Perinereis species having conical paragnaths on all areas (rarely absent on area V), except area VI with long bars, which can be shield-shaped or pyramidal paragnaths, arranged in a single-arched row; area V with paragnaths displaced posteriorly (on everted proboscis) to those on area VI; area IV rarely with merged paragnaths.

We have restricted the diagnosis of the species complex to include only unique diagnostic features. Some new characters introduced by Villalobos-Guerrero (2019) describing the faint ridges and furrows of the dorsal oral ring may prove to be useful when broader comparisons can be made. However, at this stage we consider that the form of the pharyngeal ridges and furrows is too closely allied to underlying musculature, and therefore could be unduly influenced by the fixation process and length of time in preservative. Similarly, the form (and length) of the deeply embedded paired nuchal organs may prove to be useful when more comparative data are available. However, observation of that character depends heavily on state of preservation (e.g., they are seen more clearly in specimens relaxed before preservation); in the present specimens the nuchal organs were hidden under the anterior edge of the apodous segment and thus not visible externally. Pharyngeal morphologies are reported herein by describing the form and arrangement of paragnaths on the ridges and in the furrows of the pharynx. The form and arrangement of paragnaths on area VI is unique to the genus (and family) and serves as the easiest way to recognize a member of the species complex. However, Tosuji et al. (2019) have demonstrated that in at least two East Asian species of the complex, the number of bars increases with the growth of individuals (fragmentation of the long bars produces multiple shorter bars (= shield-shaped paragnaths)). Therefore, this character should be used cautiously for species identification across the group, and comparisons are best made between individuals of similar size until we have a better understanding of the processes involved.

Holotype : DUFS 067 Al-Adabiya; west of Port Taofik, Gulf of Suez (Red Sea), intertidal, under coarse sands, at 29°56'06.0"N, 32°28'36.6"E, collection date (15.01.2015) Paratypes: 13 specimens (DUFS 057-066, 068-070) from Al-Qantara, Suez Canal, intertidal, muddy sand bottom, at 30°50'31.5"N, 32°18'54.8"E, Fayed, western shore of Great Bitter Lake, intertidal, silty mud bottom at 30°20'18.0"N, 32°18'14.9"E, and Al-Adabiya (same collection details as holotype). Collection dates (18.02.2015/ 15.01.2015/ 01.07.2017).

2 specimens (SMZ unregistered), Hurghada, Egypt (northern Red Sea), at 27°15'42.0"N, 33°48'44.7"E, intertidal, under stones, St. 9a, ‘3192', det. as Nereis sp., collected 9.01.1992

Holotype (DUFS 067) not complete, 53 chaetigers, 50 mm in length, 2 mm wide at chaetiger 10 Paratypes with 33–88 chaetigers, 32–81 mm long, 2.0–4.5 mm wide at chaetiger 10. Epidermis with orange pigmentation on anterior dorsum in some preserved paratypes.

Prostomium with entire anterior margin; as wide as long. Antennae closely set, as long as ~ 1/3 length of prostomium. Eyes black, anterior pair set slightly further apart than posterior pair; lenses not obvious.

Apodous segment ~ 1.2× or 1.6× longer than chaetiger 1. Posterodorsal tentacular cirri extending back to chaetiger 6 (6–7).

Pharynx with jaws translucent, red-brown, with 7 (7–8) teeth. Paragnaths black. Area I with 2 (1–5) conical paragnaths; area II conical paragnaths with 5 (5–10) on left and 8 (7–10) on right, in a triangular patch; area III with 10 (9–17) conical paragnaths in 2–3 rows, with two laterally isolated paragnaths; area IV conical paragnaths with 16 (11–19) on left, 13 (9–16) on right, in two or three rows, in elongated triangle; area V with 4 (2–4) conical paragnaths interspersed with one or two bars, set well proximal (on everted proboscis) to line of area VI paragnaths; area VI with 15 (14–21), shield-shaped bars with pointed tips (very close in appearance to cones), arranged in one arc, with the right and left rows almost touching; area VII-VIII with 44 (37–44) conical paragnaths arranged in a single band of two rows laterally to three or four rows deep medially (Fig. 3A, B; Table 2). Paragnath-free region between areas VI and VII-VIII broad, ca. as wide as palpophore; paragnaths of VII-VIII not visible in dorsal view (Fig. 3A).

