Ceratonereis maya, Conde-Vela, 2021

Conde-Vela, Víctor Manuel, 2021, Revision of Ceratonereis Kinberg, 1865 recorded from the Caribbean Sea, with description of two new Ceratonereis species and a new combination of Platynereis Kinberg, 1865, Zootaxa 5026 (3), pp. 301-343 : 319-323

Ceratonereis maya n. sp.

Figures 11–12

Ceratonereis sp. Perkins 1980: 32–34 , figs 13a–f.

Ceratonereis (Ceratonereis) singularis singularis Hartmann-Schröder, 1985: 45 , figs 36–39.

Ceratonereis singularis Salazar-Vallejo & Jiménez-Cueto 1997: 365 (non Treadwell, 1929).

Ceratonereis excisa Salazar-Vallejo & Jiménez-Cueto 1997: 363 , figs 1, 15, 16, 37, 38 (partim, non Grube & Müller in Grube, 1873).

Type material. Caribbean Sea, Mexico. Holotype ECOSUR 0245 , Contoy Island , Quintana Roo (21°31’44.28”N 86°48’11.53”W), 1.5 m depth, 1 March 2001 , Coll S.I. Salazar-Vallejo, L.F. Carrera-Parra . Paratypes ECOSUR 0246 (2), Contoy Island , Quintana Roo (21°31’44.28”N 86°48’11.53”W), 1.5 m depth, 1 March 2001 , Coll S.I. Salazar-Vallejo, L.F. Carrera-Parra . Paratype ECOSUR 0247 (1), Cabo Catoche , Quintana Roo (21°36’32.06’’N 87°06’52.64’’W), 2.5 m depth, 10 May 2009, Coll. S.I. Salazar-Vallejo, L.F. Carrera-Parra.

Additional material. Gulf of Mexico, Mexico. ECOSUR 1120 (1), Laguna de Términos , Campeche, 27 July 1984 , Coll. E. Escobar. Caribbean Sea, Mexico. ECOSUR P1150 (4), Laguna Yalahau , Quintana Roo (21°30’N 87°15’W), 8 September 1993 , Coll. S.I. Salazar-Vallejo. ECOSUR P1157 (1), Punta Gorda , Quintana Roo (19°47’51.03” N 87°32’49.70”W), 27 August 1984 , Coll. E. Escobar. ECOSUR P1158 (1), Laguna Nichupté , Quintana Roo (21°06’11.6”N 86°47’21.1”W), 3 February 1988 , in seagrasses, Coll. M.S. Jiménez-Cueto. ECOSUR P1167 (2), Laguna Nichupté , Quintana Roo (21°06’11.6”N 86°47’21.1”W), 30 October 1987 , Coll. M.S. Jiménez- Cueto. ECOSUR P1197 (2), Laguna Nichupté , Quintana Roo (21°06’11.6”N 86°47’21.1”W), 5 July 1988 , Coll. M.S. Jiménez-Cueto. ECOSUR P1199 (1), Ría Lagartos , Yucatán (31º35’55.25”N, 88º9’23.9”W), 18 February 1999 , Coll. S.I. Salazar-Vallejo, J. R. Bastida-Zavala. ECOSUR P1200 (1), R / V Edwin Link, Sta. 2774 (18°45.63’N 87°15.84’W), Cayo Norte, Banco Chinchorro, Quintana Roo, 20 August 1990 , Coll. E. Escobar, L. Soto. ECOSUR P1201 (1), Punta Gavilán , Quintana Roo, 25 August 1990 , Coll. E. Escobar, L. Soto. ECOSUR 1202 (3 males), Punta Gavilán , Quintana Roo, 25 August 1990 , Coll. E. Escobar, L. Soto. ECOSUR P1203 (1), Punta allen, Quintana Roo (19º47’58”N, 87º28’29”W), 2 June 1986 , Coll. F.E. Donath. ECOSUR P1206 (1), Punta Hualastok , Bahía de la Ascensión, Quintana Roo, 28 April 1987 , Coll. M.S. Jiménez-Cueto. ECOSUR P1208 (2), Laguna de Términos , Campeche (18°39’7.29”N 91°32’25.22”W), 27 July 1984 , Coll. E. Escobar. ECOSUR P1220 (1), Buenavista , Quintana Roo (18°30’42’’N 87°45’30”W), 27 September 1996 , Coll. S.I. Salazar-Vallejo, L.F. Carrera-Parra. ECOSUR P3191 (1), Camping Beach, Contoy Island , Quintana Roo (21°28’28.9” N, 86°47’22.5” W), on seashell, 26 February 2008 . ECOSUR P3192 (1), Puerto Viejo, Contoy Island (21°29’19” N, 86°47’44” W), on mangrove roots, 24 February 2008 . ECOSUR P3193 (2), Contoy Island , Quintana Roo, Mexico, 1 March 2001 . Jamaica. UMML 22.1163 (1), R / V Pillsbury, Cruise 7006, Sta. 1258 (17°03’N 78°10’W), Pedro Banks, Jamaica, 15 m depth, 15 July 1970 . Nicaragua. UMML 22.1164 (1), R / V Pillsbury, Cruise 7101, Sta. 1330 (11°51’N 83°27’W), SE Nicaragua, 24 m depth, 28 January 1971 . Venezuela. USNM 47771 (1), Cumaná Key, Mochima , 12 m depth, 21 October 1971 , Coll. Edwards. USNM 49709 (1), La Gabarra Beach, Mochima Bay , 8 m depth, 11 May 1971 , Coll. R. Edwards . British Virgin Islands. LACM-AHF 7370 (2) White Bay, Guana Island (18°28’32”N, 64°34’39”W), on artificial reef matrix structures (ARMs), 1.5 m depth, 9 July 2000 , Coll. T. Zimmerman, G. Hendler, R. Ware, K. Fitzhugh .

