Hydroides steinitzi Ben-Eliahu, 1972

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 : 35-38

Hydroides steinitzi Ben-Eliahu, 1972

Figs 13–15

Hydroides steinitzi Ben-Eliahu, 1972a: 77 , figs 1 1–4; figs 2 1–6 [Type locality: Suez Canal, Little Bitter Lake]; Zibrowius 1979b: 133–134 [ France, Toulon Port, biofouling removed from the aircraft carrier “Foch”]; Zenetos et al. 2005: 73 [classified as a “casual” alien, i.e., as a non-established alien species in the Mediterranean. Having been recorded only from ship biofouling ( Zibrowius 1979b), rather than from an actual Mediterranean habitat, "ship-transported" seems a more appropriate designation than "casual"].

Suez Canal

Hydroides steinitzi Ben-Eliahu, 1972a: 77 [SLC 85, 14.I.1969, on sandstone rock]; Ben-Eliahu 1991b: 524–525, fig. 4 [Suez Canal].

Gulf of Suez and Gulf of Aqaba

Hydroides steinitzi Ben-Eliahu, 1972a: 77 [Gulf of Suez; collected in 1870; BM(NH) 1870.12.23.62 (H. Zibrowius, pers. comm.), see “Material examined”, below]; ten Hove 1990: 119, figs 16–18 [confirmed]; Ben-Eliahu 1991b: 524– 525, fig. 4 [first sample from the Gulf of Aqaba, 6.X.1969 (see “Material examined”, below)].

Red Sea proper-Indo-West-Pacific (excluding citations from Gulf of Suez and Gulf of Aqaba already given above)

Hydroides steinitzi: ten Hove 1990: 119 [ Philippines, see “Material examined”, below]; Ben-Eliahu 1991b: 524–525, fig. 4 [south Red Sea, Dahlak Archipelago [see “Material examined”, below]; Wehe & Fiege 2002: 128 [Red Sea; list of references].

Material examined. Locations adjacent to the Suez Canal, Mediterranean side: None.

Suez Canal proper: 1 sample, Hebrew University-Smithsonian Expeditions, 1967–1973, Little Bitter Lake opp. opp. Kabrit-Km 120, SLC 85, 14.I.1969, holotype and 2 paratypes .

Suez Canal material reported herein: 17 samples, 28 specimens. Beets’ Great Bitter Lake samples, VIII / IX 1950, Stn 15, 10.4 m, from inside an empty Chama asperella shell, single tube with taphonomic residue of verticil, RMNH 18545 ( Fig. 14 ).— Hebrew University-Smithsonian Expeditions , 1967–1973, 2 samples, 4 specs: Lake Timsah opp. Isma’iliya , Km 78: SBE 8, 3 specs; Great Bitter Lake : SLC 117, 1 spec. — Great Bitter Lake “Yellow Fleet” Biofouling Samples (January 13–20, 1975): 14 subsamples, 23 specs. Material deposited in HUJ; BM (NH) ZB.1985.209, 1 spec.; Universidad del Mar UMAR-Poly 118, 3 specs; ZMA V.Pol. 3513, 1 spec.; SMF, 2 specs .

Locations adjacent to the Suez Canal, Red Sea side: Gulf of Suez, legit J.K. Lord ca. 1870, det. H. Zibrowius 1969, Ben-Eliahu (1972a), H.A. ten Hove (1990: 119, figs 16–18), 1 spec., BM (NH) 1870.12.23.62.

Gulf of Aqaba: Egypt, Marsa Abu Samra, 68 m, dredge, on Malleidae TAU-MO-19788, legit Ch. Lewinsohn 6.X.1969, det. M.N. Ben-Eliahu ca. 1985 ( Ben-Eliahu 1991b: 525, fig. 4).

Red Sea: Sudan, Sanganeb Atoll , 9 m, near Stn TQ 2, SAN 46, coral rubble with Serpula jukesii , legit D. Fiege

25.III.1991, det. H.A. ten Hove 1999; 10–15 m, near Stn TQ22b, TQ2, coral rubble with Vermiliopsis infundibulum / glandigera- complex, Protula spec. , legit D. Fiege 19.IX.1992, det. H.A. ten Hove 1992.— Eritrea: 6 samples ( TAU-NS [no numbers], 4 samples, SMF 2 samples), depth range: 9– [9–12] –36.6 m). Dahlak Archipelago, 14°58’N, 40°19’E, 9–12 m, on Plicatulidae , Israel South Red Sea Expedition, ISRSE / 65, Stn 4, legit Ch. Lewinsohn 17.X.1965, det. M.N. Ben-Eliahu ca. 1985 (Ben-Eliahu 1991: 525, fig. 4), TAU-MO- 1454, TAU-MO-2186; Stn 12, 15°35’N, 40°44’N, 36.6 m, on Malleidae , legit Ch. Lewinsohn 17.X.1965, TAU-MO-1814; with H. homoceros , S. latiscapus , S. tetraceros , det. M.N. Ben-Eliahu ca. 1985 ( Ben-Eliahu 1991b: 525, fig. 4).