Figure 3. 

Perinereis suezensis sp. nov. All pictures are from the holotype if not stated otherwise A anterior end, maxillary apparatus, dorsal view B anterior end, maxillary apparatus, ventral view C posterior end, ventral view D right parapodium, posterior view, chaetiger 7 E right parapodium, anterior view, chaetiger 33 F right parapodium, anterior view, chaetiger 64 G chaetal bundle of a right parapodium homogomph spiniger, heterogomph spiniger & heterogomph falciger, chaetiger 7 H neuropodial sub-acicular heterogomph falciger, chaetiger 7 I heterogomph falciger, chaetiger 7.

Anterior notopodia with conical dorsal and median ligules of equal length in anterior body; dorsal ligule slightly longer in mid- and posterior body. Superior lobes absent. DC length 1.1 (1.0–1.2) × DNL length anteriorly (chaetigers 10–20); posteriorly DC length 1.09 (1.0–1.3) × length of DNL length (chaetigers 75–90). DC and DNL of mid-body parapodia proportionally similar to those of posterior parapodia (Fig. 3D–F).

Dorsal notopodial ligule larger than ventral notopodial ligule anteriorly and posteriorly. Neuropodia with inferior and postchaetal lobes, ventral ligule and ventral cirri. Neuropodial postchaetal lobe lowly rounded, not projecting beyond end of acicular ligule. Ventral neuropodial ligule subconical, ca. as long as median ligule throughout. Ventral cirri extending laterally to reach tip of ventral neuropodial ligule anteriorly, extending to ~ 1/4 length of ventral neuropodial ligule posteriorly (Fig. 3D–F).

Notochaetae with homogomph spinigers throughout, blades long; teeth short. Neurochaetae in upper fascicle with homogomph spinigers with long blades; one heterogomph falciger with short blades throughout, blades serrated. Neurochaetae in lower fascicle with heterogomph falcigers, blades short and thick, teeth long; and two or three heterogomph spinigers, median long blades, teeth short present throughout body. Aciculae black, single in each ramus (Fig. 3G–I).

Pygidium with anal cirri extending to last 6 (6–7) chaetigers, 5 (5–7) mm long, whitish cream without any pigmentation (Fig. 3C).

Two specimens: one complete with 105 chaetigers, 57 mm long and 2.8 mm wide, and another with regenerating tail, 107 chaetigers, 71 mm long and 4.3 mm wide. Apodous segment ~ 1.3–1.8× longer than chaetiger 1. Posterodorsal tentacular cirri extending back to chaetigers 5 and 6. Jaws with 4–7 teeth. Paragnaths count: area I with 2; area II with 8–17 on left and 9–17 on right; area III with 11 or 12 in two or three rows; area IV with 17 or 18 on both sides, in two or three rows; area V with three or four; area VI with 8–12 on left and 8–11 on right, shield-shaped bars with pointed tips and cones arranged in one row with the right and left side rows almost touching each other; area VII-VIII with 47 or 48, arranged in a single band of two rows laterally to three or four rows deep medially. Dorsal cirrus length ~ 0.8× length of dorsal notopodial ligule anteriorly and 0.7–0.9× length of dorsal notopodial ligule posteriorly. Ventral cirri extending laterally to reach tip or half-length of ventral neuropodial ligule anteriorly. Neurochaetae in upper fascicle with 1–3 heterogomph falcigers. Neurochaetae in lower fascicle with 1–4 heterogomph spinigers, rarely absent.

Gulf of Suez, Suez Canal including Great Bitter Lake, northern Red Sea; intertidal sand and mud, under stones.

The new species is named after the port city of Suez (Egyptian Arabic pronunciation: (السويس) located on the north coast of the Gulf of Suez.

