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Competitional settlement of brown alga Iyengaria stellata and soft coral Zoanthous sansibaricus on muddy and muddy-rubble intertidal substrate in the Hormuz island
Get PDFThe effect of substrates on the surface cover by the soft coral, Zoanthus sansibaricus, and the brown alga, Iyengaria stellata, and their competitional condition, was compared in Hormuz Island by estimating of coverage area in 40 quadrates (50×50 cm). This soft coarl (Zoanthid) is a dominant species in the island’s intertidal zone and I. stellata is a dominant macroalgea most of the year. Significant negative correlation (p<0.01; r =-0.607) revealed competition between the two species for settlement on the two substrates. Soft coral with 61.7% coverage was dominant vs. 16.8% for brown algae on muddy-rubble substrate, but on sandy-rubble substrate, the brown algae was dominant with 37.8% coverage vs. 19.5% for the soft coral. It seems that better competitional conditions in settlement on unconsolidated substrate have some advantages for Z. sansibaricus
Ghana: child labour, no child’s play
Get PDFAre current interventions far-reaching enough to tackle trafficking of child labour in Ghana’s fishery
Fish trade: needed, a new paradigm
Get PDFEnsuring social sustainability in fish trade for small-scale fishers entails recognizing their economic contribution, and devoting public resources for policy
Symbiosis between Ptereleotris arabica and Cryptocentrus lutheri and Alpheus djiboutensis
No full textIreland: fishworkers, confronting a scandal
Get PDFIn fighting for the rights of migrant workers in the Irish fishing industry, the International Transport Workers’ Federation has put the government on notice
Variations in fish body and scale shape among Aphanius dispar (Cyprinodontidae) populations: insights from a geometric morphometric analysis
Get PDFPhenotypic variations in fish body and scale shape were investigated among the three populations of Aphanius dispar (Rüppell, 1829) in Southern Iran through the use of landmark-based geometric morphometric analyses.This species is widely distributed in the region, and therefore, considerable morphological variations exist among the geographically allopatric populations. Based on the Principle Component Analysis (PCA), variation in body shape of the females is prominently related to the dorsal fin region, while in the males it is related to the dorsal fin and caudal peduncle. Moreover, the shape variations in the scales are obviously linked to the tip of anterior portion of the scales, and the left and right boundaries between anterior and posterior regions of the scales. The lateral sides of the fish scales in site I are concave, while they are laterally convex in sites II and III. The observed variation seen in the fish body shape and scales among the three studied sites are probably caused by the different ecological conditions of their habitats particularly variation in water flow
Life history traits and gonad histology of an endemic cyprinid fish, Mond spotted barb, Capoeta mandica from Southern Iran
Get PDFThe life history traits and gonad development of an endemic cyprinid fish, the spotted barb, Capoeta mandica (Bianco & Banarescu 1982), from southern Iran was investigated by regular monthly collections from February 2006 through January 2007 and on the basis of microscopic and macroscopic analyses. No information on the spawning characteristics of the fish are available to date. A total of 335 specimens were captured using electrofishing including 253 males and 102 females, resulting in 2.5:1 (male: female) sex ratio, which is significantly different from the expected ratio. The commonly known five standard maturation stages were determined based on the size, shape and weight of the gonads, degree of occupation of the body cavity, presence or absence of ripe oocytes, or milt, diameter of the oocytes in the ovary, and histological observations. These stages were correlated to the reproductive indices. The ovum diameters ranged from 0.04 to 1.31 mm, with the highest mean value in May. The condition factor of male and female specimens was the highest in April. The female GSI increased from March to May, peaking in the middle of spring and decreased significantly in June. Based on the gonad maturation stages, gonadosomatic index (GSI), modified GSI, mean egg diameter, condition factor (K) and Dobriyal index (DI), it was concluded that the spotted barb spawns during May and June. The provided data, contribute baseline data towards management ecology and conservation of this endemic fish species
Parasitic infestation in Chondrostoma regium and Aphanius vladykovi of the Behesht-Abad River (Chaharmahal-va-Bakhtiary)
