Perkinsiana nuriae, Tovar-Hernández & León-González & Hendrickx, 2025

Tovar-Hernández, María Ana, León-González, Jesús Angel De & Hendrickx, Michel E., 2025, Polychaeta collected during the research cruises TALUD aboard the R / V “ El Puma ” in the Mexican Pacific: Sabellidae and Serpulidae, Zootaxa 5663 (1), pp. 1-80 : 52-55

Perkinsiana nuriae sp. nov.

urn:lsid:zoobank.org:act:FE61290D-A33E-4DBC-894D-B5A72A09E03A

( Figs 28–29 , 40L‒P )

Material examined. Type material. Holotype, ICML-EMU-14043: TALUD XV, St. 23, BS, 27º08'11"N 114º32'54"W, 01 August 2012, 681 m. Paratypes (5), ICML-EMU-14044: same data as holotype. Paratypes (5), ICML-EMU-14045: same data as holotype. Paratypes (5), ICML-EMU-14046: same data as holotype. Paratypes, UANL-8274A, 8274B and 8274C: same data as holotype. Additional material. ICML-EMU-14047: TALUD XV, St. 20, BS, 26º30'42"N 113º56'0"W, 01 August, 2012, 540– 560 m, 3 specimens .

Description. Large sabellid with body pale and crown with 3–5 purple bands distributed over outer and lateral radiole margins and adjacent pinnules ( Fig. 28A ). Body flattened dorso-ventrally. Trunk 121 mm long (94–124 mm). Body 4.2 mm wide (3.5–5 mm). Branchial crown as long as trunk length, 62 mm long (47–64 mm) with 13 pairs of radioles (12–17). Thorax with eight chaetigers (8–10). Abdomen with 119 chaetigers (107–140). Radioles not fused by palmate membrane membrane ( Fig. 28C ). Radiolar flanges absent, except for a narrow flange on radiolar tips of ventral radioles ( Fig. 29E ). All radioles with short, digitiform tips ( Fig. 29C–E ). Basal most 5–6 pinnules of dorsal most radioles broader than the superior ones ( Fig. 29A ). Dorsal collar margins U-shaped, fused to faecal groove, forming broad gap ( Fig. 28B ). Dorsal pockets well developed ( Fig. 28B ). Lateral collar margins not covering the bases of radioles ( Fig. 28C ). Ventral lappets small with straight margin, not overlapping ( Fig. 28C ). Anterior peristomial ring exposed dorsally between dorsal pockets ( Fig. 28B ). Dorsal lips as long as first three chaetigers (5.5 mm length), erect, triangular, long, with mid-rib, fused to dorsal pinnular appendages ( Fig. 29A– B ). Ventral lips rounded with ventral parallel lamellae well developed, completely concealed by ventral collar margin ( Fig. 29A–B ). Ventral sacs absent. Interramal eyespots absent ( Fig. 28E ). Ventral shield well developed, all rectangular ( Fig. 29C ). Thoracic tori occupy the entire distance between notopodia and ventral shield margins, contacting shields ( Fig. 28C ). Thoracic fascicles ( Fig. 29H ) with well developed broad notopodial lips ( Fig. 29F ) and superior group of elongate, narrowly hooded chaetae ( Figs 29I , 40M ); inferior group of broadly hooded chaetae ( Figs 29H, I , 40L ), arranged in several rows ( Fig. 29G ). Thoracic uncini with crest surmounted by 9–10 rows of numerous minute teeth, handles 2x length of main fang ( Figs 29L , 40N ), not extending beyond the base of shaft of companion chaetae. Companion chaetae with teardrop-shaped membranes ( Figs 29J , 40N ). Abdominal shields well developed, squared, divided by faecal groove ( Fig. 28D ). Abdominal neurochaetae elongate narrowly-hooded chaetae ( Fig. 29K ). Abdominal uncini with main fang surmounted by 7–8 rows of numerous minute teeth ( Figs 29M , 40P ). Chaetae from posterior abdomen twice longer than those in anterior abdomen. Pygidium rim-shaped, without eyes ( Fig. 29E ). Rigid tubes made of an inner thick layer of solidified amber mucus, hard to tear off, covered with fine sand grains.

