Claviramus villalobosi, 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 : 22-27

Claviramus villalobosi sp. nov.

urn:lsid:zoobank.org:act:C1B0D1A5-9408-4FA4-B4D8-450D99744B22

( Figs 11–13 , 39Q–S )

Material examined. Type material. Holotype, ICML-EMU-14024: TALUD XIV, St. 13, BS, 28º31'56"N 112º18'12"W, 08 April 2011, 180‒ 182 m. Paratypes, ICML-EMU-14025A and 14025B: same data as holotype. Paratype, ICML-EMU-14026: same data as holotype.

Description. Body cream, flattened dorso-ventrally ( Fig. 11A ). Trunk 4 mm long, thorax 0.7 mm wide (5–5.4 mm long, 0.8 mm wide), longer than abdomen; branchial crown 5 mm long, longer than body in holotype, which radioles are fully extended ( Fig. 11A ) (3–4.4 mm radioles curled). Crown with nine pairs of radioles (9–10 pairs), thorax with eight chaetigers, abdomen with 17 chaetigers (17 chaetigers). Radiolar lobes semi-circular; ventral radiolar appendages present, of different lengths, 1/4–1/2 length of crown; palmate membrane absent; radiolar flanges only present at radiolar tips, as foliaceous curled flanges, heart-shaped, oval or ditigiform ( Figs 11F , 12A– B ); some distal flanges without mid-length cleft (entire in oval and digitiform tips), heart-shaped tips with short to medium mid-length cleft; radiolar tips without distal filament; radiolar eyes absent. Dorsal lips triangular with radiolar appendages, ventral lips short, rounded ( Fig. 13B ). Anterior peristomial ring with ventral margin as broadly triangular lobe, not extending beyond collar margins ( Fig. 13D ); ventral margin of posterior peristomial ring collar with shallow mid-ventral incision, not forming lappets ( Figs 11C , 13D ); dorso-lateral collar margins fused to faecal groove ( Fig. 11B ), dorsal pockets present, with two pairs of large vascular coils, visible by transparency through body wall ( Fig. 11B ); lateral collar margins slightly higher than ventral and dorsal margins ( Fig. 11A–C ). Collar with a whitish triangular pad dorsally. Collar shield divided transversally into two pads, anterior pad curved, almost X-shaped posterior pad; ventral shield of chaetiger 2 also divided in two transversal sections, similar to previous shield, but with straight anterior pad; following shields entire, rectangular; abdominal shields as paired squares, separated by faecal groove ( Fig. 11C–D ). Glandular ridge on chaetiger 2 present, whitish and equally narrow all around ( Fig. 11B–C ). Chaetiger 1 with rows of narrowly hooded chaetae ( Fig. 13C ); from chaetiger 2, notochaetal superior group with six narrowly hooded chaetae and two inferior rows of eight paleate chaetae, with long mucros, each ( Figs 12C–D , 39Q ). Thoracic tori not contacting ventral shields ( Fig. 11C ), neuropodial uncini acicular ( Figs 12F , 39R ), each torus with nine uncini with main fang surmounted by 5–6 rows of very small teeth, occupying 1/2 of main fang length, hood absent ( Fig. 12F ); tip of main fang entire, in frontal view, breast as narrow swelling, and distinctly long handles ( Fig. 12F ). Abdomen shorter than thorax ( Fig. 11A ). Abdominal neuropodial fascicles with 1–2 transverse rows of elongate, narrowly hooded chaetae ( Fig. 11E ); abdominal notopodia with avicular uncini with main fang surmounted by 3–4 rows of small, equally sized teeth, occupying 1/2 of main fang length, long neck, well developed breast and short handle, as long as main fang length ( Figs 11G–H , 39S ). Pygidium rounded, without eyespots or cirrus ( Fig. 11D–E ). Tubes made of fine sand. Paratypes ICML-EMU-14025A and ICML- EMU-14026C: females with oocytes floating free in coelom of thoracic and anterior abdominal chaetigers.

Methyl green staining pattern. Ventral shields along the body fully stained ( Fig. 13A, D ). Collar with triangular pad dark blue stained, dorsally ( Fig. 11B ), ventral shield of collar X-shaped fully stained ( Fig. 13A, D ). Remaining thoracic chaetigers unstained dorsally ( Fig. 11B ). Laterally, neuropodia covered on glandular spots throughout, dark blue stained ( Fig. 11A, D–E ). Pygidium blue stained ( Fig. 11D–E ).

