Effect of Cattail (Typha domingensis) Extracts, Leachates, and Selected Phenolic Compounds on Rates of Oxygen Production by Salvinia (Salvinia minima)

Salvinia (Salvinia minima Willd.) is a water fern found in Florida waters, usually associated with Lemna and other small free-floating species. Due to its buoyancy and mat-forming abilities, it is spread by moving waters. In 1994, salvinia was reported to be present in 247 water bodies in the state (out of 451 surveyed public waters, Schardt 1997). It is a small, rapidly growing species that can become a nuisance due to its explosive growth rates and its ability to shade underwater life (Oliver 1993). Any efforts toward management of salvinia populations must consider that, in reasonable amounts, its presence is desirable since it plays an important role in the overall ecosystem balance. New management alternatives need to be explored besides the conventional herbicide treatments; for example, it has been shown that the growth of S. molesta can be inhibited by extracts of the tropical weed parthenium (Parthenium hysterophorus) and its purified toxin parthenin (Pande 1994, 1996). We believe that cattail, Typha spp. may be a candidate for control of S. minima infestations. Cattail is an aggressive aquatic plant, and has the ability to expand over areas that weren't previously occupied by other species (Gallardo et al. 1998a and references cited there). In South Florida, T. domingensis is a natural component of the Everglades ecosystem, but in many cases it has become the dominant marsh species, outcompeting other native plants. In Florida public waters, this cattail species is the most dominant emergent species of aquatic plants (Schardt 1997). Several factors enable it to accomplish opportunistic expansion, including size, growth habits, adaptability to changes in the surroundings, and the release of compounds that can prevent the growth and development of other species. We have been concerned in the past with the inhibitory effects of the T. domingensis extracts, and the phenolic compounds mentioned before, towards the growth and propagation of S. minima (Gallardo et al. 1998b). This investigation deals with the impact of cattail materials on the rates of oxygen production of salvinia, as determined through a series of Warburg experiments (Martin et al. 1987, Prindle and Martin 1996).

On-farm feed: the potential for improving profitability in aquaculture

The urge to develop a standard practical diet for farmed fish in Nigeria has been on the increase since the last decade. Since ages diets has ever represent the largest single cost item of most fish farm operations. This is the reason why careful selection of feed ingredients for use in aqafeed plays a vital role in the resultant nutritional and economic success of farmed fish. In an attempt to meet the objectives of culturing fish two main sources of fish feed have been identified for meeting the nutritional requirements of fish. These include 'on-farm feeds' and 'commercial feeds'. However, 'on-farm feed' takes the lion share out of the total annual national aquafeed product which amounts to about 70% of the estimated total of 3,570 tones of fish feed produced in year 2000. This paper takes a look at the important of non-conventional feed resource in 'on-farm feed', the place of vitamins in 'on-farm feed', the need to develop and encourage on-farm feed production and feeding strategies if aquaculture will grow further to meet the projected million metric tones production within this decade

Comparative drift studies on streams in lower Austria (Flysch, gneiss and chalk formations) [Translation from: Schweizerische Zeitschrift fur Hydrobiologie 30 138-185, 1968.]

Seasonal changes and flooding have an extraordinarily great influence on the drift of organisms. The free water space plays the main part in the provision of food for some fish (Salmo trutta - trout): drift and content of the stomach are balanced here (Simuliidae): whereas others (Thymallus vulgaris) only selectively chose certain animals living at the bottom (molluscs). The total drift, drift of organisms and drift of organic material and minerals, plays a main role in the rate of production in streams. Besides the biology of the organisms living on the river bed, also the geological and hydrographical situation of the area plays a very important role for the composition of the drift. During the years 1964-1966 three streams in the characteristical geological formations flysch, gneiss and chalk of lower Austria were studied in regard to their drift. The Tulln (above St. Christopen), the Krems (above Senftenberg) and the Schwarza (above Hirschwang) seemed to be ideal for this comparative study because they are easy to reach. After summarising the hydrography and chemistry of examined rivers, the author examines the relationship between water level and total drift and the stratification of the total drift before analysing the drift of living organisms. Also considered are seasonal changes of drift of organisms and drift of exuviae.

