Comparative investigations on the respiratory physiology of euryhaline gammarids with special reference to salinity adaptation. [Translation from: Helgolaender Wissenschaftliche Meeresuntersuchungen 23(4) 485-534, 1972.]

Members of the family Gammaridae are very closely interrelated. There arises the question as to how far they also differ amongst themselves through physiological characteristics. Comparative respiratory and physiological experiments were made on the five euryhaline species Gammarus locusta, G. oceanicus, G. salinus, G. zaddachi and G. duebeni. The respiratory measurements carried out within the framework of this experiment were occupied with the relationships between oxygen consumption and body size depending on salinity. They also had the object of determing the variations in metabolic intensity after an abrupt change in the salt content of the external medium, and to establish the period of time for the process of adaptation. As the experiments were carried out polarographically in a testing plant with continuous flow-through, and the method which was applied permitted continuous recording over prolonged intervals, there could also be carried out comparisons between metabolism at rest and under activity, and the alterations of oxygen consumption during the process of moulting could be measured.

Physiology of nitrate reduction in Pseudomonas aeruginosa. [Translation from: Z.allg.Mikrobiol. 13, 83-94, 1973.]

Pseudomonas aeruginosa has for some time been known as a denitrifier. Pseudomonas aeruginosa was chosen for further studies, because P. aeruginosa occurs abundantly in Plusssee and moreover there are contradictory assertions on the gas products of denitrification by this bacteria. In experimental research the pattern of growth and gas production of Pseudomonas aeruginosa on nutrient broth was studied.

The effects of environmental stress on the physiology of growth in rainbow trout, Salmo gairderi Richardson

There is little doubt that both mammalian and teleost growth hormones can accelerate growth and increase food conversion efficiency in all commonly-reared species of salmonid fish. In those vertebrates that have been closely studied (predominantly mammals), the pituitary hormone somatotropin (GH or growth hormone) is a prime determinant of somatic growth. The hormone stimulates protein biosynthesis and tissue growth, enhances lipid utilization and lipid release from the adipose tissues (a protein-sparing effect) and suppresses the peripheral utilization of glucose. The present study is a prerequisite for future work on growth hormone physiology in salmonids and should contribute to our understanding of the mechanisms of growth suppression in stressed fish. Plasma growth hormone (GH) levels were measured in rainbow trout using a radioimmunoassay developed against chinook salmon growth hormone.

The ecological impact of different mechanisms of chronic sub-lethal toxicity on feeding and respiratory physiology

Sub-lethal toxicity tests, such as the scope-for-growth test, reveal simple relationships between measures of contaminant concentration and effect on respiratory and feeding physiology. Simple models are presented to investigate the potential impact of different mechanisms of chronic sub-lethal toxicity on these physiological processes. Since environmental quality is variable, even in unimpacted environments, toxicants may have differentially greater impacts in poor compared to higher quality environments. The models illustrate the implications of different degrees and mechanisms of toxicity in response to variability in the quality of the feeding environment, and variability in standard metabolic rate. The models suggest that the relationships between measured degrees of toxic stress, and the maintenance ration required to maintain zero scope-for-growth, may be highly nonlinear. In addition it may be possible to define critical levels of sub-lethal toxic effect above which no environment is of sufficient quality to permit prolonged survival.

Physiological Determinants of Invasive Success Linking Distribution Patterns to Metabolic Physiology in Native and Invasive Blue Mussels (genus Mytilus)

In the early 20th century, a blue mussel species from the Mediterranean invaded the California coast and subsequently out-competed the native species south of Monterey Bay. Like other invasive species, Mytilus galloprovincialis has physiological traits that make it successful in habitats formerly occupied by the native M. trossulus, namely its adaptation to warm sea surface temperatures. This study looks at the current genotype distributions and enzymatic activities of field-acclimatized mussels within the hybrid zone where the species co-occur as well as mussels that have been acclimated for four weeks to different temperature and salinity conditions. In the field-acclimatized and laboratory-acclimated mussels, the native species exhibited significantly higher enzyme rates, which may reflect an evolutionary adaptation to compensate to low habitat temperatures. Indeed, the results of the laboratory acclimation indicate that these differences are genetically based. Whether an acclimation capacity exists may require even longer-term acclimation to different temperatures. Current findings suggest that the further spread of the invasive species is likely to be governed in large measure by the potentially counteracting effects of rising temperatures, which would favor the northerly spread of M. galloprovincialis, and increased winter precipitation, which would favor the persistence of M. trossulus. However, the success of M. galloprovincialis during acclimation to ‘dilute’ salinity (25 ppt) suggests that the invasive species can tolerate a greater salinity range than previously thought. Thus, further investigation is needed to build a comprehensive predictive model of the movement of M. galloprovincialis and the hybrid zone along the California coast.

