Neanthes farurensis, Bonyadi-Naeini & Glasby & Rahimian, 2025

Neanthes farurensis View in CoL sp. nov.

http://zoobank.org:act: 621A5381-3808-4D50-BF87-01282ACE2900

( Figures 2 A–C View FIGURE 2 , 3 A–D View FIGURE 3 , 4 A–J View FIGURE 4 )

Material examined. Holotype: Farur Island ( 26° 17' 15.03" N, 54° 32' 22.96" E), ZUTC 7076 , intertidal zone, rocky with coral, collected by Bonyadi-Naeini A., 31 December 2017. GoogleMaps

Description. Holotype, body complete with 71 chaetigers. Colour in alcohol creamy with dark brown dorsal pigmentation from anterior part to end of body ( Fig. 2A View FIGURE 2 ). Total length post-fixation 49 mm, maximum width 4 mm at chaetiger 15, including parapodia.

Body flattened and tapering posteriorly, prostomium slightly wider than long, with stout palps slightly longer than wide. Palps with barrel-shaped palpophore, slightly wider at base, and with single transverse groove; palpostyles ovoid. Palps and entire prostomium pigmented black. One pair of antennae and four pairs of tentacular cirri, with longest (postero-dorsal) reaching chaetiger 6 ( Figs 2B View FIGURE 2 , 3A View FIGURE 3 ). Four eyes. Apodous anterior segment without ventrolateral projections. Everted pharynx bearing brown to dark jaws with 7–8 teeth. Paragnaths on maxillary ring arranged as follows: I = 4 conical paragnaths in a quadrangular arrangement; II = 14–18 conical paragnaths in an elongate patch; III = a group of 29 conical paragnaths in rectangular patch and separate lateral groups; IV = approximately 22–26 conical paragnaths in wedge shape. Paragnaths on oral ring as follows: V = 0; VI = 0 ( Figs 2B View FIGURE 2 , 3A View FIGURE 3 ); and VII–VIII = 28 large conical paragnaths in two rows (figs 2C, 3B). Tentacular belt about 2x length of first chaetiger.

Parapodium of chaetiger 10 with three ligules/lobes. Dorsal ligule as large as ventral ligule and mid-one (notopodial prechaetal lobe) smaller than both. Dorsal cirri single, mid-dorsally, attached to notopodial ligule. Dorsal cirrus longer than dorsal ligule. Dorsal ligule of anterior chaetigers with distal and proximal parts, distal part is dark brown in colour

Anterior neuropodia with two ligules, postchaetal lobes present. Neuropodial acicular ligule conical, rounded distally, and smaller than ventral neuropodial ligule. Ventral cirri smaller than neuropodial acicular ligule ( Fig. 3C View FIGURE 3 ). Aciculae dark. Notochaetae homogomph spinigers ( Fig. 4A View FIGURE 4 ). Neurochaetae in dorsal fascicle include homogomph spinigers (tending toward sesquigomph) ( Fig. 4B View FIGURE 4 ) and heterogomph spinigers ( Fig. 4C View FIGURE 4 ); in ventral fascicle are heterogomph spinigers, heterogomph falcigers with short blades serrated along their whole length ( Fig. 4D View FIGURE 4 ).

Parapodium of chaetiger 30 with three ligules/lobes. Dorsal cirri single, mid-dorsally attached to notopodial ligule and as large as dorsal ligule. Dorsal ligule larger than ventral ligule and mid-one (notopodial prechaetal lobe) smaller than both. Dorsal ligule with distal and proximal parts.

Neuropodia of chaetiger 30 with two ligules, postchaetal lobes present. Neuropodial acicular ligule conical, rounded distally, and smaller than ventral neuropodial ligule. Ventral cirri smaller than both. Aciculae dark. Notochaetae homogomph spinigers. Neurochaetae in dorsal fascicle include homogomph spinigers (tending toward sesquigomph) and heterogomph spinigers; in ventral fascicle are heterogomph spinigers, and heterogomph falcigers with short and serrated blades. Notopodial prechaetal lobe reduced posteriorly and disappears by chaetiger 35 th.

Parapodium of posterior chaetigers (50 th) with dorsal cirrus as long as dorsal notopodial ligule. Dorsal notopodial ligule conical, dark brown in colour. Dorsal ligule is slightly enlarged towards posterior end. Notopodial prechaetal lobe absent. Both acicular neuropodial ligule and postchaetal lobe rounded, ventral neuropodial ligule conical and longer than acicular neuropodial ligule, ventral cirri shorter than ventral neuropodial ligule ( Fig. 3D View FIGURE 3 ). Notochaetae homogomph spinigers ( Fig. 4E View FIGURE 4 ). Neurochaetae in dorsal fascicle homogomph, spinigers and heterogomph falcigers with short blades. Neurochaetae in ventral fascicle heterogomph spinigers and heterogomph falcigers with short blades serrated along their whole length ( Fig. 4F View FIGURE 4 ).

Pygidium with a pair of conical cirriform cirri as long as last 7 th chaetigers.

Ecology. Neanthes farurensis sp. nov. was collected from the intertidal zone of Farur Island, Persian Gulf. The type locality consists of a rocky shoreline interspersed with coral formations, forming a heterogeneous habitat subject to tidal influence. A single specimen was collected from crevices and interstices among rocks and coral rubble exposed at low tide. The occurrence of N. farurensis sp. nov. in this environment suggests adaptation to dynamic intertidal conditions and contributes to the knowledge of nereidid diversity in the Persian Gulf.