The molecular data place P. suezensis sp. nov. clearly apart from all other species and the monophyly of the species is very well supported by a bootstrap value of 99 (Fig. 2A). Not considering identical sequences between specimens within each species, the average genetic distance based on the branch length in the tree to its sister-taxon, P. fayedensis sp. nov., is 6.65% (± 0.60%), while the average genetic distance within P. suezensis is only 0.24% (± 0.37%). Hence, there is a clear gap in the genetic distances.

In addition to our sequences, only three additional COI sequences for P. nuntia have been published: JX420257 (Indonesia), JX644015 (South Korea), and MH337359 (Andaman and Nicobar Islands). JX420257 and MH337359 are identical (bootstrap value of 100; Fig. 2A), however, they are distantly related to P. suezensis sp. nov. (Fig. 2A). Glasby et al. (2013) found that P. nuntia JX420257 clustered with P. helleri (Grube, 1878), and together was the sister group of P. suluana, both relationships with a high Bayesian posterior probability (> 0.95). This confirms the distant relationship between material identified as P. nuntia from the Australasian region. JX644015 nested within a group comprising otherwise only P. brevicirris with a bootstrap value of 100 (Fig. 2B). Together they clustered with the East Asian-restricted P. wilsoni. Hence, it is also dubious whether JX644015 is a P. nuntia specimen and perhaps should be considered to belong to a species related to other East Asian Perinereis based on the molecular data. Reports of P. brevicirris, which was considered a synonym of P. vallata by Wilson and Glasby (1993) but is now accepted as valid (see key in Villalobos-Guerrero 2019), are widespread throughout the Indo-Pacific but most tropical and northern hemisphere records are unlikely to represent this species, which was originally described from Ile Saint Paul, Southern Ocean.

The new species is most similar to P. nuntia, which was also described from the Gulf of Suez. Although the exact location of Savigny’s specimens has never been established, it is very likely to be from shallow waters of the port city of Suez, as for Savigny’s other polychaetes (see Villalobos-Guerrero 2019 and references therein). Perinereis nuntia was recently redescribed by Villalobos-Guerrero (2019), and based on his redescription and Lamarck’s type description, we have found two key differences between the two species (values in parentheses those of Villalobos-Guerrero). The number and shape of paragnaths in area VI: 14–21shield-shaped paragnaths in the new species, compared to 8–10 (10–12) short bars in P. nuntia; and the relative length of the posterior dorsal cirri, which are 1.0–1.3× the DNL in the new species and 4–5 (3–4) × the DNL in P. nuntia. The new species also shows similarities with P. heterodonta from Djibouti in having a high number of paragnaths on area VI and short dorsal cirri in the posterior end; however, the new species can be differentiated from P. heterodonta by the greater number of paragnaths on areas V (24 vs. 0-1) and VII-VIII (37–44 vs. 18–35) (Table 2).

The larger-sized, non-type specimens generally had more paragnaths in each area compared to the type material, except for area VI. The fewer paragnaths in area VI in the non-type specimens is most likely due to loss, as the ones present were irregularly spaced, with some gaps large enough to accommodate a lost shield-shaped bar or two cones. Another reflection on the condition of the non-type specimens is the unusually short dorsal and ventral cirri; on this point, the cirri appeared withered and many were missing, which we attribute to damage or a fixation artifact.

Holotype : DUFS 0123 Al-Adabiya, west of Port Taofik, Gulf of Suez (Red Sea), intertidal, under coarse sands, at 29°56'06.0"N, 32°28'36.6"E. Paratypes (DUFS 120–122, 124–128): 8 specimens from El-Qantara, Suez Canal, intertidal, muddy sand bottom, at 30°50'31.5"N, 32°18'54.8"E, Fayed, western shore of Great Bitter Lake, intertidal, silty mud bottom, at 30°20'18.0"N, 32°18'14.9"E, Al-Adabiya (same collection details as holotype).

Holotype (DUFS 0123) not complete, 49 chaetigers, 35 mm in length, 3 mm wide at chaetiger 10. Paratypes with 37–88 chaetigers, 30–70 mm long, 1.5–4.5 mm wide at chaetiger 10. Epidermis whitish cream with a longitudinal beige pigmentation stripe on ventral side of posterior chaetigers in some preserved.