Effects of hydrocarbons on reproductive physiology of the pearl oyster, Pinctada fucata

There are a lot of evidence that show hvdrocarbones cause some defect in reproduction and growth of bivalves. Bivalves are filter-feeder, thus accumulate more hydrocarbones in their tissue. In this study adult pearl producing oysters (Pinctada fucata) are used for all experimens. Samples of oysters, water and sediment from four natural beds; Nakhiloo (clean), Hendurabi (semipolluted), Lavan 1 (semipolluted) and Lavan 2 (polluted) were gatherd for 13 succesive months. Temperature, salinity, pH, oxygen and turbidity were recorded in each sampling. Oysters were kept in laboratory for adapation and then their length (DVM) were measured. Hemolymph samples were collected by insuline syring. Sediments and soft tissues of oysters were dissolved in carbon tetrachloride and when heated to extract oil hydrocarbones. UV, GC and IR were used to assay oil hydrocarbones. Accumulation of hydrocabones in soft tissue were as follows : Kakhiloo

Survey of reproductive physiology on Epinephelus coioides in Khozestan province, Persian Gulf

Epinephelus coioides (family serranidae) is protogynous. This species is one of the most important fishes in food chain of marine proteins of persian Gulf. Therefore knowing about the reproductive biology and physiology of this species is an important role on aquaculture procedures. Monthly samples of Epinephelus coioides were obtained in khozestan Bahrekan province from 2001 to 2002 for annual variation of base line of reproductive hormone. The hormones such as: 17-B estradiol, Testosteron, Progesterone, Gonadotropin I ,II GTHI, II) and cortisol have assayed and also different stages of gonads from the histological point of view were studied by light and electron microscope. Aditional to morphometric and fecundity measurements, the important factors such as : Gonadosomatic index (GSI) Hepatosomotic index (HSI) and Condition factor (KF) were also studied. Environmental factors such as temperature, salinity, photoperiod and pH were analyzed for the determination of effective factors responsible for the changes of reproductive cycles. The flactmation of estroid hormones and gonadotropines show a significant variation in different stages of maturation, e.g 17-B estradiol's concentration in the third stages, GTH II in fourth stages of sexual maturation or final oocyte maturation, plasma Testosteron in post ovulation and Progesterone during maturation indicates the highest levels of above mentioned hormones. The total calcium concentration was high in all year. calcium concentration was correlated with GTH II synthesis and increases with GTH II in June. 17-B estradiol concentration was also correlated with GSI. The high concentration of cortisol throughout the year was an index of stress and development of ovary maturational processes. This species was protogynous synchronous hermaphrodites , and belongs to annual spawning species, being monandric. The sexual transition was found to occure in individuals of 51.2- 105 cm in length. GSI and HSI level confirms the time of spawning period is in April- June. Electrone microscopic studies of gonad tissues showed some changes in mitochondria and endoplasmic reticulum in the post ovulation, maturation and post spawning periods. During the monthly sampling the biochemistry of tissues variations indicated decrease in protein and lipid content, but an increase in water content of spawning fishes which was correlated to the maturation of Epinephelus coioides . sex ratio indicative of higher frequences of females to males during monthly sampling periods. The females were smaller than males in sizes, therefore the females lived in 8-15m depth, but males were living in upper limits of depth. The results indicated that the temperature was the most effective parameter in reproductive cycle of Epinephelus coioides and the mean 24°c was a convenient temperature for spawning. Photoperiod was the second effective. factor on the reproductive cycle for this species. It seemed that the increase in the photoperiod between January to May caused a development of the oocyte. Regarding to the results of this research, it seems that the period of spawning in Epinephelus coioides is in May- June and the aquaculture procedure of Epinephelus coioides could be performed in the above mentioned periods.

