Bhawania bastidai n. sp.

Figs 10, 12

LSID: urn:lsid:zoobank.org:act: 9ADB2A08-0FF3-4A41-970E-567E3F217162

Bhawania cf. goodei . — Cruz-Gómez & Bastida-Zavala 2018: 65–66, Figs 4A–J, 14F, 15C. (Chacahua Lagoon, Oaxaca). Bhawania sp. 1 .— Cruz-Gómez et al. 2021: 179, Fig. 4P (key of chrysopetalids from Tropical America).

Type locality: El Faro breakwater, Mazatlán, Sinaloa, México .

Type material. Holotype: ECOSUR-261, prostomium damaged, El Faro breakwater, Mazatlán, Sinaloa, México, northern Mexican Pacific, on rock, 1 m, February 23, 2004, coll. MTH & PSS . Paratype: ECOSUR-262, same as holotype .

Other material examined. Tropical Eastern Pacific: México: Seven spec . Baja California: ECOSUR- 3213 fragments, Bahía de los Ángeles, March 17, 1985, coll. Lalo & Carolina. Baja California Sur: ECOSUR- 3214, fragments, La Paz Bay, February 23, 2004 . Nayarit: ECOSUR-3215, 2 spec. La Manzanilla, 20º44´39”N, 105º23´11”W, on rock with sponge and algae, 2 m, November 29, 2004, coll. BY & PSS . Jalisco: ECOSUR-3216, fragments, Melaque, on rock with algae, 3 m, December 2, 2004, coll. BY & PSS . Michoacán: UMAR-Poly 937, Faro de Bucerías, October 4, 1994, coll. RBZ & SGM . Oaxaca: UMAR-Poly 855, mouth of Chacahua Lagoon, 15º57´59’’N, 97º40´44’’W, on tubes of sabellariids, 0.5 m, April 3, 2008, coll. JJG . Costa Rica: Eleven spec . Puntarenas: UMAR-Poly-OH-025, Cabo Blanco, on volcanic rock, 1 m, November 11, 2012, coll. TVG . UMAR-Poly- OH-023, UMAR-Poly-OH-022, same as UMAR-Poly-OH-025. Guanacaste: Seven spec. MAGNT n.n., UMAR- Poly-OH-016, UMAR-Poly-OH-021, UMAR-Poly-OH-024, UMAR-Poly-OH-026, Cabuyal beach, on dead coral, 0.5 m, November 4, 2012, coll. TVG . Panamá: One spec . Balboa: ECOSUR-P3217, Punta Culebra, on sponge, May 30, 2002, coll. SSV . Grand Caribbean region: 1 spec. of Bhawania goodei Webster, 1884 Yucatán: ECO- SUR-PXXX, San Felipe, 21°34´16.0”N 88°13´40.2”W, on rock, 2–4 m, February 18, 1999, coll. RBZ & SSV .

Description. Based on the holotype: complete with 102 segments. TL= 16.2 mm, TW= 1.4 mm. Body long, narrowed, reduced posteriorly (Fig. 10A). Body orange to brown, reddish along with dorsal and ventral cirri bases. Paleae fan bright yellow to golden, strongly imbricated dorsally.

Prostomium damaged. Prostomium from another specimen (ECOSUR-3215) retracted among the first three segments. Lateral antennae long, inserted on antero-ventral prostomial margin median antenna slightly shorter than lateral ones, inserted in front of the anterior eyes. Eyes red-violet, two pairs. Nuchal organ, conical nuchal fold, partially covering prostomium (Fig. 10B). Palps long, cylindrical, visible in dorsal view. Mouth fold small, placed between segment 3 and 4 (Fig. 10C). Pharynx eversible, not exposed, stylet thick.

Parapodium from segment 22, notochaetae in three main groups (Fig. 10D). Notochaetae: lateral group inserted below notaciculum, 10–13 paleae, slender and asymmetrical with (2) 3–5 (7) internal ribs, barely seen (Fig. 10E); subunit 1, 1–2 paleae, symmetrical with (5) 6–7 (8) internal ribs and serrated margins (Fig. 10F). Main group, 11–13 paleae, broad and symmetrical, with (16) 18–21 (22) internal ribs and 3 raised ribs (Fig. 10G). Median group, 3 paleae, short, very broad and symmetrical; the distal-most palea with 12–14 internal ribs and (3) 4 raised ribs; the next proximal palea smaller with 14 internal ribs and 4 raised ribs, and the proximal-most, smallest with (13) 14–16 internal ribs and (2) 3–4 raised ribs (Fig. 10H–I).

Neuropodium conical, smaller than notopodium. Neurochaetae: unit 1, 2–4 superior spinigers, blades straight and long, 9–10 times longer than wide (Fig. 10J). Unit 2, 4–5 falcigers, blades straight and medium-sized, 2–3 times longer than wide (Fig. 10K). Unit 3, 4–6 falcigers, blades straight and short to medium-sized, 2–3 times longer than wide (Fig. 10L). Unit 4, 2–3 falcigers, blades straight and short, 2–3 times longer than wide (Fig. 10M). Pygidium rounded with a ventral cone and two subulate anal cirri (Fig. 10N). Oocytes not seen.

Habitat. Intertidal to subtidal (1–3 m). Specimens of this species were collected mainly on rocks, volcanic rock, dead coral, and as epibionts of algae, sponges, and tubes of sabellariids (Cruz-Gómez & Bastida-Zavala 2018).

Distribution. From Bahía de los Ángeles, Baja California, México to Punta Culebra, Balboa, Panamá (Fig. 12).

Remarks. In the Pacific coast of tropical America, the genus Bhawania has been repeatedly recorded as B. goodei Webster, 1884, a species with natural distribution in the Grand Caribbean. The latter is comprehensible; the Bhawania morphology is quite similar among species, which makes it difficult to separate from each other. However, a comparison of the TEP material with non-type specimens of B. goodei from the Grand Caribbean region, along with observations by Webster (1884), Perkins (1985), and Watson (Pers. Comm. 2020) revealed subtle but consistent disparities (Table 1).

Differences were noticed once middle region segments were dissected. Bhawania bastidai n. sp. have neuropodia shorter than notopodia, with a short neuracicular lobe, 1/2 neuropodia length; while B. goodei have larger neuropodia, as long as notopodia, with large neuroacicular lobe, 1/3 neuropodia length. This consistent feature was noted in similar size mature specimens; moreover, notes and drawings made by Webster (1884: Plate VII, Fig. 11) help to confirm this.

The distinct characters that help to separate both species are found in the main paleae. Specimens of B. bastidai n. sp. possess slightly slender main paleae, with a higher number of internal ribs; while specimens of B. goodei possess broader main paleae, with a lower number of internal ribs (18–21 vs 16–18). Despite the evident overlap of the numbers of internal ribs, the consistency of the ranges between these species leads to separate them.

Etymology. This species is named after J. Rolando Bastida-Zavala, a dear colleague, friend, and my first academic guide on polychaetes, as recognition of his great labor on polychaetes in México and his tireless effort to build new Mexican taxonomists on marine invertebrates. The epithet is a noun in the genitive case (ICZN 1999, Art. 31.1.2).