Paleanotus karlyae, 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 : 11-13

Paleanotus karlyae n. sp.

Figs 5 , 12

LSID: urn:lsid:zoobank.org:act:B4CD57F4-73BC-41EE-8FB4-7CA6AD7B4B07

Paleanotus bellis — Cruz-Gómez & Bastida-Zavala 2018: 77 , Fig. 11 , 13 , 14K , 15H (non Johnson, 1897).

Paleanotus sp. — Humara-Gil & Cruz-Gómez 2019: 517 (among epibiont community of exotic bryozoan Amathia verticillata ); Chávez-López & Cruz-Gómez 2019: 159 (Polychaetes from Oaxaca, México).

Paleanotus sp. 1 .— Cruz-Gómez et al. 2021: 183, Fig. 6F (key of chrysopetalids from Tropical America).

Type locality: Pinitos Beach , Mazatlán, México .

Type material. Holotype: ECOSUR-258 , Pinitos Beach , Mazatlán, Sinaloa, México, northern Mexican Pacific, on bivalve, 4 m, March 27, 2004 . Paratype: ECOSUR-259 , Cerritos Beach , Mazatlán, Sinaloa, México, northern Mexican Pacific, May 6, 1980, coll. EE .

Other material examined. Twenty-five specimens. Baja California Sur: ECOSUR-3072 , La Marina, 24º09.319´N, 110º19.630´W, La Paz Bay , on pier pile, 0.5 m, 1 spec. in 250 cm 2, August 14, 2011, coll. TVG & ADL ; Sonora: ECO- SUR-3073, Guaymas, 27°54.041´N, 110°51.26´W, on buoys, 0.5 m, 1 spec. in 250 cm 2, August 11, 2011, coll. TVG & MAC ; Guerrero: ECOSUR-P2975, 21 spec. La Quebrada, 16º50´47”N, 99º54´55”W, Acapulco , on Muricanthus sp. , 6–8 m, May 25, 2000, coll. AM ; ECOSUR-P2973, 14 spec., La Quebrada, 16º50´47”N, 99º54´55”W, Acapulco , on Pinctada mazatlanica ( Hanley, 1856) 6–8 m, May 25, 2000, coll. AM ; ECOSUR-P2970, 8 spec. Los Cantiles, approx. 16º51´32”N, 99º55´37”W, Acapulco , on bivalves, 5–8 m, May 26, 2000 coll. AM . Oaxaca: ECOSUR-PXXX, Corralero Lagoon, 16º14´11”N, 98º11´36”W, on algae, 0.3 m, March 22, 2010, coll. EMD ; UMAR-Poly-OH-028, Puerto Ángel, 15º39´55”N, 96º29´28”W, on pier piles, 1 m, May 6, 2017, coll. CVG; UMAR-Poly-OH-029, Santa Cruz Bay , on the exotic soft bryozoan Amathia verticillata (delle Chiaje, 1822) , 1 m, April 10, 2018, coll. CCG .

Description. Based on the holotype: complete with 41 segments. TL= 4.6 mm, TW= 1.1 mm. Body short, broad, tapered posteriorly ( Fig. 5A ). Body whitish to pale yellow. Paleae fan translucent, slightly imbricated dorsally.

Prostomium visible between the first two segments. Lateral antennae short, inserted on antero-ventral prostomial margin, median antenna barely longer than lateral ones (only noted on the holotype), inserted in front of the anterior eyes. Eyes red-violet, two pairs. Nuchal organ small, oblong, partially covering the prostomium ( Fig. 5B ). Palps short, oval, visible in ventral view. Mouth fold wide, placed between segment 3 and 4. Pharynx muscular eversible, not exposed, stylets slender.

Parapodium from segment 23, notochaetae in three main groups ( Fig. 5D ). Notochaetae: lateral group inserted below notaciculum, 3–7 paleae, slender and symmetrical with 4–5 (7) internal ribs ( Fig. 5E ); subunit 1, 1 palea, shorter and symmetrical with 4–5 internal ribs ( Fig. 5F ). Main group, 10–11 paleae, broad, curved and asymmetrical with (12) 13–15 (16) internal ribs, these paleae intersperse internal ribs following by finely raised ribs ( Fig. 5G–H ). Median group, 4–5 paleae, long and asymmetrical; the distal-most slightly longer than main paleae, with 13 internal ribs and 3 finely raised ribs; the next proximal shorter with 13 internal ribs and 2 finely raised ribs; the proximalmost, shortest with 10 (11) internal ribs, raised rib absent ( Fig. 5I–J ). All paleae groups are covered with denticles over each internal rib.

Neuropodium conical, larger than notopodium. Neurochaetae: unit 1, 1–2 superior spinigers, blades slightly curved and long, 10 times longer than wide ( Fig. 5K ). Unit 2, 3–5 falcigers, blades straight and medium-sized, 2–3 times longer than wide ( Fig. 5L ). Unit 3, 3–4 falcigers, blades straight and medium-sized, 3 times longer than wide ( Fig. 5M ). Unit 4, 2–3 falcigers, blades straight and short, 2–3 times longer than wide ( Fig. 5N ). Pygidium quadrate, slightly notched with two anal cirri ( Fig. 5C ). Oocytes not seen.

Habitat. Intertidal to subtidal (0.3– 8 m). Specimens of P. karlyae n. sp. were collected as epibionts of bivalves Maricanthus sp. and Pinctada mazatlanica , and on the exotic bryozoan Amathia verticillata , as well among fouling communities.

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

Remarks. Paleanotus karlyae n. sp. stands out among the Paleanotus distributed in the region due to its notochaetal features. Specimens of P. karlyae n. sp. are recognized by having main paleae narrow, slightly straight, with reduced apex; further, the range of internal ribs is the lowest among TEP species. On the other hand, P. karlyae n. sp. resembles P. aquifolia Watson, 2015 , described from Queensland, Australia. Specimens of both species share the same reduced apex and relatively same length of main paleae ( Watson 2015: 719, Figs 4A–C ). However, P. karlyae n. sp. differs in having neurochaetal blades broad and strongly falcate, while P. aquifolia has longer, slender blades ( Watson 2015: 719, Figs 4D–H ).

Etymology. This species is named after Karla J. Humara-Gil, aka “Karly”, a dear colleague and specialist on brittle stars, as a token of appreciation for her support during many years. She is the bright light that has guided me through the shadows. The epithet is a noun in the genitive case ( ICZN 1999, Art. 31.1.2).

Figures

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 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 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 11. Paleaequor nicoyensis Watson Russell, 1986, non-type specimen (UMAR-Poly 954). A) Complete body. B) Drawing of prostomium, ventral view. C) Drawing of pygidium, ventral view. D) Parapodium from segment 20. E) Lateral paleae. F) Subunit 1. G) Main palea. H) Median palea. I) Unit 1. J) Unit 2. K) Unit 3. L–M) Unit 4. Scales: 20 µm (EFGHI- JKLM), 50 µm (BC), 200 µm (D), 1 mm (A).

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

FIGURE 13. Paleaequor psamathe Watson Russell, 1986, non-type specimen (ECOSUR-3068). A) Complete body. B) Drawing of prostomium, ventral view. C) Drawing of pygidium, ventral view. D) Oocyte. E) Parapodium from segment 15. F) Lateral paleae. G) Subunit 1, two kinds of paleae. H) Main paleae. I) Median paleae. J) Unit 1. K) Unit 2. L) Unit 3. M–N) Unit 4. Scales: 10 µm (JKLMN), 50 µm (BCFGHI), 200 µm (E), 2 mm (A).

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).