Mexieulepis weberi (Horst 1922)

Mexieulepis weberi (Horst, 1922)

Eulepis weberi Horst, 1922:199, fig. 2.

Mexieulepis weberi.—Pettibone, 1969:18, figs. 11–14 [synonymy].—Uebelacker, 1984:24–3, figs. 24–1, 2a–n.

Pareulepis fimbriata.—Rullier, 1974:21 [not Treadwell, 1901].

MATERIAL EXAMINED.—North Atlantic off North Carolina: 14 miles E of Cape Lookout, 20 m, Jun, Aug 1977, D.W. Weston, 4 juveniles (USNM 67487). 33°49′N, 78°23′W, Aug 1977, G.R. Gaston, juvenile (USNM 56536). 33°50′N, 78°24′W, 11 m, R/V Pierce sta 1A, 9 Feb 1977, juvenile (USNM 60399).

Off South Carolina: 32°57′N, 79°17′W, 12 m, R/V Pierce sta 2A, 12 Feb 1977, 1 specimen (USNM 60928).

Off Georgia: 31°25′N, 81°06′W, 11 m, Sep 1970, A.S. Leiper, juvenile (USNM 67064). 30°59′N, 80°08′W, R/V Pierce sta 5G, 46 m, 1 May 1977, juvenile (USNM 60400). 31°01′N, 80°17′W, 40 m R/V Pierce sta 5F, 30 Aug 1977, 1 specimen (USNM 61097); 24 Nov 1977, juvenile (USNM 60401). 31°03′N, 80°26′W, 34 m, R/V Pierce sta 5E, 24 Nov 1977, juvenile (USNM 60398).

Off Florida: Fleming Key, Key West, 24 May 1967, M.L. Jones, 1 specimen (USNM 67063). 30°23′N, 80°36′W, 35 m, R/V Pierce sta 6D, 1 Mar 1977, 1 specimen (USNM 61388); 1 Sep 1977, juvenile (USNM 59315).

Gulf of Mexico: 29°51′N, 86°06′W, 41 m, medium sand, MAFLA sta 2530, Jul 1976, 1 specimen (USNM 55801).

Belize, Carrie Bow Cay: S of island, 50–75 m, coral rubble and sand, 13 May 1977, M.L. Jones, 1 specimen (USNM 67067).

Panama (Atlantic), Punto de Roto: Fort Sherman, Thalassia substrate, sta 100, 25 Apr 1972, M.L. Jones, 1 specimen (USNM 67065).

Venezuela, Turpialito: 20 km E of central Cumaná, mud bottom, 16 Jan 1978, M.L. Jones, advanced juvenile (USNM 67068).

Puerto Rico, Barceloneta: 18°29′N, 66°33′W, 27 m, 8 Nov 1974, G. Mayo, 2 juveniles (USNM 67066).

The additional seven adult specimens examined agree with the previous descriptions of the species. The collection of some juveniles that are referred to this species show some characters that differ from the adults and thus do not fit into the keys based on the adults. The basis for referring the small juveniles from waters off North Carolina, Georgia, Florida, Venezuela, and Puerto Rico to Mexieulepis weberi and separating them from juveniles of Grubeulepis spp. is the presence of acicular neurosetae in most of the parapodia, as they are in the adults of this species. They were found in the same general areas as the adults. Some 13 juveniles, with 17 to 28 segments, and one more advanced juvenile, with 35 segments, were collected, compared to the adults with 44 to 52 segments, 24–48 mm long, and 8–10 mm wide.

DESCRIPTION OF JUVENILES.—Juveniles with 17–23 segments 2.5–4 mm long, 1–2.5 mm wide; juveniles with 25–28 segments 4–7 mm long, 2–3.5 mm wide; more advanced juvenile with 35 segments 13 mm long and 3 mm wide.

