Intertidal scale worms ( Polychaeta , Polynoidae and Sigalionidae ) from the northern coasts of the Persian Gulf and Gulf of Oman

Sampling of Polychaeta has been performed in the Persian Gulf and Gulf of Oman during December 2006 to October 2007. So far, 10 species belonging to six genera from two families have been identifi ed. Seven species from the family Polynoidae (Lepidonotus natalensis, L. purpureus, Parahalosydnopsis arabica, Harmothoe hirsuta, H. liaoi, Paralepidonotus ampulliferous) and one species from the family Sigalionidae (Sthenelais boa) are new records for the Gulf of Oman. Th ormora jukesii and H. marerubrum (Polynoidae) are new records for the Persian Gulf. Lepidonotus tenuisetosus could be recorded for both gulfs. Th e most diverse genera in the area are Lepidonotus and Harmothoe with each of them represented by three species. Th e most common species was Lepidonotus tenuisetosus, which was collected from 25 locations. Th e highest diversity of polychaetes species could be observed in rocky habitats containing stones covered with algae.


Introduction
Scale worms form one of the major taxa within the Polychaeta.However, the knowledge on their biodiversity in the two gulfs remained fragmentary so far.For this reason an expedition from December 2006 to October 2007 to the northern coasts of the Per-sian Gulf and Gulf of Oman was conducted with a particular focus on the collection of scale worms.During this campaign, 34 stations on the intertidal zone with diff erent physical characteristics could be visited.
Currently, 34 species confi ned to fi ve of the six currently accepted families of scale worms (Acoetidae Kinberg 1858, Aphroditidae Kinberg 1856, Eulepethidae Chamberlin 1919, Pholoidae Kinberg 1857, Polynoidae Kinberg 1856and Sigalionidae Kinberg 1856) have been reported for the Persian Gulf.Most of them originated from the south-western parts of the Persian Gulf, and the Gulf of Oman (Wesenberg-Lund 1949;Wehe and Fiege 2002;Wehe 2006Wehe , 2007)).Th e family Eulepethidae has not been recorded for the area so far.
In the present study we report on 10 species belonging to six genera from the families Polynoidae and Sigalionidae.Nine species represent new records, seven for the Gulf of Oman and two for the Persian Gulf.

Material and methods
Th e 34 collecting sites in the intertidal zone were selected according to diff ering habitat conditions in order to also sample more specialized taxa.Th e major features addressed were rocky shores, stony, sandy and muddy beaches.Th ey were distributed along the northern coasts of the Persian Gulf to the Gulf of Oman from the Imam Khomeini jetty in the northwest to Guatr in the southeast (Fig. 1).Additional samples were taken in the intertidal zone of two islands, Qeshm and Hengam, which are located in the Strait of Hormuz (Fig. 2).Details on the collecting sites are presented in Table 1.
Collected specimens were relaxed using 8% MgCl 2 , and fi xed in 5% formalin diluted in seawater for 24h.Th en, the specimens were washed with tap water and   transferred to 70% ethyl alcohol for permanent storage.Th e specimens were studied under the stereo microscope.Parapodia and elytra were detached, mounted in glycerin and studied under a compound microscope.Drawings were made using a camera lucida.Identifi cation followed the identifi cation keys supplied by Wehe (2006Wehe ( , 2007)).All specimens reported here are deposited in the Zoological Museum, University of Tehran (ZUTC).Measurements are given in millimeter (mm) including a minimummaximum (mean) order.Measurement of the width of animals includes parapodia and chaetae.Th e number of examined specimens per species is indicated by "n".Type locality: Port Edward, Natal, South Africa, Indian Ocean.

Family
Material examined: ZUTC ann.2040Remarks: Th e only specimen examined here is broken in two parts; thus, no mea surements of this specimen could be taken.However, the specimen is similar to those described by Wehe (2006) except for the position of the nephridial papillae, which Wehe observed to start from segment 7 onwards, while in our fragmented specimen they start from segment 8.   stan Journal of Marine Sciences 12(1): 70-72, fi g. 12; Barnich et al. 2004, Species Diversity 9: 300-301; Wehe 2006, Fauna of Arabia 22: 107-109, fi g. 24 a-l.
Type locality: Djibouti, Gulf of Tadjoura, Gulf of Aden.
Remarks: According to Wehe (2006), there are microtubercles on the elytra of Th ormora jukesii, usually confi ned to the lateral part of the surface of the body.Th ey are numerous from the second pair of elytra onwards.Additionally, small globular papillae are found scattered along the margin of the body.However, on specimens of T. jukesii found in Hengam Island, the microtubercles decreased from the second pair of the elytra onward, and globular papillae along the margin of specimens were missing (Fig. 6c, f ).
Distribution: Th is is a new record for the Gulf of Oman.Remarks: Th e only specimen examined here was broken into three parts, so no measurements were taken.Nephridial papillae from segment 7 onwards as described by Barnich et al. (2004) could not be observed in our specimen (Fig. 8 a, e).

Family Sigalionidae
Sthenelais boa (Johnston, 1833)  Remarks: On some specimens a few ampulla-shaped structures with a stem could be observed on the elytra.
Distribution: Th is is the fi rst record for this species for the Gulf of Oman.Th e high number of new records demonstrates that a much higher diversity of scale worms and polychaetes in general is present on the north-eastern coasts of the Persian Gulf as well as from the northern coasts of the Gulf of Oman than known so far.It can be expected that more intensive fi eldwork in additional stations will yield additional records for this relatively unexplored coast.

Figure 1 .
Figure 1.Collecting sites along the mainland coasts of the Persian Gulf and the Gulf of Oman. 17

56°F igure 2 .
Collecting sites on the Island of Qeshm and Hengam.

Figure 4 .
Figure 4. Parahalosydnopsis arabica.a anterior end, dorsal view b 1st right elytron c microtubercles of lateral elytra surface from b d elytron from posterior end e fringing papillae from b f balloon-shaped papilla on surface of posterior elytron.

Figure 6 .
Figure 6.Th ormora jukesii.a anterior end, dorsal view b everted proboscis c 2nd left elytron d globular papillae on surface of fi rst elytron e microtubercles f 1st right elytron g macrotubercles on surface of fi rst elytron.

Figure 8 .
Figure 8. Harmothoe liaoi.a anterior end, dorsal view b 2nd right elytron c microtubercles d papillae on elytra margin e, f parapodium of middle segment: e posterior view f anterior view g notochaeta h neurochaeta.

Figure 9 .
Figure 9. Paralepidonotus ampulliferus.a anterior end, dorsal view b 1st right elytron c ampullae on elytra d fringing papillae e microtubercles f papillae on surface g ventral lamellae h 21st left parapodium, anterior view i notochaeta j upper neurochaeta k middle neurochaetae l lower neurochaeta.

Figure 11 .
Figure 11.Sthenelais boa. a anterior end, dorsal view b 1st right elytron c fringing papillae d microtubercles e 7th right parapodium, anterior view f lower neurochaeta g middle neurochaeta h upper neurochaeta i notochaeta j simple neurochaeta.

Table 1 .
Table showing information about material examined, collection numbers, date and position of sampling and habitat locations.