Pollentia perezi, Capa & Pons & Jaume, 2022

Capa, María, Pons, Joan & Jaume, Damià, 2022, Discovery of a new scale worm (Annelida: Polynoidae) with presumed deep-sea affinities from an anchialine cave in the Balearic Islands (western Mediterranean), Zoological Journal of the Linnean Society 196, pp. 479-502 : 490-498

publication ID	https://doi.org/ 10.1093/zoolinnean/zlac046
publication LSID	lsid:zoobank.org:pub:551AB3FF-DB0B-425D-A3DA-C64537F92876
DOI	https://doi.org/10.5281/zenodo.7036979
persistent identifier	https://treatment.plazi.org/id/417CF579-FFC2-FF97-FC6D-FB00FD15FD29
treatment provided by	Plazi
scientific name	Pollentia perezi
status	sp. nov.

Treatment

POLLENTIA PEREZI View in CoL SP. NOV.

( FIGS 3 View Figure 3 , 4 View Figure 4 , 5 View Figure 5 , 6 View Figure 6 )

Zoobank registration: urn: lsid: zoobank. org:act: DF4ED4DA-818A-49E0-9996-AFDB2FAD73FA

Type material: Cova des Bastons (also known as Cave C-11), Alcúdia , Mallorca , Balearic Islands, 39°53 ′ 03.1 ″ N, 3°11 ′ 45.1 ″ E. GoogleMaps Holotype: specimen preserved in ethanol; collected by J. Pérez at 17 m depth on bare rock with some patches of calcareous silt, 11 March 2020 ( MNCN 16.01 View Materials /18955) (Supporting Information Video S 15). GoogleMaps Paratype: specimen preserved in ethanol, divided into two fragments, same collector, locality, substratum and depth, 30 June 2019 ( MNCN 16.01 View Materials /18956) GoogleMaps .

Additional material examined: specimen preserved in RNAlater, same collector, locality, substratum and depth as holotype (deposited at IMEDEA collection) (see Supporting Information Video S16).

Description of holotype: Body length 18 mm, maximum width 6 mm at midbody segments (including parapodia;

*A pair of large eyes was described in Bathymoorea renotubulata by Pettibone (1967) and in Bathymoorea lucasi by Bonifácio & Menot (2019), but these are considered herein as potential misinterpretations.

excluding chaetae). Body 27-segmented, flattened dorsoventrally, anterior margin blunt, tapering posteriorly ( Fig. 4 View Figure 4 ). Specimen pale when alive, with some tiny brown spots scattered over dorsum, forming narrow segmental transverse bands near base of notopodia and elytrophores, and on ventrum near base of parapodia ( Figs 4 View Figure 4 , 5C, D View Figure 5 ). Head intensely coloured dark red (pigmented brain visible through translucent epithelium; Figs 4A, C, D View Figure 4 , 5A–C View Figure 5 ).

Prostomium bilobed, wider than long, with lobes extending anteriorly to form ceratophores of lateral antennae ( Figs 5A–C View Figure 5 , 6A View Figure 6 ). Median antenna inserted proximal to anterior margin of prostomium; ceratophore bulbous, longer than wide ( Figs 5B View Figure 5 , 6A View Figure 6 ); style tapering, reaching segment 3 ( Fig. 5B View Figure 5 ). Lateral antennae with styles also tapering, shorter than median antenna ( Fig. 5A, B View Figure 5 ). Median and lateral antennae with scattered long papillae on styles ( Fig. 6A–C View Figure 6 ). Palps stout and longer than antennae, reaching segment 6, heavily wrinkled and covered with minute oval papillae ( Figs 4D View Figure 4 , 5A View Figure 5 , 6B, E, F View Figure 6 ). Eyes absent ( Figs 4A, C, D View Figure 4 , 5A–C View Figure 5 ).

Tentacular segment (segment 1) with short lobe inserted lateral to prostomium; aciculae not penetrating epidermis; bundle of about six notochaetae ( Figs 5A, C View Figure 5 , 6B, H View Figure 6 ). One pair of tentacular cirri present on each side of segment; tentaculophores longer than wide, ventral larger than dorsal ( Fig. 6H View Figure 6 ); tentacular styles tapering, dorsal and ventral of similar length, reaching segment 5 ( Fig. 4D View Figure 4 ); styles covered with elongated papillae ( Fig. 6I View Figure 6 ). Mouth lips strongly developed, protruding when pharynx not everted ( Fig. 5E View Figure 5 ). Facial tubercle absent, but slightly inflated longitudinal ridge present on upper lip ( Fig. 6B, G View Figure 6 ). Pharynx not everted in holotype and dissected in paratype, with ring of elongate, blunt subconical papillae of similar size ( Fig. 6M View Figure 6 , not counted) and two pairs of jaws with smooth margins ( Fig. 6N View Figure 6 ). Segment 2 devoid of nuchal pads and folds ( Fig. 6A–C View Figure 6 ).

Thirteen pairs of elytra, one on each of segments 2, 4, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23 and 26. Elytra large, covering dorsum, lacking papillae, each with microtubercles along external edge ( Fig. 7A–D View Figure 7 ) and on dorsal surface of posterior third ( Fig. 7E View Figure 7 ). Surface of anterior part of elytra smooth ( Fig. 7F View Figure 7 ). Dorsal cirri present on non-elytrigerous segments from segment 3 onwards; cirrophores cylindrical ( Fig. 8A–C View Figure 8 ); styles elongated and tapering, largely surpassing length of parapodia and chaetae, of similar length ( Figs 4C, D View Figure 4 , 8F, H View Figure 8 ), with some long, scattered papillae. Dorsal tubercles inconspicuous, low and conical, more evident on elytrigerous segments ( Fig. 8B View Figure 8 ).

