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Quantitative evaluation and FT-IR analysis of alginate from brown seaweeds of Karachi coast
Get PDFIn this study alginate was extracted for the first time from few species of Phaeophycota (Cystoseira indica, Padina tetrastromatica and Jolyna laminarioides) whereas Spatoglossum variabile and Sargassum tenerrimum, has been reported earlier from Karachi coast. Chemical bonding of extracted alginate was examined by using FTIR spectroscopy. Furthermore in pre-extraction step seaweeds were treated with diluted sulfuric acid solution for two different time intervals, all the selected alginophytes showed increased yield of alginate at 12 hrs treatment as compare to 5 hrs treatment
The effect of ethanol extract of a macroalgae Laurencia snyderia on growth parameters and vibriosis resistance in shrimp Litopenaeus vannamei
Get PDFBacterial diseases have been reported to be the major limiting factor in shrimp production. The use of natural products such as antimicrobials has been reported as a solution to the problem. The crude extract of a red seaweed Laurencia snyderiae obtained from the Persian Gulf was evaluated for shrimp growth performance and to determine in vivo efficacy of this seaweed in the prevention of shrimp Vibriosis. The ethanol extract from L. snyderiae (EELS) that was fed to the Artemia instar I for their enrichment was found to be non toxic to them. Shrimp Litopenaeus vannamei juveniles were fed with these enriched Artemia at 0 mg mL^-1 (Control group), 200 mg mL^-1, 400 mg mL^-1 and 600 mg mL^-1 for 30 days. The results obtained showed a significant increase (p<0.05) in survival rate in treatment groups compared with that in the control group. Shrimps fed with enriched Artemia showed a significant improvement in growth parameters when compared to those in the control group. When these juvenile shrimps were exposed to Vibrio harveyi (after 30 days) they showed notably lower mortality than the control. These results indicate that EELS has a good potential in promoting growth and antibacterial activities against V. harveyi that is useful in shrimp aquaculture
Short communication: The effect of spawning season on fatty acid composition of tigertooth croaker, Otolithes ruber from Abadan and Khoramshahr areas (Iran)
Get PDFFatty acids especially Docosahexaenoic (DHA) and Eicosapentaenoic acid (EPA) as more prevalent among the essential fatty acids are very important for normal physiology of marine fishes and also very beneficial to human health in particular for reducing risk of heart diseases, growth of fetal nerve tissue and infant brain and visual function (Colquhoun et al., 2008; Khoddami et al., 2009; Oksuz et al., 2011; Khoddami et al., 2012). Few studies have been conducted on fatty acid content and composition of fish carcass during the spawning season. Tziask et al., (2007) showed that the fat content of Mediterranean horse mackerel, Trachurns mediterraneus carcass reaches its lowest level during the spawning season. Also, the lipid content of two fish species Sardinella longicep and Sardinella fimbriata was found to be higher in fish sampled before sexual maturation compared to those sampled at the peak of sexual maturation (Som and Radhakrishnan, 2013). However, there was no significant difference in lipid content of mackerel, Rastrelliger kanagurta before sexual maturation and at the peak of sexual maturation (Ganga, 2010). Also, There were significant differences (P<0.05) in the levels of SFA,MUFA and PUFA in terms of species, season and muscle types of Mediterranean Octopuses (Ayas, 2012)
Study of growth ring formation on scales of mullet Liza saliens in the Caspian Sea
Get PDFThis study is attempted to compare the number of rings and circular scales that are formed during various ages on Liza saliens. Sampling was carried out monthly during 2012-2013 using beach seine fishing nets. 102 specimens of different sizes were collected and transferred to the laboratory in boxes containing ice. The age of fish was determined by the number of annual rings as well as, the number of rings in each annual area. The distance between rings in each annual area was also measured. The results showed that the maximum growth was demonstrated in the first and second years. In the first year of life, the scale radius was nearly 2823.3±366.5(µm) which decreased to 1223.9±236.0(µm). The result indicated that 48 percentage of growth scales occurred in the first year and this value is only 21.8% in the second year. The number of growth rings in the annual regions decreased with increase in age. The result demonstrated that the average number of rings was 95.5±17.6 in the first life year of the fish. If you take into account the number of growth ring through years in comparison with the number of days in a year, it is clear that one ring was nearly made in four days in the first life year and it gradually reached 7.5, 15.9, 21.9 and 31.7 in the second, fourth and sixth years of life, respectively. One ring was approximately made in each month at higher ages
