Fauveliopsis levensteinae, Salazar-Vallejo & Zhadan & Rizzo, 2019

Salazar-Vallejo, Sergio I., Zhadan, Anna E. & Rizzo, Alexandra E., 2019, Revision of Fauveliopsidae Hartman, 1971 (Annelida, Sedentaria), Zootaxa 4637 (1), pp. 1-67 : 22-27

Fauveliopsis levensteinae new species

Figures 10–12

urn:lsid:zoobank.org:act:B499DAF2-4812-451E-9912-A9D6D5CC102C

Fauveliopsis challengeriae: Levenstein 1970: 227–228 , Fig. 1 (partim; perhaps Sta. 301 F. challengeriae; specimens not available, probably lost); Levenstein 1972: 173, Table 2 (partim, non McIntosh, 1922).

TL: North Pacific Ocean, off Aleutian Islands, 5000 m depth.

Type material. North Pacific, off Aleutian Islands. Holotype ( SIORAS Vi 6142) and paratype, R/V Vityaz, cruise 45, Sta. 6142 (52°16.0’ N, 163°34.0’ W), 5000 m, 14 Jun. 1969 . Additional materials. North Pacific. One specimen ( SIORAS Vi 3166), off Kamchatka Peninsula, R / V Vityaz, cruise 19, Sta. 3166 (44°42.9’ N, 153°49.0’ E), 5027 m, 10 Mar. 1954 (specimen in tubular foraminiferan, body becoming wider medially and posteriorly, markedly bent in the last third of the body; 10 mm long, 1 mm wide, 34 chaetigers; GP chaetiger 11, right anterior margin; swollen, half-moon shaped, but not reaching notochaetal insertion level). One specimen ( SIORAS Vi 3156), RV Vityaz, cruise 19, Sta. 3156 (39°57’ N, 165°07.8’ E), 5526 m, 28 Sep. 1954 (tube dirty orange, faintly annulated; specimen with part of its body inside tube; removed from it; most of body preserved inside tube portions narrower than body width, collapsing anterior chaetigers including the one with GP, where the glandular parapodial cushion is not visible at all (but visible in other body regions); even then, papillae placed above the notochaetal insertion; body 20 mm long, 0.9 mm wide, 33 chaetigers; GP on right anterior margin of chaetiger 11, as long as the distance between adjacent chaetal fascicles) . One specimen ( SIORAS Vi 3255), off Kamchatka Peninsula, R / V Vityaz, cruise 20, Sta. 3255 (48°20’ N, 157°42.3’ E), 5340 m, 16 May 1955 (splendid specimen, body becoming wider medially and posteriorly, body wall broken towards pygidium; 16 mm long, 1 mm wide, 34 chaetigers; GP chaetiger 14, right anterior margin; swollen, half-moon shaped) . One specimen ( SIORAS Vi 3363), RV Vityaz, cruise 20, Sta. 3363 (48°14.7’ N, 169°39.3’ E), 6280 m, 10–11 Jun. 1955 (tube fragment granu- lose; body broken medially, bent, damaged) . One specimen ( SIORAS Vi 4138), RV Vityaz, cruise 29, Sta. 4138 (54°23.8’ N, 134°41.4’ E), 2630 m, 11 Nov. 1958 (tube dirty orange, faintly annulated; body ends damaged, broken, medially collapsed) . Three specimens ( SIORAS Vi 3575), two complete, R/ V Vitjaz, cruise 24, Sta. 3575 (37°55.5’ N, 146°24.4’ E), 5465 m, 6 May 1957 (complete specimens from tubular foraminiferans, one tube with irregular growth rings, the other without growth rings; most of body preserved while inside the tube; complete 9.8– 14.8 mm long, 0.7–0.9 mm wide, 31–37 chaetigers; GP on right side of chaetiger 11–12; shorter specimen immersed for 20 sec in methyl blue stain and photographs) . 13 specimens ( SIORAS Vi 3578), and four empty scaphopod shells and two fragments ( Epirhabdoides ivanovi Steiner, 1999 ) off Japan, R/ V Vityaz, cruise 24, Sta. 3578 (38°35’ N, 42°53’ E), 1641 m, 11 May 1957 (4–11 mm long, 0.5–1.0 mm wide, 29–37 chaetigers; GP left, chaetiger 11, rarely right, or in chaetigers 12–15) . Fifteen specimens ( SIORAS Vi 4074), 9 little distorted, off Japan, R/ V Vityaz, cruise 29, Sta. 4074 (40°19.7’ N, 175° 45.3’ W), 6010 m, 20 Oct. 1958 (nine relaxed, little distorted specimens but segments longer than other specimens preserved within their tubes, 4 with body slightly widened medially, others thinner anteriorly, becoming wider posteriorly; 9–16 mm long, 1.0– 1.5 mm wide, 33–36 chaetigers; GP in anterior dorsal side of chaetiger 11–12, as long as ½– 2 / 3 chaetal glandular lobe, often surpassing the notochaetal insertion level) . Three specimens ( SIORAS Vi 5605), RV Vityaz, cruise 39, Sta. 5605 (46°10’ N, 153°07’ E), 4985 m, 18 Aug. 1966 (body brownish anteriorly or pigment reaching the medial region, paler medially and posteriorly; tubes almost cylindrical, tapered basally, with subtle paler, irregular rings; segment length variable, medium-sized anteriorly, short medially, long in median posterior region, short posteriorly; 11.5–20.0 mm long, 0.7–1.1 mm wide, 31–34 chaetigers, GP right side of chaetiger 11, 9 / 10 – 8 / 10 as long as adjacent parapodial gland cushion) . Five specimens ( SIORAS Vi 5606), 2 complete, outside the tubular foraminiferan, R/ V Vityaz, cruise 39, Sta. 5606 (46°13’ N, 153°16’ E), 5095 m, 18 Jul. 1966 (small specimens 7.5–10.0 mm long, 1 mm wide, 30–32 chaetigers) . One specimen ( SIORAS Vi 5620), RV Vityaz, cruise 39, Sta. 5620 (44°48’ N, 156°33’ E), 5030 m, 15 Aug. 1966 (tube fragment blackish, non-annulated; body with anterior end in regeneration, darker towards the medial region, covered with salt adsorbed particles; 10.8 mm long, 0.9 mm wide, 34 chaetigers, GP on right anterior side of chaetiger 13, as long as 9/10 adjacent parapodial glandular cushion) . Nine specimens ( SIORAS AK 5624 ), R/ V Akademik Kurchatov, cruise 39, Sta. 5624 (45°22’ N, 154°00’ E), 5220 m, 20 Aug. 1966 (and one sipunculan, damaged, living in the same type of foraminiferan; vari- ously damaged) . One specimen ( SIORAS Vi 5624b), RV Vityaz, cruise 39, Sta. 5624 (45°22’ N, 154° 00’ E), 5240 m, 20 Aug. 1966 (still partially inside a straight, foraminiferan tube; removed from it; body bent dorsally, J-shaped, pygidium exposed; body 12.5 mm long, 0.8 mm wide, 31 chaetigers; GP in right side of chaetiger 11, as an asymmetrical fusiform lobe) . One specimen ( SIORAS Vi 5633), RV Vityaz, cruise 39, Sta. 5633 (44°07’ N, 149°34’ E), 6 Sep. 1966 (tube dirty orange, with blackish particles, without annulations, with soft inner lining and sediment; body distorted, anterior region broken, very narrow) . One specimen ( SIORAS Vi 5637), RV Vityaz, cruise 39, Sta. 5637 (44°29’ N, 149°06’ E), 3015 m, 9 Sep. 1966 (small specimen, 3.5 mm long, 0.5 mm wide, 30 chaetigers; GP not visible) . 20 specimens ( SIORAS Vi 6088), off Aleutian Islands, R / V Vityaz, cruise 45, Sta. 6088 (53°58’05” N, 157°36’00” W), 5740 m, 4 May 1969 (10.0– 22.5 mm long, 0.6–1.0 mm wide, 25–40 chaetigers; GP right, chaetiger 11, rarely on 12.

