Egyptian Mediterranean Waters Research Articles

First record of Coolia monotis Meunier along Alexandria coast – Egypt

The distribution and abundance of epiphytic and planktonic Coolia monotis Meunier along the Alexandria coast were studied through five annual cycles; from summer 2005 to summer 2010 at four sites: Abu Qir Beach, Stanly, Eastern Harbour and Mex Beach. The morphology of C. monotis was characterised by noticeable small size specimens in the E.H., the D.V. diameter is not exceeding 20μm and width between 10 and 15μm. On the other hand, the epiphytic specimens showed a normal cell size. The species was most abundant as planktonic form in the E.H., reaching 15.2×103celll−1 during summer 2010. The epiphytic forms showed lower density, with a maximum of 454cellg−1fwm during autumn 2005, 2006 and summer from 2007 to 2010. The fluctuations of cell abundance of C. monotis showed a significant negative correlation with salinity and a weak positive correlation with temperature.This study represents the first report of Coolia monotis Meunier in the Egyptian Mediterranean waters.

Benthic bryozoan fauna from the Northern Egyptian coast

The present paper presents taxonomical information on a small bryozoan fauna collected from the Eastern Mediterranean coast of Egypt. Eight species of benthic bryozoans are reported from the trash crop of a trawling net in the area between Damietta and El-Manzalah. These species belong to 7 genera in 7 families of the orders Cyclostomata, Ctenostomata and Cheilostomata. Four species (Hornera sp., Nolella dilatata, Copidozoum planum and Schizomavella triangularis) are new records of the Egyptian Mediterranean waters. All species are described and photographed.

Effect of lessepsian immigrant species on demersal catches operating along the Egyptian Mediterranean waters

Effect of lessepsian immigrant species on demersal catches operating along the Egyptian Mediterranean waters

Effect of Lessepsian Immigrant Species on Demersal Catches Operating Along the Egyptian Mediterranean Waters

Effect of Lessepsian Immigrant Species on Demersal Catches Operating Along the Egyptian Mediterranean Waters

ACINETA TUBEROSA EHRENBERG, 1834 (CILIOPHORA: SUCTORIA) FROM EGYPT: NEW RECORD, IMPROVED DIAGNOSIS AND SYNONYMS OF THE SPECIES AND REVIEW OF ITS SUBSTRATE ORGANISMS

Acineta tuberosa Ehrenberg, 1834 (Ciliophora: Suctoria) is recorded for the first time in the Egyptian Mediterranean waters at Port-Said, Egypt, as an epibiont of the marine filamentous green alga Cladophora sp. The body is oval or bell-shaped, 29.8 µm long. The cytoplasm almost completely or completely fills the lorica. Two actinophores are present, each bearing 4 or 5 tentacles. The tentaclular tips appear funnel-shaped because almost all tentacles of the obtained specimens function in sucking meiozoospores of the Cladophora alga. An oval macronucleus is centrally located. Stalk varies from short wedge-shaped to tubular with an average stalk length 27.8 µm. Cluster analysis approach was used to confirm that all the obtained specimens belong to A. tuberosa. The cluster analysis also showed that the length of the body and stalk contributed much to the clustering process (i.e. the most important taxonomically) followed by the mean number of tentacles per fascicle. The morphological variations within the obtained specimens proved not to be significant, if considered globally to be assigned to species other than A. tuberosa. A review of its substrate organisms and synonyms is also provided.

First records of polychaetes new to Egyptian Mediterranean waters

Nineteen benthic polychaete species were recorded for the first time in the intertidal zone of the Alexandria coast, south-eastern Mediterranean Sea. They belong to Syllidae (7 species), Hesionidae (3 species), Serpulidae (2 species) and 7 other families (one species each). Of these species Eunice miurai Carrera-Parra & Salazar-Vallejo 1998 appears to be new to the Mediterranean Sea, while four of the alien species earlier recorded in the Mediterranean were found for the first time in Egyptian waters: Opisthosyllis brunnea Langerhans 1879, Loimia medusa Savigny 1822, Syllis schulzi Hartmann-Schröder 1960, Phyllodoce longifrons Ben-Eliahu 1972.The newly recorded species demonstrated markedly different patterns of frequency of occurrence and numerical abundance. Spirobranchus triqueter Linnaeus 1758, S. schulzi, L. medusa and Salvatoria clavata Claparède 1863 were permanent and abundant species in fouling samples along the Alexandria coast. Saccocirrus papillocercus Bobretzky 1872 persisted in the sediments at two sites, with a much higher count at the stressed one, while Protodrilus sp. inhabited sediments at two other sites throughout the year, sometimes in very high numbers. In addition, the alien species found earlier, Brania arminii Langerhans 1881, Odontosyllis fulgurans Audouin & Milne-Edwards 1833 and O. brunnea Langerhans 1879, were frequently observed along the Alexandria coast.

