Fauveliopsis olgae Hartmann-Schröder, 1983

Zamora, José Luis, Parapar, Julio, Helgason, Gudmundur V. & Moreira, Juan, 2020, Taxonomy and distribution of Icelandic Fauveliopsidae (Annelida) collected during the BIOICE project, Journal of Natural History 53 (47 - 48), pp. 2951-2974 : 2959-2964

Fauveliopsis olgae Hartmann-Schröder, 1983

( Figures 1 (b), 2(a), 3(a–c), and 4–7; Table 1)

Material examined

Three hundred and fifty-eight specimens (4.08% of the total) collected in 42 samples ( Figure 1 (b); Table 1). Many specimens found within gastropod and scaphod shells and foraminiferan thecae ( Figure 4 (c–f)).

Description of BIOICE specimens

Body elongated, club-shaped, posterior end more swollen ( Figures 3 (a), 4(a), 5(a), 6(a), and 7(a)). Specimens 2.0– 8.3 mm long with 25–38 chaetigers. Body width about 0.5 mm in first chaetiger, up to 1.0 mm in midbody in larger specimens. Cuticle thick, opaque, with many

striations ( Figures 5 (c), 6(c), and 7(e)), thinner in midbody; intestine and oocytes visible by transparency. Body divided in three regions: 1) anterior: from prostomium to CH 16, chaetigers short, rugose ( Figures 3 (b), 5(b,c), 6(b), and 7(b,c)); 2) median: swollen, segments wider, longer ( Figure 6 (c)); 3) posterior: narrow, segments short, rugose with many micropapillae ( Figure 6 (e,f)). Parapodia birramous, parapodial lobes small, inconspicuous ( Figures 5 (c) and 6(c)). CH 1–3 with two unidentate aciculars per rami ( Figures 5 (b) and 7(b)) covered with minute scales ( Figure 7 (f)). Following chaetigers with only one acicular and one capillary (usually broken) per rami ( Figures 3 (c), 5(c), and 6(c)), pattern variable in median and posterior body regions ( Figure 7 (d)). One interramal pyriform papilla ( Figure 6 (d)) in all chaetigers, sometimes bifid ( Figure 5 (d)), better developed in anterior and median regions. Genital papilla, single, round, swollen, dorsally on right side of intersegmental border between CH 10–11 ( Figures 6 (b,c) and 7(c)); one specimen (sample 2423) with papilla on CH 16 .

Habitat and distribution

Originally described from deep-sea bottoms (4,040–4,060 m) off SW Ireland (Hartmann- Schröder 1983). BIOICE specimens were collected at SW Iceland at depths of between 304 and 1,819 m; temperature range: 2.55–7.11ºC ( Figure 2 (a)); most specimens were found off South Reykjanes Peninsula ; near continental shelf and around Vestman and Surtsey islands ( Figure 1 (b)), also reaching Westernfjords to the NW and deeper bottoms off the coast near Faxaflói Bay .

Remarks

According to the diagnosis provided by Salazar-Vallejo et al. (2019), this species is characterised by showing an increase in the number of chaetae along the body towards the posterior end, rugose body surface and posterior chaetigers provided with 3–4 aciculars and 3–4 capillaries per parapodial rami; this species belongs to the group that also includes Fauveliopsis glabra (Hartman in Hartman & Barnard, 1960) and Fauveliopsis scabra Hartman & Fauchald, 1971 because of having chaetigers bearing three or more chaetae along medial and posterior body regions ( Salazar-Vallejo et al. 2019). Fauveliopsis olgae differs from F. glabra in having a rugose body surface and up to four aciculars and four capillaries chaetae per rami instead of having a smooth body and 2–3 chaetae of each kind per rami; F. scabra has also a rugose body but the genital papilla is located on the posterior border of CH 8 instead of between CH 10–11 as in F. olgae ( Salazar-Vallejo et al., 2019) .

On the other hand, Fauveliopsis brattegardi Fauchald, 1972 was the first species of the genus described from Europe ( Norway). It differs, however, from BIOICE specimens because of having the same chaetal formula across all body segments, i.e. two short aciculars and two slender capillaries per parapodial ramus ( Fauchald 1972; Salazar-Vallejo et al. 2019). This pattern is also found in the Atlantic species Fauveliopsis jameoaquensis Núñez in Núñez, Ocaña & Brito, 1997 but this species differs from F. scabra , F. brattegardi and F. olgae in having only 10 chaetigers and smooth body surface.