Survey of biosystematic and sexual reproductive physiology in Holothuroidea on Hormozgan Province

Sea cucumbers belong to phylum Echinodermata, order Holothuroidea are an abundant and diverse group of Invertebrates, with over 1400 species occuring from the intertidal to the deepest oceanic trenches. Sea cucumbers are important components of the food chain in temperate and coral reef ecosystems and they play an important role as deposite feeders and suspension feeders. Rapid decline in populations may have serious consequences for the survival of other species that are part of the same complex food web,as the eggs, larve and juveniles constitute an important food source for the other marine species including crustaceans, fish and mollusks. In addition sea cucumbers are often called the earthworms of the sea, because they are responsible for the extensive shifting and mixing of the substrate, and recycling of detrital matter. Sea cucumbers consume and grind sediment and organic material into finer particles , turning over the top layers of sediment in lagoons , reefs and other habitats and allowing the penetration of oxygen. While the taxonomy of the holothurian families is generally well known , the distinction of similar species is difficult. There are relatively few holothurian taxonomist.Most sea cucumber species can be identified by Holothurin taxonomists by using the calcareous skeletal ossicles found in the body wall. In this study , at first a sea cucumber from Kish island in Persian gulf has recognized. Individuals collected from west and east extend far away into north and south of coral reefs by diving. I have checked them morphologically and anatomically.Then with key to the orders of the Holothuroidea, They belong to the Aspidochirotida with key to the families of Aspidochirotida, they were in Stichopodidae families and with key to the genus of Stchopodidae, they were Stichopus. Then ossicles were extracted at National Museum of Natural History, by Dr David Pawson. The ossicles were measured on a transect across a slide prepared from the mid-dorsal region of each specimen.The one we have in the shallow waters of Kish island, is Stichopus hermanni, a massive holothurian, body broad, considerably flattened ventraly ,the dorsal side slightly arched and the lateral sides almost vertical; body wall fairy thick and soft ; mouth subterminal; anus central; tentacles usually 20 in number of length and leaf shaped. Numerous ossicles consisting of table with large discs having usually 7 to 15 peripheral holes, but often irregular or incomplete and spire of moderate height ending in a group of spinelets, rosettes of variable development, and c-shaped rods. Color (exept papillae)partly remained after preservation in alcohol which is found at the depth of 4 to 8 meters, on coral reef. Furthermore, the sexual reproductive cycle was described using standard methods. Gonads were removed and transferred to Bouin's fixative for four weeks and then processed according to standard embedding technique. To prevent the loss of tubule contents during embedding, the tubule sections, were cut well beyond the segment selected for sectioning. For each individual, six sections, each section with 5µm diameter by microtome were cut from tubules. These sections were first placed on gelatin coated slides (the gelatin was heated to 42°c) and then transferred to the oven at 37°c for one hour. This technique usually prevents the fragil tubules from breaking and the loss of gametes. The slides were stained with Eosin and Hematoxylin, and good resolution of the various cell types achieved.A second series of slides was stained with the Periodic Acid Schiff(PAS) to identify polysaccharides(glycogen). Monthly sampling was occurred.The sexual reproductive cycle was defined through the combined use of these criteria: Monthly percentages of the gonad stages for each sex, the monthly gonad index (GI) , given as the ratio of the wet gonad weight (G) to the dray weight (DW)and the monthly percentage of individuals that undetermined sex. The gonad consists of two tufts of tubules on which saccules develop. Gonadal development was classified into five stages: post spawning, recovery, growth, advanced growth, and mature stage that were adapted from the earlier studies of holothurians. Histological preparations showed that the sex of larger individuals could be identified by the presence of oogonia and young oocytes in females, and spermatogonic stages in males.The mean diameter of the tubules and gonadal mass follow annual cycles, increasing from late winter through spring, and dropping abruptly after spawning in the summer. Gametogenesis is generally a prolongate process and begins in March. By summer the ovarian tubules contain oocytes with diameter of 120-240 pm and the testicular tubules contain an abundance of spermatozoa (diameter 5-6 gm ).Following spawning the predominant activity within the spent tubules is phagocytosis of the residual gamets.The active phase of gametogenesis (March to July), coincides with an increasing photoperiod regim, and an accelerated gametogenesis occurs in July when temperature is high. Throughout the year, the gonad of Stichopus hermanni is larger in males than in females, and this is due to the number of tubules in the testis rather than to tubules length or diameter.

