Perinereis anderssoni Kinberg, 1865

Conde-Vela, Víctor Manuel, 2022, Reinstatement of Perinereis bairdii (Webster, 1884) and description of P. websteri sp. nov. from Bermuda, including the reproductive morphology of two Atlantic Perinereis species (Annelida: Errantia: Phyllodocida), European Journal of Taxonomy 787 (1), pp. 104-145 : 107-111

Perinereis anderssoni Kinberg, 1865

Figs 2 , 13

Perinereis anderssoni Kinberg, 1865: 175 .

Nereis minor Hansen, 1882: 12 , pl. 4 figs 8 – 12.

Perinereis anderssoni – Hartman 1948: 72–73. — De León-González & Solís-Weiss 1998: 675, figs 1a – g (partim).

Material examined

BRAZIL • 7 specs; Rio de Janeiro, Praia Vermelha ; 16 Aug. 2012; M. Coutihno and V. Schawn leg.; ECOSUR P3208 .

Description

BODY AND MEASUREMENTS. Non-type specimens (ECOSUR P3208) in good conditions, complete, largest specimen 23 mm long, 1.9 mm wide at chaetiger 10 excluding parapodia, 67 chaetigers. Body dorsally pigmented, with reddish brown pigmentation in palps, prostomium and chaetigers, intense in anterior region, progressively discoloring posteriorly ( Fig. 2A–B ). Pale lines present in dorsum of first 12 chaetigers ( Fig. 2A ), fingerprint-like pattern from chaetiger 13.

PROSTOMIUM. Subpyriform, as long as wide; anterior region distally entire, rectangular, slightly longer than posterior region, dorsal groove present ( Fig. 2A ); anterolateral gap between antenna and palpophore as long as diameter of antennae.

ANTENNAE. Digitiform, not passing palps, lacking pigments, half as long as prostomium, gap between them as long as basal wide of antennae ( Fig. 2A ).

PALPS. Palpophores ovoid, swollen, 1.5 × as long as wide, shorter than prostomium, subdistal transverse groove present ( Fig. 2A ). Palpostyles rounded.

EYES. Rounded, anterior and posterior pairs subequal, in trapezoidal arrangement, posterior pair covered by anterior margin of tentacular belt ( Fig. 2A ).

TENTACULAR BELT. 1.5× as long as chaetiger 1, covering posterior pair of eyes, anterior dorsal margin straight ( Fig. 2A ).

TENTACULAR CIRRI. Moniliform, not jointed, basal segment largest, remaining ones decrease in size progressively toward distal end longest cirri reaching end of chaetiger 1 ( Fig. 2A ).

PHARYNX. Dissected; jaws brown, cutting edge with 10 rounded teeth ( Fig. 2D ). Maxillary ring: I = 5 cones in triangle; II = 11–12 cones in arc; III = 19 cones in rectangle; IV = 19–33 cones in arc. Oral ring: V = 3 cones in triangle, two cones over each lateral edges; VI = 1–1 smooth bars; VII–VIII = 40 cones in two bands: anterior band with 8 paragnaths in a furrow row with 1 cone on the regions a–d, and 12 paragnaths in ridge row with 1 cone on each B–G regions; posterior band with 8 paragnaths in furrow row with 1 cone on the regions a–d, and 12 paragnaths in ridge row with 2 cones on region A and 1 cone on the regions B–F ( Fig. 13 ). Furrow pattern of areas VI–V–VI, Π- shaped ( Fig. 13 ).

DORSAL CIRRI. Digitiform in first chaetigers, filiform thereafter, attached basally to dorsal ligule in anteriormost chaetigers, medially in middle chaetigers, and subdistally in posterior chaetigers ( Fig. 2E– I ); 1.5 × as long as distal lobe of dorsal ligule in chaetiger 1, 2.2 × in chaetiger 10, 2.3× in chaetiger 28, 2.5× in chaetiger 45, 3.2× in chaetiger 62 ( Fig. 2E–I ); 4.7 × as long as proximal lobe of dorsal ligule in chaetiger 1, 2.7 × in chaetiger 10, 2.6 × in chaetiger 28, 1.5 × in chaetiger 45, 1× length in chaetiger 62 ( Fig. 2E–I ).

DORSAL LIGULES. Subconical with blunt tip in anterior and middle chaetigers, becoming pennant-like toward posterior chaetigers, with distal lobes longer than proximal ones in first chaetigers, becoming as long as in anterior and shorter than in middle and posterior chaetigers ( Fig. 2E–I ). Distal lobe of dorsal ligule subconical throughout; as long as median ligule in chaetigers 10 and 28, 1.8 × as long as in chaetiger 45, 2.8× in chaetiger 62 ( Fig. 2E–I ).

