Hydroides dianthus ( Verrill, 1873 )

Ben-Eliahu, M. Nechama & Ten Hove, Harry A., 2011, Serpulidae (Annelida: Polychaeta) from the Suez Canal- From a Lessepsian Migration Perspective (a Monograph) 2848, Zootaxa 2848 (1), pp. 1-147 : 14-16

Hydroides dianthus ( Verrill, 1873)

Serpula dianthus Verrill, 1873: 620–621 [Type locality: U.S.A., New England, Vineyard Sound (see “ Material examined”, below)].

Hydroides dianthus: Zibrowius 1971: 697–707 , figs 1–5 [redescription, synonymy; U.S. eastern Atlantic from New England to Gulf of Mexico; Mediterranean: France, Spain, Tunisia, Italy, Turkey (Aegean); in estuaries and lagoons. In the eastern Atlantic, also on the coast between intertidal to 20 m or more—a distribution that suggests it is indigenous to that area; Zibrowius 1973a: 683–686 [see above distribution]; Bianchi 1981: 59–62, figs 20a–d [ Italy, particularly in ports and coastal lagoons]; Bastida-Zavala & ten Hove 2003a: 143–146, figs 23–24 [eastern U.S.A., N. Gulf of Mexico and Netherlands Antilles, Curaçao, 0.6– 28 m]; Zenetos et al. 2005: 73 [classified it as an “established cryptogenic alien invasive species” in the Mediterranean; as concerns the "cryptogenic" characterization, see remarks below].

Eastern Mediterranean

Hydroides uncinata ( Philippi, 1844) : Ghobashy 1977: 214–215, table 1 [Alexandria, under rocks; det. S.A. Selim 1973– 4 (?), possible first record from Levant coast— Ghobashy & Ghobashy (2005: 90) retroactively synonymised this material with H. dianthus ].

not Hydroides cf. dianthus sensu Ben-Eliahu 1976: 106–107 , fig. 1 [ Israel, Shavé Ziyyon]; Ben-Eliahu & Safriel 1982: 387 [same], corrected herein to H. operculatus ( Treadwell, 1929) , see remarks below.

? not Hydroides dianthus sensu Zibrowius & Bitar 1981: 159–160 [ Lebanon, see remarks below].

Hydroides dianthus: Ergen 1979: 79 [Aegean, Bay of Izmir]; Ghobashy 1984: table 1 [ Egypt, Alexandria, Eastern Harbour, based on S.A. Selim (1978, see App. Table 4), 1978 is the first record from Egyptian coast; Selim 1997b: 87– 90, figs 2a–f [ Egypt, Port Said]; El-Komi 1991a: table 3 [Alexandria]; Knight-Jones et al. 1991: 841 [Aegean, near Izmir, Güzelbahca Harbour]; Ben-Eliahu & Payiatas 1999: 101–119 [ Cyprus, Limassol harbour, on ship propeller]; Koçak et al. 1999: 6 [Aegean, Bay of Izmir, 3 m, panels]; Selim 2009: 73 [ Egypt, Alexandria; Eastern Harbour, Port Said harbour fouling].

Suez Canal

Hydroides dianthus: Selim 2009: 73 , [table 1, Lake Timsah. This appears to be the first record of H. dianthus from within the Suez Canal].

Material examined. More than 16 samples at the AMNH, USNM and YPM, with> 150 specimens, e.g., the following six samples :

U. S. A., Connecticut, off New Haven, 11–15 m, syntypes YPM 2698, 2699, 8 specs— Massachusetts, New Bedford, from piles under wharf, legit R. Hall & A. Elwyn 2.VIII.1909, det. W.G. van Name, redet. H.A. ten Hove; this H. dianthus is a “reef” (a solid aggregation of cemented tubes), AMNH 1122 (not counted, but at least 11 specimens).— New Jersey, Greater Egg Harbour, legit, det. H.E. Webster (1880: 128, 159), transferred by M. Pettibone to H. uncinata , redet. H. Zibrowius 1970 H. dianthus, USNM 381, 1 spec. — Florida, Alligator Harbour, Wilson’s Beach, Stn 22, Tall Timbers, legit J. Rudloe 25.III.1966, det. H.A. ten Hove 1971 (unpubl.), USNM 51862, 2 specs.

Mediterranean, Naples, Gulf, Zoological Station 1888, separated from Hydroides diramphus, RMNH 392, ZMA V.Pol. 3206, 1 spec. —without further data, det. K.J. Bush (1910: 498) Eupomatus uncinatus , redet. H.A. ten Hove 1985, YPM 2839, 10 dried specs.

Locations adjacent to the Suez Canal, Mediterranean side: Cyprus, Limassol Harbour entrance, Cy- AI, ca. 0.3 m depth, scuba, from a ship propeller, legit G. Payiatas & P. Orfanou 27.X.1997, det. M.N. Ben- Eliahu, HUJ-Poly-80, 2 specs .