Changes in some proximate, colour and textural characteristics of ozone-processed shrimp: Combined effects of increasing ozone discharge and iced storage
Get PDFChanges in proximate composition, colour and textural characteristics of ozone-processed shrimp as affected by combined effects of increasing ozone exposures and iced storage were investigated and for the first time. Whilst proximate composition comprised of fat, moisture, and protein contents and colour comprised of L*, a*, b* and metric chroma (C), the texture comprised of adhesiveness, fracturability and hardness parameters. Essentially, increasing ozone exposures were safely discharged via commercially available domestic ozone facility. Notably, the storage study lasted for up to eleven days. The results showed that the differences in proximate contents appeared superficial with increasing ozone exposures and iced storage. However, it was the colour, adhesiveness and fracturability attributes that showed noticeable effects (p0.05). It is plausible that the behavior of adhesiveness and fracturability of ozone-processed shrimp samples may well be complementing those of hardness textures. Overall, the data provided by this study objectively and realistically demonstrates the promising food technological potentials of domestic ozone facilities
Short communication: Morphometric, growth and condition factor variations of Boleophthalmus boddarti in the Mekong delta, Vietnam
Get PDFInformation on length-weight relationship (LWR) is useful for fishery management and stock biomass assessment (Froese, 1998; Froese and Pauly, 2000; Gonzalez Acosta et al., 2004; Mahmood et al., 2012). Fish growth pattern is determined using the slope value (b) obtained from the LWR regression (Froese, 2006), and the differences in fish well-being between genders and locations are related to the variations in condition factor (K) (Abdoli et al., 2009). However, little is known about the morphometric changes, LWR and condition factor in many gobiid species that live in the muddy flat in the Mekong delta. Boleophthalmus boddarti (Pallas, 1770) is an elongated mudskipper (Murdy, 1989) and a commercial fish in some Asian regions (Ip et al., 1990; Dinh, 2014). Although this fish is widely distributed (Froese and Pauly, 2015), information on it has been limited to its external morphology (Tran et al., 2013), living habitat (Clayton and Vaughan, 1986; Dinh et al., 2014), diet reference (Ravi, 2013; Dinh, 2015), growth pattern (Dinh, 2014) and reproductive biology (Dinh et al., 2015). Little has been known on the body condition and variation between genders, season and fish size of B. boddarti; and morphometric change of this fish has also been limited. Therefore, this study aims to understand body shape variations, growth pattern and condition factor (K) of this mudskipper species. The variations of growth threshold (e.g., slope value or b value) and K value with gender, season and fish size were also examined. The results of the present study will provide fundamental knowledge on this fish species
Short communication: Determination of total mercury in common carp, Cyprinus carpio, large scaled barb, Barbus grypus, tiger tooth croaker, Otolithes ruber and from surface waters in Khuzestan, Iran
Get PDFFishes are a valuable source of dietary protein and minerals for seafood consumers and are also used in pharmaceutical products (Mozaffarian, 2009). Over the past several decades aquatic ecosystems have been extensively contaminated with pollutants released from domestic and industrial waste waters and other anthropogenic activities in Khuzestan, Iran. Heavy metals such as mercury are considered as one of the four most important pollutants of aquatic life because of their high toxicity and ability to bioaccumulate in tissue of aquatic organisms (Hajeb et al., 2009). The toxicity of Hg is highly dependent on its chemical form. Organic mercury compounds are more toxic than inorganic mercury salts which may bioaccumulate to levels that could increase health risks to seafood consumers (Syversen and Kaur, 2012). Since most mercury in fish tissue is present as methyl mercury (Me-Hg), it has been recommended that T-Hg in tissues can serve as a surrogate for Me-Hg (Kannan et al., 1998)
