Pseudonereis gallapagensis Kinberg 1865
Creators: name: Conde-Vela, Víctor M.
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Animalia
Annelida
Polychaeta
Phyllodocida
Nereididae
Pseudonereis
Pseudonereis gallapagensis

description: Pseudonereis gallapagensis Kinberg, 1865
Figures 2B, 3I, 9A–K
Pseudonereis gallapagensis Kinberg 1865: 174; 1910: 52, Pl. 20, Figs. 3B, 3C, 3 C’, 3F10, 3G s, 3G u. Gravier 1909: 629 –633, Pl. 16, Figs. 15–20. Hartman 1948: 68 –69 (partim). Hartmann-Schröder 1962b: 432 –434. Bakken 2007: 157 –159 (partim).
Type locality. Indifatigable Island (Santa Cruz Island), Galapagos Islands, Ecuador.
Material examined. Eastern Pacific Ocean, Peru. USNM 24262 (7), Salaverry, 19 October 1926, Coll. WL Schmitt. USNM 24263 (1), Paita, 6 October 1926, Coll. WL Schmitt. Ecuador. USNM 24264 (2), Salinas, 14 September 1926, Coll. WL Schmitt. USNM 24265 (3), Salinas, Coll. WL Schmitt. Chile. USNM 33263 (12), Valparaiso, 10 February 1963, Coll. WL Klawe.
Description. Specimens used for description (USNM 24265) complete, in good conditions. Largest specimen 49 mm long, 2 mm wide at chaetiger 10, 82 chaetigers; another one complete, 39 mm long, 1.7 mm wide at chaetiger 10, 80 chaetigers. Body soft, translucent in mid body, pigmentation absent (Fig. 9A–B).
Prostomium as long as wide; antennae cirriform, half as long as prostomium, not passing the palps; eyes black, rounded, subequal, in rectangular arrangement (Fig. 9A). Achaetous ring as long as first chaetiger; four pairs of anterior cirri, cirrophores conspicuous, longest one reaching chaetiger 4 (Fig. 9A).
Pharynx everted; jaws dark brown, cutting edge dentate. Maxillary ring: I= 2 cones in vertical line; II= 3-3 comb-like rows in triangle; III= 4 comb-like rows in triangle; IV= 6-6 comb-like rows and additional cones, merged cones and P-bars, in sigmoid (Figs. 2B, 9C–D). Oral ring: V= 1 cone; VI=1-1 shield-shaped bars with pointed and blunt tips; VII–VIII= one furrow row with 12 P-bars and one ridge row with 9 cones in a single band, rows vertically displaced; furrow and ridge regions with one paragnath each (Figs. 2B, 3I, 9C–D).
Parapodial cirri pattern: Dorsal cirri longer than notopodial dorsal ligules in anterior region, becoming shorter toward posterior end; basally inserted to dorsal ligules in most anterior segments, displaced medially in medial segments, subdistal in posterior segments and distal in posterior ones, extending beyond notopodial dorsal ligules throughout body. Ventral cirri subequal and basally inserted to neuropodial ventral ligules throughout body.
First two chaetigers with neuroaciculae only, remaining ones with both noto- and neuroaciculae. In first two chaetigers (Fig. 9H), dorsal cirrus basal, 1.5 times longer than dorsal ligule. Dorsal ligule digitiform, 1.5 times longer than neuroacicular ligule. Neuroacicular ligule subconical, subequal than neuropodial ventral ligule, distally bilobed, superior lobe smaller than inferior one; postchaetal lobe subconical, blunt, half as long as neuroacicular ligule; neuropodial ventral ligule digitiform. Ventral cirrus basal, as long as neuropodial ventral ligule.
In anterior chaetigers (Fig. 9I), dorsal cirrus medial, 1.2 times longer than notopodial dorsal ligule. Notopodial dorsal ligule subconical, blunt, subequal than notopodial ventral ligule and neuroacicular ligule; notopodial ventral ligule rounded. Neuroacicular ligule subconical, twice as long as neuropodial ventral ligule, distally bilobed, superior lobe much smaller than inferior one; postchaetal lobe subconical, half as long as neuroacicular ligule; neuropodial ventral ligule digitiform. Ventral cirrus basal, as long as neuropodial ventral ligule.
