Pseudonereis trimaculata ( Horst, 1924 )

Bonyadi-Naeini, Alieh, Rastegar-Pouyani, Nasrullah, Rastegar-Pouyani, Eskandar, Glasby, Christopher J. & Rahimian, Hassan, 2017, Nereididae (Annelida: Phyllodocida) of the Persian Gulf and Gulf of Oman, including description of two new species and 11 new records, Zootaxa 4244 (1), pp. 91-117 : 105-106

Pseudonereis trimaculata ( Horst, 1924)

Nereis (Pseudonereis) trimaculata Horst, 1924: 187 –188, pl. XXXVI, figs 8, 9. Pseudonereis rottnestiana forma costatodentata. Hartmann-Schröder, 1979: 119, figs 220–222. Pseudonereis trimaculata . Bakken 2007: 166, fig. 13.

Material examined. Iran, Gulf of Oman: Ramin , six specimens ( ZUTC Ann. 1104), Genaveh Jetty ( ZUTC Ann. 1166), Persian Gulf : Qeshm Island West coast of Basaidu, ( ZUTC Ann. 1152), Bing Village ( ZUTC Ann. 1176) , Qeshm Island-Tola village, eight specimens ( ZUTC Ann. 1190) , Qeshm Island- Kani ( ZUTC Ann. 1191) , Qeshm Island- Simin Beach 12 specimens ( ZUTC 6145 ), Djod, one specimen ( ZUTC 6163 ), Djod, five specimens ( ZUTC 6144 ), Abu Musa Island-Beach Park, six specimens ( ZUTC 6146 ), Abu Musa Island-Meteorology station , four specimens ( ZUTC 6147 ) .

Description. Material examined 20–54 mm long, 1.7–4.5mm wide at chaetiger 10 (including parapodia). Color in alcohol light brown, with darker brown pigment on dorsal surface of prostomium and anterior segments. Longest tentacular cirri extending to chaetiger 4–10. Paragnaths on maxillary and oral ring arranged as follows: I = 1 conical paragnath, II =p-bar paragnaths in 3–4 rows arranged in regular comb-like rows, III =p-bars in 3–4 rows arranged in comb-like rows, IV = p-bars and smooth bars (near jaws) in 3–5 rows. V = 1 conical paragnath with sharp tip, VI = 1 large shield-shaped paragnath, VII–VIII = 20–24 large conical paragnaths and two rows of p-bars. In anterior chaetigers, notopodia have two distally rounded ligules equal in length to neuropodial ligules. DC/DNL in anterior parapodia 2.9–6.0. Ventral neuropodial ligules distally rounded in all parapodia. Ventral cirrus similar in length to ventral ligule in anterior parapodia but shorter in posterior ones. Anterior neurochaetae are homogomph spinigers and heterogomph falcigers in dorsal fascicle and heterogomph falcigers in ventral fascicle and homogomph spinigers heterogomph falcigers in dorsal fascicle.

Remarks. Material described in the present study is very similar to the description of P. trimaculata from Gulf of Oman by Yousefi et al. (2011) and material from Eastern Indonesia and North-west Australia described by Bakken (2007), but differs from both in certain pharyngeal and parapodial features: Bakken’s specimens have 51– 69 paragnaths in Area III while material in the present study has 24–56 paragnaths and those from Gulf of Oman has 12–45; the number of paragnaths in Area VII–VIII is fewer (20–24) than in specimens studied from Gulf Oman (23–25) and same as the Persian Gulf (20–24) Also, they have only one paragnath in area V like Yousefi et al.’s specimens but they differ from Bakken’s material which has 1–3 paragnaths in Area V. The specimens in this study are smaller than the Oman specimens and Bakken’s specimens. Bakken (2007) refers to the paragnaths in Area IV near the jaws as cones but those in the present specimens, and those from Gulf of Oman comprise P-bars and smooth parallel bars nearer to the jaws. Lastly, we investigated the correlation between body size (length and width) and paragnath numbers in Area III of specimens collected from the Persian Gulf, and found no correlation between the length/width of the body and the number of paragnaths in Area III (r=-0.107, p=0.628/r=0.233, p=0.284). Thus we conclude that the differences in Area III paragnath number between Bakken’s specimens and specimens from Persian Gulf and Gulf of Oman may be taxonomically significant, but further character data, including molecular, are required before a new species can be described.

Distribution. Geser, Indonesia (type locality); North-west Australia ( Bakken 2007), Gulf of Oman.