Type locality. Contoy Island , Quintana Roo, Mexico, at 1.5 m depth ( Fig. 1 ) .

Etymology. The specific term maya is a noun in apposition. ‘Mayan people’ is a collective term commonly used to refer indigenous peoples living mainly in southeast Mexico, Guatemala, Belize, Honduras, and El Salvador.

Description. Holotype (ECOSUR 0245) is a complete atoke female, in excellent condition ( Fig. 11A–B, D–F ), 240 mm long, 2.6 mm wide at chaetiger 10 excluding parapodia, 130 chaetigers, with oocytes present. Paratype (ECOSUR 0247) complete and in good condition ( Fig. 11C ), 56 mm long, 1.5 mm wide at chaetiger 10 excluding parapodia, 65 chaetigers.

Body pale or yellowish, tapering ( Fig. 11A–F ); with brown pigmentation in paratype ( Fig. 11C ), prostomium with spots in the incision of anterior margin, two spots over the eyes, and a cordiform spot between posterior pair of eyes, achaetous ring and anterior segments with two transverse narrow bands, giving it a striate appearance, pigmentation progressively faded out toward posterior end.

Prostomium 1.5x wider than long, subpentagonal, anterior margin deeply incised, dorsal groove present ( Fig. 11A, C–D ).

Antennae lanceolate, 1.3x longer than prostomium, not extending slight beyond palps ( Fig. 11A, C–D ).

Eyes rounded, subequal, in trapezoidal arrangement, blackish, as wide as basal diameter of antennae, lenses not visible, anterior pair sometimes reniform, posterior pair not covered by achaetous ring ( Fig. 11A, C–D ).

Achaetous ring twice longer than chaetiger 1, anterior margin convex ( Fig. 11A, C–D ).

Tentacular cirri smooth, posterodorsal cirri extending backwards to chaetiger 16 ( Fig. 11A, C–D ).

Pharynx everted in holotype ( Fig. 11A, E–F ). Jaws brown with 8 teeth along cutting edge ( Fig. 12H ). Maxillary ring cylindrical, oral ring frustum-shaped, 1.6x longer and 1.4x wider than maxillary ring ( Fig. 11E–F ).

Maxillary ring: I=0; IIa= 8 and IIb= 7 cones in arc; III= 8 cones in round; IVa= 9 and IVb= 10 cones in round ( Fig. 11E–F ). Oral ring: V= 0; VIa-b= 1 rounded papilla; VII-VIII= 0 ( Fig. 11E–F ). Ridge pattern of areas VI–V–VI, λ-shaped.