Prostomium with entire anterior margin; wide as long. Antennae closely set, as long as ~ 1/3 length of prostomium. Eyes black, anterior pair set slightly further apart than posterior pair; lenses not obvious.

Apodous segment ~ 1.5× longer than chaetiger 1. Posterodorsal tentacular cirri with distinct cirrophores, extend back to chaetiger 7 (6–8).

Pharynx with jaws translucent red-brown, with 8 (7–8) teeth. Maxillary ring of pharynx with paragnaths, arranged in discrete areas, areas II-IV arranged in regular comb-like rows. Area I with 2 (1–2) conical paragnaths in vertical arrangement; area II with 9 (7–10) in left and 9 (7–10) in right conical paragnaths, three or four rows in a triangular patch; area III with 2 (2–5) conical paragnaths in vertical arrangement; area IV with 13 (12–15) in left, 14 (12–15) in right, conical paragnaths without bars; area V with 4 (1–3) conical paragnaths; area VI with 17 (14–17), shield-shaped bars with pointed tip present, cones paragnaths absent; area VII-VIII with 38 (28–40) conical paragnaths with small p-bars interspersed arranged in a single band of 3–5 rows (Fig. 4A, B; Table 2). Paragnath-free region between areas VI and VII-VIII broad, ca. as wide as palpophore; paragnaths of VII-VIII not visible in dorsal view (Fig. 4A).

Figure 4. 

Perinereis fayedensis sp. nov. All pictures are from the holotype if not stated otherwise A anterior end, maxillary apparatus, dorsal view B anterior end, maxillary apparatus, ventral view C posterior end, ventral view D right parapodium, anterior view, chaetiger 16 E right parapodium, posterior view, chaetiger 32 F right parapodium, posterior view, chaetiger 67 G chaetal bundle of a right parapodium, homogomph spiniger and heterogomph falcigers, chaetiger 17 H neuropodial chaetal bundle of a right parapodium, homogomph spiniger & heterogomph falciger, chaetiger 33 I heterogomph falciger, chaetiger 33.

Notopodia with conical dorsal and median ligules of equal length throughout. Superior lobes absent. DC length 1.2 (0.9–1.2) × length of DNL length anteriorly (chaetigers 10–20); posteriorly, DC length 1.2 (1.1–1.2) × length of DNL length (chaetigers 75–90). DC and DNL of mid-body parapodia proportionally similar to those of posterior parapodia (Fig. 4D–F).

Neuropodia with inferior and postchaetal lobes, ventral ligule and ventral cirri. Neuropodial postchaetal lobe lowly rounded, not projecting beyond end of acicular ligule. Ventral neuropodial ligule subconical, ca. as long as median ligule throughout. Ventral cirri extending laterally to halfway to tip of ventral neuropodial ligule in anterior and midbody, extending to ~ 1/3 length of ventral neuropodial ligule posteriorly (Fig. 4D–F).

Aciculae black, single in each ramus (Fig. 4G). Notochaeta with homogomph spinigers throughout, spinigers of long blades; teeth short. Neurochaetae with homogomph spinigers and heterogomph falcigers in the supra and sub-acicular fascicle (Fig. 4G–I). Acicula black, single in each ramus.

Pygidium with anal cirri fine, tapering, extending to last 7 (6–8) chaetigers, 50 (45–55) mm long (Fig. 4C).

The molecular data place the new species, P. fayedensis, clearly apart from all other species and as sister to P. suezensis (Fig. 2A). The monophyly is well supported by a bootstrap value of 99. Not considering identical sequences between specimens within each species, the average genetic distance to its sister-taxon, P. suezensis, is 6.65% (± 0.60%), while the average genetic distance within P. fayedensis is substantially lower with a value of 0.01% (± 0.00%). Hence, there is again a clear gap in the genetic distances.

