Paraeupolymnia carus Young & Kritzler 1987

Paraeupolymnia carus Young & Kritzler, 1987

Figures 7 A–D

Paraeupolymnia carus Young & Kritzler, 1987: 687 –690, Figure 1.

Material examined: Paratypes USNM 98909 (2) North Atlantic Ocean, Caribbean Sea, Belize, Twin Cays, 9 May 1984, 2.25 m. Mexican Caribbean: ECOSUR TERE­9 E2 (1) Xahauyxol (18°30’15’’N 87°45’32’’W), 27 Sep. 1996, 0.25 m. (1) E22 Buenavista (18°3’42’’N 87°45’30’’W), 27 Sep. 1996, 1.1 m. (4) E25 Buenavista (18°30’42’’N 87°45’30’’W), 27 Sep. 1996, 1 m. (5) E2A39 Majahual (18°40’09.6’’N 87°43’01.4’’W), 30 May 1997, 0.1 m. (1) Bajo Pepito, Mujeres Island, Jun. 1997, on algae. (1) R6, (1) R8 Punta Nizuc, Cancún (21°02’11.7’’N 86°46’44.2’’W), 31 Aug. 1997, 2 m. (2) R7 Punta Nizuc, Cancún (21°02’11.7’’N 86°46’44.2’’W), 1 Sep. 1997, 2 m. (1) E2RB3 Buenavista (18°30’42’’N 87°45’30’’W), 31 Oct. 1997, 0.25 m. (1) Leeward of Contoy Island (21°30’8.4’’N 86°47’45.3’’W), 10 Jun. 1999, 3 m, in Ircinia sp. (2) Lighthouse, Contoy Island (21°30’8.4’’N 86°47’45.3’’W), 1 Mar. 2001. (1) R/V “Edwin Link”, sta. 2777, Southern Chinchorro (18°26’02’’N 87°18’82’’W), 21 Aug. 1990. Gulf of Mexico: (2) Alacranes Reef, Perez Island, 26 Jun. 1988.

Description: Best paratype complete, with 85 segments, 24 mm long; thorax 7.2 mm long and 3.0 mm wide (Figure 7 A). Tentacles short; eyespots small, restricted to the midlateral sides of tentacular membrane, each group with 12–15. Upper lip with free edge spoon­like; lower lip thin, poorly swollen. One pair of lateral lappet on segment 3; more developed ventrally, perpendicular to body axis, three times as long as length of notopodia. Two pairs of branchiae, branched, on segments 2 and 3. First pair longer than the second one, with three to four levels of ramification, second pairs with three levels only. Nephridial papillae absent. Fifteen ventral shields present, starting from segment 2; anterior shields broader laterally and shorter; from midthorax, shields similar to each other, rectangular and thinner laterally. Thorax with 17 pairs of notopodia starting from segment 4. Notochaetae as equal­sized, unilimbate capillaries (Figure 7 B). Neuropodia starting from segment 5, with uncini arranged in single rows from segment 5 to 10, in double rows from segment 11 to 20, in face to face position, from segment 21 until pygidium arranged in single row. Thoracic uncini with dental formula MF:1:3–5 (Figures 7 C–D), with narrow upper subrostrum, well­developed subrostral process, without subrostral appendix; concave lower subrostrum; both anterior process and filament absent; basis curved, finishing in an angulated posterior process; lower occipitium concave, upper occipitium convex, ending by toothed capitium. Abdominal uncini with dental formula MF:2–3:4–6, similar to thoracic uncini, but with more secondary teeth. Pygidium very short and small, with about 10 anal papillae. Tube pale green to brown, short and thin, somewhat broader than the body of the worm; with sand attached to mucous membrane.

Variation: Some specimens from the Mexican Caribbean have tentacles with dark transverse lines; this feature differs from paratypes, which have pale tentacles without such lines. Ventral shields can vary from 10 to 15, and the total number of segments in all specimens complete revised varies from 51 to 85 segments.

Remarks: The original description indicates that the holotype shows a “virtual absence of ventral glandular shields [ventral shields]”. However, ventral shields are present in the paratypes and in all the material examined. Also, Young & Kritzler (1987) described the lateral lappet as present on the second segment, but it is in fact on segment 3. They emphasized the number of branchiae as a useful character to separate Paraeupolymnia from Eupolymnia; we would also use the numbers of pairs of lateral lappets to separate these genera: Eupolymnia has three poorly developed lateral lappets on segments 2–4, while Paraeupolymnia has only one well developed lateral lappet on segment 3.

Distribution: Gulf of Mexico, Mexican Caribbean and Belize.