Perinereis nuntia (Savigny in Lamarck, 1818 )

Villalobos-Guerrero, Tulio F., 2019, Redescription of two overlooked species of the Perinereis nuntia complex and morphological delimitation of P. nuntia (Savigny in Lamarck, 1818) from the Red Sea (Annelida, Nereididae), Zoosystema 41 (24), pp. 465-496 : 469-473

Perinereis nuntia (Savigny in Lamarck, 1818) , restricted

( Figs 1 D-F; 2A-P)

Lycoris nuntia Savigny in Lamarck, 1818: 312-313 . — Savigny 1822: 33, pl. 4, figs 2.1-2.10.

Nereis (Neanthes) nuntia – Gravier 1899: 237 (partim); 1902: 164- 167 (partim).

Perinereis nuntia – Ben-Eliahu 1991: appendix table 1. — Wilson & Glasby 1993: 266-268, fig. 11a-g (partim). — Yousefi et al. 2011: 59 , figs 2d, 7a-e (partim).

Perinereis nuntia typica – Fauvel 1919: 415-416 (partim); 1927: 432- 433 (partim); 1932: 109-110 (partim). — Ben-Eliahu 1972: 221.

MATERIAL EXAMINED. — Three specimens of Perinereis nuntia, ZMB 4019-Q, Red Sea, identified by A.E. Grube as Nereis nuntia , in poor conditions.

DIAGNOSIS. — Specimens with antennae nearly joined, nuchal organs subequal to posterior eyes, postero-dorsal tentacular cirri reaching chaetigers 4-6. Jaws with 2 canals. Maxillary ring: AI= 1-3; AII = 9-11; AIII = 11-19, two lateral cones; AIV = 14-19, merged paragnaths absent. Oral ring: AVI-V-VI pattern, χ -shaped; AV= 2-4, paragnaths behind AVI; AVI = 8-10, arc long, oblique, bars short, even; AVII-VIII =36-50, 4-5 transverse rows, proximal with smaller cones. Gap between AVI and AVII-VIII narrow. Dorsal cirri 3-4 times longer than dorsal ligule, inserted posteriorly on one-half of it. Dorsal ligule barely uneven throughout body, subequal to median ligule; distal lobe conical posteriorly. Ventral cirri cirriform. Homogomph spinigers with blades finely serrated, evenly spaced; absent in subacicular neurochaeta. Heterogomph spinigers with blades finely serrated, evenly spaced; present throughout. Heterogomph falcigers with medium and long blades.

HABITAT. — Shallow waters, mud under rocks (Ben-Eliahu 1972, 1991).

TYPE LOCALITY. — Gulf of Suez (possibly Suez, Egypt, fide Álvarez-Campos et al. 2015).

DISTRIBUTION. — Gulf of Suez ( Savigny 1822; Ben-Eliahu 1972, 1991); probably only in the Northern and Central Red Sea. DESCRIPTION

Body. Non-type, ZMB 4019-Q, atoke female, complete, LT =220 (135-220) mm, L15= 24 (9.7-24) mm, W15= 4 (2.2-4) mm, and 127 (109-127) chaetigers. Muscle almost completely digested, soft specimens. Body epidermal and glandular pigmentation completely faded.

Head. Prostomium sub-pentagonal, narrow anterior end ( Fig. 2A ); 1.3 times wider than long; anterolateral sides 2 times wider than antennal diameter. Palpophores oval ( Fig.2A ), thick, as long as wide, nearly equaling entire length of prostomium; one deep wrinkle placed horizontally in distal third of palpophore. Antennae nearly joined, gap one-third of antennal diameter; digitiform, thickened, extending backward to nearly two-fifths of prostomium. Eyes and lens unpigmented due to long-term preservation, trapezoidal arrangement, anterior and posterior pairs separated (gap subequal to size of posterior; Fig. 2A ); lens not visible. Anterior pair of eyes rounded, two-thirds width of antennal diameter. Posterior pair of eyes rounded, similarsized to anterior pair. Nuchal organs deeply embedded, slightly oblique, short, subequal to posterior eyes ( Fig. 2A ).

Apodous anterior segment & tentacular cirri. Apodous anterior segment 4.7 (4.3-4.7) times wider than long, 1.4 (1.3-1.5) times longer than chaetiger 1. Tentacular cirri pattern: Postero-dorsal cirri 1.7 times longer than antero-dorsal ones; anterior-ventral cirri two-thirds length of postero-ventral one. Antero-dorsal cirri reaching chaetiger 2 (2-3); antero-ventral three-quarters length of (or subequal to) palpophore. Postero-dorsal reaching chaetiger 4 (4-6); postero-ventral extending over prostomium to reach one-half of it. Cirrophores damaged, limp.