Indo-West-Pacific: Philippines, Banacon Island, Danajon Bank, N.W. Bohol Island, reef and sand, on clams, legit C. Short, II–III.1976; det. H.A. ten Hove 1986 (ten Hove 1990: 119), Australian Museum, 2 specs.

Suez Canal depth and substrates: 0.4–10.4 m; on sponges, on molluscs: Brachidontes pharaonis , Chama asperella , Pinctada radiata and Spondylus spinosus ; on bryozoans, tunicates, sandstone rock, and on a muddy tin can.

Colouration. Lake Timsah field notes describe bodies with red-orange pigmentation.

Distribution. Suez Canal: Lake Timsah, Great Bitter Lake, Little Bitter Lake; Red Sea: Gulfs of Suez and Aqaba, South Red Sea—Dahlak Archipelago; Philippines.

Remarks. There have not been many records of this species. Hydroides steinitzi was described from 3 specimens collected from the Little Bitter Lake in 1969 ( Ben-Eliahu 1972a). Its verticil is unusual in being comprised of a single element with out-pocketing, somewhat resembling a peeled orange when seen in apical view. The verticil of the holotype had 6 out-pockets (bulges), and the funnel 12 pointed radii ( Ben-Eliahu 1972a). Note variability in the shape as well as in the number and the degree of chitinisation of the funnel radii ( Figs 13A–G ).

Hydroides steinitzi was first collected from the Gulf of Suez by the J.K. Lord Expedition in 1870 (specimen BM(NH) 1870:12:23:62), presumably from a coral reef habitat (the sample largely consisted of Spirobranchus species that inhabit living coral [ten Hove 1970b: 49–50]). The original sample, BM(NH) 1870:12:23:31, was subdivided into 5 different taxa in 1969, during a visit by one of us (HAtH) to the Natural History Museum, London; two of the taxa were Spirobranchus spp. , three taxa, Hydroides spp. In 1971 , H. Zibrowius re-identified the provisionally identified specimens of Hydroides , giving them temporary BM(NH) codes. On receiving the Ben-Eliahu manuscript describing Hydroides steinitzi, H. Zibrowius identified one of these Gulf of Suez specimens (BM(NH) 1971: 21), as H. steinitzi , and the newly identified specimen was then assigned a permanent code by the museum, BM(NH) 1870.12.23.62. Unfortunately, Zibrowius’ reply to Ben- Eliahu (letter, 26.XI.1971) reporting the existence of the Gulf of Suez specimen came when the issue with the description was already in production, but a “note added in press” was permitted, mentioning the record (Ben- Eliahu 1972a). The Gulf of Suez specimen measured ca. 11 mm in length, body 65 chaetigers, with ca. 10 radioles per lobe; the operculum had 6 out-pockets in the verticil and 10 radii in the funnel (H. Zibrowius, pers. comm.; ten Hove 1990: figs 16–18). The operculum resembled Figs 13C 1 and C 2 in form.

The first record of Hydroides steinitzi from within the Suez Canal, from 1950, is from the Great Bitter Lake, from a tube within a shell collected by Beets that contained a taphonomic residue of a verticil (RMNH 18545 [ Fig. 14 ]).

We have no way of knowing the date when the species settled in the canal. Altogether, it has been collected on four separate occasions (see above). Presently, the total number of H. steinitzi specimens from the Suez Canal comes to 30, with most of the specimens obtained from the Great Bitter Lake “Yellow Fleet” biofouling aggregation. These later specimens enabled providing a first description of the tube (the tubes of the type specimens were unwittingly damaged). Hydroides steinitzi was considered to be a potential Lessepsian migrant as it had been found both in the Bitter Lake and in Lake Timsah ( Ben-Eliahu 1991b). Subsequent reports from the Suez Canal or from the Mediterranean areas adjacent to it (e.g., Alexandria) have not included it, but this may be due to not sampling in its preferred microhabitats or on preferred substrate taxa (e.g., molluscs, bryozoans, etc.). H. Zibrowius (1979b) reported it among ship-transported biofouling taxa removed from the aircraft carrier “Foch” that arrived in Toulon Port (via the Suez Canal) after voyaging for 7 months in the western Indian Ocean.

A first description of the Hydroides steinitzi tube ( Figs 14 , 15 ): The tube has three longitudinal ridges close together on the upper surface and transversal ridges, which give it a generally rugose (not delicate) appearance. The median longitudinal ridge may be as prominent as the lateral longitudinal ridges as seen in three of the four tubes figured from above ( Figs 15A, B and E ) and in some cross-sections ( Figs 15D, E ); in Figs 14F 1 and F 2 , the median ridge is lower, but it can be discerned. Note that in Figs 14A, B, a median longitudinal ridge cannot be perceived; the tube surface appears to be covered by a granular overlay—as in many of the H. steinitzi specimens—obscuring the surface sculpturing ( Fig. 15B ); it is not clear whether the overlay is made by the worm. In some cross-sections ( Figs 15C, D ), the tube appears generally rounded, with a flattened upper surface, but in others (e.g., Figs 15E, F ) the tube is sub-trapezoidal, expanded basally; the upper surface may appear flattened. The tube may be somewhat coiled or looped ( Figs 14A, B , 15B ).

