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Distribution of the sea squirt Ecteinascidia thurstoni Herdman, 1890 (Ascidiacea: Perophoridae) along Suez Canal and Egyptian Red Sea coasts

100%

Gab-Alla A. A.-F. A.

Oceanologia

2008

tom 50

nr 2

239-253

Ecteinascidia thurstoni is a colonial sea squirt. It has a seasonal rhythm and a tropical and subtropical distribution; it is usually present during the summer months. It synthesizes a group of molecules called ecteinascidins. One of these is ET-743, a compound that has a most original anti-tumoral activity and is today considered to be one of the most promising substances effective against various solid-type tumors (currently sold under the trade name of Yondelis for the treatment of sarcomas and related tumors; it is undergoing phase II/III clinical trails for other kinds of tumors). Worldwide, Ecteinascidia species represent the only available source of this bioactive compound, which was first discovered in E. turbinata. During the present study, the ecology of E. thurstoni along the Suez Canal and Red Sea was investigated. Its populations were observed to be highly gregarious due in part to their low larval dispersal, which is very localized; larvae therefore tend to settle close to their parent colonies. It is only recorded in shallow waters (0.5–1.5 m) as an epiphyte on the pneumatophores of mangroves by the Red Sea, on the pilings of jetties, and the metal or cement banks of the Suez Canal. The morphometric characteristics (zooid length, zooid weight, colony weight) of the Suez Canal population differ significantly from those of the Red Sea. Studying the distribution of this species and locating its different populations along the Suez Canal and Red Sea could help to characterize their genetics, chemistry and bacterial communities at different isolated locations. Ultimately, this will help to define the sources of ET-743 and hence promote its biosynthesis on a commercial scale.

Effect of transplantation on heavy metal concentrations in commercial clams of Lake Timsah, Suez Canal, Egypt

63%

Gabr H. R., Gab-Alla A. A.-F. A.

Oceanologia

2008

tom 50

nr 1

83-93

Ruditapes decussatus and Venerupis pullastra are commercially fished clams with a wide distribution in the shallow inshore waters of Lake Timsah, Egypt. They are usually contaminated with heavy metals. Consumption of such contaminated clams can pose a public health risk. To minimize this risk, therefore, the clams should be removed from the contaminated waters and transferred to an approved area to reduce the high levels of metals before being marketed. The aim of this work was to study the effect of transplantation on levels of heavy metals (Fe, Mn, Zn, Cu,Ni, Co,Cd,Pb) in these clams. The clams were removed from their polluted site and transplanted to a relatively clean area for a period of 120 days. Although the salinity at the transplantation site was higher than at the polluted site, it was stable and did not appear to have any adverse effect on clam growth. Heavy metals were analysed in the water, sediment and clam tissues from both the polluted and the transplantation sites. Although in both species transplantation evidently reduced heavy metal levels, these still exceeded the maximum permissible levels laid down by the WHO (1982).

Ograniczanie wyników

2 Oceanologia

2 Gab-Alla A. A.-F. A.

1 Gabr H. R.

2 2008

Wyniki wyszukiwania

Distribution of the sea squirt Ecteinascidia thurstoni Herdman, 1890 (Ascidiacea: Perophoridae) along Suez Canal and Egyptian Red Sea coasts

Effect of transplantation on heavy metal concentrations in commercial clams of Lake Timsah, Suez Canal, Egypt