In middle chaetigers (Fig. 9J), dorsal cirrus medial, as long as notopodial dorsal ligule. Notopodial dorsal ligule subconical, blunt, subequal than notopodial ventral ligule; notopodial ventral ligule digitiform, subequal than neuroacicular ligule. Neuroacicular ligule subconical, twice as long as neuropodial ventral ligule, distally bilobed, superior lobe smaller than inferior one; postchaetal lobe subconical, blunt, half as long as neuroacicular ligule; neuropodial ventral ligule digitiform. Ventral cirrus basal, as long as neuropodial ventral ligule.
In posterior chaetigers (Fig. 9K), dorsal cirrus distal. Notopodial dorsal ligule foliose, pennant-like, twice as long as wide, 2.6 times longer than dorsal cirrus, 7–8 times longer than notopodial ventral ligule; notopodial ventral ligule subconical, blunt, as long as neuroacicular ligule. Neuroacicular ligule subconical, as long as neuropodial ventral ligule, distally bilobed, superior lobes smaller than inferior one; postchaetal lobe subconical, blunt, subequal than neuroacicular ligule; neuropodial ventral ligule digitiform. Ventral cirrus basal, as long as neuropodial ventral ligule.
Notochaetae homogomph spinigers. Neurochaetae homogomph spinigers and heterogomph falcigers in supraacicular fascicles, heterogomph spinigers and falcigers in sub-acicular fascicles.
Neuropodial heterogomph falcigers falcate, pectinate, narrow teeth, half to two thirds of inner edge edentate, distal tip stout; blades of heterogomph falcigers in anterior chaetigers narrower than in posterior ones, supraacicular falciger stouter than sub-acicular ones (Fig. 9F–G).
Pygidium crenulated; anal cirri cirriform, as long as last five segments (Fig. 9B).
Remarks. The original description by Kinberg (1865) is short and focused on the head features; some illustrations of the anterior end, the pharynx, a parapodium from chaetiger 10, a spiniger and a falciger were added in another publication (Kinberg 1910). The current description agrees with the mentioned features. Hartman (1948: 68–69) examined the type, but only detailed the distal attachment of dorsal cirri in posterior chaetigers and presence of spinigers and falcigers in neuropodia and made reference to previous redescriptions by Gravier (1909) from Peru, and by Fauvel (1914) from Gulf of Guinea. Day (1967: 331) synonymized P. gallapagensis with P. variegata based on specimens from South Africa. The specimens examined agree with the description by Gravier (1909), but the specimens and description from Gulf of Guinea by Fauvel (1914) match P. fauveli sp. n., and the description by Day (1967) matches Nereis mendax Stimpson, 1856 species group but not with P. gallapagensis (see Remarks section of P. fauveli sp. n.).
Bakken (2007) redescribed P. gallapagensis based on the type material of the species and type material of P. formosa Kinberg, 1865, previously regarded as synonym by Hartman (1948: 68–69); both authors agreed that type material of P. gallapagensis is in poor conditions, and consequently Bakken (2007) illustrated the species with the type of P. formosa. Based on specimens herein described, P. gallapagensis has some morphological differences with P. formosa, and consequently they are regarded as a valid species (see Remarks section of P. formosa). Also, P. gallapagensis have high resemblance with P. brunnea sp. n., differences between them are discussed above (see Remarks section of P. brunnea sp. n.).
Rozbaczylo & Bolados (1980: 219) studied 28 specimens identified as P. gallapagensis from Iquique, northern Chile, and including a short description, but there are some differences based on the current description. In specimens from Iquique, the area I has one paragnath, whereas the examined specimens have two paragnaths in the area I. Also, in specimens from Iquique, the areas VI have crescent-shaped bars, whereas the examined specimens have shield-shaped bars in such areas (but see Discussion). Furthermore, specimens from Iquique have ventral cirri longer than neuropodial ventral ligules at least until the third posterior of the body, whereas in the examined specimens they are shorter. Finally, in specimens from Iquique, neuropodial heterogomph spinigers in sub-acicular fascicles were not observed, whereas in the examined specimens they appear from the middle chaetigers. Therefore, specimens from Iquique likely belong to a different species than P. gallapagensis as currently defined.
Distribution. Ecuador, Peru, Chile.
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 264-266, DOI: 10.11646/zootaxa.4471.2.2, http://zenodo.org/record/1439650