Get PDFParasitic infestation of two native fish species in Behesht-Abad River were investigated at spring 2013. In this study 52 Chondrostoma regium and Aphanius vladykovi (26 from each species) were sampled and transferred to the laboratory. Then the weight and total length of fish were measured and investigated their infestation to parasites by microscope and stereomicrpscope. Some of the observed parasites are reported for the first time as new host records of: Philometra sp on the abdominal cavity of C. regium, Moreover, some external and internal parasites identified to the species and genus level including: Ichthyophthirius multifiliis in skin and gill of C. regium and A. vladykovi, one immature digenean; Allocreadium isoporum on the intestine of A. vladykovi and Trichodina sp on gill and skin of C. regium and A. vladykovi. The highest frequency of I. multifiliis (96.15%) was observed in gill of A. vladykovi and the lowest frequency was related to Tricodina sp in skin of C. regium (23.07%). A. isoporum Infestation was only observed in the intestine of A. vladykovi (mean±SD; 5.42±3.73) and philometra sp infection was only observed in the abdominal cavity of C. regium (mean±SD; 3.25±.82). The maximum average (±SD) infection intensity belonged to I. multifiliis in skin of C. regium (69.9±72.07, range: 12-196)
The effect of oregano (Origanum vulgare) extract on prevention of S. ineae experimental infection in rainbow trout (Oncorhynchus mykiss)
Get PDFThis study was performed in order to determine the effect of Oregano (Origanum vulgare) extract on Streptococcus ineae infection in rainbow trout. 063 rainbow trout weighing 15±1 gr were randomly allocated into three treatment groups with three repetition, including: 1) Control group, 2) Oregano extract treated group (1% of diet), 3) Felorfenicol treated group (10mg/kg fish), all feed one time a day for two weeks. At the end of the second week, 5 fish of each repetition collected and sampled from their blood and tissue of spleen and kidney. After the bleeding, all the samples injected with streptococcus ineae. After two weeks mortality rate calculated and after the bleeding, sampled from the spleen and kidney of the samples. Total cunt analysis conducted on the spleen samples in 4 logarithmic concentrations. in the second phase all the samples primarily injected with S.ineae and then treated with Oregano concentration and Felorfenicol for two weeks. After the two steps of bleeding, in sterile qualifications, the spleen of the fishes sampled for total cunt analysis. Blood cells counting and lisosym activity indicated in all blood samples. The results shown that total mortality in both of the phases of experiment in Oregano extract (OE) treatment was significantly lower comparing to control group (p<0.05). Furthermore the results of blood cells counting shown that WBC and monocyts percents were significantly higher in Oe and Felorfenicol treatment groups (p<0.05). This phenomenon was because of the effects of Oe and Felorfenicol. Nevertheless the lysozym activity degreased comparing to control group (p<0.05). But total count analysis shown that bacterial audience in spleen degreased treating Oe and felorfenicol. It was concluded that supplementation of Oe registered lower mortality and bacterial audience, and better hematological parameters in fishes, compared with control group. Therefore supplementation of Oe in fish diet would be effective in prevention and treatment of S.iniae in rainbow trout
Determination of the frequency of infestation of (Penaeus indicus and Litopenaeus vannamei) within internal protozoan Gregarine in Bandar Abbas, southern Iran
Get PDFOne of the dominant species of bandar abbas is (Penaeus indicus) which its propagation is in addition to problems of propagation attention to environmental, nutritional, health, diseases, parasitics infestation and etc. are important.In this titled : Determination of the frequency of Infestation of (Penaeus indicus and Litopenaeus vannamei) within internal protozoan Gregarine , Penaeus indicus samples randomly by traditional fishing with bottom trawl fishing located in the CIRIk (2013) was prepared and samples Litopenaeus vannamei shrimp farms of North Tyab prepared (2013) and sent to the laboratory and the Wet mount preparation method of the digestive tract was investigated.Frequency of examined shrimps according the times of the catch as following: From 100 specimens of the Litopenaeus vannamei examined in the year 2013, none were infected with the protozoan in trophozoite or Gametocystic state. From 100 specimens of the Penaeus indicus shrimp only 31 specimens were infected with Gregarine. 13 individual were female and 18 of them were male. 31 of these shrimps were infected with parasitic Gregarine as trophozoite or Gametocystic state or both of them, thus their prevalence of infection were 31 percent (trophozoite state: 54.83% and Gametocystic state: 64.51%). Frequency of infestation Trophozoite was 10.29 and Gametocyst was 72.45. It appears that the frequency of infestation with Gregarine increase according to the length of the shrimp. In the length group of 114-133 mm it was 50 percent and in the length group of 164-185 mm it was 77 percent