Feeding behavior of lessepsian fish Etrumeus teres (Dekay, 1842) from the Mediterranean Waters, Egypt

The present work studies the food and feeding habits of lessepsian fish, Etrumeus teres (Dekay, 1842) to know its feeding behavior in relation to sex, length and season as well as its preference for food items. Fish samples were collected monthly from Alexandria landing centers during 2008 and a total of 490 individuals were selected to be examined for this study. The results indicated that round herring E. teres feeds on a variety of food materials mainly small crustaceans (shrimp larvae, isopods and amphipods) followed by fish larvae (Engraulidae, Mugilidae and Labridae); Mollusk (few gastropods and cephalopods) as well as food remains. The feeding intensity showed the highest values during winter and spring (82% and 50.55%, respectively) while the lowest values were during summer and autumn (40.14% and 38.1%, respectively). Round herring E. teres shifted their fullness index as they grow in length where the lowest value of this index was recorded for a length group of 9–15cm TL and the highest value was recorded for a length group of 15–20cm TL. According to the modified food index (MFI), crustaceans were the first preferable food item represented mainly by shrimp larvae (61.69%) followed by fish larvae which were represented mainly by Engraulids (23.58%). Diversity index (H′) of food items for males was higher than females; while this index (H′) for the small length group (9–15cm) was higher than the other length groups which suggest that fishes of smaller length seemed to be more active in capturing different food items. Also, the value of diversity index (H′) of Autumn was higher than other seasons. The overlap test (T) showed no obvious differences between males and females and between different length groups where the value was found to be “1” indicating that all fishes have the same mode of feeding. Food items were attracted and aggregated by artificial light of purse-seine using light giving a positive effect of this fishing method for pelagic fishes particularly E. teres to feed on those materials. From the previous findings, it can be speculated that, round herring E. teres from the Egyptian Mediterranean Waters is zooplanktivorous.

Potentially harmful Ostreopsis spp. in the coastal waters of Alexandria - Egypt

Ostreopsis spp. has been reported for the first time from the Egyptian Mediterranean waters. Macroalgal samples were collected monthly between June 2005 and December 2007, from the rocks at Abu Qir, from less than 1.5 m depth, and their associated microalgae examined. Populations of two Ostreopsis morphotypes were found to occur in this location, east of Alexandria, viz., O. cf ovata Fukuyo and Ostreopsis morph1. The Ostreopsis spp. was abundant and dominant during the summer. They were more abundant as epiphytes of the brown algae Padina sp. and Sargassum sp., less abundant on the red algae Corallina sp., Jania sp., Laurencia sp. and even less so on the green algae Ulva spp. Ostreopsis cf. ovata was also identified during the summer months on the same macroalgal species, although in a much lower abundance. Ostreopsis spp. alternated in dominance with the benthic cyanobacteria Oscillatoria spp. and the diatom Licmophora sp. Other benthic dinoflagellates recorded at low abundance included Amphidinium carterae, Gymnodinium sp. and Prorocentrum lima.

Feeding behavior of the European hake Merluccius merluccius Linnaeus, 1758 (Family: Gadidae) from Egyptian Mediterranean waters off Alexandria

The feeding habits of the European hake, Merluccius merluccius Linnaeus, 1758, collected by the trawlings operated from the Egyptian Mediterranean waters off Alexandria during the period from March 2009 till February 2010 was investigated with respect to season and fish size. Stomach contents of 549 specimens, total length (TL) of 14.2–53.3cm, showed that only (32.2%) were full of food, the rest had their stomachs either renversed (30.6%) or empty (37.2%). The filling index was maximum during winter (4.6). Analysis of food contents revealed that this species is mostly carnivorous fish. It feeds on various food items including pisces, crustacea, molluscs, algae and plant detritus. The main fish prey in the diet of these fishes were Sardinella aurita (11.9%), Caranx rhonchus (6.8%) and Engraulis encrasicollus (3.4%). Test of feeding diversity according to size groups were found to be high for fishes of size group (20–30cm) (H=2.107). Seasonal feeding diversity showed a high value during summer (H′=2.118). The test of food overlap according to season show insignificant difference between all seasons except between spring and autumn (0.55). Also, differences food overlap according to size groups were found to be significant (<20cm, 20–30cm and >30cm).

Aliens in Egyptian Mediterranean waters. A check-list of Erythrean fish with new records

The historical role of the Suez Canal as a pathway for migrations between the Red sea and the Mediterranean is recalled. A check-list of 42 immigrant Erythrean fish in Egyptian Mediterranean waters is given. The list comprises four new records. 17 of the immigrant species are commercially exploited, whereas 15 are known from single records. While the Erythrean fish as invasive species are beneficial to local fisheries, in our view, they do not have an important impact upon the ecosystem.

