Boudemos cf. flokati (Dahlgren, Glover, Baco & Smith, 2004)

Cruz-Gómez, Christopher, 2021, A new genus and seven new species of chrysopetalids (Annelida, Chrysopetalidae) from the Tropical Eastern Pacific, Zootaxa 5068 (1), pp. 1-59 : 6

Boudemos cf. flokati

Figs 2 , 12

Type locality of the nominal species: Santa Cruz Basin , California, on whale falls at 1,000–1,700 m ( Dahlgren et al. 2004) .

Material examined. United States: ECOSUR-3006 , 2 spec., San Clemente , California, 2,000 m, on whale falls, coll. EE .

Description. Based on the largest specimen: anterior fragment with 172 segments. TL= 66.7 mm, AT= 4.8 mm. Body damaged, depressed, and slender, anterior segments slightly tapered ( Fig. 2A ). Body whitish to pale yellow. Notochaetae thick spines, translucent, shiny, inserted on lateral notopodial margins. Prostomium reduced, fused with the first segment, also reduced ( Fig. 2B, D ). Lateral antennae reduced inserted on antero-ventral prostomial margin. Median antenna, eyes, and nuchal organs absent. Palps reduced, oval, on posterior margins of the first segment. Mouth fold notched, placed between first and second segment, visible ventrally ( Fig. 2C ). Pharynx not exposed, seen by transparency, stylets robust, short. Additional specimen with pharynx exposed with a ring of marginal papillae ( Fig. 2E ).

Parapodium from segment 69 with notopodium conical, dorsal cirrus short, slightly larger in anterior segments ( Fig. 2F ). Notochaetae: thick spines, inserted on lateral notopodial margin, 5–13 spines, surrounding notaciculum, each spine with internal horizontal striae and margins slightly denticulate ( Fig. 2G ). Notochaetae as long as neuropodium. Largest notochaetae found distally, smallest one in proximal section.

Neuropodium conical, twice as long as notopodium. Ventral cirrostyle short inserted over a small cirrophore. Neurochaetae, one group: Unit 1, falcigers heterogomph. Chaetae with long bidentate shafts, distal tip of blades bidentate, straight and long, 5–6 times longer than wide, slightly concave ( Fig. 2H–I ). Pygidium unknown. Oocyte size: 11.5–33.3 µm (n=6) ( Fig. 2J ).

Habitat. Bathyal (1,000 –1,700 m). Specimen collected on whale falls, same as the nominal species recorded by Dahlgren et al. (2004) and Watson et al. (2016).

Distribution. Only known from San Clemente Basin, California ( Fig. 12 ).

Remarks. This specimen resembles Boudemos flokati ( Dahlgren, Glover, Baco & Smith, 2004) but some differences were detected. The specimen of B. cf. flokati shows very reduced notopodia, while specimens of B. flokati have a larger notopodium, as long as neuropodium ( Dahlgren et al. 2004: 1881, Fig. 5a ). Moreover, the size of the dorsal and ventral cirri on the specimen B. cf. flokati is smaller than those in specimens of B. flokati , being as long as noto- and neuropodia, respectively. The first two anterior segments of B. cf. flokati have a long dorsal cirrus inserted on the margin of the segment, whereas specimens of B. flokati have a short dorsal cirrus inserted submarginally.

Recently, Watson et al. (2016) used the neurochaetae and dorsal and ventral cirri to differentiate two Boudemos species , B. flokati and B. ardabilia (Wiklund, Glover, Johannessen & Dahlgren, 2009) . These same features were revised in the examined specimens; observations suggest that B. flokati and B. cf. flokati are distinct species. However, the latter morphospecies must be revised using well-preserved and complete specimens to define its status.

Figures

FIGURE 2. Boudemos cf. flokati, non-type specimen (ECOSUR-3006). A) Fragmented body, arrow indicates prostomium. B) Drawing of prostomium, dorsal view. C) Drawing of prostomium, ventral view. From a different specimen: D) Prostomium, dorsal view. E) Prostomium, ventral view, arrow indicates pharynx ring. F) Parapodium from segment 69. G) Detail of dorsal spines. H–I) Unit 1. J) Oocyte. Scales: 20 µm (J), 30 µm (GHI), 200 µm (BCF), 4 mm (A).

FIGURE 5. Paleanotus karlyae n. sp., holotype (ECOSUR-258). A) Complete fragmented body. B) Drawing of prostomium, dorsal view. C) Drawing of pygidium, ventral view. D) Parapodium from segment 23. E) Lateral paleae. F) Subunit 1. G) Main palea. H) Apex of G. I–J) Median paleae. K) Unit 1. L) Unit 2. M) Unit 3. N) Unit 4. Scales: 10 µm (KLMN), 20 µm (CEFH), 50 µm (IJ), 100 µm (B), 200 µm (D), 500 µm (A).

FIGURE 12. Previous and new records of chrysopetalids in the Tropical Eastern Pacific. Empty symbols indicate historic records.