Morphologically, P. fayedensis is intermediate between P. nuntia and P. heterodonta described from Obock, Djibouti, Gulf of Aden. It differs from the former most notably in the number of paragnaths in area III (2–5 vs. ~ 15 in P. nuntia) and area VI (14–17 vs. 8–12 in P. nuntia), and the relative length of the DC (1.1–1.2× DNL in the new species vs. 3–5× DNL in P. nuntia; Table 2). Perinereis fayedensis can be distinguished from P. heterodonta by having fewer paragnaths in area III (2–5 in one row vs. a cluster of 6–7 in P. heterodonta) and more paragnaths in area VII-VIII (28–40 vs. 18 in P. heterodonta) (see Table 2).

Gulf of Suez, Suez Canal including Great Bitter Lake; intertidal sand and mud, under stones.

The new species is named after the Egyptian city of Fayed on the western shore of Great Bitter Lake approximately halfway along the Suez Canal.

Holotype : DUFS 055, Hurghada (northern Red Sea), Grand Aquarium beach, subtidal area, clay bottom, at 27°07'59.2"N, 33°49'51.2"E. Paratypes: 22 specimens (DUFS 027–048) and non-type material 6 specimens (DUFS 049-054) from Al-Adabiya, west of Port Taofik, Gulf of Suez (Red Sea), intertidal, under coarse sands, at 29°56'06.0"N, 32°28'36.6"E and from Hurghada, National institute of Oceanography beach, intertidal and upper subtidal area, from muddy and sand bottoms, at 27°17'03.1"N, 33°46'19.8"E (Egypt).

Holotype (DUFS 055) not complete, 94 chaetigers, 62 mm in length, 4.5 mm wide at chaetiger 10. Paratypes with 42–96 chaetigers for 30–115 mm long and 1.5–7 mm wide at chaetiger 10. Epidermis with orange and gold pigmentation on anterior dorsum and ventrum in some preserved samples.

Prostomium with entire anterior margin; relatively large, longer than wide, two pairs of eyes, dark green with black lenses, and two large palps longer than antennae, palpostyles conical. Antennae closely set, as long as ~ 1/3 length of prostomium. Lenses not obvious.

One apodous anterior segment, ~ 1.6× longer than chaetiger 1. Tentacular cirri with distinct cirrophores, longest tentacular cirri extend back to chaetiger 2 (2–4).

Pharynx with jaws black, 4 (4–5) reddish brown teeth. Paragnaths black with light brown base; those of maxillary ring pointed conical paragnaths. Paragnath counts: area I with 0 (0–2); area II with 2 (1–5) on the left side and 3 (2–5) on the right side; area III with 4 (3–9) in one transverse row; area IV with 14 (10–21) on the left side and 16 (10–20) on the right side; arranged in irregular row of unequal paragnaths. Area V with 0 (0–1); area VI with 24 (24–40) conical paragnaths arranged in one arc; area VII–VIII with 24 (16–32), similar in size, arranged in two rows (Fig. 5A, B). Paragnath-free region between areas VI and VII–VIII broad, ca. as wide as palpophore; paragnaths of VII–VIII not visible in dorsal view (Fig. 5A).

Figure 5. 

Perinereis damietta sp. nov. All pictures are from the holotype if not stated otherwise A anterior end, maxillary apparatus, dorsal view B anterior end, maxillary apparatus, ventral view C posterior end, ventral view D right parapodium, posterior view, chaetiger 9 E right parapodium, posterior view, chaetiger 41 F right parapodium, anterior view, chaetiger 56 G chaetal bundle of a right parapodium, homogomph spiniger & heterogomph falciger chaetiger 56 H neuropodial chaetal bundle of a right parapodium, heterogomph falciger, chaetiger 56 I heterogomph falciger, chaetiger 67.

Anterior notopodia with conical dorsal and median ligules of equal length in anterior body; dorsal ligule slightly longer in mid- and posterior body. DC length 0.8 (0.7–1.0) × length of DNL length anteriorly (chaetigers 10–20); posteriorly, DC length 1.1 (0.9–1.2) × length of DNL (chaetigers 75–90). DC and DNL of mid-body parapodia proportionally similar to those of posterior parapodia (Fig. 5D).