Segment 2 with subbirramous parapodia, enlarged conical acicular lobe, and noto- and neurochaetae ( Fig. 6H View Figure 6 ). Ventral cirri of segment 2 (buccal cirri) inserted basally, with large cirrophores; stylode longer than subsequent counterparts, with elongated papillae ( Fig. 6I View Figure 6 ). Rest of segments also with subbiramous parapodia and with thin and long, tapering acicular lobes projecting on both rami; notoacicular lobe shorter than neuroacicular and hidden under the inferior notochaetae ( Fig. 8B View Figure 8 ); neuroacicular lobe conspicuous ( Fig. 8E, G View Figure 8 ); noto- and neuroaciculae not penetrating into lobes ( Fig. 8D, E, G View Figure 8 ). Notopodia rounded, one-third the length of neuropodium; latter subconical, with further indistinct lobes other than the acicular projections ( Fig. 8E–G View Figure 8 ). Ventral cirri inserted at midlength of neuropodia ( Fig. 8E–G View Figure 8 ), with short ceratophore and smooth, tapering style reaching about midlength of parapodia ( Fig. 8A, B View Figure 8 ). Styles of ventral cirri of segments 2 and 3 longer than subsequent counterparts, with elongated papillae ( Fig. 8H–K View Figure 8 ); styles from segment 4 onwards all similar in length, without papillae ( Fig. 8I, L View Figure 8 ). Semispherical papillae ventrally at base of parapodia ( Fig. 8M View Figure 8 ).

Notochaetae of all segments similar, of only one type (~20 on parapodia of anterior and midbody segments), stouter than neurochaetae, arranged in dense, radiating tufts ( Fig. 9A, B View Figure 9 ). Notochaetae smooth and straight basally, slightly curved and tapering, with welldeveloped spinous rows along convex margin ( Fig. 9 View Figure 9 A-C) and pointed, conical tips. Two types of neurochaetae (30–40 on parapodia of midbody segments) arranged in transverse rows. Superior neurochaetae flattened, with one side bearing faintly spinous rows ( Fig. 9 View Figure 9 D-F); tip tridentate, with a slightly hooked tooth and two additional smaller teeth ( Fig. 9F View Figure 9 ). Inferior neurochaetae shorter and thinner than superior counterparts, each with a cylindrical proximal half and a broader, lanceolate and flattened distal half; one of sides with well-developed spinous rows reaching the tip ( Fig. 9G, H View Figure 9 ).

Unpigmented nephridial papillae present at base of parapodia from segment 5 onwards, small and bulbous. Nephridial papillae from segment 8 onwards connect to posterior half of body through long ducts, visible under light microscopy. Pygidium small, rounded, not enclosed by last segment ( Fig. 5G View Figure 5 ), with anus placed terminally. Pair of anal cirri longer than dorsal cirri.

segment number. Intraspecific variability: Paratype, with 26 segments, measuring 18 mm long (including tentacular segment) and maximum width 6 mm at midbody segments (including parapodia; excluding chaetae). Pigmentation pattern similar to holotype ( Figs 4 View Figure 4 , 5 View Figure 5 ). Specimen with most elytra detached after preservation. Most other morphological features as for holotype ( Figs 4 View Figure 4 , 5 View Figure 5 ).

Ecology: The first specimen was found and collected after scuba divers accidentally dropped an object on the sandy bottom of the cave and the animal escaped from danger, ascending to the water column (Supporting Information Videos S 15, S16). The other two specimens were each found in subsequent visits to the cave, crawling on the sediment. In all cases, specimens were found at 17 m depth in full-strength marine water (38 PSU) at 19 °C ( Fig. 1C View Figure 1 ).

Etymology: Species named after the Mallorcan cave diver Joan Pérez, who discovered the species and kindly offered the material to us for study.

Remarks: The new Mallorcan cave polynoid bears an overall resemblance to members of the subfamily Eulagiscinae , in that they all share the terminal or subterminal insertion of the lateral antennae on anterior extensions of the prostomium, and the parapodia display notopodia shorter than neuropodia, unlike members of other related subfamilies ( Wehe, 2006; Bonifácio & Menot, 2019). However, there are some morphological features that are unique among the current members of Eulagiscinae . The number of pairs of elytra, 13 in Pollentia perezi , is the lowest reported in the subfamily ( Table 5 View Table 5 ; Pettibone, 1967, 1997; Bonifácio & Menot, 2019). In addition, the chaetal morphology and arrangement in Pollentia perezi are unique amongst members of Eulagiscinae and even Polynoidae . Thus, body segments from segment 2 onwards bear only stout notochaetae with spinous rows and pointed tips, similar to those described in Eulagisca and Bathymoorea lucasi ( Table 5 View Table 5 ). Neurochaetae are of two types: the superior flattened, spinous and with a tridentate tip, whereas the inferior are shorter and thinner, lanceolate, spinous and tapering ( Table 5 View Table 5 ). Furthermore, the superior neurochaetae are unique amongst those of Polynoidae , because they have a tridentate tip, with a main larger tooth and two additional smaller teeth. The inferior neurochaetae resemble the pectinate forms described in members of Eulepethidae (Pettibone, 1969) .

Both Eulagisca and Paraeulagisca are oculate (each bearing two pairs of eyes). The two nominal species of deep-sea Bathymoorea were described as bearing a pair of large eyes, but we consider this to be a misinterpretation of the brain occupying most of the prostomial lobes, as in the anchialine Pollentia perezi , which is eyeless. Like its deep-sea relatives, Pollentia perezi lacks body pigmentation except for a few scattered spots distributed as described above.