Paleanotus 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 : 13-14

Paleanotus sp.

Figs 6 , 12

Paleanotus sp. 3 .— Cruz-Gómez et al. 2021: 183, Fig. 6H–I (key of chrysopetalids from Tropical America).

Material examined. Only fragments. Costa Rica: UMAR-Poly-017, cruise pier, Puntarenas, on pier piles, 1.5 m, Nov 22, 2012, coll. TVG .

Description. Based on the fragment collected: only six middle segments. TL= 1 mm, TW= 0.2 mm. Body pale yellow, paleae fan translucent to bright yellow, slightly imbricated dorsally ( Fig. 6A ).

Parapodium from middle segments, notochaetae in three main groups ( Fig. 6B ). Notochaetae: lateral group inserted below notaciculum, 2–4 paleae, slender and symmetrical with 4–5 internal ribs ( Fig. 6C ); subunit 1, 2 paleae, shorter and asymmetrical with 5 internal ribs. Main group, 10–12 paleae, broad, curved and asymmetrical with 14–15 (16) internal ribs ( Fig. 6D ). Median group, 4 paleae, shorter and asymmetrical; the distal-most shorter than main paleae with 11 internal ribs; the next proximal shorter with 12 internal ribs; the proximal-most, shortest with 10 internal ribs and 1 raised rib ( Fig. 6E–G ). Internal ribs of all paleal groups with fine denticles.

Neuropodium conical, as long as notopodium. Neurochaetae: unit 1, 2 superior spinigers, blades slightly curved and long, 13–14 times longer than wide ( Fig. 6H ). Unit 2, 4–6 falcigers, blades straight and medium-sized, 4–5 times longer than wide ( Fig. 6I ). Unit 3, 4–5 falcigers, blades straight and medium-sized, 3–4 times longer than wide ( Fig. 6J ). Unit 4, 2–4 falcigers, blades straight and short, 5 times longer than wide ( Fig. 6K ). Pygidium and oocytes not seen.

Habitat. Subtidal (1.5 m). Specimens of this species were collected on pier piles.

Distribution. Only recorded from Puntarenas, Pacific side of Costa Rica ( Fig. 12 ).

Remarks. Fragments of the specimen of Paleanotus sp. resembles P. macrophthalmum ; however, these differ in some body and chaetal features. Paleanotus sp. has a cylindrical body, median paleae short, about 2/3 main paleae length, and neurochaetae with relatively short and slender blades. The fragments of this specimen possibly belong to a new species, but it is necessary find complete specimens to appropriately describe it.

Figures

FIGURE 6. Paleanotus sp., non-type specimen (UMAR-Poly-017). A) Fragments. B) Parapodium from middle segment; B) Lateral paleae; C) Main palea; D–F) Median paleae; G–H) Unit 1; I) Unit 2; J) Unit 3; K) Unit 4; L) Pygidium, ventral view. Scales. Scales: 10 µm (HIJK), 20 µm (CDEFG), 100 µm (AB).

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