Suez Canal proper: No previous records from the Suez Canal.

Locations adjacent to the Suez Canal, Red Sea side: No records

Distribution. Temperate to subtropical coasts of northeast America and western Europe (not north of the English Channel). Atlantic Africa. Mediterranean: Italy, Naples; Cyprus (on ship propeller); Turkey, Aegean; Egypt, Alexandria, eastern harbour, Port Said, Suez Canal (Lake Timsah). Japan, Tokyo Bay.

Remarks. Hydroides dianthus apparently originates from the Atlantic coast of North America and is common in biofouling along the U.S. western Atlantic seaboard ( Zibrowius 1971: 704, 1973a: 684). Contrary to the situation in the western Atlantic, there seemed to be no extensive populations in the eastern Atlantic and in the Mediterranean, except those in some Mediterranean lagoons (e.g., Thau lagoon). In the Mediterranean, Hydroides dianthus also occasionally occurs in harbours (H. Zibrowius, pers. comm.). The distribution pattern, conjunct in the western Atlantic and disjunct elsewhere, and the larger reservoir along the U.S. coast, supports the diagnosis of the western Atlantic as the provenance of this species (H. Zibrowius, pers. comm.). Zibrowius (1971) characterized it as tolerating a wide range of salinities and temperatures, between 28–50 ‰ and 5–30 °C. Its first record in the eastern Mediterranean (Aegean, near Izmir) was in 1865 ( Zibrowius 1973a). Knight-Jones et al. (1991: 841) reported it from the only station in the Bay of Izmir with eutrophic conditions (turbid waters and rocks covered with Ulva and Mytilus ). A first record from Cyprus (X.1997) was that of two decaying individuals removed from a propeller of a ship in Limassol Harbour ( Ben-Eliahu & Payiatas 1999), one an operculum without a body; this record does not provide a definitive proof of settlement in Cyprian waters. Hydroides dianthus has not been reported along the Mediterranean coast of Israel (M.N. Ben- Eliahu, unpubl. data); the specimen erroneously published long ago as H. cf. dianthus ( Ben-Eliahu 1976: 106– 107, fig. 1, and Ben-Eliahu & Safriel 1982: 387) is corrected herein to Hydroides operculatus , a Lessepsian migrant (see also Çinar 2006: 229–230, fig. 6). Moreover, Zibrowius & Bitar’s (1981) report of Hydroides dianthus from Lebanon was regarded as questionable ( Ben-Eliahu & ten Hove 1992: 37); the two small Lebanese specimens, when re-examined by one of us (H.A. ten Hove) in 1998 appeared rather to belong to Hydroides cf. brachyacanthus Rioja, 1941 , a Lessepsian migrant present on the coasts of Israel and Lebanon as well as the Levant coast of Turkey ( Ben-Eliahu & ten Hove 1992: 43, Zibrowius & Bitar 2003, Çinar 2006: 225– 226, fig. 2, respectively).

Selim's (1988) first record of Hydroides dianthus from the southern Levant coast (Eastern Harbour, Alexandria), and a later record from Port Said, not within the canal proper, were documented by a well-illustrated operculum ( Selim 1997b fig. 2a). However, Selim’s recent record (2009: 78) of Hydroides dianthus from within the canal, ca. 37 km from its northern mouth, from El Cap, referred to Ben-Eliahu's erroneous record of Hydroides cf. dianthus illustrated with a figure of the H. operculatus operculum ( Ben-Eliahu 1976: 106, fig. 1), and the other references cited ( Fauvel 1927: 357–358, Bellan 1964: 174–175 and Zibrowius 1968: 109– 112) referred not to Hydroides dianthus , but rather to H. uncinatus , confused for it (reviewed in Zibrowius 1971). The verticil spines of Hydroides operculatus , a well known Lessepsian migrant, all point inwards (Çinar 2006: 229–230, fig. 6), whereas the spines in H. dianthus all point in the same (ventral) direction ( Zibrowius, 1973a: 683). Despite the uncertainty created by Selim’s use of these citations and our inability to review a voucher specimen, given Selim’s (1997) illustration, we tend to hypothesize that the identification is correct. If that is true, the record is also presumed to be a first record of Hydroides dianthus from within the Suez Canal. This could be indicative of a recent Atlantic-Mediterranean incursion into the canal, a finding with biogeographic significance. However, its disjunctive distribution—it is lacking along the northward Israeli coast but present in the Egyptian ports of Alexandria and Port Said—suggests it could rather be indicative of ship-transport as has been observed in Hydroides elegans and Hydroides diramphus . This is supported by a recent article by Link et al. (2009) that reported its first occurrence in East Asia, Tokyo Bay on artificial hard substrates, presumably due to ship transport, and a subsequent report from Osaka Bay by Otani & Yamanishi (2010). In the Discussion section below, we have enumerated Hydroides dianthus as a member of the Suez Canal serpulid fauna.