Our living oceans: report on the status of U.S. living marine resources, 6th edition

The National Marine Fisheries Service (NMFS) is dedicated to the stewardship of living marine resources (LMR’s). This is accomplished through science-based conservation and management, and the promotion of healthy ecosystems. As a steward, NMFS has an obligation to conserve, protect, and manage these resources in a way that ensures their continuation as functioning components of healthy marine ecosystems, affords economic opportunities, and enhances the quality of life for the American public. In addition to its responsibilities within the U.S. Exclusive Economic Zone (EEZ), NMFS plays a supportive and advisory role in the management of LMR’s in the coastal areas under state jurisdiction and provides scientific and policy leadership in the international arena. NMFS also implements international measures for the conservation and management of LMR’s, as appropriate.NMFS receives its stewardship responsibilities under a number of Federal laws. These include the Nation’s primary fisheries law, the Magnuson Fishery Conservation and Management Act. This law was first passed in 1976, later reauthorized as the Magnuson-Stevens Fishery Conservation and Management Act in 1996, and reauthorized again on 12 January 2007 as the Magnuson-Stevens Fishery Conservation and Management Reauthorization Act (MSRA). The MSRA mandates strong action to conserve and manage fishery resources and requires NMFS to end overfishing by 2010 in all U.S. commercial and recreational fisheries, rebuild all overfished stocks, and conserve essential fish habitat.

Does the California market squid (Loligo opalescens) spawn naturally during the day or at night? A note on the successful use of ROVs to obtain basic fisheries biology data

The California market squid (Loligo opalescens Berry), also known as the opalescent inshore squid (FAO), plays a central role in the nearshore ecological communities of the west coast of the United States (Morejohn et al., 1978; Hixon, 1983) and it is also a prime focus of California fisheries, ranking first in dollar value and tons landed in recent years (Vojkovich, 1998). The life span of this species is only 7−10 months after hatching, as ascertained by aging statoliths (Butler et al., 1999; Jackson, 1994; Jackson and Domier, 2003) and mariculture trials (Yang, et al., 1986). Thus, annual recruitment is required to sustain the population. The spawning season ranges from April to November and spawning peaks from May to June. In some years there can be a smaller second peak in November. In Monterey Bay, the squids are fished directly on the egg beds, and the consequences of this practice for conservation and fisheries management are unknown but of some concern (Hanlon, 1998). Beginning in April 2000, we began a study of the in situ spawning behavior of L. opalescens in the southern Monterey Bay fishing area.

Influence of salinity on population growth of a rotifer, Brachionus plicatilis (Mullen)

The rotifer Brachionus plicatilis plays an important role in prawn hatcheries. It tolerates a wide range of salinities. The present experiments were conducted to find the optimum salinity for its mass culture. Experiments conducted on various ranges of salinities starting from 0 to 40 ppt at an interval of 5 ppt revealed that Brachionus plicatilis did not survive at salinities 0 and 40 ppt. Optimum salinity studies conducted at 5-15 ppt with an interval of 1 ppt showed that the production of 70 individuals/ml was highest at 10 ppt salinity and the doubling time ranged from 1.728 to 1.317 days.

Acute toxicity of copper, zinc and mercury on intertidal gastropods of Mumbai coast

The acute toxicity test conducted by static bioassay techniques have revealed that among selected heavy metals, copper is more toxic than zinc and mercury to Planaxis sulcatus and Trochus radiatus. The natural availability of heavy metals in the surrounding environment of these organisms is found to be deciding factor for their toxicity. Natural habitat of the animal also contributes to the sensitivity of a particular animal to the heavy metals tested. In addition the tendency of the animal to overcome the adverse conditions in their surrounding also plays a significant role in toxicity of pollutants.