Figures

FIGURE 1. Map of Suez Canal showing salinity and temperature relations in the areas joined by the canal compiled from various sources. 1—Ben-Eliahu 1977: 70, Table 21, salinity ‰—seasonality, the extreme range of monthly means of sea surface salinity based on daily 00:08 recordings taken by the Nahariyya hydrographic station, northern Israel, 1968–1972 and the Elat hydrographic station, northern Gulf of Aqaba, 1962–1973, 2—Ben-Eliahu et al. 1988: 263, seasonality of sea surface temperature, Mediterranean coast of Israel and Elat, Gulf of Aqaba in °C (data from hydrographic stations listed above), 3—Por 1978: 118–119, fig. 32, southern Cyprus, summer surface isotherm 25°C; summer upwelling; 22°C, 4—Por 1978: 61, depressed salinity in Port Said due to Nile flood, 23.1‰ in autumn, 1872, 5—Ben-Tuvia 1970: 183, depressed surface salinity in Port Said due to Nile flood, autumn peak, IX & X.1960, 6—Thorson 1971: 842– 843, initial salinity at Great Bitter Lake, bottom, 8 m: 68–80‰; surface: 50–52‰, 7—Ghobashy & el-Komi 1981a: 169, 171, seasonality of Lake Timsah salinity and temperature between II.1977–I.1979; Ghobashy & el-Komi 1981b: 180, southern canal, seasonality of salinity and temperature at the Little Bitter Lake (Kabrit) and Suez between II.1977– I.1979, 8—Por 1972: 113–114. Gulf of Suez coast of Sinai, Ras el Missala and Ras es Sudr, 15 and 50 kms south of Suez, respectively, X.1970, Ras el Missalla along the shore, 44.25‰ and 25 m offshore 43.93‰; Ras es Sudr high VIII.1970, 44.25‰; X.1970, 41.69‰ and I.1971, 42‰, 9—Oren 1970: 226 reported 18°C temperature for the Gulf of Suez; however, Por 1972: 114, 1978: 83 noted even lower winter temperatures, particularly inshore, and found that the temperature decrease from south to north of Gulf of Suez corresponds with the depletion of the tropical fauna (i.e., of corals and associated taxa), from the south to the north of the Gulf, 10—Ben-Tuvia 1966: 255, mean monthly sea surface temperatures at Massawa, Eritrea, 11—Oren 1964: 12, table 3, III.1962, profile of Stn 7, surface to 110 m (low to high value, respectively) taken in the south Red Sea off Eritrea, off Entedebir and Dahlak Kebir Islands, 12—Brit 2000 (E. Spanier, pers. comm.): High peak temperature (9 m) prevailing off Haifa, northern Israel during August, 2000.

FIGURE 2. Biofouling on a ship that was trapped in the Suez Canal for 8 years when the canal was shut down due to the June 1967 war (adapted from Barracca & Thomas 1975). Scale: 1 m.

FIGURE 13. Variability of opercula in a population of Hydroides steinitzi from the Great Bitter Lake “Yellow Fleet” aggregation (App. Table 2D). Opercula B–F correspond to tubes B–F in Fig. 15; C1—lateral view, C2—apical view of C1. Note variability in height of verticil and in the degree of chitinisation of funnel radii and constriction of peduncle. Scales, 0.5 mm.

FIGURE 14. First record of Hydroides steinitzi in the Suez Canal from a taphonomic residue of the operculum. Operculum, collected in 1950, was within tube inside Chama asperella valve (Beets’ Stn 15, 10.4 m, see App. Table 2B). A— Tube in situ, B—Tube removed from valve; note upper surface somewhat encrusted with granular layer, C—Dried opercular residue (verticil) found within the tube had “lasted” 50 years (compare with those in Fig. 13). Scales: B—1 mm, C—100 µm.

FIGURE 15. First description of Hydroides steinitzi tubes. Tubes rugose with 3 longitudinal ridges on upper surface, more or less developed, with middle longitudinal ridge often lower than lateral ones (e.g., F1), and with transverse ridges. Lumen of tube circular, with tube more or less expanded at base, thus, tubes C, D rounded in cross-section; tubes E and F with expanded base, more trapezoidal in cross-section; C1 and C2 are sections of the same tube. Figs E1 and E2, and F1 and F2 are paired cross-section and upper views (of two different tubes). Tubes B–F correspond to opercula B–F in Fig. 12. Scales: 1 mm.