Neopsammolyce fragilis, Cruz-Gómez, 2022

Cruz-Gómez, Christopher, 2022, Pelogeniinae Chamberlin, 1919 (Annelida, Sigalionidae) from the Grand Caribbean Region, European Journal of Taxonomy 807, pp. 1-59 : 23-27

Neopsammolyce fragilis sp. nov.

urn:lsid:zoobank.org:act:1449449F-81B3-4703-A6C7-22FCF62B97A1

Figs 9–10

Diagnosis

A species of Neopsammolyce with long palps, exceeding segment eleven; with first elytra oval and notched with expanded lobes separated by the notch, and lateral margin convex; second elytra oval with one posterior process; elytra and parapodia with papillae entire; neurochaetae from segment III with blades bifid.

Etymology

The specific name of the species is derived from the Latin singular adjective ‘ fragilis (-e)’, meaning ‘fragile’ or ‘easily broken’. The name indicates the brittleness and fragility of the elytra, and it is in feminine to match the generic gender ( ICZN 1999, Art. 31.2).

Material examined

Holotype MEXICO • incomplete spec.; Quintana Roo, off Tzucox; 18°58′ N, 87°28′ W; R/V Pillsbury, Stn 604; depth 979 m; 17 Mar. 1967; UMML 22.1088 .

Paratype MEXICO • 1 incomplete spec., 69 segments, 2.9 cm long, 0.9 cm to segment 30, 0.6 cm wide; same collection data as for holotype; UMML 22.1018 .

Other material

MEXICO • 1 incomplete spec., 12 segments, 0.4 cm long, 0.2 cm wide; Yucatán shelf ; 23°30′ N, 88°33′ W; O/V UAT 1 CIDIPORT; depth 57 m; 4 Sep. 2016; Sara B. Balam leg.; ECOSUR-P3224 • 2 incomplete specs, 57–78 segments, 1.4–2.4 cm long, 0.7–1.1 cm to segment 30, 0.2–0.3 cm wide; Yucatán shelf; 21°53′18″ N, 90°31′10″ W; O/V Justo Sierra; depth 49 m; 14 Sep. 2010; Anabel León leg.; ECOSUR-P3225 • 1 incomplete spec., 40 segments, 1.6 cm long, 1.2 cm to segment 30, 0.5 cm wide; Quintana Roo, off Xahuayxol; 18°30′ N, 87°37′ W; R/V Pillsbury, Stn 607; depth 751 m; 17 Mar. 1967; UMML 6802-607 .

UNITED STATES OF AMERICA • 1 incomplete spec., 42 segments, 3.2 cm long, 1.4 cm to segment 30, 0.6 cm wide; Florida; 24°40′ N, 80°04′ W; R/V Gerda, Stn 226; depth 803 m; 23 Jan. 1964; UMML 6402-226 .

Description (holotype)

BODY. Pale yellow, cylindrical, broad ( Fig. 9A–B ); 47 segments, 2 cm long, 1.2 cm to segment 30, 0.6 cm wide. Middorsal line covered with white foreign particles and foraminifera attached to adhesive papillae ( Fig. 9F ). Venter covered with short bulbous and long dendritic papillae ( Fig. 9G ).

PROSTOMIUM. Spherical. Two pairs of poorly defined eyes, anterior eyes larger, covered by the median antenna ceratophore. Lateral antennae short, bulbous; ceratophores as long as styles, dorsally fused with tentacular segment, covered by median antennal ceratophore ( Fig. 9E ). Median antenna with tapered ceratophore, slightly longer than prostomium, with dorsal ridges; style short, as long as prostomium ( Fig. 9B–C ). Middorsal lobe of segment II with a longitudinal ridge. Facial tubercle short, visible between palps ( Fig. 9D ). First segment directed anteriorly; fused with tentacular segment; biramous, chaetae simple verticillate. Dorsal tentacular cirrus longer than neuropodia including chaetae, ventral

tentacular cirrus shorter than dorsal one; palps long, reaching segment 11, with inner palpal sheaths ( Fig. 9D ).

ELYTRA. First right elytron subtriangular deeply notched, covered with foraminifera and coarse sand ( Fig. 10F ), two kinds of papillae: flat papillae, and pedunculate papillae with flat tips, more abundant in elytral center; elytral margins with short dendritic papillae ( Fig. 10J–K ). Second right elytron oval notched, with one posterior process ( Fig. 10G ), same kinds of papillae on elytral surface, elytral margin with short and long dendritic papillae ( Fig. 10I ). Posterior elytra oval with one medial process ( Fig. 10H ), same kinds of papillae on elytral surface, elytral margin with short dendritic papillae. All elytra very brittle.

RIGHT PARAPODIUM FROM SEGMENT II ( Fig. 9H ). Notopodia conical, papillate, short, half as long as neuropodia, notopodial flange leaf-shaped. With up to 70 simple verticillate notochaetae, shortest ones as long as notopodia, longest ones 4× as long ( Fig. 9I ). Neuropodia conical, papillate and larger than notopodia. Neurochaetae only falcigers, most blades falcate, bifid: unit A, two falcigers with handles slender with 8–9 transverse rows of spines, blades long, 28–30 × as long as wide ( Fig. 9J ); unit B, four falcigers with handles thick with 41–48 barely perceptible transverse rows of denticles, blades long 21– 23 × as long as wide ( Fig. 9K ); unit C, six falcigers with handles slender with 30–34 barely perceptible transverse rows of denticles, blades soft, long, 40 × as long as wide ( Fig. 9L ); unit D, four falcigers with handles slender with 8–10 barely perceptible transverse rows of denticles, blades long, 10–12 × as long as wide ( Fig. 9M ).

