Perinereis suezensis, Elgetany & Struck & Glasby, 2022

Elgetany, Asmaa Haris, Struck, Torsten H. & Glasby, Christopher J., 2022, Three new species of the genus Perinereis (Annelida, Nereididae) from Egyptian coasts, ZooKeys 1132, pp. 163-188 : 163

Perinereis suezensis sp. nov.

Fig. 3

Material examined.

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) .

Non-type material.

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

Description.

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 ).

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 ).

Variation (non-type material).

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.

Distribution and habitat.

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

Etymology.

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.

Remarks.

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.

Figures

Figure 2. ML tree (logL = - 11297.8710) of the Perinereis species in this analysis shown in three parts (A, B, C). The points, where we cut the branches, are indicated by letters. The new species P. suezensis sp. nov., P. fayedensis sp. nov., and P. damietta sp. nov. are highlighted by boxes and in bold. Perineris nuntia is also highlighted in bold. Bootstrap values equal to and more than 95 indicating strong support are given at the branches. The three relevant bootstrap values are highlighted in bold. The scale bar shows substitutions / position.

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.