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Etymology. The species is named after Farur Island, Persian Gulf, the location where the worm was collected.

Remarks. Comparisons were made with Neanthes species previously reported from the Persian Gulf and/or Gulf of Oman ( Table 3). Our material differs markedly from N. acuminata ( Ehlers,1868) , N. biparagnatha Bonyadi-Naeini et al., 2017 , N. deplanata Mohammad, 1971 , N. trifasciata ( Grube, 1878) , N. unifasciata ( Willey, 1905) , and N. willeyi ( Day, 1934) in many morphological features, although they have a few common features with the material studied here ( Table 4).

Further comparisons were made with similar species among the approximately 25 Neanthes species occurring in the Indo–West Pacific, based on 10 key features identified by Villalobos-Guerrero & Idris (2021, Table 4). The studied material most resembles N. chilkaensis ( Southern, 1921) and N. mossambica ( Day, 1957) in seven different features; N. indica brunnea ( Day, 1957) and N. pachychaeta ( Fauvel, 1918) in six different features. However, the new species differs from these four species in having a highly distinctive darkly pigmented head (dark brown palps and prostomium) and the absence of paragnaths in Area VI. Further, these four species differ from the new species in the following additional features:

Neanthes farurensis View in CoL sp. nov. differs from N. chilkaensis View in CoL ( Southern, 1921) in the number of paragnaths in Area I (4 vs 5–10) and Area VII–VIII (28 vs 37>). Also, the shape of the dorsal ligule is similar throughout the body in N. chilkaensis View in CoL ( Southern, 1921) but is slightly enlarged towards the posterior end in the material studied here. Neanthes farurensis View in CoL sp. nov. differs from N. mossambica ( Day, 1957) View in CoL in the number of paragnaths in Areas I and II. It has fewer conical paragnaths in Area I (4 vs 6), more paragnaths in Area II (29 vs 20) than N. mossambica ( Day, 1957) Also View in CoL , the shape of dorsal ligule is similar throughout the body in N. mossambica ( Day, 1957) View in CoL but is slightly enlarged towards the posterior end in the material studied here. Neanthes farurensis View in CoL sp. nov. differs from N. indica brunnea ( Day, 1957) View in CoL in the number of paragnaths in Area I (4 vs 2–3), Area II (29 vs 7–10), Area VII–VIII (28 vs 38). Also, the shape of the dorsal ligule is similar throughout the body in N. indica brunnea ( Day, 1957) View in CoL but is slightly enlarged towards the posterior end in the material studied here. Neanthes farurensis View in CoL sp. nov. differs from N. pachychaeta ( Fauvel, 1918) View in CoL in the number of paragnaths in Area II (29 vs 1–8) and Area VII–VIII (28 arranged in two rows vs 0–8 in one row).

The material studied here was also compared with Neanthes chingrighattensis ( Fauvel, 1932) View in CoL , originally described from Kolkata, West Bengal, India, but also occurring in Bangladesh and elsewhere in India (Muir & Maruf Hossain 2014); and N. glandicincta View in CoL ( Southern, 1921) also originally described from Kolkata, West Bengal, but now known to occur across southern and south-east Asia ( Lee & Glasby 2015). Neanthes farurensis View in CoL sp. nov. differs from Neanthes chingrighattensis ( Fauvel, 1932) View in CoL in the number of paragnaths in Area III and V, shape of dorsal ligule and presence/absence of homogomph spinigers among subacicular neurochaetae and in the presence/absence of superior neuropodial lobes The material studied here has more conical paragnaths in Area III (29 vs 5) than N. chingrighattensis ( Fauvel, 1932) View in CoL , and paragnaths in Areas V and VII–VIII are merged in N. chingrighattensi . Also, the shape of the dorsal ligule is similar throughout the body in N. chingrighattensis ( Fauvel, 1932) View in CoL but is slightly enlarged towards the posterior end in the material studied here. Further, the material studied here has no homogomph spinigers among the subacicular neurochaetae, but they are present in N. chingrighattensis ( Fauvel, 1932) View in CoL . Also, N. chingrighattensis ( Fauvel, 1932) View in CoL has superior neuropodial lobes, which are absent in the material studied here.

The material studied here differs from N. glandicincta ( Southern, 1921) type material and material recorded from Singapore ( Lee & Glasby 2015) in the number of paragnaths in Area III and V, and shape of the dorsal ligule. The material studied here has fewer conical paragnaths in Area III in comparison to Southern's type material (29 vs 50) and in material recorded from Singapore (29 vs 30–63). Paragnaths in Areas VII–VIII are more in the material studied here in comparison to Southern’s type material (29 vs 0) and in material recorded from Singapore (29 vs 0–8). Also, the shape of dorsal ligule is similar throughout the body in Southern’s type material, material recorded from Singapore and Southern’s material but is slightly enlarged towards the posterior end in the material studied here. Moreover, the material studied here has more conical paragnaths in Area III (29 vs 13–28), more paragnaths in Areas VII–VIII (28 vs 0) than material recorded by Bonyadi-Naeini et al. (2017b) from the Persian Gulf and Gulf of Oman and paragnaths in Areas VII–VIII are arranged in two rows. Also, the material studied here has no superior neuropodial lobes, but they are present in N. glandicincta ( Southern, 1921) recorded from the Persian Gulf and Gulf of Oman.