Pharynx. Everted between jaws only examined in one specimen, blackish in distal third, then brownish to yellow amber; 7 denticles, more or less developed, restricted to distal two-fifths of jaw, 1 denticle ensheathed proximally, inner margin of fang flattened, equaling next 2 (2-3) denticles; pulp cavity four-sixth length of jaw ( Fig. 2B ), distal apex not leveling denticles; 2 longitudinal canals emerging from pulp cavity ( Fig. 2C ). Maxillary ring ( Fig. 2A, D, G ): paragnaths conical, none worn, reddish amber colored, slightly smaller than those in oral ring. AI = 1 (1-3), slightly longer than the longest of AII (longitudinal regular line when>2). AIIa= 9 (9-10), AIIb =9 (9-11), oblique sub-oval patch, 2 (2-3) irregular rows. AIII= 11 (11-19), rectangular (quadrangular or rectangular) patch, 2 (2-3) irregular transverse rows, two cones laterally isolated in each side. AIVa = 14 (14-19), AIVb = 15 (15-18), crescent-shaped patch, medial cones bigger, merged paragnaths absent. Oral ring ( Fig. 2 E-F): AVI-V-VI pattern, χ- shaped; AVI overlapping proximally AV further behind arc of paragnaths ( Fig. 2F ). Paragnaths conical and shield-shaped bars, brownish amber (brownish amber or reddish amber) colored. AV= 2 (2-4), oblique (oblique or sub-triangular) patch, cones placed further behind from those on AVI, distal cone bigger. AVIa = 8 (8-9), AVIb= 10 (8-10), arc of paragnaths long, oblique (forming an obtuse angle with distal vertex), shield-shaped bars; bars short, tip campanulate or blunt, similar in length; ridges barely prominent, narrow, three-quarters width of palpophore. AVII-VIII=36 (36-50), conical paragnaths, single band of 4 (4-5) transverse rows, increasing in number dorsoventrally from 2 to 4 (4-5) rows, distal rows with bigger cones, distal-most row regular, following two ones irregular because apparently mixed, proximal row slightly regular, smaller cones. Gap between AVI and AVII-VIII broad, as wide as palpophore ( Fig. 2E ).

Notopodia. Dorsal cirrus digitiform, longer than dorsal ligule throughout body; barely longer than ligule in first parapodia ( Fig.2H ), 2 (1.5-2) times longer in anterior parapodia ( Fig. 2I ), 2.5 (2-3) times longer in median ( Fig. 2J ), 3 (3-4) times longer in posterior ones ( Fig. 2K ); cirrus longer than length of proximal lobe of dorsal ligule throughout body, much more longer from median parapodia ( Fig. 2 I-K); cirri inserted on one-third in anterior parapodia, two-fifths in median, one-half in posterior ones. Dorsal ligule somewhat uneven throughout body, becoming barely expanded from parapodia 88 (80-88); ligule 2.5 (2.2-2.5) times width of median ligule in posterior parapodia ( Fig. 2K ). Distal lobe of dorsal ligule bluntly conical in anterior parapodia, conical from median parapodia; distal lobe longer than proximal one in anterior parapodia, subequal to proximal in median, barely shorter in posterior ones. Dorsal ligule barely longer than median ligule in anterior parapodia ( Fig. 2I ), subequal to it from median ones ( Fig. 2J, K ). Glandular patches in dorsal ligule present but damaged by longterm preservation. Notopodial prechaetal lobe not developed.

Neuropodia. Neuracicular ligule shorter, 1.5 times wider than ventral ligule throughout body. Superior lobe blunt, shorter than inferior lobe throughout body, projecting beyond end of neuracicular ligule only in few first parapodia. Inferior lobe rounded, thickened, projected beyond end of neuracicular ligule in anterior parapodia, leveling it from median ones. Ventral ligule one-half (one-half or two-thirds) length of median ligule in anterior parapodia, three-quarters length from median ones, except in last parapodia, subequal to it. Ventral cirri cirriform, smaller than ventral ligule throughout body except in first parapodia, as long as it or barely longer.

Chaetae. Notochaetae with homogomph spinigers, blade finely serrated towards toothed edge, evenly spaced. Neurochaetal supracicular fascicle with homogomph spinigers and heterogomph falcigers, both present throughout; spinigers as notopodial ones ( Fig. 2L ), more numerous than falcigers in same fascicle; falcigers with medium blades (b/a =1.37-1.74 times), serrated region 0.42-0.53 of total blade length ( Fig. 2N ). Neurochaetal subacicular fascicle with heterogomph spinigers and heterogomph falcigers, both present throughout; spinigers with blade finely serrated towards toothed edge, evenly spaced ( Fig. 2M ), less numerous than falcigers; falcigers with medium and long blades (b/a = 1.56-2.15 times), serrated region 0.49-0.56 of total blade length ( Fig. 2O ).