Anterior 12 pairs of elytra increasing in size toward middle of body, then decreasing somewhat, with 12th elytra not extra large, as in adults (Figures 2A–F, 4A–D, 6A–E). First pair of elytra with papillae on anterior border and few on surface (Figures 2A, 4A, 6A). Lateral fimbriation of following elytra differing from adults (Pettibone, 1969, fig. 11a–c) by different shapes of lateral processes: bulbous, with terminal buds (Figure 2B–F); digitiform or filiform with terminal buds or with 2–3 articles (Figures 4B–D, 6B–E); additional buds or papillae on posterior borders and scattered on surface; scattered microtubercles on anterior part of elytra present or absent. Posterior small elytra not developed on juveniles of less than 27 segments. On advanced juvenile of 35 segments, posterior elytra with more numerous lateral processes (Figure 6F), compared to adult (Pettibone, 1969, fig. 11d).

Tentaculophores of tentacular segment with filiform dorsal tentacular cirrus and large oval ventral tentacular cirrus (Figures 1A, 2G), thus differing from adult (Pettibone, 1969, fig. 11e,g). Parapodia of buccal segment 2 similar to adult; some capillary notosetae thicker, spinous; middle neuroseta thicker, ending in blunt or tapered slender tips (Figures 1B–D, 2H–J). Parapodia of segment 3 with dorsal cirrus on posterior side of notopodium, bundle of capillary notosetae and stout notopodial hooks with tips tapered or spatulate, smooth or spinous along bend; neuropodium with upper limbate capillaries, 2–3 middle denticled, slightly roughened or smooth acicular setae and lower limbate and non-limbate capillaries (Figures 1E–G, 3A–C).

Biramous parapodia similar in shape and composition to adults (Figures 1H–J, 3D–K, 4E–H, 5A–D). Notopodial hooks mostly spinous along bend and distal part, instead of smooth as in adults (Figures 1I, 3B,E,J; 4G, 5C). Middle acicular neurosetae 1–5 in number, slightly hooked, mostly denticled (Figures 1G,J, 3G, 4H, 5D), in contrast to smooth acicular neurosetae in adults (Pettibone, 1969, figs. 11k, 12f, 13e). Posterior parapodia of more advanced juveniles showing same modification as in adults: stouter upper group of acicular neurosetae bent downward but tubercled (Figures 5E,G, 6G,H,J) and not smooth as in adults (Pettibone, 1969, fig. 14a,c).

DISTRIBUTION.—Off North Carolina to Florida, Gulf of Mexico, Belize, Panama, Venezuela, West Indies (Curaçao, Puerto Rico, Cuba), in low intertidal to 46 meters.

Lamelleulepethus, new genus

TYPE-SPECIES.—Lamelleulepethus orensanzi, new species. Gender: masculine.

DIAGNOSIS.—Segments about 35. Elytra 12 pairs, on segments 2, 4, 5, 7, alternate segments to 21, 24; elytra with lateral borders fimbriated. Dorsal cirri on segments 3 and 6. Branchiae 12–13 pairs, on segments 8, 10, alternate segments to 22, 23, 25, 26, 27, (28). Posterior dorsal lamellae beginning on segment 28 or 29, continuing posteriorly. Large ventral lamellae on ventrolateral sides of body, beginning on segments 7–8 and continuing to segments 26–28.

ETYMOLOGY.—From the Latin Lamella (plate) plus the generic epithet Eulepethus, referring to the presence of the characteristic ventral lamellae on the eulepethid polychaete.

Lamelleulepethus agrees with Grubeulepis Pettibone in all respects, except for the addition of the unique large ventral lamellae on the middle region of the body. Although differing in shape and arrangement, they are like the ventral lamellae in Gastrolepidia Schmarda and Paralepidonotus Horst in the Polynoidae because they all have similar attachment on the ventrolateral sides of the bases of the neuropodia.

COMPOSITION.—Lamelleulepethus includes two new species: L. orensanzi and L. biminiensis.

Mexieulepis weberi (Horst)

Eulepis weberi Horst, 1922, p. 199, fig. 2.—Augener, 1927, p. 43.