Etymology. This species is named after a dear friend and colleague Nuria Méndez Ubach (RIP). She was in charge of the operations related with the collection of sediments, separation of organisms - particularly the Polychaeta - during all TALUD cruises, from 1989 to 2014. Her sympathy, joy and grace were spreading to the entire crew, making cruises fun and light. The species-group name is a noun in the genitive case ( ICZN 1999, Art. 31.1.2).

Remarks. Perkinsiana nuriae sp. nov., constitutes the largest sabellid known in Mexico, reaching up to 17.9 cm in length (paratype UANL-8274C). Perkinsiana nuriae sp. nov., and P. araceliae sp. nov., were found together within the same stations. Perkinsiana nuriae sp. nov., is remarkable larger than P. araceliae sp. nov., and both have the following differences. In P. araceliae sp. nov., the ventral shield of collar is transversally divided in two areas (it is entire in P. nuriae sp. nov.); the ventral lappets of collar are high and rounded in P. araceliae sp. nov. (low with straight margin in P. nuriae sp. nov.); the mid-dorsal collar margins are not fused to faecal groove in P. araceliae sp. nov. (fused to faecal groove in P. nuriae sp. nov.); the branchial crown is as long as 1/2 of the body length in P. araceliae sp. nov. (as long as body length in P. nuriae sp. nov.); in P. araceliae sp. nov., the notopodial lips are not developed (well developed in P. nuriae sp. nov.); and the inferior group of thoracic notochaeta are paleate in P. araceliae sp. nov. (broadly-hooded in P. nuriae sp. nov.).

Among the currently valid species of Perkinsiana , P. nuriae sp. nov. has abdominal chaetae elongate, narrowly hooded (Type C) such as P. araceliae sp. nov., P. brigittae , P. acuminata and P. minuta . In P. nuriae sp. nov., the anterior peristomial ring is partially exposed among dorsal lappets (fully exposed dorso-laterally in P. araceliae sp. nov., and P. brigittae , or not exposed in P. minuta ). In P. acuminata the ventral lappets of collar are overlapped (not overlapped in P. nuriae sp. nov., and all other species).

Abiotic conditions. The specimens of P. nuriae sp. nov., were collected from 540‒681 m deep, under the following environmental conditions. Temperature: 6.44‒8.38°C; salinity: 34.45‒34.51; dissolved oxygen: 0.07‒ 0.15 ml O 2 /l; %MO: 5.15‒5.47; sediments dominated by sand and silt (45.2 to 47.1% each) ( Table 1).

Distribution. West coast of Baja California Sur, Mexico.

Genus Potamethus Chamberlin, 1919

Figures

FIGURE 28. Perkinsiana nuriae sp. nov. A) Body, ventral view, B) thorax, dorsal view, C) same, ventral view, D) midabdomen, E) posterior end. Scale bars: A) squares 2 cm, B–C) 2.5 mm, D–E) 2 mm. A–E: holotype ICML-EMU-14043.

FIGURE 29. Perkinsiana nuriae sp. nov. A) Base of left radiolar lobe and internal lips, B) base of right radiolar lobe and internal lips, C) radiolar tip from dorsal radiole, D) same from lateral radiole, E) same from ventral radiole, F) notopodial lip indicated with asterisk, G) irregular rows of broadly hooded chaetae (inferior group of thoracic notochaetae), H) thoracic chaetiger, I) elongate narrowly hooded and broadly hooded chaetae from thorax, J) thoracic uncini and companion chaetae, K) abdominal chaetiger and detail of narrow hoods, L) thoracic uncinus, M) abdominal uncini. Abbreviations: dl—dorsal lip, vl—ventral lip. Scale bars: A) 1.5 mm, B) 2 mm, C–E) 0.2 mm, F–H) 0.5 mm, I) 25 μm, J, L–M) 40 μm, K) 100 μm. A–B) paratype ICML-EMU-14044), C–M) holotype ICML-EMU-14043.

FIGURE 40. Line drawings of chaetae and uncini. A, G–H, L–M, S) Thoracic chaetae. B, E, J, O, Q, T) Thoracic uncini. C–D, F, K, P, U) Abdominal uncini. I, N, R) Companion chaetae. A–D) Myxicola bruscai sp. nov. E–F) Myxicola dilianae sp. nov. G–K) Perkinsiana araceliae sp. nov. L–P) Perkinsiana nuriae sp. nov. Q–U) Potamethus pepei sp. nov. Scale bar: 30 μm.