Pygidium. With short, slender anal cirri ( Fig. 2P ), as long as last 6 (6-7) chaetigers, cirrophores poorly developed.

REMARKS

The species was briefly described but illustrated in detail based on at least two specimens (one with 118 segments) from the Gulf of Suez (Red Sea) (Savigny in Lamarck 1818; Savigny 1822), very likely from shallow waters of the city of Suez, as for others Savigny’s polychaetes (e.g. Álvarez-Campos et al. 2015). Up to date, these materials have not been found within the polychaete collection at the MNHN, which currently preserve the types collected by Jules César Savigny during the Napoleonic campaign to Egypt. According to Solís-Weiss et al. (2004), some types remain “hidden” in this collection and the only possibility to find them is to inspect all the tubes in the different jars of the species in question; nevertheless, my focused search of the types of P. nuntia at the MNHN was not successful. Former zoologists who worked on this polychaete collection did not even mention the original P. nuntia material in their texts as they did for other Savigny’s species (see Audouin & Milne-Edwards 1833; de Quatrefages 1866; Gravier 1902). It is likely that the type material was missing ever since. I follow Wilson & Glasby (1993) in regarding the specimens as lost.

The species was redescribed by Gravier (1902) using specimens from the southern Red Sea, separating it from other similar species, such as P.brevicirris ( Grube, 1866) and P. quatrefagesi , based mainly on the length of dorsal and tentacular cirri, and on the number and arrangement of paragnaths on the pharynx. Fauvel (1911) recorded the species from Djibouti, the Persian Gulf, and the Reunion Island. Afterward, Fauvel (1919, 1921) introduced the six varieties within P. nuntia , regarding it as a single polymorphic species, widely distributed. The relevant features used by Fauvel to distinguish these varieties were the number of paragnaths on AI and AV, the length of the tentacular and dorsal cirri, the shape of ligules, and the form of paragnaths on AVI.

In their revisionary effort of the P. nuntia species complex, Wilson & Glasby (1993) mainly used the following features to differentiate the species: the number of paragnaths on the pharyngeal areas, the shape of paragnaths on AIV, AVI, and AVII-VIII, the number of rows on AVII-VIII, and the presence of heterogomph spinigers in anterior chaetigers. Regarding P. nuntia, Wilson & Glasby (1993) redescribed the species using some specimens from the Red Sea collected by Felix Joussaume in 1894 (MNHN A108), but no details on a particular locality were given. According to several records of this and other Red Sea polychaetes collected by Joussaume in the same year (e.g. Gravier 1902, 1906; Hanley 1991; Wehe 2006), it is very likely that the material comes from the Perim Island, located at the Bab el-Mandeb Strait that connects the Red Sea and the Gulf of Aden. This place is about 2000 km of distance from the type locality, both placed in distant marine ecoregions ( Spalding et al. 2007). Later, Glasby & Hsieh (2006) expanded the previous redescription of P. nuntia , regarding it as a species with a wide distribution in the tropical Indo-Pacific, northern Australia, Taiwan, the Gulf of Aden, and the Red Sea; however, their specimens should be regarded as a distinct species (see below).

Yousefi et al. (2011) stated that their Iranian P. nuntia material fits well with the description of the species by Savigny (1822); however, some relevant differences are evident between them. The Iranian specimens have more paragnaths on AVI (13-20) than Savigny’s (10-11; Savigny 1822: pl. 4, fig. 2.3), and the tentacular cirri are notoriously longer (extending backward to chaetigers 8-14) than those illustrated by Savigny (reaching about chaetiger 4). Indeed, the Iranian material has one of the highest number of paragnaths on AVI within the P. nuntia complex (see Wilson & Glasby 1993; Glasby & Hsieh 2006; Park & Kim 2007). Furthermore, Yousefi et al. (2011) noticed some differences between their material and the redescription of P. nuntia ( Wilson & Glasby 1993) . For example, the Iranian specimens had more paragnaths on the oral ring and more transverse rows on AVII-VIII. Likewise, they also recognized some distinctions in accordance to Glasby & Hsieh’s P. nuntia material, such as the presence of heterogomph spinigers throughout body (absent in anterior neuropodia sensu Glasby & Hsieh 2006) and the posterodorsal tentacular cirri reaching chaetigers 8-14 (6-8 in Glasby & Hsieh’s specimens).