Classification of Sharks in the Egyptian Mediterranean Waters Using Morphological and DNA Barcoding Approaches

The identification of species constitutes the first basic step in phylogenetic studies, biodiversity monitoring and conservation. DNA barcoding, i.e. the sequencing of a short standardized region of DNA, has been proposed as a new tool for animal species identification. The present study provides an update on the composition of shark in the Egyptian Mediterranean waters off Alexandria, since the latest study to date was performed 30 years ago, DNA barcoding was used in addition to classical taxonomical methodologies. Thus, 51 specimen were DNA barcoded for a 667 bp region of the mitochondrial COI gene. Although DNA barcoding aims at developing species identification systems, some phylogenetic signals were apparent in the data. In the neighbor-joining tree, 8 major clusters were apparent, each of them containing individuals belonging to the same species, and most with 100% bootstrap value. This study is the first to our knowledge to use DNA barcoding of the mitochondrial COI gene in order to confirm the presence of species Squalus acanthias, Oxynotus centrina, Squatina squatina, Scyliorhinus canicula, Scyliorhinus stellaris, Mustelus mustelus, Mustelus punctulatus and Carcharhinus altimus in the Egyptian Mediterranean waters. Finally, our study is the starting point of a new barcoding database concerning shark composition in the Egyptian Mediterranean waters (Barcoding of Egyptian Mediterranean Sharks [BEMS], http://www.boldsystems.org/views/projectlist.php?&#Barcoding%20Fish%20%28FishBOL%29).

Two new species of parasitic copepods (Crustacea) on two immigrant rabbitfishes (Family Siganidae) from the Red Sea

Two new species of parasitic copepods, one from each of the families Hatschekiidae and Bomolochidae, are reported from two immigrant species of rabbitfishes (Family Siganidae), both of which originated from the Red Sea but are now established in the Mediterranean. The descriptions of Hatschekia siganicola n. sp. and Nothobomolochus neomediterraneus n. sp. are based on material of both sexes obtained from the gills of Siganus luridus Rüppell and S. rivulatus Forsskål, respectively, caught in Egyptian Mediterranean waters off the Alexandrian coast.

Growth, mortality and spawning stock biomass of the striped red mullet Mullus surmuletus, in the Egyptian Mediterranean waters

Population parameters such as age, growth, mortality and maturity-at-age are crucial parameters for accurate stock assessment and management plans to ensure the sustainable development of fisheries. Also, they are essential for the calculation of spawning stock biomass (SSB) and equilibrium yield as well as biological reference points including Fmax, F0.1 and F30%SSB. Age and growth parameters were estimated for the striped red mullet, Mullus surmuletus, sampled from commercial landings of the trawl fishery in the Egyptian Mediterranean waters, using the otolith reading technique. M. surmuletus has a longevity of 5 years, but over 70% of fish were less than 2 years old. The growth parameter estimates were K= 0.47 yrs-1, L∞= 31.74 cm, and to= -0.3 yrs. Natural mortality (M) was 0.43 yrs-1, fishing mortality (F) was 0.73 yrs-1, survival rate (S) was 0.31 and exploitation ratio was 0.63 yr-1. Length-at-50% maturity was estimated at 15.1 cm TL, while the length at first capture was estimated at 11.6 cm TL. SSB analysis showed that effort reduction is strongly recommended such that F be reduced by 40% to rebuild spawner biomass to acceptable levels. Per-recruit analysis revealed that F should be reduced by about 27% to achieve the maximum Y/R. All approaches point to the need for drastic reduction in fishing pressure by about 30-40% in the Egyptian Mediterranean fisheries.

Fouling Bryozoa from some Alexandria harbours, EGYPT. (I) Erect species

The fouling erect Bryozoa settled on polystyrene test panels immersed half a meter deep in the water of Abu Qir Harbour, the Eastern Harbour and El-Dekheila Harbour were studied. The present study yields 5 species of erect bryozoa. These areAmathia pruvoti, Zoobotryon verticillatum, Bowerbankia gracilis,Bugula neritina and Bugula stolonifera. The first three ones pertain to 3 genera of the family Vesiculariidae belonging to suborder the Stolonifera; while the other two species affiliate to the genus Bugula belonging to the family Bugulidae of suborder Anasca. The present record of Amathia pruvoti is the first from the Egyptian Mediterranean waters. A re-description, supplied with full structural illustrations of the recorded species is given. Moreover, the temporal and spatial distributions of the species recorded are encountered.