Etymology. The species name is made after Dr. Raisa Y. Levenstein in recognition of her publications on deep-sea polychaetes, and especially because she studied specimens of this species. The epithet is a noun in the genitive case.

Diagnosis. Fauveliopsis with 30–40 chaetigers. Integument finely annulate. Interramal papillae fungiform. Median chaetigers with a single acicular and one capillary per bundle. Posterior chaetigers with 2–3 aciculars and one capillary per bundle. Chaetal formula 1A1c/1c1A (ant.), 1A1c/1c1A (med.), 3A2–3c/2–3c3A (post.). GP on posterior margin of chaetiger 11 (11–15). In scaphopods and tubular foraminiferans.

Description. Holotype (SIORAS Vi 6142) complete, mature female ( Fig. 10A ). Body subcylindrical, slightly wider medially, pygidium slightly bent ventrally ( Fig. 10F ); body 14.5 mm long, 1 mm wide, 36 chaetigers. Trunk with four distinct regions regarding segment length, parapodial development and integument corrugation; anterior thorax includes chaetigers 1–7, about as long as wide and thick, finely annulated integument ( Fig. 10B ), posterior thorax includes chaetigers 8–17, wider than long, with thick, smooth integument ( Fig. 10C, D ); abdomen includes chaetigers 18–22, about twice longer than wide with thin, smooth integument ( Fig. 10E ); and posterior region with chaetigers 23–36, wider than long, with thick, dark, annulated integument ( Fig. 10F ). A fine mid-ventral line can be seen throughout most of the body ( Fig. 11 A–C, F).

