Bhawatsonia sp.

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 : 36-37

Bhawatsonia sp.

Figs 19 , 26

Bhawania sp. 4 .— Cruz-Gómez et al. 2021: 180, Fig. 5C (key of chrysopetalids from Tropical America).

Material examined. Six specimens. Costa Rica: UMAR-Poly-OH-033, Cabuyal beach, Guanacaste, Gulf of Papagayo , Costa Rica , on dead coral, 0.5 m, November 02, 2012, coll. TVG ; MAGNT-XXX , UMAR-Poly-OH-009, UMAR-Poly-OH-034, UMAR-Poly-OH-035, UMAR-Poly-OH-036, cruise pier, on pier pile, 1.5 m, November 22, 2012, coll. TVG .

Description. Based on the largest specimen: complete with 162 segments. TL= 14.7 mm, TW= 1.3 mm. Body stiffed, slender, long, narrowed posteriorly. Body whitish to pale violet, dorsal and ventral cirri bases darker ( Fig. 19A ). Paleae fan bright maroon to golden bright, non-imbricated dorsally.

Prostomium completely retracted among the first four segments, caused by the fixation method. Antennae, prostomium, nuchal organ not seen. Palps short, ovoid, visible only in ventral view. Mouth fold small, placed between segment 3 and 4. Pharynx eversible, not exposed, stylets slender.

Parapodium from segment 81, notochaetae in three main groups ( Fig. 19B ). Notochaetae: lateral group inserted below notaciculum, 1 palea, very slender and symmetrical with 2–3 internal ribs ( Fig. 19C ); subunit 1, 1 palea, slender and symmetrical, with a acute projection distally, with 12–13 (14) internal ribs ( Fig. 19D ). Main group, 12 paleae, broader and symmetrical, with 18–21 internal ribs and 4 finely raised ribs ( Fig. 19E ). Median group, 3 paleae, broader and asymmetrical; the distal-most palea with 9 internal ribs and 1 raised rib; the next proximal smaller with 8–9 internal ribs and the proximal-most and smallest with 9 internal ribs ( Fig. 19F ).

Neuropodium conical, smaller than notopodium. Neurochaetae: unit 1, 2 superior spinigers, blade straight and long, 11–12 times longer than wide ( Fig. 19H ). Unit 2, 4 falcigers, blades straight and short, 3–4 times longer than wide ( Fig. 19I ). Unit 3, 3 falcigers, blades straight and short, 2–3 times longer than wide ( Fig. 19J ). Unit 4, 2 falcigers, blades straight and medium-sized, 5–6 times longer than wide ( Fig. 19K ). Blades bidentate, bent distally. Pygidium conical with two anal cirri ( Fig. 19L ). Oocyte size: 60.3–88.3 µm (n=2) ( Fig. 19G ).

Habitat. Intertidal to subtidal (0.5–1.5 m). Specimens were collected on pier piles.

Distribution. From Cabuyal Beach, Costa Rica to Taboga Island, Panamá ( Fig. 26 ).

Remarks. Specimens of Bhawatsonia sp. resembles B. fusa n. sp. by having broad main paleae and median paleae slender. However, these species could be differentiated using the features in the main and subunit 1 paleae (see B. fusa n. sp. remarks). Monro (1933) recorded “ C.” riveti from Panamá, using a specimen with characteristics that resemble Bhawatsonia sp. such as depressed body, ovoid palps, and large dorsal cirrus. However, the record should be confirmed by the examination of the Monro’s specimen, and specimens of “C.” riveti from the type locality.

Figures

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 19. Bhawatsonia sp., (UMAR-Poly-OH-033).A) Complete body. B) Parapodium from segment 81. C) Lateral paleae. D) Subunit 1. E) Main palea, arrow indicates finely raised ribs. F) Median paleae. G) Oocyte. H) Unit 1. I) Unit 2. J) Unit 3. K) Unit 4. Scales: 5 µm (G), 10 µm (HIJK), 20 µm (CDEF), 50 µm (L), 100 µm (B), 1 mm (A).

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