Dorsal notopodial ligule; triangular with conical tip, slightly longer than notopodial ventral ligule throughout. Ventral notopodial ligule rounded triangular. Dorsal and ventral notopodial ligules marked decreasing in size on posterior chaetigers. Neuropodium with dorsal rounded lobe in anterior chaetigers, with one black acicula, less developed posteriorly. Ventral neuropodial ligule digitiform, similar in length to acicular ligule on anterior chaetigers; slightly longer than acicular ligule in posterior chaetigers. Ventral cirri extending to ~ 1/3 length of ventral neuropodial ligule anteriorly and posteriorly (Fig. 5D–F).

Notochaetae with homogomph spinigers, long and thin serrated blade throughout. Neurochaetae dorsal fascicle: homogomph spinigers; median thick serrated blade present and heterogomph falcigers present on anterior and posterior chaetigers, blades serrated. Neurochaetae ventral fascicle: heterogomph falcigers with median long and wide blades with a single terminal tooth, in anterior and posterior chaetigers (Fig. 5G–I). Aciculae black with red-brown base, single in each ramus.

Pygidium with anal cirri cirriform, cirri extending to last 2 (2–4) chaetigers (Fig. 5C).

Gulf of Suez, northern Red Sea; intertidal and subtidal, sand and mud, under stones.

The new species is named after the university of the first author, Damietta University, a noun in apposition. Damietta (Egyptian Arabic: Dumyāț (دمياط) is also a port city located on an eastern distributary of the Nile Delta, ~ 15 km from the Mediterranean Sea.

Perinereis damietta sp. nov. is well supported by the highest bootstrap value of 100 (Fig. 2C) and clearly set apart from the other Perinereis species in the tree. According to the present molecular phylogeny, the sister group to P. damietta is P. vallata, which is also a former variety of P. nuntia (Wilson and Glasby 1993; Glasby and Hsieh 2006). Not considering identical sequences between specimens within each species, the average genetic distance to its sister group is 42.57% (± 6.72%), while the average genetic distance within P. damietta is 1.12% (± 0.74%) and hence substantially lower. Hence, there is again a clear gap in the genetic distances.

Herein, P. vallata also includes one specimen (JX966314) assigned to P. brevicirris (Fig. 2C). This is probably a misidentification given the very strong bootstrap support values of 100 for both the monophyly of P. vallata and the group of P. brevicirris specimens mentioned above (Fig. 2A, C).

Perinereis damietta is morphologically most similar to P. heterodonta (type locality: Obock, Djibouti, Gulf of Aden). Both species belong to the group of the P. nuntia complex that lack heterogomph spinigers in anterior parapodia, which is unlike P. nuntia. Other key differences between P. damietta /P. heterodonta and P. nuntia are the shorter tentacular cirri and the fewer paragnaths in area V (0–1) (Table 2). Perinereis damietta differs from P. heterodonta most notably in having 24–40 pyramidal paragnaths in area VI (vs. 10–16 in P. heterodonta). In this regard, it has the highest number of area VI paragnaths of any species in the P. nuntia species complex, exceeding the next highest (12–16 bars) found in P. vallata (Wilson and Glasby 1993).

Another species originally described from Djibouti, Perinereis djiboutiensis, is unfortunately poorly known, especially in respect to the presence or absence of heterogomph spinigers in anterior parapodia and numbers of paragnaths in areas III and VII–VIII (Table 2). Although it resembles the new species in having one, or no, paragnaths in area V, it may be differentiated from the new species in having only six or seven short bars (may also include cone-shaped paragnaths) in area VI, which is the lowest of all species of the Perinereis nuntia species group in the region (Table 2), and in this regard it is closer to material described as Perinereis nuntia from the Red Sea by Wilson and Glasby (1993).

A novel character introduced by Villalobos-Guerrero (2019), the size of the gap between areas VI and VII–VIII, may also set this new species (and others in this study) apart from other members of the P. nuntia complex. The gap in all three species described here is about ‘as wide as palpophore’, which is similar to P. nuntia according to Villalobos-Guerrero (2019), but differs from the Southern Ocean species P. latipalpa (Schmarda, 1861) from South Africa and P. vallata from Chile in which the gap is only as wide as the palpostyle (Wilson and Glasby 1993; Villalobos-Guerrero 2019).