Prostomium low, blunt cone, directed ventrally. In ventral view, a deep longitudinal furrow along prostomium ( Fig. 11A ). Peristomium barely exposed, forming an inverted T. Anterior thoracic region with first 7 chaetigers. Segments progressively longer; first three barely annulated, bent ventrally, following ones with fine annulations. Posterior thorax with chaetigers 8–17, segment length progressively reduced in chaetigers 8–10 and then of about same length but poorly defined. Segments homogeneously annulated. Third region with chaetigers 19–24, segments twice as long as wide, with integument barely annulated, almost smooth, transparent, parapodial lobes depressed. Fourth region with chaetigers 23–36, homogeneously short, with integument annulated and parapodial lobes well developed.

Parapodia biramous, displaced dorsally throughout ( Fig. 10D ). Interramal papillae capitate, peduncle as long as distal, globose region ( Figs 11B , 12C ). Parapodial development varies along body. Chaetigers 1–4 with chaetal lobes flat, not projected nor glandular. Chaetigers 5–18 with chaetal lobes long, fusiform, then wider, crescent shaped up to chaetiger 14, where they become shorter, rounded ( Fig. 11B, C ). Abdomen with chaetigers 19–24 with chaetal lobes barely visible, not projected or glandular ( Fig. 11D, E ); chaetigers 25–35 with parapodial lobes ovoid, projected and glandular.

Chaetigers 1–3 with two aciculars per bundle. Chaetigers 4–30 with a single acicular and one capillary per bundle ( Fig. 12A ). Some terminal chaetigers with 2–3 aciculars and one capillary per bundle. Acicular and capillaries smooth; finely pilose subdistally under higher magnifications ( Fig. 12D, E , inset, F).

Pygidium bent ventrally, without anal cirri; some papillae along dorsal surface ( Fig. 12G ); anus terminal. Genital papillae on right side, chaetiger 12, 1 / 3 as long as adjacent parapodial lobe, its upper margin surpasses notochaetal insertion level ( Figs 10C, D , 11B , 12B ). Oocytes in chaetigers 19–24, 100 µm in diameter each ( Figs 10E , 11 C–E).

Paratype (SIORAS Vi 6142p) complete, mature male. Body subcylindrical wider medially and posteriorly, tapered into a conical pygidium with anus exposed; body 24.5 mm long, 0.9 mm wide, 37 chaetigers. Body shape distorted with two smooth regions, and others with parapodial lobes more pronounced. Chaetigers 1–8 darker, short, chaetal lobes projected, glandular; chaetigers 9–14 longer, chaetal lobes flat; chaetigers 15–21 longer, chaetal lobes flat, glandular; following chaetigers with chaetal lobes projected, glandular. Testis extending along chaetigers 14–19. Genital papillae not visible.

Methyl blue staining. Chaetal lobes and glands do not stain ( Fig. 10D ); pigment tends to be concentrated along the anterior and posterior regions, but the first four chaetigers in female do not stain at all, similarly, the integument in the region carrying oocytes does not stain. Male with a similar pattern but in longer, relaxed segments, integument becomes very smooth and the stain is barely incorporated.

Variation. The body was 4.0– 22.5 mm long, 0.5–1.1 mm wide, with 25–40 chaetigers. Genital papillae were usually present on left side of chaetiger 11, but it could be present rarely on the right side of the same chaetiger instead, or along the left side of chaetigers 12–15. Some small specimens (SIORAS Vi 6010) being 8.5 mm long, have small GP in the typical position, but they are small, rounded, placed at the level of notochaetal insertion, such that the GP might grow ventrally and dorsally as body grows. It is interesting to note that, after Petersen (2000:501, Fig. 1G ), the holotype of F. challengeriae is 15 mm long and its GP is short, not reaching the notochaetal insertion. Another specimen, 10.5 mm long, has a long GP with its anterior region surpassing notochaetal insertion. GP wider than long, about 2 / 3 – 3 / 4 the length of the adjacent parapodial glandular lobe, extending beyond notochaetal insertion, whereas in F. challengeriae the GP is shorter, wider than long, but about 1 / 4 – 1 / 3 the length of the parapodial glandular lobe. Neurochaetae are found in some specimens such that their absence in the holotype of F. challengeriae stated by Petersen (2000) can be regarded as an artifact of preservation and not a distinguishing feature.