Age and growth of Boops boops ( L.) from Egyptian Mediterranean waters off Alexandria

study of age and growth of Mediterranean bouge; Boops boops (L.)> from Egyptian Mediterranean coast off Alexandria was carried out during the period from April 2003 to March 2004 by examining the growth increment on their otoliths. The individuals of B. boops fall into 4 age groups (I to IV). The weight- length relationship was estimated as W = 0.0254L2,660 The growth parameters were estimated according to the Von Bertalanffy growth model as follows: U =30.105 cm, K = 0.1511 and to =1.5083, Wo.-218.07g. The growth performance index O was found to be 2.136.

Feeding habits of the Atlantic stargazer fish Uranoscopus scaber Linnaeus, 1758 (Family: Uranoscopidae) in Egyptian Mediterranean waters

The ej^mination- of 418 -stomachs of Uranoscopus scaber in the Egyptian Mediterranean waters showed that the feeding intensity had a maximum value during April (85%). Analysis of food contents revealed that this species is mostly carnivorous fish, that feeds on a broad food items including pisces, crustaceans, molluscs, echinoderms, annelids, algae and higher plants. Spicara smarts and S, flexuosa (Family: Centracanthidae) were the main fish prey in the diet of stargazers. The test of seasonal diversity index of food items exhibited high value during spring (H5 = 1.43) than in other seasons, due to wide diversity of food. Regarding the feeding diversity according to size groups, it was found to be high for fishes of large size groups of more than 20.0 cm (H* = 1.41). The test of food overlap according to seasons showed significant overlapping among all seasons with exception between autumn and winter. Significant overlapping was found between all size groups ( 20 cm).

NEWLY RECORDED SPIONID SPECIES (POLYCHAETA) FROM THE EGYPTIAN WATERS, WITH SPECIAL REFERENCE TO POLYDORIDS HABITATS

n the present study, 9 spionid species were reported. Five of them are new records to the Egyptian waters. In order to achieve this study fouling components and sediments samples were collected from different sites of Egyptian waters. The recorded spionid species were described and figured in details. The identification of the two Dipolydora species has been corrected. The relation between the surrounding habitat, major spines of setiger 5 and boring activity of the recorded polydorid species was discussed. The geographic distribution of five new taxa recorded indicated that Scolelepis carunculata, Pnonospio aucklandica and Pseudopolydora paucibranchiala appeared for the first time in the Mediterranean Sea. They are of indo-pacific origin and migrated through Suez Canal. While Pnonospio steenslrupi is new to the Egyptian Mediterranean waters and Spiophanes kroeyeri new to the Egyptian Red Sea waters (Suez Bay). I

SOME BIOLOGICAL CHARACTERS OF CHUB MACKEREL (SCOMBER JAPONICUS, HOUTTUYAN, 1782) FROM THE MEDITERRANEAN WATERS OF EGYPT

Fishes of chub-mackerel (Scomber japonicus, Houttuyan, 1782) are mainly caught by purse-seine nets using light attraction. The structure of S. japonicus catch in the Egyptian Mediterranean waters showed that tlus species attains ages not exceeding more than four years. Fishes of age group II dominated the catch, whereas those having age groups 0 (juveniles) and I were absent. The length of51 japonicus reached 25.9 cm during its second year of life. This was followed by a slight increase in length during the third and fourth years reaching 29.6 cm and 32.2 cm respectively. The back calculated weight for £ japonicus showed gradual increase in weight as the fish gets older, where weight at the fourth year (252.56 g) was nearly twice that obtained during the second year (133.36 g). The theoretical length (LM) and weight (W*,) calculated by von Bertalanfly equations were 39.42 cm and 453.24 g respectively. The values of condition factor, hepato-somatic and gonado-somatic indices were minimum in August following the end of the spawning season which extends from May to July. The shoals of S* japonicus were characterized by lacking immature fishes, so the length and age at the first sexual maturity cannot be determined. The relative fecundity of this species showed that a female produces from 382 to 625 eggs per gram of body weight.

A study of water circulation along the Egyptian Mediterranean coast using a three dimensional numerical model

The Egyptian Mediterranean coast lies between longitudes 25° 30' E. and 34° E and extends northward to latitude of 33° N. Its water volume is 224,801.55 km3, and has a surface area of about 154,840 km2. Striking features of this area are the presence of different water masses which converge and mix. The Princeton Ocean Model (POM), which makes use of a curvilinear orthogonal grid and of a sigma‐coordinate system, was used to study the general circulation of the Egyptian Mediterranean waters. The model bathymetry was obtained from the bilinear interpolation of the depth data into the model grid. The model grid contains 35 × 11 points with a resolution ranges from 22 to 27 km. The model has three open boundaries to the west, east and north.

A Comparative Study on the Morphometric Characters of Fishes Belonging to Family: Centracanthidae in the Egyptian Mediterranean Waters

A Comparative Study on the Morphometric Characters of Fishes Belonging to Family: Centracanthidae in the Egyptian Mediterranean Waters