Chone tamai, 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 : 19-22

Chone tamai sp. nov.

urn:lsid:zoobank.org:act:069639A0-4E27-4651-8CF9-55DB1BB09865

( Figs 9–10 , 39K–P )

Material examined. Type material. Holotype, ICML-EMU-14020: TALUD X, St. 18, BC, 27º09'06"N 111º46'54"W, 12 February 2007, 1,540 m . Paratypes ICML-EMU-14021A, 14021B and 14021C: same data as holotype; paratypes: ICML-EMU-14022A, 14022B, 14022C, ICML-EMU-14023A, 14023B, and 14023C: same data as holotype.

Description. Trunk cylindrical ( Fig. 9A ), 5 mm long (5–7.5 mm), thorax 1 mm wide (0.7–1 mm), branchial crown 8 mm long excluding radiolar tips (5.8–9 mm), longer than trunk ( Fig. 9A ), with seven pairs of radioles, eight thoracic chaetigers ( Fig. 9A, E–F ), 26 abdominal chaetigers (26–27 chaetigers). Radioles fused by palmate membrane extending up to 3/4 of radiolar length. Radioles with extra long filiform tips, as long as half radiolar length ( Fig. 9A–C ); long pinnules located at last third of crown, twice as long as basal ones; lateral flanges narrow; one pair of long ventral radiolar appendages about half length of branchial crown (different lengths in paratypes) ( Fig. 10G–H ). Dorsal lips triangular with mid-rib ( Fig. 10G–H ); ventral lips triangular, half length of dorsal lips ( Fig. 10G–H ). Origin of crown not exposed all around ( Fig. 9D–F ). Ratio of posterior peristomial ring collar length versus chaetiger 2 length, in lateral view: 2:1. Collar entire ventrally, with rounded margin slightly higher than lateral margins ( Fig. 9E–F ); collar ventral shield horse-shoe shaped, twice wider than long ( Fig. 9F ); collar lateral margins slightly oblique, covering anterior peristomial ring ( Fig. 9E–F ). Anterior peristomial ring not exposed beyond collar. Glandular ridge on chaetiger 2 narrow all around, whitish; ventral shields well developed ( Fig. 9F ). Thoracic notopodia with two groups of chaetae: superior group with elongate, narrowly hooded chaetae ( Fig. 10D ); inferior group with two rows of chaetae: anterior row with bayonet hooded chaetae ( Figs 10A , pointed with arrow, 39M), posterior row with paleate chaetae with long mucros (slightly longer than paleae width) ( Figs 10A , 39K ). Thoracic neuropodia bearing 10–12 acicular uncini with long handles (≈6 times the length of main fang), 4–5 rows of teeth above the main fang, all similar in size ( Fig. 10B ), covering 1/2–3/4 of main fang length, hoods present ( Figs 10B–C , 39L ). Abdominal glandular shields well developed, remarkably swollen ( Fig. 9G ). Abdominal chaetigers with elongate, narrowly hooded chaetae, those from posterior abdominal chaetigers 25% longer than those of anterior abdominal chaetigers ( Figs 10D , 39P ). Anterior abdominal uncini with squared to rectangular breast, handles absent ( Figs 10E , 39N ), dentition as series of nearly uniformly sized teeth, covering 1/2 of main fang on anterior abdominal chaetigers ( Fig. 10E ); last seven abdominal chaetigers progressively narrower towards pygidium, with shallow pre-pygidial depression ( Fig. 9G ); uncini from posterior abdominal tori similar in shape from those on anterior abdomen, but smaller and with dentition covering 3/4 of main fang length ( Figs 10F , 39O ). Pygidium rounded, pygidial eyes and pygidial cirrus both absent ( Fig. 9G ).

Methyl green staining pattern. Ventral epithelium stains nearly uniformly, except for distinct inter-segmental grooves and glandular ridge on chaetiger 2 that remains unstained ( Fig. 9D–F ). Mid-dorsal collar margins unstained ( Fig. 9D ). Glandular shields stained uniformly.