Remarks. Fauveliopsis levensteinae n. sp. belongs in the group of species having two chaetae per rami in anterior and median regions, but with many chaetae along posterior chaetigers, together with F. magalhaesi n. sp., F. adriatica , and F. magna . However, as indicated in the key above, F. levensteinae is the only species with integument annulated, and genital papillae in chaetiger 11.

F. levensteinae n. sp. has been confused with F. challengeriae . These species differ in three basic features: the genital papillae relative size, its position regarding notochaetal insertion, and in the affinity of the parapodial cushions for staining with methyl blue. In F. levensteinae n. sp., the genital lobes are as long as 1 / 2 – 9 / 10 the adjacent parapodial cushion, and usually surpass the level of notochaetal insertion, whereas in F. challengeriae , the genital lobes are shorter, being at most half the length of the adjacent parapodial cushion, and do not surpass notochaetal insertion level. Further, in F. levensteinae n. sp., the parapodial cushions do not take the stain whereas in F. challengeriae they take the same intensity of pigmentation as the adjacent body wall regions.

Petersen (2000) noticed some homogeneously depressed or reinforced areas along the body wall. We cannot confirm them; the depressed areas can be formed depending on the worm’s relative position within the shell or tubular foraminiferans, and on those surfaces more closely fitting the inner walls. Other midventral reinforcements were not detected despite the use of stains.

The body can be modified if the organism was preserved inside or outside the tubular foraminiferans or scaphopod shells they occupy, such that the anterior region has segments with variable lengths. If they were preserved within their shelters, their body is not expanded and the segments have different lengths, which can be used as a diagnostic feature. In addition, if there was a long time between sampling and fixation, the organism may be so relaxed that body segments become longer. Consequently, the segment relative length could only be used to separate similar species if they were preserved more or less under the same conditions. The other interesting difference relies on the relative length of the basal cushion of genital papillae. The genital papillae have been regarded as formed by a conical projection from the body wall, just ahead of one of the anterior chaetigers chaetal bundles. However, most specimens have a variable development for this projection and there is usually a basal ridge associated with the genital papillae. This ridge can be reduced, being as long as 1 / 3, smaller than the adjacent parapodial glandular cushion, or it can be longer, being at least half as long as the adjacent parapodial glandular cushion. This difference is often linked to a slight change in the relative position of the genital papillae upper region; in the Northern Pacific form, it usually surpasses the notochaetal insertion level, whereas in the Southern Pacific form, it does not surpass this relative position. These two differences can help separate what has been regarded as F. challengeriae from the North Pacific Ocean, from those present in abyssal depths from the Equator to Antarctic Ocean localities. A third method to separate them, which needs confirmation, relies on the biochemical affinities for methyl blue. In the Northern Pacific form, the parapodial glandular cushions do not take up the stain, whereas in the southern form the stain is easily incorporated into parapodial cushions.

Distribution. In abyssal sediments (1641–6280 m) along the Northern Pacific Ocean from off Japan and Kamchatka Peninsula to the Aleutian Islands.

Figures

FIGURE 1. Fauveliopsis adriatica Katzmann & Laubier, 1974, non-type specimens.A. Seven specimens, one in a scaphopod, three others in gastropods, and three others removed from shells (Ca: Cadulus, Ol: Olivella, Se: Seguenzia, Vi: vitrinellid, fragment), (LACM 7527). B. Another specimen (LACM 7525) preserved inside a scaphopod, methyl green stained (inset: genital papillae before chaetiger 11). C. Same, anterior end, dorsal view. D.Another specimen (LACM 7525), mature female, preserved within a gastropod shell. Scale bars: A: 1.6 mm, B: 0.9 mm, C: 140 µm, D: 0.6 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 12. Fauveliopsis levensteinae n. sp., non-type specimens (SIORAS AK 5624). A. Chaetiger 13, right parapodium, frontal view showing genital papilla (GP). B. Another specimen, chaetigers 10–13, right parapodia, frontal view, showing genital papilla (GP), arrow points to an interramal papillae enlarged in C. C. Interramal papilla, oblique frontal view. D. Notochaetal acicular and broken capillary, anterior chaetiger. E. Notochaetal spine and capillary, mid-body segment (inset: enlargement of hirsute capillary). F. Posterior acicular with spinulose posterior margin. G. Posterior region, oblique right lateral view (larger inset: pygidium showing abundant papillae; smaller inset: single papilla indicated by an asterisk, frontal view). Scale bars: A: 170 µm, B: 0.1 mm, C: 15 µm, D: 20 µm, E, F: 30 µm, G: 0.2 mm.