Salazar-Vallejo et al. (2019) identified as F. olgae some material collected off Galician coasts (Iberian Peninsula) and specimens previously reported in the NE Atlantic by Amoureux (1982) as Fauveliopsis sp. BIOICE specimens were found in samples with a wide range of depth and temperature values; some relevant morphological features differed in comparison to the holotype, such as the lack of ventral shield, while others show some variability (i.e. chaetiger of location of genital papilla). Therefore , this suggests the possibility of cryptic species within this taxon .

Figures

Figure 1. Geographical distribution of Fauveliopsidae species found in BIOICE samples. (a) BIOICE samples with fauveliopsids. (b) Fauveliopsis olgae Hartman-Schröder, 1983. (c) Laubieriopsis brevis (Hartman, 1967). (d) Laubieriopsis cabiochi (Amoureux, 1982). (a): blue area marking position of samples with specimens of the three species; (b–d): red areas marking samples/group of samples with high number of specimens; numbers (1–4): marking samples/group of samples with high number of specimens (see also Figure 2).

Figure 2. Values of temperature versus depth for BIOICE samples with Fauveliopsidae specimens. (a) Fauveliopsis olgae Hartman-Schröder, 1983. (b) Laubieriopsis brevis (Hartman, 1967). (c) Laubieriopsis cabiochi (Amoureux, 1982). Numbers as in Figure 1.

Figure 3. Line drawings of BIOICE fauveliopsids. Fauveliopsis olgae Hartman-Schröder, 1983: (a) Complete specimen, dorsal view. (b) Anterior end, dorsal view. (c) Chaetiger 12, lateral view. Laubieriopsis brevis (Hartman, 1967): (d) Complete specimen, dorsal view. (e) Chaetiger 3, lateral view. (f) Chaetiger 9, lateral view (e,f), same scale bar. Laubieriopsis cabiochi (Amoureux, 1982): (g) Complete specimen, dorsal view. (h) Anterior end, dorsal view. BIOICE samples 2404 (IINH40686, (a– c)), 3072 (IINH40767, (d–f)) and 2716 (IINH40862, (g,h)). Abbreviations: A – acicular chaeta; a – thin acicular chaeta; AR – anterior body region; c – capillary chaeta; gp – genital papilla; irp – interramal papilla; MR – median body region; PR – posterior body region.

Figure 4. Stereomicrographs of several BIOICE specimens of Fauveliopsis olgae Hartmann-Schröder, 1983 removed from mollusc shell during sorting process (a,b), in foraminiferan tubular thecae (c,d), in gastropod (e) and scaphopod empty shells (f). BIOICE samples 3504 (IINH40713, (a–d)) and 2864 (IINH40702, (e–f)).

Figure 5. Fauveliopsis olgae Hartmann-Schröder, 1983. SEM micrographs, BIOICE sample 2435 (IINH40690). (a) Complete specimen, left lateral view. (b) Detail of anterior region, left lateral view (framed in (a)). (c) Median region chaetigers,left lateral view (framed in (a)). (d) Bifid interramal papilla (framed in (c)). Abbreviations: A – acicular chaeta; a – thin acicular chaeta; AR – anterior body region; c – capillary chaeta; CH – chaetiger; ian – integumental annulations; irp – interramal papilla; isb – intersegmental border; MR – median body region; PR – posterior body region.

Figure 6. Fauveliopsis olgae Hartmann-Schröder, 1983. SEM micrographs, BIOICE sample 3260 (IINH40707). (a) Complete specimen, dorsolateral view. (b) Anterior region, detail, dorsolateral view (framed in (a)). (c) Median region chaetigers, left lateral view. (d) Pyriform interramal papilla. (e) Posterior region chaetigers, lateral view. (f) Posterior body end, dorsolateral view (framed in (a)). Abbreviations: A – acicular chaeta; a – thin acicular chaeta; AR – anterior body region; c – capillary chaeta; CH – chaetiger; gp – genital papilla; imp – integumental micropapillae; irp – interramal papilla; isb – intersegmental border; MR – median body region; pyg – pygidium.

Figure 7. Fauveliopsis olgae Hartmann-Schröder, 1983. SEM micrographs, BIOICE samples 2864 ((a–c); IINH40701) and 3501 ((d–f); IINH40711). (a) Complete specimen, dorsal view. (b) Anterior end, detail, dorsal view (framed in (a)). (c) Median region chaetigers, dorsal view (framed in (a)). (d) Posterior region chaetigers, lateral view.(e) Median region,two chaetigers, lateral view.(f) Acicular chaeta, scale covering. Abbreviations: A – acicular chaeta; AR – anterior body region; c – capillary chaeta; CH – chaetiger; gp – genital papilla; ian – integumental annulations; irp – interramal papilla; isb – intersegmental border; MR – median body region; PR – posterior body region.