RIGHT PARAPODIUM FROM SEGMENT III ( Fig. 9N ). Notopodia conical, short, papillate, ⅓ as long neuropodia, notopodial flange leaf-shaped. With up to 80 simple verticillate notochaetae, shortest ones as long as notopodia, longest ones twice as long ( Fig. 9O ). Neuropodia truncated, papillate, larger than notopodia. Neurochaetae only bifid falcigers: unit A, two falcigers with handles slender with 9–10 transverse rows of spines, blades long, 19 × as long as wide ( Fig. 9P ); unit B, three falcigers with handles thick with 8–12 barely perceptible transverse row of denticles, blades long, 9× as long as wide ( Fig. 9Q ); unit C, 10 falcigers with handles slender, smooth, blades long, 28–30× as long as wide ( Fig. 9R ); subunit 1, two falcigers with handles thick, smooth, blades long, 8–10 × as long as wide ( Fig. 9S ); unit D, six falcigers with handles slender, smooth, blades long, 25 × as long as wide ( Fig. 9T ).

RIGHT PARAPODIUM FROM SEGMENT 31 (MIDDLE SEGMENT) ( Figs 9U , 10A ). Notopodia conical, smooth (nonpapillate), short, ⅓ as long as notopodia; notopodial flange bulbous. With up to 50 simple verticillate notochaetae, shortest ones twice as long as notopodia, longest ones 3× as long ( Figs 9V , 10B ). Neuropodia truncated, papillate, larger than notopodia. Neurochaetae only bifid falcigers: unit A, two falcigers with handles thick, barely noticeable 2 rows of denticles, blades long, 9–10 × as long as wide ( Fig. 9W ); unit B, two falcigers with handles thick, smooth, blades lost (posterior segment, blades medium-sized, 5–6 × as long as wide) ( Figs 9X , 10C ); unit C, six falcigers with handles thick, smooth, blades short, 4 × as long as wide ( Figs 9Y , 10C ); subunit 1, two falcigers with handles slender, smooth, blades mediumsized, 6× as long as wide ( Figs 9Z , 10E ); unit D, four falcigers with handles slender, smooth, blades short, 4× as long as wide ( Fig. 9 AA).

POSTERIOR REGION. Lost.

Remarks

Neopsammolyce fragilis sp. nov. resembles N. occidentalis ( McIntosh, 1885) as described and illustrated by Pettibone (1997), in having long palps, first elytra notched, notopodia reduced, and neuropodia highly papillate. However, both species differ in the shape of the first and second elytra, and the neurochaetae from segment III. Specimens of N. fragilis sp. nov. have an oval and notched first elytra with two expanded

lobes, and lateral margin convex; an oval second elytra with a posterior process, and neurochaetae from segment III with blades bifid; whereas specimens of N. occidentalis have first elytra subrectangular and notched with two narrow lobes, and a concave lateral margin ( Pettibone 1997: 14, fig. 8d); an oval second elytra, notched, without processes ( Pettibone 1997: 14, fig. 8e), and neurochaetae from segment III with blades bifid and entire ( Pettibone 1997: 13, fig. 7f).

Distribution

Gulf of Mexico. From Florida to Quintana Roo.

Figures

Fig. 9. Neopsammolyce fragilis sp. nov., holotype (UMML 22.1088). A. Incomplete worm, dorsal view. B. Anterior end, covered by elytra. C. Anterior end, dorsal view. D. Anterior end, ventral view. E. Detail of prostomium, arrowhead indicates lateral antenna. F. Dorsal papillae (close-up in box). G. Ventral papillae (close-up in box). H. Right parapodium from segment II. I. Notochaeta from same. J. Unit A. K. Unit B. L. Unit C. M. Unit D. N. Right parapodium from segment III. O. Notochaeta from same. P. Unit A. Q. Unit B. R. Unit C. S. Subunit 1. T. Unit D. U. Right parapodium from segment 31. V. Notochaeta from same. W. Unit A. X. Unit B. Y. Unit C. Z. Subunit 1. AA. Unit D. Scale bars: A–D = 1 mm; E, H, N, U = 500 μm; F–G = 50 µm; I–M, O–T, V–AA = 100 μm.

Fig. 10. Neopsammolyce fragilis sp. nov., holotype (UMML 22.1088). A–E, K. SEM micrographs. A. Right parapodium from segment 24. B. Notochaetae from same. C. Units B and C. D. Close-up of unit A, arrowhead indicates subdistal denticle. E. Subunit 1. F. First right elytron. G. Second right elytron. H. Right posterior elytra. I. Detail of margin from G. J. Detail of margin from H. K. Surface of H, flat papillae and pedunculate papillae with flat tips. Abbreviations: a = anterior; p = posterior. Scale bars: A, I–J = 100 μm; B, D = 5 μm; C, E = 50 μm; F–H = 1 mm; K = 20 μm.