Protein composition of the threat induced epidermal secretion from the Arabian Gulf catfish, Arius thalassinus (Ruppell)

1. When threatened or injured, the Arabian Gulf catfish (Arius thalassinus, Ruppell) secretes a thick gel-like layer of proteinaceous material to its skin surface mainly from unicellular glands of the epidermis termed club cells. 2. Since a preparation from this secretion has been implicated in stimulation of the rate of wound healing in man and other test animals, the total gel protein composition was analysed by chemical, chromatographic and electrophoretic techniques. 3. Gel proteins were separated into soluble and insoluble fractions by extractions with increasingly strong solubilizing agents and the most insoluble components were solubilized only upon treatment with 10% SDS or concentrated organic acids. 4. Some of the soluble proteins from the secretion are also present in the insoluble protein fractions, indicating that the insoluble material is formed in part by aggregation of the soluble proteins. 5. The secretion was shown to be distinct from the catfish venom and differed greatly from typical fish mucus secretions in its composition and distribution of protein components.     

A hemolytic protein secreted from epidermal cells of the Arabian Gulf catfish, Arius thalassinus (Ruppell)

1. A fright or shock induced toxic secretion (gel) from the epidermis of the Arabian Gulf catfish, Arius thalassinus, exhibits hemolytic activity when tested against red blood cells from many different sources. 2. An enzyme with hemolytic activity, which represents 1.1% of the total soluble gel protein fraction, has been purified to homogeneity. 3. Molecular sieve chromatography and SDS polyacrylamide gel electrophoresis of the purified protein indicate a mol. wt of 34,000. 4. One additional protein component with hemolytic activity was found in the epidermal secretion. 5. Specific activity of the catfish epidermal factor is 20.6 units/mg protein, a level somewhat lower than those of most protein hemolytic factors. 6. The catfish hemolytic factor was not ichthyotoxic when tested against small fish and did not cause lethality when administered intravenously to rabbits.     

Purification and properties of a hemagglutination factor from Arabian Gulf catfish (Arius thalassinus) epidermal secretion

A galactose specific lectin was isolated from an epidermal proteinaceous gel secretion of the Arabian Gulf catfish, Arius thalassinus, Ruppell. The lectin was extracted and purified to near homogeneity by exclusion chromatography, affinity chromatography and isoelectric focusing. The lectin appears to be active as a single polypeptide chain with a mol. wt near 200,000, which can form oligomers and heteropolymers. The lectin comprises about 2% of the total gel protein, lacks carbohydrates and contains no unusual types or amounts of amino acids. The lectin agglutinates a wide range of red blood cell types.     

Platelet activating factors (AGEPC) from epidermal secretions of the Arabian Gulf catfish, Arius bilineatus, which stimulate wound healing

High levels of platelet activating factor (PAF) activity were demonstrated by platelet aggregation and serotonin release assays to be present in fright induced epidermal secretions of the Arabian Gulf catfish, Arius bilineatus (Valenciennes, 1840). The PAF activity was purified by thin-layer chromatography. Mass spectral analysis combined with chemical and enzymatic modification of the purified PAF and inhibitor studies indicated that PAF activity was due to the presence of 1-O-alkyl-2-acetyl-sn-glycero-3-phosphorylcholine (AGEPC) molecules. The total AGEPC concentration in the epidermal secretions based on PAF assays was 8 x 10(8) M, well above the threshold level for platelet activation which is near 5 x 10(-11) M. Thus, stimulated epidermal secretory cells of Arius bilineatus supply platelet activating molecules at physiologically high concentrations to sites of injury.     

Comparative biochemical and pharmacological properties of epidermal secretions from Ariid catfish of the Arabian Gulf

1. Comparative biochemical and pharmacological studies on epidermal secretions from three species of Ariid catfish were carried out to determine whether they share common properties. 2. Protein compositions are generally similar, but show some differences in size and numbers of proteins. 3. Lipids also differ. However, seasonal and dietary changes in lipid compositions exceed the differences among species. 4. Enzymes in the secretions appear common to each fish species, though some differences are noted in relative activities. 5. Toxicity responses of rabbits to injections with secretions from each of the catfish species indicated that two were lethal, with similar lethal dose levels when injected intravenously. 6. Secretions from all three catfish induced changes in plasma enzyme levels indicative of heart and liver damage, and also induced changes in blood glucose and cholesterol levels.     

中国海鲇属海鲇的分类学厘定及一新记录种--双线海鲇(鲇形目:海鲇科)

长期以来,国内绝大多数有关研究者将海鲇属Arius中腭骨齿单侧3群的个体鉴定为海鲇A．thalassinus。基于中国科学院动物研究所标本馆馆藏海鲇标本的研究发现,标本中存在两种腭骨齿的分化类型;经文献查证,其中一种应为双线海鲇A．bilineatus,该种在我国尚未见有研究报道,为一新记录种。双线海鲇与海鲇外形相似,但前者吻较钝,唇薄,腭骨齿于前部相连,游离脊椎骨数目较多(46—51 vs 38—43),臀鳍鳍条数较多(15—18 vs 1316),无囟门沟,从而可与后者相区别[动物学报51(3)：423—430,2005]。     

Arius peronii: A distinct species of Fork-tailed catfish (Pisces: Ariidae)

An Indian Ocean ariid catfish Arius peronii (Valenciennes) is redescribed. It is compared with the morphologically similar Ketengus typus Bleeker.     

Lipid composition of the secretion from human bronchial explant culture

In this study, we identified and quantitated the lipid components in the secretions of human bronchial explants cultured in a serum-free medium over a period of 50 days. Total lipids represented 6% of the dry material. This amount is considerably lower than that reported for 'normal' human sputum and suggests that the latter is contaminated by serum transudates, alveolar secretions, and microorganisms. Such serum-free culture systems are highly suitable to study cell physiology as it relates to human disease.     

