Bispira nunezi, 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 : 13-15

Bispira nunezi sp. nov.

urn:lsid:zoobank.org:act:9D2AE88C-C40C-4D90-A145-C80D68EA0906

( Figs 5–6 , 39F–J )

Material examined. Type material. Holotype, ICML-EMU-14015: TALUD VIII, St. 11, BS, 24º54'24"N 110º25'36"W, 17 April 2005, 920 m, attached to a bryozoan mat.

Description. Body flattened dorsoventrally. Trunk 14 mm long, thorax 1.2 mm wide; branchial crown 10 mm long, shorter than body length, with nine pairs of radioles. Thorax with eight chaetigers, abdomen with +42 chaetigers. Radiolar lobes slightly involuted ventrally, dorsal basal flanges absent ( Fig. 5A ). Radioles fused by palmate membrane, radioles with flanges and 10 paired serrations along radiolar length, more pronounced distalwards ( Fig. 5D–F ), radiolar eyes absent. Radiolar tips of medium length, occupying space of 13 pinnules width, filiform ( Fig. 5D, G ). Dorsal lips elongated, erect, finger-like, mid-rib radiolar appendages not discernible, 2.5 mm long, as long as thorax; ventral lips small, rounded, poorly developed. Ventral sacs about 1/2 length of collar ventrally, out of crown ( Fig. 5B ). One pair of short, undeveloped ventral radioles (not longer than three thoracic chaetigers). Collar lateral margins diagonal, not covering junction of crown and thorax ( Fig. 5A, C ); dorsal collar margins not fused to faecal groove, separated dorsally by wide gap, anterior peristomial ring exposed dorsally, between collar margins ( Fig. 5A ); ventral collar margin incised, forming two small subtriangular, not overlapped ventral lappets ( Fig. 5B ). First segment slightly longer than following thoracic chaetigers, in ventral view; collar ventral shield with anterior margin distinct, W-shaped, following thoracic shields rectangular; thoracic tori all separated from ventral shields ( Fig. 5B ). Interramal eyespots absent throughout. Wide faecal groove on thorax ( Fig. 5A ), thin and narrow on abdomen, ventrally. Collar chaetae with long broadly hooded chaetae, conspicuous limbation thin, on both sides of the axis; chaetae of following thoracic segments in two groups, superior chaetae long, elongate narrowly hooded ( Fig. 39F ), inferior chaetae in two tiers of shorter spine-like chaetae with hood as wide as shaft ( Figs 6A–B , 39G ). Neuropodia with progressively smaller ventralwards uncini; uncini with around 8–10 rows of teeth above main fang, all similar in size, occupying half of main fang length; breast well-developed and short handled ( Fig. 39H ), as long as distance between main fang and breast, slightly longer in ventralmost uncini; companion chaetae with distal teardrop shaped membranes ( Fig. 6C, F ). Abdominal neurochaetae arranged in C-shape, on elevated neuropodia; anterior abdominal neurochaetae spine-like on both anterior and posterior rows; posterior abdominal neurochaetae spine-like on anterior rows, and modified, elongate, narrowly hooded on posterior rows ( Figs 6D–E , 39J ). Abdominal uncini similar to thoracic ones ( Fig. 6G ), with around eight rows of teeth above main fang and handle similar as long as distance between main fang and breast ( Fig. 39I ). Pygidium blunt, without pygidial lobes or eyes. Tube made of an inner thick layer of solidified amber mucus, difficult to tear off.

Etymology. The species is named after the late Arturo Núñez Pasten (RIP), a very friendly, caring and collaborative colleague who participated in many TALUD cruises. The species-group name is a noun in the genitive case ( ICZN 1999, Art. 31.1.2).

Remarks. Within the genus Bispira only two species are known to have radioles with serrations: B. serrata Capa, 2007 (described from Queensland, Australia) and B. nunezi sp. nov. In the holotype and only known specimen of B. nunezi sp. nov., radiolar serrations are found through all the radiolar length, separated from each one by wide gap, whereas in members of B. serrata serrations are only present distally, closer to one another. In addition, members of B. serrata have paired compound eyes, which are absent in the holotype of B. nunezi sp. nov.

The specimens of B. nunezi sp. nov., and B. beatrizae sp. nov., were found in the same sample. Both species, however, differ in the following aspects: 1. the holotype of B. nunezi sp. nov., has ventral sacs fully exposed above ventral lappets, as long as 1/2 length of collar ventrally (short, as long as 1/4 the length of collar ventrally and mostly covered by ventral lappets in members of B. beatrizae sp. nov.). Radioles of Bispira nunezi sp. nov., have wide radiolar flanges (flanges absent in Bispira beatrizae sp. nov.); 2. the holotype of B. nunezi sp. nov., does not have abdominal interramal eyespots (present on posterior abdominal segments of members of B. beatrizae sp. nov.); and 3. the anterior peristomial ring is exposed laterally between collar margins in the holotype of B. nunezi sp. nov., whereas it is covered by collar in members of Bispira beatrizae sp. nov. only exposed dorsally.

Abiotic conditions. The specimen of B. nunezi sp. nov., was collected from 920 m deep, under the following environmental conditions. Temperature: 5.00°C; salinity: 34.50; dissolved oxygen: 0.20 ml O 2 /l; %MO: 6.03; sediments dominated by mixed mud (71.1%) ( Table 1).

Distribution. Southern Gulf of California, Mexico.

Genus Branchiomma Kölliker, 1859

Figures

FIGURE 5. Bispira nunezi sp. nov. A) Thorax, dorsal view, B) same, ventral view, C) same, lateral view, D) branchial crown and zoom of serrations, E) radiolar serrations at first basal quarter of radiole, F) radiolar serrations at mid-radiolar length, G) radiolar tip.Abbreviations: apr–anterior peristomial ring, vs–ventral sac, vsc–ventral shield of collar. Scale bars:A) 1 mm, B–C) 0.4 mm, D) 2 mm, E–G) 0.1 mm. A–D) Stained with methyl green.A–G: holotype ICML-EMU-14015. White arrow in B shows the undeveloped ventral radiole, arrows in D–G points to radiolar serrations.

FIGURE 6. Bispira nunezi sp. nov. A) Thoracic chaetiger, B) inferior broadly hooded chaetae, C) thoracic uncini and companion chaetae, D) chaetiger from posterior abdomen, E) abdominal elongate, narrowly hooded chaetae, F) thoracic uncinus, G) abdominal uncinus. Scale bars: A) 30 µm, B) 15 µm, C) 5 µm, D) 100 µm, E) 50 µm, F–G) 2.5 µm. A–G: holotype ICML- EMU-14015.

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.