Treptopale watsonae ( Cruz-Gómez & Bastida-Zavala, 2018 ), Cruz-Gómez, 2021

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 : 14-17

Treptopale watsonae ( Cruz-Gómez & Bastida-Zavala, 2018) n. comb.

Figs 7 , 12

LSID: urn:lsid:zoobank.org:act:9A3C9FD2-2DAC-4EC8-BFBF-ACEBD3F97091

Arichlidon watsonae Cruz-Gómez & Bastida-Zavala, 2018: 62–65 , Figs 2A–L , 8 , 14A–D , 15A . — Cruz-Gómez et al. 2021: 179, Fig. 4L (key of chrysopetalids from Tropical America).

Type locality: Coral Beach , Ixtapa Island, Guerrero, México, on dead coral at 1.5 m ( Cruz-Gómez & Bastida-Zavala 2018) .

Material examined. Five specimens. Baja California Sur: ECOSUR-3218 , La Marina, La Paz Bay , 24º09.319´N, 110º19.630´W, on pier pilings, 50 cm, 1 spec. / 250 cm 2, August 14, 2011, coll. TVG & ADL . Guerrero: UMAR-Poly 935, 3 spec. Coral Beach, 17º40´36”N, 101º39´22”W, Ixtapa Island , on dead coral, 1.5 m, September 19, 2007, coll. SGM et al. Oaxaca: UMAR-Poly 936, Corralero Lagoon, 16º14´11”N, 98º11´36”W, on sand, June 18, 2009, coll. JMM & JRC .

Description. Based on the best-preserved specimen (UMAR-Poly 935): complete with 82 segments. TL= 5.3 mm, TW= 0.7 mm. Body long, broad, tapered posteriorly ( Fig. 7A ). Body pale orange to bright yellow. Paleae fan translucent, imbricated dorsally.

Prostomium visible among the first five segments. Lateral antennae short, inserted on the antero-ventral prostomial margin, median antenna about the same length of lateral ones. Eyes red-violet, two pairs, fused. Nuchal organ, large, not covering the prostomium ( Fig. 7B ). Palps short, oval, visible in ventral view. Mouth fold wide, placed between segment 2 and 3. Pharynx eversible, not exposed, stylets slender.

Parapodium from segment 22, notochaetae in three main groups ( Fig. 7E ). Notochaetae: lateral group inserted below notaciculum, 4–6 paleae, slender and symmetrical, with 3–6 internal ribs ( Fig. 7F ); subunit 1, 1 palea, broad and symmetrical, with 8–12 internal ribs ( Fig. 7F , arrow). Main group, 6–7 paleae, broad and symmetrical, with 15–17 (19) internal ribs and 3–5 raised ribs ( Fig. 7G ). Median group, 2–3 paleae, curved and asymmetrical, with (7) 8–11, and 1–2 raised ribs ( Fig. 7H–I ). All paleal groups are covered with scattered granules.

Neuropodium conical, slightly longer than notopodium. Neurochaetae: unit 1, 3–4 superior spinigers, blades curved and long, 15 times longer than wide ( Fig. 7J ). Unit 2, 4–6 falcigers, blades curved and medium-sized, 3–4 times longer than wide ( Fig. 7K ). Unit 3, 4–5 falcigers, blades curved and medium-sized, 3–4 times longer than wide ( Fig. 7L ). Unit 4, 2–4 falcigers, blades curved and short, 5 times longer than wide ( Fig. 7M ). Pygidium quadrate, with two anal cirri ( Fig. 7C ). Oocyte size: 8.8–10.9 µm (n=5) ( Fig. 7D ).

Habitat. Intertidal to subtidal (1–4 m). Specimens of this species were collected mostly on dead coral, rocks, algae, as epibiont of bivalves and sponges ( Cruz-Gómez & Bastida-Zavala 2018), as well as a member of the fouling community.

Distribution. From La Paz Bay, Baja California Sur to La Tijera, Oaxaca ( Fig. 12 ).

Remarks. Perkins (1985) and Watson (2010; 2015) clarified the differences among Treptopale and similar genera, such as Paleanotus and Arichlidon . This morphological proximity led to a mistake by the author in a previous survey. Here, A. watsonae is recognized and proposed as member of Treptopale under the new combination T. watsonae n. comb.