MEDIAN LIGULES. Subconical with blunt tip in anterior chaetigers, becoming sharper thereafter ( Fig. 2E– I ); 1 × length of neuroacicular ligule in chaetiger 10, 4.3× in chaetiger 28, 2× in chaetigers 45 and 62 ( Fig. 2E–I ).

NEUROACICULAR LIGULES. Subconical in anterior and middle chaetigers, becoming rounded in posterior ones ( Fig. 2E–I ); 0.7× length of ventral ligule in chaetiger 1, 2× in chaetiger 10, 1 × in chaetiger 28, 2× in 45, 1.6 × in chaetiger 62 ( Fig. 2E–I ).

NEUROPODIAL SUPERIOR AND INFERIOR LOBES. Present in anterior and middle chaetigers, both rounded, inferior one wider than superior one throughout ( Fig. 2E–I ).

NEUROPODIAL POSTCHAETAL LOBES. Rounded, half as long as neuroacicular ligule throughout.

VENTRAL LIGULES. Digitiform throughout ( Fig. 2E–I ).

VENTRAL CIRRI. Digitiform throughout ( Fig. 2E–I ); 1× length of ventral ligule in chaetiger 1, 0.8× length thereafter ( Fig. 2E–I ).

ACICULAE. Dark brown throughout ( Fig. 2A–I ); notoaciculae absent in first two chaetigers ( Fig. 2E ). NOTOCHAETAE. All homogomph symmetrical spinigers. Blades of spinigers with basal pectinate, coarse teeth, becoming minute toward distal end.

NEUROCHAETAE. Homogomph symmetrical spinigers and heterogomph falcigers in supra-acicular fascicles, heterogomph spinigers and falcigers in sub-acicular fascicles. Neuropodial homogomph spiniger as notopodial ones. Heterogomph spinigers with blades pectinate, minute teeth and decreasing in size toward distal end. Heterogomph falcigers pectinate, long and narrow teeth, half of inner edge of blade dentate, distal tips stout, stouter in supra-acicular falcigers ( Fig. 2J–K ).

PYGIDIUM. Crenulated, bilobate ( Fig. 2B ); anal cirri subulate, as long as last three chaetigers ( Fig. 2B ).

Remarks

Kinberg (1865) included few features in the original description of P. anderssoni , all focused on features of the anterior end of the body. Hartman (1948) briefly redescribed the species and regarded Nereis bairdii Webster, 1884 , and doubtfully P. ponteni Kinberg, 1865 , as junior synonyms. Morphological differences between P. anderssoni and P. ponteni have been pointed out in recent studies (e.g., Coutinho & Santos 2014; Coutinho et al. 2015), and here the synonymy of N. bairdii is rejected (see remarks of Perinereis bairdii below). Epitokes were not available for this study, but recently Peixoto & Santos (2016) detailed the reproductive biology of P. anderssoni , finding four epitokal stages in both males and females.

De León-González & Solís-Weiss (1998) redescribed P. anderssoni based on the best-preserved specimen of the syntype series, but they highlighted the poor conditions of the type series and the absence of pigmentation. To improve the available redescription, a complementary description is provided based on topotypes in better condition of preservation. De León-González & Solís-Weiss (1998) also recorded the species from Chile and the Gulf of Mexico, regarding it as amphiamerican. The inclusion of material from Juan Fernández, Chile is explained after Hartman (1948) noted some similarities in parapodia between P. anderssoni and P. pseudocamiguina ( Augener, 1922) (type locality: Juan Fernández) ( Augener 1922; Hutchings et al. 1991), but there are differences between them: 1) P. pseudocamiguina has 1–2 cones in area I, 7–13 cones in area III, and occasionally bars in areas IV; whereas P. anderssoni has 4–5 cones in area I, 19–21 cones in areas III, and no bars in areas IV; 2) in P. pseudocamiguina , dorsal cirri in posterior chaetigersare 0.5–0.6×as long as proximal lobe of dorsal ligule, whereas in P. anderssoni they ate as long as; 3) in P. pseudocamiguina , dorsal cirri are 2.0–2.2 × as long as distal lobe of dorsal ligules, whereas in P. anderssoni they are 3.2 × longer; 4) in P. pseudocamiguina , the dorsal ligules in posterior chaetigers are longer than wide and with dorsal surface slightly convex; whereas in P. anderssoni , they are wider than long and with dorsal surface strongly convex. Finally, Hartman (1948), following Augener (1934), also considered N. minor Hansen, 1882 (type locality: Rio de Janeiro, Brazil) as a probable junior synonym of P. anderssoni ; the original description is succinct, but the illustrations included show the high similarities in the arrangement of paragnaths and the parapodia (probably from anterior chaetigers), so the synonymy with N. minor is retained until a further revision of type material.