Etymology. This species is named after our late colleague Sergio Rendón Rodríguez “Tama” (RIP), a dear friend who provided a very important support during the TALUD cruises and many field-work activities, particularly in the general academic life of the first author. The specific epithet is derived from his nickname, “Tama”, and is a noun in apposition.

Remarks. The radiolar crown of C. tamai sp. nov., is remarkably long, longer than the body length. The radiolar tips are also distinctly long, half of radiolar length; radiolar tips of similar length of are found in specimens of C. rosea Hartmann-Schröder, 1965 ( Tovar-Hernández 2007), but in these latter the collar ventral shield is like a pair of glasses-shaped (horseshoe-shaped in members of C. tamai sp. nov.).

Except for C. mollis , in which specimens the anterior peristomial ring is exposed between collar ventral margins, in the other North American specimens of Chone that lobe is covered by collar margins. In members of C. aurantiaca ( Johnson, 1901) , C. gracilis Moore, 1906 , C. magna ( Moore, 1923) , C. picta ( Verrill, 1885) , and C. tamai sp. nov., the collar ventral shield is horse-shoe shaped, but in specimens of C. aurantiaca , C. magna and C. picta it is as long as wide, whereas in representatives of C. gracilis and C. tamai sp. nov., it is twice wider than long.

Chone gracilis was originally described from Alaska, from 4 to 56 m deep ( Moore, 1906), and previously reported by Méndez (2006, 2013) in samples of the TALUD IV, VI–VII cruises; those records, however, are questionable, requiring re-examination of the specimens. Anyway, in individuals of C. gracilis , the radiolar tips are short and broad lateral flanges run along radioles versus radiolar tips extremely long and radioles without flanges in members of C. tamai sp. nov.

Abiotic conditions. The specimens of C. tamai sp. nov., were collected from 1,540 m deep, under the following environmental conditions. Temperature: 3.17°C; salinity: 34.59; dissolved oxygen: 0.51 ml O 2 /l. No other environmental data available ( Table 1).

Distribution. Central Gulf of California, Mexico.

Genus Claviramus Fitzhugh, 2002

Figures

FIGURE 9. Chone tamai sp. nov. A) Body, lateral view, B–C) radiolar tips, D) collar and thoracic segments, dorsal view, E) thorax, lateral view, F) same, ventrolateral view, G) posterior end, lateral view.Abbreviations: gr2–glandular ridge on chaetiger 2, vsc–ventral shield of collar. Scale bars:A) 2.2 mm, B–C) 0.8 mm, D–G) 0.4 mm.A–G: holotype ICML-EMU-14020, stained with methyl green.

FIGURE 10. Chone tamai sp. nov. A) Thoracic paleate chaetae and bayonet chaetae, the latter indicate with arrow, B) thoracic uncini and details of dentition in inferior boxes, C) heads of thoracic uncini, D) thoracic elongate narrowly hooded chaeta, E) torus from anterior abdomen and detail of dentition in left box, F) torus from posterior abdomen with detail of dentition in right box, G) left base of branchial crown and associated structures, H) dorsal and ventral lips, A–D) Chaetiger 3, E) Chaetiger 12, F) Chaetiger 20. Abbreviations: d—dorsal, dl—dorsal lip, v—ventral, vl—ventral lip, vra—ventral radiolar appendage. Scale bars: A, D) µm, B) 50 µm, C) 40 µm, E–F) 25 µm, G–H) 0.5 mm. A–F: holotype ICML-EMU-14020, G–H: paratype ICML- EMU-14022D.

FIGURE 39. Line drawings of chaetae and uncini. A–B, F–G, K, Q, T–U, X) Thoracic chaetae. C, H, L, R, W, Z) Thoracic uncini. D, I, N–O, S, V, Z1) Abdominal uncini. E) Companion chaeta. J) Abdominal chaeta. M, Y) Bayonet chaetae. A–E) Bispira beatrizae sp. nov. F–J) Bispira nunezi sp. nov. K–P) Chone tamai sp. nov. Q–S) Claviramus villalobosi sp. nov. T–W) Euchone nmercedesae sp. nov. X–Z1) Jasmineira agustinae sp. nov. Scale bar: 30 μm.