Identification of metallothionein gene structure in sterlet (Acipenser ruthenus)
Get PDFAquatic organisms present, not only simple sources of accumulated metal, but can interact with metals, altering their toxicity. Due to exposition of biosphere with metals, organisms have developed various defense mechanisms to protect themselves against adverse effects of these ions and their compounds. Metallothionein (MT) is one of that which represents a critical mechanism for detoxification of metals. The sterlet (Acipenser ruthenus) is a bottom feeding sturgeon species and because the fish are dependent on invertebrate species for food throughout their life cycle, the sterlet could be a good indicator of the quality of the state of water ecosystem. Addition of copper to water leads to the induction of MT. The present study analyzed MTgene primary structure that was excreted from the liver of sterlet exposed to sub-lethal copper concentrations (0.075 mgL^-1 ). At the beginning to identify the molecular structure of Metallothionein of sterlet, a cDNA encoding MT was purified from livers of sterlet, and the MTgene was amplified. The primary structure of sterlet metallothionein (S-MT) contained 20 cysteine residues, which is the same as MTs of teleost fishes. Although, the primary structure of S-MT contained 63 amino acids, which is longer than any MT identified in teleost fishes but similar to the structure of MT gene in lake sturgeon and white sturgeon. The complete nucleotide sequence of the S-MTgene has been detected. We have determined the structure of the fish copper-binding protein by DNA sequence analysis of the gene
Chaetodon melapterus (Guichenot, 1863)
Get PDFChaetodon melapterus also known as Black-finned Melon Butterflyfish, Blackfin Butterflyfish and Arabian Butterflyfish is a piscine so stunningly gorgeous, but we daren’t look directly at it lest we succumb to its spell. This species is usually found in coastal reefs rich in coral growth interspersed with sand patches. C. melapterus lives in coral rich areas of shallow coastal reefs; occasionally in aggregations. They feed exclusively on coral polyps and nothing else. Maximum length is 13 cm in Persian Gulf (Kish Island, Iran). It is found at depths between 2-16 m. C. melapterus are usually encountered in pairs, but sometimes observed in larger aggregations numbering in excess of 20 individuals. C. melapterus is oviparous breeders and monogamous, they form pairs during breeding. Monitoring of this species is needed in conjunction with coral monitoring, as well as determination of the degree of co-dependence between this species and corals. C. melapterus is not recommended for reefs as they will pick at or eat a wide variety of corals, fan worms, and other invertebrates. C. melapterus are known to pick at Aiptaisia, a parasitic anemone
A study of migrant fishers from Andhra Pradesh in the Gujarat marine fishing industry
Get PDFThe International Collective in Support of Fishworkers (ICSF) has been engaging with issues of concern to fishers and fish workers since its inception in 1986. Among other issues, it studies migration, both international and internal, in the fisheries and the particular vulnerabilities facing migrant fishers with a view to improving the conditions on board vessels through legal and policy interventions. ICSF also engaged with the process leading to the adoption of the Work in Fishing Convention at the 96th International Labour Conference of the International Labour Organization in 2007, of which India is a signatory. In June 2014, India, along with other member states of the United Nations Food and Agricultural Organization (FAO), adopted the Voluntary Guidelines for Securing Sustainable Small-Scale Fisheries in the Context of Food Security and Poverty Eradication, whose charter encompasses employment conditions and social development of fishers, including that of migrants. ICSF believes that improving working and living conditions on fishing vessels can positively influence fisheries management