Paired oesophageal caeca absent.

Dorsal cirri filiform, progressively relatively longer; 3.2x longer than neuroacicular ligule in chaetiger 1, 5.5x longer in chaetiger 12, 9x longer in chaetiger 30, 6.8x longer in chaetiger 81, 10.4x longer in chaetiger 121 ( Fig. 12A–F ).

Dorsal ligule subconical or digitiform, progressively shorter toward posterior chaetigers, present throughout; 1.4x longer than neuroacicular ligule in chaetiger 12, 1.2x longer in chaetiger 30, 0.2x length of neuroacicular ligule in chaetiger 81, strongly reduced from chaetiger 121 ( Fig. 12A–E ); posterior chaetigers in paratype with dorsal ligules throughout, 0.3x length in chaetiger 52, 0.6x length in chaetiger 65 ( Fig. 12F–G ).

Notopodial prechaetal lobe absent throughout.

Median ligule subconical; 1.5x longer in chaetiger 12, 1.8x longer in chaetiger 30, 0.7x length of neuroacicular ligule in chaetiger 81, 0.8x length in chaetiger 121 ( Fig. 12A–G ).

Neuroacicular ligule subconical throughout, mucronate in middle and posterior chaetigers, progressively relatively longer and wider toward posterior chaetigers ( Fig. 12A–G ). Neuropodial superior and inferior lobes absent ( Fig. 12A–G ).

Neuropodial postchaetal lobe digitiform in first two chaetigers, lamelliform and shorter than neuroacicular ligules thereafter, disappearing toward most posterior chaetigers ( Fig. 12A–G ).

Ventral ligule digitiform throughout, progressively shorter toward posterior chaetigers; 1.3x longer than neuroacicular ligule in chaetiger 1, as long as in chaetiger 12, 0.6x length of neuroacicular ligule in chaetiger 30, 0.2x length in chaetiger 81, 0.3x length in chaetiger 121 ( Fig. 12A–G ).

Ventral cirrus filiform, extending beyond tip of neuroacicular ligule in posteriormost chaetigers; 1.6x longer than neuroacicular ligule in chaetiger 1, 1.7x longer in chaetigers 12 and 30, 1.2x length in chaetiger 81, 2x length in chaetiger 121 ( Fig. 12A–G ).

Aciculae amber throughout. Notoaciculae present in first two chaetigers ( Fig. 12A ). Notoaciculae narrower than neuroaciculae in anterior chaetigers, becoming as wide as in following chaetigers ( Fig. 12A–G ).

Notochaetae both short-bossed heterogomph spinigers and falcigers; spinigers in all chaetigers, pectinate, teeth minute, decreasing in size toward tip ( Fig. 12K ); falcigers appearing from chaetigers 15–17, pectinate, basal teeth minute and greatly increasing in size toward distal blade, distal teeth not extending beyond blade tip in middle chaetigers and extending beyond toward posterior ones ( Fig. 12I–J ), blade tip rounded throughout, shaft becoming slightly stouter toward posterior chaetigers ( Fig. 12I–J ).

Supracicular neurochaetae short-bossed heterogomph spinigers and long-bossed heterogomph falcigers; spinigers with blades as in notopodial ones; falcigers pectinate, increasing in size toward distal blade, distal teeth extending beyond blade tip, blade tip rounded throughout, blades becoming wider toward posterior chaetigers ( Fig. 12M ).

Infracicular neurochaetae both long-bossed heterogomph spinigers and falcigers; spinigers with blades pectinate, basal teeth coarse and greatly decreasing in size and becoming minute toward distal blade ( Fig. 12N ); falcigers pectinate, basal teeth minute and greatly increasing in size toward distal blade ( Fig. 12L, O ), distal teeth extending beyond blade tip, blade tip rounded throughout ( Fig. 12L, O ), blades shorter than supracicular falcigers in anterior chaetigers and becoming longer toward posterior ones, uppermost falcigers with longer and narrower blades than lowermost ones ( Fig. 12L ).

Pygidium swollen, funnel-shaped; anal cirri missing ( Fig. 11B ).

