterior region, ventral view. Scale bars: A: 0.4 mm, B–F: 0.3 mm.

FIGURE 23. Laubieriopsis arenicola (Riser, 1987), holotype (USNM 97494). A. Anterior region, dorsal view. B. Posterior region, dorsal view. C. Paratype (USNM 97495), oblique lateral view. Scale bars: A: 140 µm, B: 160 µm, C: 150 µm.