Etymology. The species name is dedicated to Tulio F. Villalobos-Guerrero, an enthusiast and hardworking colleague, active participant in the TALUD XIV cruise, during which these fanworms were collected. The species-group name is a noun in the genitive case ( ICZN 1999, Art. 31.1.2).

Remarks. Claviramus Fitzhugh, 2002 is a group of six species currently including C. villalobosi sp. nov., described herein, from the northern Gulf of California. Claviramus candelus ( Grube, 1863) , the type species of the genus, was originally described as Sabella candela Grube, 1863 , from the Northern Adriatic Sea. Langerhans (1884) transferred the species to Jasmineira Langerhans, 1880 , and described a new species, J. oculata Langerhans, 1884 , from Madeira. Cochrane (2000) redescribed the species assigned to Jasmineira in detail, based on the type material and additional specimens, and Fitzhugh established the genus Claviramus , based on the presence of radiolar tips with foliaceous flanges ( Fitzhugh 2002: fig. 43), and transferred J. candelus and J. oculata to Claviramus . The third species, C. grubei Fitzhugh, 2002 , was described from Thailand, Andaman Sea. Claviramus kyushuensis Nishi, Tanaka & Tovar-Hernández, 2019 was described from Japan. The fifth species was described from Indonesia, C. olivager Tovar-Hernández, ten Hove & García-Garza, 2020 . The diagnosis of the genus was emended by Tovar-Hernández et al. (2020), in order to include the presences of collar vascular coils, thoracic uncini with bifid main fangs, and abdominal ventral shields.

A peculiarity of species recognized in Claviramus is the presence of a thorax longer than the abdomen, except for C. grubei Fitzhugh, 2002 , but this feature requires a re-examination in that species. In type material of C. villalobosi sp. nov., the branchial crown is longer than the trunk whereas in representatives of all the other species in the genus it is shorter than the trunk, and there is, in C. villalobosi sp. nov., a glandular pad in the dorsal side of the collar, a unique, distinctive feature for specimens of the genus.

Abdominal glandular shields are present in specimens of C. villalobosi sp. nov., C. candelus , C. kyushuensis , and C. olivager , whereas members of C. grubei and C. oculatus lack abdominal shields. Individuals of C. villalobosi sp. nov., mostly resemble specimens of C. olivager , as both share the presence of collar ventral shield transversely divided into two sections, a narrow glandular bar anteriorly, and an almost X-shaped shield posteriorly. However, in members of C. villalobosi sp. nov., a glandular ridge on chaetiger 2 is present whereas it is absent in representatives of C. olivager ; and radiolar tips present mid-ventral incisions extending for half of flange length in individuals of C. olivager , whereas members of C. villalobosi sp. nov., have mid-ventral incisions of variable length, from short to medium incisions, to entire margins (not incised).

Abiotic conditions. The specimens of C. villalobosi sp. nov., were collected from 180‒182 m deep, under the following environmental conditions. Temperature: 12.5°C; salinity: 34.94; dissolved oxygen: 1.25 ml O 2 /l; %MO: 2.47; sediments dominated by sand (69.1%) ( Table 1).

Distribution. Northern Gulf of California, Mexico.

Genus Euchone Malmgren, 1866

Figures

FIGURE 11. Claviramus villalobosi sp. nov. A) Body, lateral view, B–C) base of crown and anterior thoracic segments, dorsal and ventral view, respectively, D–E) posterior thorax and abdomen, ventrolateral and dorsolateral views, respectively, F) distal half of branchial crown. Scale bars: A) 2 mm, B–C) 0.7 mm, D–F) 1 mm. A–F: holotype ICML-EMU-14024, stained with methyl green.

FIGURE 12. Claviramus villalobosi sp. nov. A–B) Radiolar tips, C) thoracic chaetiger, D) paleate chaetae and elongate narrowly hooded chaeta, E) abdominal chaetiger, F) thoracic uncini, G–H) abdominal uncini. Scale bars: A–B) 0.5 mm, C, E) 100 µm, D, G–H) 10 µm, F) 20 µm. A–B: paratype, ICML-EMU-14026C. C–H: holotype ICML-EMU-14024.

FIGURE 13. Claviramus villalobosi sp. nov. A, D) Ventral shield of collar and first thoracic chaetigers, B) dorsal and ventral lips, C) collar chaetiger with elongated, narrowly hooded chaetae. Scale bars: A, D) 0.7 mm, B) 0.5 mm, C) 50 μm. A–D: paratype, ICML-EMU-14025-A.

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.