Treptopale watsonae n. comb. resembles T. rudolphi Perkins, 1985 from Florida Keys, in having broad main paleae, short palps, and neurochaetal blades long. However, specimens T. watsonae n. comb. have a tapered, short body (<7 mm), while specimens of T. rudolphi have an elongated, long body (> 7 mm) ( Perkins 1985; Watson 2010; CCG Pers. Obs.). Furthermore, T. watsonae n. comb. has a distinct large nuchal organ, while T. rudolphi has a barely perceptible nuchal organ ( Perkins 1985: 906, Fig. 26A, C ). Regarding notochaetae, T. watsonae n. comb. has subunit 1 broad and symmetrical, and all groups of notochaetae very ornamented with granules, while T. rudolphi has subunit 1 slender and asymmetrical, and the surface of notochaetae rather smooth ( Perkins 1985: 906, Fig. 27A–D; Watson 2010: 41, Fig. 1A–D ). This is the first record of Treptopale from the TEP.

Figures

FIGURE 1. Study area. The Tropical Eastern Pacific, and southmost part of Warm Temperate Northern Pacific, with the names of the main localities.

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 4. Paleanotus macrophthalmum (Hartmann-Schröder, 1959), non-type specimen (UMAR-Poly-OH-020). A) Complete fragmented body. B) Parapodium from segment 10. C) Lateral paleae. D) Subunit 1. E) Main palea. F–G) Median paleae. H) Unit 1. I) Unit 2. J) Unit 3. K) Unit 4. L) Drawing of pygidium, ventral view. Scales: 10 µm (HIJK), 20 µm (CDEFGL), 100 µm (B), 500 µm (A).

FIGURE 7. Treptopale watsonae (Cruz-Gómez & Bastida-Zavala 2018), non-type specimen (UMAR-Poly 935). A) Complete fragmented body, arrow indicates anterior end. B) Drawing of prostomium, dorsal view. C) Drawing of pygidium, ventral view. D) Oocyte. E) Parapodium from segment 22. F) Lateral paleae, arrow indicates subunit 1. G) Main palea. H–I) Median paleae. J) Unit 1. K) Unit 2. L) Unit 3. M) Unit 4. Scales: 5 µm (D), 50 µm (BCFGHIJKLM), 200 µm (E), 500 µm (A).

FIGURE 8. Hyalopale zerofskii Watson, Tilic & Rouse, 2019, non-type specimen (ECOSUR-2998). A) Complete fragmented body, arrow indicates anterior segments. B) Drawing of prostomium, dorsal view. C) Drawing of pygidium, ventral view. D) Parapodium from segment 5. E) Lateral spine. F) Main palea, lateral-most. G) Main palea, mid-most. H) Main palea, midlinemost. I) Unit 1. J) Unit 2. K) Unit 3. L) Unit 4. Scales: 10 µm (C), 20 µm (BIJKL), 50 µm (DEFGH), 100 µm (A).

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

FIGURE 14. Bhawatsonia fusa n. sp., holotype (ECOSUR-263). A) Complete fragmented body. B) Drawing of prostomium, dorsal view. C) Drawing of prostomium, ventral view. D) Prostomium, dorsal view. E) Prostomium, ventral view; arrow indicates Mo. F) Right side of middle segments, arrow indicates dorsal cirrus. G) Dorsal side of the specimen, showing the middorsal line paleae free. H) Parapodium from segment 49. I) Lateral paleae. J) Subunit 1. K) Main palea, arrow indicates finely raised rib. Scales: 20 µm (IJK), 100 µm (BCDEFH), 500 µm (G), 1 mm (A).

FIGURE 15. Bhawatsonia fusa n. sp., holotype (ECOSUR-263). A–B) Median paleae. C) Unit 1. D) Unit 2. E–F) Unit 3. G) Unit 4. H) Pygidium, ventral view. I) Complete body, largest specimen (ECOSUR-3219). Scales: 10 µm (CDEFG), 20 µm (AB), 50 µm (H),1 mm (I).

FIGURE 26. Previous and new records of chrysopetalids in the Tropical Eastern Pacific. Empty symbols indicate historic records.