Ecosystem structure of Gomishan Wetland

Gomishan Wetland is situated in the extreme southern part of the eastern coast of Caspian Sea. It is connected to the Caspian Sea, so its hydrological features are directly generated from the sea. The whole wetland area (which also consists of the northern part of the wetland that is situated in Turkmenistan republic) is calculated with the aid of the Satellite Images for the years of 1977, 1987 and 1998 respectively 5070, 16320 and 29520 hectares. To have better ideas about food chains in the aquatic ecosystem, five permanent stations was appointed in different parts of the wetland. During one year field study, at the beginning of each month, physical, chemical and biological characteristics of the water and the sediment was surveyed and different specimens were gathered, fixed and took to the laboratories for the relevant analyses. The factors measured in water samples were mainly consist of turbidity, pH, EC, DO, BOD, PO4, NO3, alkalinity, Cl and hardness . The factors measured from sediment samples were the percentage of Sand, Very Fine Sand, Silt, Clay, K, P, N, and Organic Carbon. Biological examinations of the water has been consist of planktonic sample collections, determination, counting and analysis of both phyto and zoo planktons of the wetland. For example the zooplanktons of the Gomishan Wetland are determined in 15 groups, belonging to 5 phyla. The seasonal changes are recognized considerable. The least density of the zooplanktons is occurred in February. The density of most of the groups is seen from the beginning of the summer until the mid autumn. The annual mean density for any 15-zooplankton groups and also the minimum and maximum density with %95 confidences, for each of them, is calculated for the environment of all of the stations and also for the whole wetland. The spatial distribution of the individuals within the population of each of the groups is introduced, according to regular or contagious or random distribution. Diversity indices are calculated for the zooplanktons living in the environment of the stations. Comparison of the wetland, with the southeastern Caspian Sea, from the point of view of zooplankton density and diversity is also obtained. Benthos invertebrates in each station from sediment samples were also extracted. The specimens were colored by Rose Bengal solvent and then were determinate and counted, in separate groups of macro and meio benthos. Among the macro benthos, the highest density was seen in the species of Fyrgula caspia. After that, more density was seen respectively in Apra ovata, Cerastoderma sp., Balanus sp., Nerds divesicolarr, lifytilaster lineatus and Dreissena sp. Among the meio benthos, the most density was seen in Foraminifera and then respectively in Ostracoda, Nernatoda and Bivalve larvae. The indices of diversity and distribution are also calculated. As the birds in this lagoon are of prime importance, all mid winter waterfowl censuses available from recent 13 years are gathered and analysis. Also a whole year (12 times, each at the beginning of one month) waterfowl census was undertaken, throughout the wetland. According to this study, the Eastern Ecosystem of the wetland, is supporting the most population (%75) of the waterfowls, the Middle Open Water Ecosystem and the Western Reed bed Ecosystem, are supporting respectively %14 and %11 of the population. Four of the species are found in the global threatened red list, and the wintering population of the 20 species of the site, in some years, are observed more than %I of the global populations. The Waterfowl Species Diversity and Similarity Indices are given also.

Étude morphologique comparative du sang de quelques poissons marins: la phagocytose des substance inertes

Morphological studies on fish blood have been undertaken by many authors. The species used for the present study are: Arius thalassimus, Diploprion bifasciatum, Epinephelus maculatus, Lutjanus chrysotaenia, Lutjanus sanguineus, Scolopsis dubiosus, Plectorhynchus lineatus, Pomacanthus semicirculatus, Platax orbicularis, Amphiprion polylepis, Pseudoscarus nuchipunctatus, Seriola nigrofasciata, Pseudorhombus neglectus, Cynoglossus bilineatus, Acanthurus strigosus, Balistes stellatus.

Plotosus lineatus (Thunberg, 1787)

The Striped Catfish can be recognized by its striped coloration, barbels around the mouth, and its body shape which tapers to a point posteriorly. Small juveniles are black and large adults may be less distinctly striped. Plotosus lineatus can reach a maximum length of 32 cm (13 in) and about 40cm in Persian Gulf. The body is brown with cream-colored or white longitudinal bands. The most striking feature of this species is in the fins; in fact the second dorsal, caudal and anal are fused together as in eels. In the rest of the body is quite similar to a freshwater catfish: the mouth is surrounded by four pairs of barbells, four on the upper jaw and four on the lower jaw. The first dorsal and each of the pectoral fins have a highly venomous spine. They may even be fatal. Juveniles of P. lineatus form dense ball-shaped schools of about 100 fish, while adults are solitary or occur in smaller groups of around 20 and are known to hide under ledges during the day. Adult P. lineatus search and stir the sand incessantly for crustaceans, mollusks, worms, and sometimes fish. Striped eel catfish is an oviparous fish; this species has demersal eggs and planktonic larvae. This species has evolved long ampullary canals in its electrosensory organs.