Monsoon trawl ban and its effects on the livelihood of trawl labourers: the case with Versova fishing village in Maharashtra

Indian fisheries sector in view of its potential contribution to national income, nutritional security, employment opportunities, social objectives and export earnings, plays an important role in the socio-economic development of the country. Fisheries sector contributes 4.3% to the agricultural GDP and export earnings are presently valued at over INR 68 billion from a volume of 460,000 tons. In addition, it provides direct and indirect employment and dependency for over seven million people in the country. With an estimated production potential of 8.4 million tons, the present level of production in the country is 5.9 million tons with almost equal contribution from both marine and inland sectors. The estimated fisheries potential from the Indian exclusive economic zone was found to be 3.9 million tons. But in spite of the increased efforts in fish production, the catch stagnates around 2.9 million tons. The stagnation in catches, mainly due to the over exploitation of dwindling marine resources, forced the government to impart some management measures to regulate the fishery and for the sustenance of the marine resources. The monsoon trawl ban in fisheries was one of the major reforms, which had created a substantial increase in fish production in the past few years. The ban on trawling during monsoon season was introduced in Maharashtra, after a series of studies, from 1992 for a period of 65 days from 10 June to 15 August or Naralipoornima, whichever is earlier. A notable increase in production from the marine sector of the country occurred in the post-ban period. Nevertheless, it had created problems in employment, poverty and income distribution of fishermen during the ban period and was always a matter of unrest between mechanized and traditional sectors of fishing. The aim of this study was to understand the impact of the ban on monsoon trawling in employment pattern, poverty and income distribution of fishermen along the coast of Maharashtra. The study was conducted at the Versova fishing village, Mumbai, and provides reflections on the possible impact of monsoon ban in the livelihood and standard of living of the fishermen in the state.

A study on the effect of Zataria multiflora Bioss essential oil and Nisin on the growth of Lactococcus garvieae in the rainbow trout fillet (Oncorhynchus mykiss)

The ever-increasing population of the world and the growing need for animal protein has doubled the modern man’s demand for food. Additionally, the improvement in the general public health, and the worsening of environmental/ecological pollution have prompted today’s world to look for ways to procure healthy food. And one such attempt is the use of natural preservatives to decrease the bacterial load in foodstuffs, in other words, to increase their durability. This study evaluates the effects of different concentrations of Zataria multiflora Bioss (EO 0, 0.005, 0.015, 0.045, 0.135, 0.405%) and Nisin (0, 0.25, 0.5, 0.75 μg/ml) and storage time (9 days) on the growth of Lactococcus garvieae Ir-170A(856bp) alone, and their combination in a food model system (fillets of the rainbow trout (Oncorhynchus mykiss). Additionally, the growth of a sample of this bacteria in laboratory conditions was studied. The results of this study showed that different concentrations of Nisin had a significant impact (p<0.05) on Lactococcus garvieae. With the value of t in 0.75 μg/ml, the effectiveness rose to 65.77%; the biggest effect on Lactococcus garvieae. And the effect at 4 0C exceeded 80C. The study has also demonstrated that all concentrations of Zataria multiflora Bioss were effective against Lactococcus garvieae. However, with the value of t at 0.405%, the effectiveness was 71.91%. This value had the biggest effect on Lactococcus garvieae. At 4 0C, the effect surpassed the one at 80C. The synergistic effects of the EO and Nisin showed that with the value of t at 0.405% EO and 0.75 μg/ml Nisin was 14.62% had the greatest effect on Lactococcus garvieae. In this study, multi-factorial effects for different concentrations of Zataria multiflora Bioss (EO 0, 0.005, 0.015, 0.0025%), three different concentrations of 122 Nisin (0, 0.25,0.75 μg/ml) and two different levels of PH (5.5 , 7) at two incubation temperatures (15,37) on logp% of Lactococcus garvieae during 43 days in BHI broth were evaluated. Most of the effects on Lactococcus garvieae occurred in PH 5.5 and at a temperature of 150C.