Remarks. The holotype is the largest specimen, being several times larger than the remaining material and more than 100 chaetigers. Of the specimens examined, only the holotype (last 5 chaetigers) and one paratype (ECOSUR P1150) (last 2 chaetigers) have inconspicuous dorsal ligules in posterior-most chaetigers. In the first instance, the inconspicuous dorsal ligules in a few posterior-most chaetigers were attributed to the size and number of chaetigers in the holotype. This situation is similar to that found in Ceratonereis australis Hartmann-Schröder, 1985 having inconspicuous dorsal ligules in few posterior-most chaetigers and the number of chaetigers of the holotype is 100 chaetigers or greater ( Hartmann-Schröder 1985). However, the finding of a complete small specimen demonstrated the presence of very reduced dorsal ligules, so the size was discarded for this species as a factor for this feature.

Perkins (1980) studied some specimens from Venezuela, finding a high resemblance to C. singularis ; however, the condition and number of species prevented an adequate description for a new species, naming it as Ceratonereis sp. Specimens studied by him, and deposited in USNM, were examined and are identical to those collected in the Mexican Caribbean. Hartmann-Schröder (1985) proposed the new subspecies Ceratonereis (Ceratonereis) singularis singularis for the form identified by Perkins as Ceratonereis sp. Type and additional materials of C. singularis from Western Mexico were examined to study if they belong to the same species, and they demonstrate to be distinct, and a new name for the new species C. maya n. sp. is proposed to avoid homonymy with C. singularis Treadwell, 1929 when elevated to the species level.

There are several differences between C. singularis and C. maya n. sp. allowing their clear separation: 1) in C. maya n. sp., dorsal cirri are relatively longer throughout body than in C. singularis ; 2) in C. maya n. sp., the dorsal ligules are much narrower than neuroacicular ligules in middle chaetigers, whereas in C. singularis they have similar wide; 3) in C. maya n. sp., both dorsal and ventral ligules reduce greatly their size toward posterior chaetigers, becoming papillae-like in posterior-most chaetigers and even inconspicuous, whereas in C. singularis they are relatively larger in posterior chaetigers; 4) the blades of notopodial short-bossed heterogomph falcigers in C. maya n. sp. are subequal in the same fascicle, whereas in C. singularis they can have different lengths; 5) pygidium in C. maya n. sp. is funnel-shaped, whereas in C. singularis it is tripartite and minute.

Distribution. Caribbean Sea.

Figures

FIGURE 1. Maps with the locations of the examined material. A, Caribbean Sea, Gulf of Mexico, and a section of the Sargasso Sea. B, Mexican Eastern Tropical Pacific. C, Brazilian Western Atlantic.

FIGURE 11. Ceratonereis maya n. sp. Holotype A, B, D–F (ECOSUR 0245); paratype C (ECOSUR 0247). A, anterior end dorsal view. B posterior end, dorsal view. C, anterior end, dorsal view. D, close-up of prostomium, dorsal view. E, pharynx, dorsal view (arrow tips point rounded papillae in areas VI). F, pharynx, ventral view. Scale bars: A, 1 mm; B–F, 0.5 mm.

FIGURE 12. Ceratonereis maya n. sp. Holotype A–E, I–O (ECOSUR 0245); paratype F–H (ECOSUR 0247). A, chaetiger 1, right parapodium. B, chaetiger 12, right parapodium. C, chaetiger 30, right parapodium. D, chaetiger 81, right parapodium. E, chaetiger 121, right parapodium. F, chaetiger 52, right parapodium. G, chaetiger 65, right parapodium. H, left jaw, dorsal view. I, notopodial short-bossed heterogomph falciger, chaetiger 29. J, notopodial short-bossed heterogomph falciger, chaetiger 121. K, notopodial short-bossed heterogomph spiniger, chaetiger 121. L, sub-acicular long-bossed heterogomph falcigers, chaetiger 29. M, supra-acicular long-bossed heterogomph falciger, chaetiger 121. N, sub-acicular long-bossed heterogomph spiniger, chaetiger 121. O, sub-acicular long-bossed heterogomph falciger, chaetiger 121. Scale bars: A–D, G, H, 0.3 mm; E, 0.5 mm; F, 0.2 mm; I–O, 10 µm.