The P. nuntia specimens herein examined from the Red Sea, which once belonged to A. E. Grube’s collection and are now deposited at the ZMB, match in accuracy with the Savigny’s original description and illustrations of P. nuntia . For instance, the sub-pentagonal prostomium with narrowing end; the χ- shaped pattern of AVI-V-VI; the triangular arrangement of cones on AV; the number of paragnaths on AI (1-3 in Grube’s vs 1 in Savigny’s), AII (9-10 in Grube’s vs 6-10 in Savigny’s), AIII (11-19 in Grube’s vs 14 in Savigny’s), AIV (14-19 in Grube’s vs 14 in Savigny’s), AV (2-4 in Grube’s vs 3 in Savigny’s), and AVI (8-10 in Grube’s vs 10-11 in Savigny’s); the 4-5 transverse rows of paragnaths on AVII- VIII (2-3 most proximal rows with smaller cones). Also, the slender dorsal cirri which show similar size variations, they are much longer than the dorsal ligule in posterior parapodia (3-4 times in Grube’s vs 4-5 times in Savigny’s); the absence of merged paragnaths on AIV; and even the unusually short tentacular cirri. These are some of the most relevant features to distinguish P. nuntia sensu stricto from the species within the complex, as well as the two canals in the jaws, and the presence of heterogomph spinigers in all the neuropodial subacicular fascicles. Therefore, these specimens are also different from those previously referred as P. nuntia by Gravier (1902) and Wilson & Glasby (1993) from the southern Red Sea, Glasby & Hsieh (2006) from the Indo-Pacific, and Yousefi et al. (2011) from the Gulf of Oman. The several records of P. nuntia in several regions need to be thoroughly assessed.

On the other hand, collecting data are scarce in the catalog and labels for the Grube’s specimens of P. nuntia . Most of the material from the Red Sea revised by Grube was collected by Christian Gottfried Ehrenberg and Georg Ritter von Frauenfeld, and many of them resulted in previously undescribed taxa ( Grube 1868, 1869; see also Wiktor 1980 and Hartwich 1993). The marine invertebrates collected by Ehrenberg and von Frauenfeld were mainly obtained from the sediments or coral reefs of the Northern and Central Red Sea ( Ehrenberg 1828; von Frauenfeld 1856). However, despite the similar morphology to those specimens originally described from the Northern Red Sea (Savigny in Lamarck 1818), there is no certainty of the precise Red Sea location nor the collector. Therefore, some of the required conditions to establish a neotype could not be met (ICZN 1999, Art. 75.3).

Figures

FIG. 1. — Areas VI-V-VI patterns of the pharynx shaped by the ridges and furrows: A-C, Perinereis latipalpa (Schmarda, 1861) n. comb. with a λ-shaped pattern; D-F, Perinereis nuntia (Savigny in Lamarck, 1818) with a χ-shaped pattern; G-I, Perinereis larentukana (Grube in Peters, 1881) n. comb. with a υ-shaped pattern; J-L, Perinereis shikueii Glasby & Hsieh, 2006 with a ɔc-shaped pattern; A, D, G, J, dorsal portion of oral ring; B, E, H, K, same with a slightly irregular line drawings on the shape formed by AVI-V-VI pattern; C, F, I, L, symmetrical line drawings of the AVI-V-VI patterns. Scale bars: 1 mm. J, K, after Glasby & Hsieh (2006).

FIG. 2. — Perinereis nuntia (Savigny in Lamarck,1818),topotypes (ZMB 4019-Q):A, F, I-P, from complete specimen;B-E, G, from incomplete specimen;A, anterior region, dorsal view; inset: left nuchal organ; B, right jaw, ventral (left) and dorsal (right) views; C, same, close up of pulp cavity, ventral view (arrow points canal); D, maxillary ring of pharynx, ventral view; E, pharynx, lateral view; F, oral ring of pharynx, dorsal view; black arrowhead, distal portion of χ-shaped pattern; white arrowhead,proximal portion of χ-shaped pattern; black arrow,pointing anterior region; G, pharynx, ventral view; H-K, parapodia, anterior view (numbers refer the chaetiger); L, neuropodial homogomph spiniger, supracicular (chaet. 64); M, heterogomph spiniger, subacicular (chaet. 24); N, heterogomph falciger, supracicular (chaet. 24); O, same, subacicular (chaet. 119); P, posterior region, dorsal view. Scale bars: A, 3 mm; B, D-G, P, 1 mm; C, 0.2 mm; H-K, 0.5 mm; L-O, 15 µm.