Pseudonereis citrina Conde-Vela 2018, sp. n.
Creators: name: Conde-Vela, Víctor M.
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Animalia
Annelida
Polychaeta
Phyllodocida
Nereididae
Pseudonereis
Pseudonereis citrina

description: Pseudonereis citrina sp. n.
Figure 7
Pseudonereis gallapagensis Liñero-Arana & Reyes-Vásquez 1979: 8 –9, Pl. 7, Figs. 1–10. Salazar-Vallejo & Jiménez-Cueto 1997: 369, Figs. 35, 36, 51 (non Kinberg, 1865).
Type material. Caribbean Sea, Mexico. Holotype ECOSUR 0 194, Mahahual, Quintana Roo (18°43'27.06"N 87°42'1.53"W), 19 January 2001, in corals, Coll. SI Salazar-Vallejo. Paratypes ECOSUR 0 195 (2), Akumal, Quintana Roo (20°23'38.41"N 87°18'55.61"W), 23 February 1986, Coll. M Aguilar, A Gómez. ECOSUR 0 196 (2), Xamach, Quintana Roo (19°55'36.85"N 87°26'9.17"W), 28 February 1986, Coll. M Aguilar, J Fernández.
Additional material. Caribbean Sea, Mexico. ECOSUR P1108 (1), Mahahual, Quintana Roo (18°43'27.06"N 87°42'1.53"W), 20 May 1997, Coll. SI Salazar-Vallejo, LF Carrera-Parra. ECOSUR P1222 (1), Playa Sol y Mar, Quintana Roo (18°46'36''N 87°40'14.4''W), 18 January 2000, Coll. SI Salazar-Vallejo, LF Carrera-Parra. ECOSUR P2278 (1), Vigía Chico, Quintana Roo (19°46'22.84"N 87°35'11.38"W), 27 February 1986, Coll. SI Salazar-Vallejo. ECOSUR P2932 (4), Puerto Morelos, Quintana Roo (20°50'52''N 86°52'29''W), 15 December 1986, Coll. P Gómez. Panama. USNM 73683 (2), Galeta Reef Flat, Canal zone, 1973, Coll. HO Brattstrom.
Type locality. Mahahual, Quintana Roo, Mexican Caribbean (18°43'27.06"N 87°42'1.53"W).
Etymology. The specific name stems from the Latin adjective citrinus, - a, - um, meaning lemon yellow, referring to the yellowish body and the presence of yellow glandular masses that are very conspicuous in the notopodial dorsal ligules of the posterior chaetigers.
Description. Holotype (ECOSUR 0194) complete, 19 mm long, 1.5 mm wide, 62 chaetigers, body damaged at chaetiger 30. One paratype (ECOSUR 0196) complete, 10 mm long, 0.8 mm wide at chaetiger 10, 51 chaetigers; another paratype (ECOSUR 0195) complete, 19 mm long, 3.9 mm wide at chaetiger 10, 70 chaetigers. Body pale, yellowish, translucent toward posterior end, tapered, pigments absent in all specimens.
Prostomium longer than wide; antennae lanceolate, half as long as prostomium, slightly passing the palps; eyes rounded, subequal, black, in trapezoidal arrangement (Fig. 7A). Achaetous ring 1.5 times longer than first chaetiger; anterior cirri with cirrophore conspicuous, longest cirri reaching chaetiger 5 (Fig. 7A).
Pharynx dissected; jaws brown, 13 teeth, distal end slightly incurved, cutting edge completely dentate (Fig. 7C). Maxillary ring: I= 3 cones in vertical line; II= 4–5 comb-like rows in triangle; III= 4 comb-like rows in triangle; IV= 4-4 comb-like rows and additional cones, merged cones and P-bars, in sigmoid. Oral ring: V= 0; VI= 1-1 shield-shaped bars with pointed (Fig. 7D) and blunt (Fig. 7E) tips; VII–VIII= one furrow row with 11 P-bars and one ridge row with 10 cones in a single band, rows vertically displaced; furrow and ridge regions with one paragnaths each.
Parapodial cirri pattern: Dorsal cirri several times longer than notopodial dorsal ligules in anterior and middle body, largest in middle body, becoming shorter in posterior-most chaetigers; basally inserted to dorsal ligules in most-anterior segments, displaced medially in anterior and medial chaetigers, subdistal in posterior chaetigers, and distal in posterior-most ones. Ventral cirri longer than neuropodial ventral ligules in anterior-most chaetigers; subequal from anterior to posterior chaetigers, slightly shorter in posterior-most segments; basally inserted to neuropodial ventral ligules throughout body.
First two chaetigers with neuroaciculae only, remaining ones with both noto- and neuroaciculae; conspicuous glandular masses on tips of ligules and lobes throughout body. In first two chaetigers (Fig. 7F), dorsal cirrus basal, 1.5 times longer than dorsal ligule. Dorsal ligule digitiform, as long as neuropodial ventral ligule, slightly longer than neuroacicular ligule. Neuroacicular ligule digitiform, twice wider than long, distally bilobed, both superior and inferior lobes subequal, sometimes inconspicuous; postchaetal lobe rounded, as long as neuroacicular one; neuropodial ventral ligule digitate. Ventral cirrus basal, slightly longer than neuropodial ventral ligule.
In anterior and middle chaetigers (Fig. 7G–H), dorsal cirrus medial, 2–3 times longer than notopodial dorsal ligule. Notopodial dorsal ligule subconical, blunt, subequal than notopodial ventral ligule; notopodial ventral ligule subconical, blunt, shorter than neuroacicular ligule. Neuroacicular ligule subconical, twice wider than long, twice as long as neuropodial ventral ligule, distally bilobed, both superior and inferior lobes subequal, sometimes inconspicuous; postchaetal lobe rounded, as long as neuroacicular one; neuropodial ventral ligules digitiform. Ventral cirrus basal, subequal to neuropodial ventral ligule.