Hydrocarbon accumulation by picocyanobacteria from the Arabian Gulf

AIMS: The objective of this work was to study picocyanobacteria in the Arabian Gulf water in relation to oil pollution. METHODS AND RESULTS: Epifluorescent microscopic counting showed that offshore water samples along the Kuwaiti coast of the Arabian Gulf were rich in picocyanobacteria which ranged in numbers between about 1 x 10(5) and 6 x 10(5) ml(-1). Most dominant was the genus Synechococcus; less dominant genera were Synechocystis, Pleurocapsa and Dermocarpella. All isolates grew well in an inorganic medium containing up to 0.1% crude oil (w/v) and could survive in the presence of up to 1% crude oil. Hydrocarbon analysis by gas liquid chromatography (GLC) showed that representative strains of the four genera had the potential for the accumulation of hydrocarbons (the aliphatic n-hexadecane, aromatic phenanthrene and crude oil hydrocarbons) from aqueous media. Electron microscopy showed that the cells of these strains appeared to store hydrocarbons in their inter thylakoid spaces. Analysis by GLC of constituent fatty acids of total lipids and individual lipid classes from representative picoplankton strains grown in the absence and presence of hydrocarbons showed, however, that the fatty acid patterns were not markedly affected by the hydrocabon substrates, meaning that the test strains could not oxidize the accumulated hydrocarbons. CONCLUSION: The Arabian Gulf is among the water bodies of the world richest in picocyanobacteria. These micro-organisms accumulate hydrocarbons from the water body, but do not biodegrade these compounds. It is assumed that hydrocarbon-utilizing bacteria that were always found associated with all picocyanobacteria in nature may carry out the biodegradation of these compounds. SIGNIFICANCE AND IMPORTANCE OF THE STUDY: The results shed light on the potential role of picocyanobacteria in controlling marine oil pollution.     

Gonapodasmius epinepheli n. sp. (Didymozoidae) from the grouper Epinephelus tauvina from the Arabian Gulf

A new species, Gonapodasmius epinepheli (Didymozoidae: Gonapodasmiinae), is described from the fish Epinephelus tauvina from the Arabian Gulf. It differs from most other members of the genus in the presence of a bulbous swelling at the distal end of the ovary, the presence of a characteristic bulge in the genital junction region, in the dense mass of glandular cells around the intestinal limbs and in the presence of an empty metraterm and vas deferens in the male and female respectively. The new species represents the first record of a didymozoid trematode from fishes in the Arabian Gulf.     

Epididymal protein secretion and its androgenic control in wall lizards Hemidactylus flaviviridis (Ruppell)

The total protein level in different segments of epididymis of normal lizard exhibited noticeable increase from early February to late March of a same reproductive phase. Comparison among the protein level of different epididymal segments showed insignificant variation from anterior to posterior part in early February but in late March, the protein level in posterior segment was appreciably higher than in anterior and middle segments. Further, testosterone-induced epididymal protein did not exhibit any significant quantitative variation among different regions. The electrophoretic pattern of luminal fluid from different epididymal regions of normal lizard showed 28 protein bands without any marked regional difference. However, only 16 protein bands could be demonstrated in the epididymal fluid of any region. Unlike molecular size, isoelectric focussing of testosterone induced epididymal proteins revealed that three regions of epididymis differ in their nature of protein. The number of proteins having alkaline pH range in anterior and middle regions were 4 and 3, respectively which increased upto 6 in posterior region.     

Oil-utilizing bacteria associated with fish from the Arabian Gulf

AIMS: The objectives were to count and identify the oil-utilizing bacteria associated with fish, and to study their hydrocarbon-degradation potential. METHODS AND RESULTS: The standard dilution-plate method using a medium with crude oil as a sole source of carbon and energy revealed that 10 different fish sorts from the Arabian Gulf and two from fish farms accommodated millions of oil-utilizing bacteria per square centimetre of fish surface and per gram of gills and guts. According to their 16S rRNA sequences, those bacteria were affiliated to Psychrobacter, Vibrio, Planococcus, Pseudomonas and Actinobacterium. Planktonic and benthic biomass samples from the Gulf were also rich in oil-utilizing bacteria, but with different composition. All isolates could grow on n-alkanes from C(8) to C(40) and three representative aromatics as individual sole sources of carbon and energy. Quantitative analysis of hydrocarbons by gas-liquid chromatography revealed that the biomass samples of the individual bacteria could consume crude oil, n-octadecane and phenanthrene in liquid media. CONCLUSIONS: The abundant oil-utilizing bacterial associated with fish have the potential for cleaning oily waters. SIGNIFICANCE AND IMPORTANCE OF THE STUDY: Aquatic fauna accommodates rich consortia of oil-utilizing bacteria.     

Macrozooplankton studies in Kuwait Bay (Arabian Gulf). I: Distribution and composition of the ichthyoplankton

Fifty taxa of fish larvae were identified during a 12 monthstudy in Kuwait Bay. Dominants included ‘Sparidae-type’larvae, clupeids and gobies. Peak numbers and types of larvaeoccurred during late spring/early summer with the minimum duringwinter. The bay could be divided into three subareas based uponfaunal, sedimentary and hydrographic characteristics. Low larvalconcentrations were generally found in the vicinity of the Khoral Sabiya—an area of below average salinities. Westernbay stations had either the highest mean temperatures and/orsalinities and low larval densities. During spring and summer,only goby and clupeid larvae were more abundant here than inthe outer bay. Most of the dominants, particularly gobies, Bregmacerosand pomadasyids, occurred at above average concentrations atthe northeastern and outer bay stations.