Pareulepis weberi.—Hartman, 1959, p. 123.

Mexieulepis elongatus Rioja, 1961, p. 238, figs. 1-29.—Hartman, 1965, p. 15.

MATERIAL EXAMINED.—Spaansche Haven, Curaçao, West Indies, van der Horst, collector—holotype (ZMA 220). Spaansch Water, Curaçao, van der Horst, collector, 4 May 1920—1 specimen (ZMH 10324).

Sapelo Beach, Sapelo Island, SE Georgia, low intertidal, muddy sand, J. M. Teal, collector, 25 June 1957—1 specimen (USNM 32359).

DESCRIPTION.—Length of holotype 52 mm, width, including setae, 12 mm, segments 52. Length of other specimen from Curaçao (ZMH 10324) 13 mm, width, including setae, 3 mm, segments 37. Length of specimen from Georgia (USNM 32359) 75 mm, width, including setae, 11 mm, segments 62. Anterior 12 pairs elytra larger, fimbriated along external border (flattened, leaflike processes); first pair elytra fimbriated on anterior border; elytral surface smooth except for scattered microtubercles on anterior part; elytriphores large, inflated, converging middorsally (Figure 11a-c, e). Smaller elytra on all posterior segments, beginning on segment 27 [specimens from Curaçao and Veracruz (Rioja, 1961)] or segment 28 (large specimen from Sapelo Island); elytra with few lateral processes or simply notched, attached by anterior borders to elytriphores, which are fused medially (Figure 11d). Branchiae 11-12 pairs, ciliated on underside, with distal branchial cirri (Figure 13b). Dorsal cirri, on segments 3 and 6, subulate (Figures 11e, 12a).

Prostomium partially hidden by and attached to underside of segment II; median antenna short, oval, inserted anterodorsally on prostomium; lateral antennae longer, conical, inserted anteroventrally; ventral palps elongate-tapered, extending slightly beyond parapodial lobes; no eyes visible; nuchal organs clavate, lateral to prostomium (Figure 11e). Tentacular parapodia (I) with short subulate tentacular cirri, ventral pair slightly longer than dorsal pair; 2 acicula with hooked tips; 2 bundles long, spreading capillary setae (Figure 11e,g). Ventral buccal cirri of segment II stouter and longer than those following (Figure 11h).

Biramous parapodia supported by reddish amber-colored acicula and neuropodial hammer-shaped distal plates (Figures 12a,b; 13a,b). Notopodial acicula with hooked tips. Notopodial capillary setae smooth and finely spinous, forming long spreading bundles on posterior parts of notopodia; some of capillary setae on segment II stouter, with spinous rows (Figure 11i); stout reddish amber-colored notopodial hooks, beginning on segment III, smooth, with tips finely tapered or flattened spoon-shaped (Figures 11j, 12c, 14b). Neuropodial acicula with conspicuous hammer-shaped distal plates. Neurosetae of several kinds: 1-2 upper pectinate setae (Figures 12d, 13c); upper and lower limbate and nonlimbate capillaries (Figures 12e,g; 13d,f); lower posterior bundles of long capillary setae (Figures 11h, 12a,b); middle stout smooth acicular setae, beginning on segment II (Figures 11k, 12f, 13e). In posterior region, upper neurosetae stout, bent downward, with tips slender or blunt; lower neurosetae slender, slightly limbate, with slender tips curved upward (Figure 14a,c,d). Ventral cirri of anterior few segments slender, tapered (Figure 12a,b); rest globular, with short distal tips (Figure 13a,b). Pygidium with single long anal cirrus on right side; cirrus papillate along one side; left cirrus short bulbous. Pharynx extended on specimen from Georgia, with 13 pairs larger papillae and small lateral pair; 2 pairs platelike chitinous ridges (not toothlike, as in Polynoidae or Sigalionidae; (Figure 11e,f).

DISTRIBUTION.—West Indies (Curaçao), Gulf of Mexico (Veracruz), Georgia (Sapelo Island). Low intertidal.