In posterior chaetigers (Fig. 7I), dorsal cirrus subdistal, 1.5 times longer than notopodial dorsal ligule. Notopodial dorsal ligule subconical, blunt, shorter than notopodial ventral ligule; notopodial ventral ligule subconical, blunt, subequal to neuroacicular ligule. Neuroacicular ligule subconical, blunt, twice wider than long, twice as long as neuropodial ventral ligule; postchaetal lobe inconspicuous; neuropodial ventral ligule digitiform. Ventral cirrus subulate, shorter than neuropodial ventral ligule.
In posterior-most chaetigers (Fig. 7J), dorsal cirrus distal. Notopodial dorsal ligule foliose, pennant-like, twice as long as wide, 1.6 times longer than dorsal cirrus, 5–6 times longer than notopodial ventral ligule; notopodial ventral ligule subconical, blunt, twice as long as neuroacicular ligule. Neuroacicular ligule subconical, blunt, 1.5 times wider than long, twice as long as neuropodial ventral ligule; postchaetal lobe inconspicuous; neuropodial ventral ligule digitiform. Ventral cirrus subulate, shorter than neuropodial ventral ligule.
Notochaetae homogomph spinigers. Neurochaetae spinigers and heterogomph falcigers in supra-acicular fascicles, heterogomph spinigers and falcigers in sub-acicular fascicles.
Notopodial homogomph spinigers pectinate, coarse teeth, decreasing in size toward end (Fig. 7O). Neuropodial homogomph spinigers as notopodial ones; heterogomph spinigers serrate, basal teeth coarse, decreasing in size toward distal end (Fig. 7K, P). Neuropodial heterogomph falcigers falcate, pectinate, coarse teeth, half of inner edge edentate, distal tip stout; supra-acicular falcigers stouter than sub-acicular ones, falcigers become stouter toward posterior chaetigers (Fig. 7L – N).
Pygidium crenulated; anal cirri subulate, as long as last five chaetigers (Fig. 7B).
Variation. The results of the analysis of body variation and paragnaths number are summarized in Tables 1 and 2. W3 had the highest coefficient of correlation with TL, followed by nCh, W10, L10 and L3; RTC had no correlation with TL. Variation in paragnath number was very low, varying in one or two paragnaths in the areas I, V and VII– VIII. The number of paragnaths in the areas V, VI and VII–VII is similar to found in other Pseudonereis species (Bakken 2007, Table 1).
Remarks. Pseudonereis citrina sp. n. resembles P. gallapagensis, but they have several differences. In P. citrina sp. n., the dorsal cirri are 2–3 times longer than notopodial dorsal ligules in anterior chaetigers, whereas in P. gallapagensis they are 1.2 times longer. Also, in P. citrina sp. n., notopodial dorsal ligules in posterior-most chaetigers are 1.6 times longer than dorsal cirri, whereas in P. gallapagensis they are 2.6 times longer. Furthermore, in P. citrina sp. n., the neuroacicular ligules are distally bilobate in anterior chaetigers only and sometimes they are no evident, whereas in P. gallapagensis they are distally bilobate throughout body. Finally, in P. citrina sp. n., teeth of neuropodial heterogomph falcigers are stouter and less numerous that in P. gallapagensis sp. n. P. citrina sp. n. resembles P. fauveli sp. n., mainly because the similar body size, the large dorsal cirri in anterior and middle chaetigers, and the translucent notopodial dorsal ligules in posterior chaetigers, but the former species can be readily recognized by having falcate dentate jaws, whereas P. fauveli sp. n. has helical edentate jaws; additional differences are discussed below.
The yellowish color of body in this species and the spotted notopodial dorsal ligules were observed in all material examined. The small size, the body color and enlarged dorsal cirri allow the easy recognition of this Caribbean species. The description of specimens as P. gallapagensis by Liñero-Arana & Reyes-Vásquez (1979) from Caribbean Venezuela matches with the current description of P. citrina sp. n., mainly in the parapodial proportions; Díaz-Díaz & Liñero-Arana (2002: 33) and Vanegas-Espinosa et al. (2007: 122), provided additional records of P. gallapagensis for Venezuela and argued that they are the same as described by Liñero-Arana & Reyes-Vásquez (1979), so likely they belong to P. citrina sp. n. as well. Record of P. variegata by Fauchald (1977a: 33) does not belong to P. citrina sp. n. nor P. brunnea sp. n. because the dorsal cirri are shorter than notopodial dorsal ligules in posterior chaetigers, whereas in the specimens described by Fauchald (1977a) both dorsal cirri and notopodial dorsal ligules are equal in length. Augener (1927: 48–49) recorded P. variegata from Curaçao based on epitokes and his specimens match P. citrina sp. n. in the terminal dorsal cirri of posterior-most chaetigers; however, because the epitoke morphology of P. citrina sp. n. is unknown, Augener’s record could represent another undescribed species.
Distribution. Caribbean Sea.
description: Published as part of Conde-Vela, Víctor M., 2018, New species of Pseudonereis Kinberg, 1865 (Polychaeta: Nereididae) from the Atlantic Ocean, and a review of paragnath morphology and methodology, pp. 245-278 in Zootaxa 4471 (2) on pages 257-260, DOI: 10.11646/zootaxa.4471.2.2, http://zenodo.org/record/1439650