Reproductive physiology of ribbon fish (Trichiurus lepturus)

The ribbon fishes ‘of the family Trichiuridac are represented as one of the most important food resources in Indian ocean. High density of the dominant species of ribbon fish (Trichiurus lepturus) in Oman sea and the 'Tillable catch in last yeas (more than 7000 tones per year) makes a trust area for studing their population biolog and stock assessment. As our knowledge on reproductive biology of this species has an important role on their fisheries management, as well as conservation of this stock from decline or over fishing, this research was held to determine some aspects of reproductive physiology of ribbon fish and the effects of environmental factors in gonadal cycle. The goals of the present thesis is to determine some aspects of reproductive physiology such as gonadosomatic index (GSI) , hepatosomatic index (HSI), condition factor (Ko, fecundity, sex ratio, size at first maturity, size at maturity (LM5O) and their relative hormonal & biochemical fluctuations. In this regards annual variation of sex hormones ic. estradiol 17-B, progestron, cortisol, testostrone and gonadotropins FSH (GTH-I) , LH (GTH-ll)I were measured ; gonadal histological studies were done by light & electron micrography. The research was carried out from April 1995 to January 19% in Ras Nleidani in the north part of Oman sea, and the environmental factors such as temperature, salinity, oxygen, rainfall and pH were measured. The effects of these parameters on reproductive cycle and hormonal fluctuationswere discussed by using correlation and principle component analysis (PCA). Female Ribbon fish reproductive strategy shows the same paterns of nonguarder marine teleosts. T. lepturus has more than one spawning season (existance of egges in different size in each month) and therfore it must have asynchronous ovaries and belong to continious spawners. GSI and HSI are good evidences for this type of reproductive patern. The testis of the lobular type , which is typical of most teleosts , is composed of numerous lobules which are separated from each other by a thin layer of fibrous connective tissue. GSI fluctuations revealed prolong- spawning time in males. There is significant increase in 17-13 estradiol. progestrone , cortisol and gonadotropins with maturity and prespawning period of female T lepturus. Plasma concentration of E2 and GTH II incresaed along with water temperature increasing (3300).. Spawning was observed from Nov. 1995 to Apr. 1996 in this species. Progestrone increased significantly with increasing rainfall in this season (P<0.01). Plasma cortisol levels increased with maturation and vitelpgenesis and also with the peak of spawning. From lenght-weight frequency and size distribution in each age groups and also minimum size at first maturity (52a cm) it would he concluded that T. lepturus must be matured at 2 years of age. Serum cholestrol and triglicerides significantly increased when maturation occured in this species. The relationship between alkaline phosphatase activity and hormonal fluctuations with maturity and vitelogenesis were discussed. Proximate compostion (muscle) shows significant variation with spawning period and maturity. Absolute individual fecundity (17420-159150) increased with body length and weight. Ultrastructural observations show dramatic variation in cell membrane (0ocyte membrane), yolk vesicles and, nucleolus dispersal in relation to maturity stages. fluctuations of gonadal hormones were discused in relation with vitelogenesis. Testosterone increased in males from Nov: to Mar. due to environmental impacts and spawning time. Sex ratio in different depth (10-40 m ,80-110 m) shows significnt differences in this ratio for two depths. In 10-40 m depth female shows dominant abundance to male in each months that may be due to their reproductive migration behaviour. The effects of temperature photoperiod and rainfall to maturity and spawning were discussed. According to -pawning period of T. leptunts in our sampling area it could be suggested that ribbon fish fi,theries must be restricted in the peak of spawning seasons (Feb. to Mar.) and in the spawning grounds (under 40 m depths). Other suggestions for population conservation have been mentioned.