Liñero-Arana & Reyes-Vásquez (1979) reported P. anderssoni from Venezuela, but based on the redescription and the current description, there are key differences between Venezuelan specimens and P. anderssoni : 1) in Venezuelan specimens, numbers of paragnaths in some pharyngeal areas as follows: I = 10–18, II = 20–27, V = 1, whereas in P. anderssoni are as follows: I = 5, II = 11–12, V = 3; 2) in Venezuelan specimens, dorsal cirri in posterior chaetigers are 0.6× as long as proximal lobes and 1.5× as long as distal lobes of dorsal ligules, whereas in P. anderssoni , dorsal cirri are as long as proximal lobes and 3.2× as long as distal lobes of dorsal ligules; 3) in Venezuelan specimens, the dorsal ligules are at least 3.5× as long as median ligules and the ventral ligules are 2–4 × longer than neuroacicular ligules in posterior chaetigers, whereas in P. anderssoni , the dorsal ligules are 2.8 × as long as median ligules and ventral ligules are shorter than neuroacicular ligules. These specimens are closer to P. ponteni or P. bairdii than to P. anderssoni because of the large number of paragnaths in area I and a single paragnath in area V, recorded a couple of times ( Díaz-Díaz & Liñero-Arana 2002; Vanegas-Espinosa et al. 2007). The two Perinereis species described from Venezuela, P. mochimaensis Liñero-Arana, 1983 and P. cariacoensis Liñero-Arana, 1983 , are also different, therefore Venezuelan specimens belong to another, undescribed species.

Following Hartman (1948), Rioja (1960) reported P. anderssoni for Veracruz, Mexico but recognizing that the specimens are closer to P. ponteni . Key differences among these Mexican specimens and P. anderssoni are the following: 1) in Mexican specimens, area I has 10–12 cones and area V has 1 cone, whereas in P. anderssoni , area I has 5 cones and area V has 3 cones; 2) in Mexican specimens, antennae are 0.3 ×as long as prostomium, whereas in P. anderssoni they are half as long; 3) in Mexican specimens, dorsal cirri in anterior chaetigers are shorter than distal lobes of dorsal ligules, whereas in P. anderssoni they are longer; 4) in Mexican specimens, dorsal cirri are 2× as long as distal lobes of dorsal ligules and ventral ligules are 2.5 × as long as neuroacicular ligules in posterior chaetigers, whereas in P. anderssoni dorsal cirri are 3.2 × longer and the ventral ligules are shorter than. Salazar-Vallejo & Jiménez-Cueto (1997) reported P. anderssoni for the Mexican Caribbean, but these specimens differ from Brazilian ones in the following features: 1) in the Caribbean specimens, dorsal cirri are 1.4× as long as distal lobes of dorsal ligules and median ligules are as long as neuroacicular ligules in anterior chaetigers, whereas in the Brazilian ones the dorsal cirri are 2.2 × longer and median ligules are subequal; 2) in the Caribbean specimens, dorsal cirri are 0.5× as long as proximal lobes and as long as distal lobes of dorsal ligules in posterior chaetigers, whereas in the Brazilian ones the dorsal cirri are as long as proximal lobes and 3.2× as long as distal lobes. Records of P. anderssoni in other Caribbean regions (e.g., Fauchald 1977; Ibárzabal 1986) deserve a new evaluation.

Distribution

Brazil.

Figures

Fig. 2. Perinereis anderssoni Kinberg, 1865. Topotype (ECOSUR P3208). A. Anterior end, dorsal view. B. Posterior end, dorsal view. C. Posterodorsal tentacular cirri. D. Left jaw, dorsal view. E. Chaetiger 1, right parapodium.F. Chaetiger 10, right parapodium. G. Chaetiger 28, right parapodium. H. Chaetiger 45, right parapodium. I. Chaetiger 62, right parapodium. J. Supra-acicular heterogomph falciger, chaetiger 62. K. Sub-acicular heterogomph falciger, chaetiger 28. Scale bars: A–C = 1 mm; D = 0.25 mm; E–I = 0.1 mm; J–K = 10 μm.

Fig. 13. Arrangement of paragnaths in the ridge and furrow regions of areas VII–VIII in species of Perinereis Kinberg, 1865. Filled figures with solid edges represent paragnaths observed in all specimens examined, no-filled figures with dashed edges represent paragnaths observed in some specimens only.