Influence of cold storage time on the protein changes and fatty acids deterioration of (Rutilus frisi kutum) during frozen storage

The main aim of this research was to identify fatty acids composition of Caspian sea of White fish Rutilus frisi kutum tissue and their changes during one year cold storage (-18Ċ).The secondary aim was to determine the changes of moisture, ash, protein, fat, and to investigate the effects of storage time on peroxide, TBAi, FFA, and extractability of myofibrillar proteins of the fish tissue during one year cold storage (-18 Ċ). 10 samples of (Rutilus frisi kutum) were randomly collected from Anzali landings. The samples were frozen at -30 Ċ and kept in cold storage at -18Ċ for one year. According to time table, the samples were examined. The results showed that 27 fatty acids were identified. The unsaturated fatty acids (UFA) and saturated fatty acids (SFA) were 74/09 and 21/63 %, respectively, in fresh tissue. So that DHA (C22:6) oleic acid (C18:1c) had high amounts (15/07 ,20/57 ) among the UFA and palmitic acid (C16:0) was the most (13/09 %) among the SFA. The effects of freezing and cold storage on fish tissue showed that UFA and SFA contents have reached to 58/79 and 22/17 %, respectively, at the end of cold storage. It indicated that these compound change to each other during frozen storage. Also ω-3 and ω-6 series of fatty acids was 24/22 and 15/56% in fresh tissue, but their contents decreased to 8/68 and 5/11% at the end of period. Among the fatty acids C22:6, C18:1c and C16:0 had the most changes. The changes of fatty acids were significantly at 95% level expected for C18:0. Results showed that moisture, ash, protein, and fat contents were 75/9±0/03, 1/28±0/012, 21/8±0/2, and 4/1±0/01 % respectively, in fresh tissue. The moisture, ash, protein, and fat contents were 72/3±0/04, 1/83±0/05, 1/91±0/01 and 19/9±0/01 % respectively, at the end of storage period. Lipid damage was measured on the basis of free fatty acids (FFA), peroxide value (PV), and Thiobarbituric acid index (TBA-i). PV, TBARS and FFA concentration of frozen Caspian Sea white fish stored at -18 Ċ the temporal variation of these three variables were statistically significant (p<0.001). Results of White fish myofibrillar proteins showed aggregation of bound reduced for stored at 12 months. SDS-PAGE analysis revealed that, the intensity of the myosin heavy chain and actin bound was reduced with increasing storage time. SDS-PAGE patterns showed that myosin heavy chain was much more susceptible to hydrolysis than actin. Key words: Rutilus frisi kutum, frozen storage, ω-3, ω-6, protein myofibrillar

Study biological characteristics related with development and reproduction in Barbus capito on the southern coast of the Caspian Sea, Gilan Province

In the present research, a total of 207 pieces of fish from 25 sampling stations in Gilan Province coasts in the years 2001-2002 were biologically studied in terms of their growth and development, reproduction and feeding. The average length and weight of the fishes are increased, as they get older. The highest index of length and weight growth is observed in the years 1 to 2. As the age increases, gradient of length and weight growth diagrams decrease. In studying the relation between length and weight, it was observed that proportionate to the total length, the weight is increased progressively. The fatness coefficient index in the initial years of life and prior to maturity is higher than the post maturity period. As the age increases, the decrease of this index is observable. The fatness coefficient index rate is directly related to index of fullness. The highest Gonadosomatic Index is seen in the months of June and July, i.e. at the times of spawning; and the lowest index rate is observed in the months of November and December. The appropriate temperature for reproduction of these species is from 18 to 22 degree centigrade. The Gonadosomatic Index is higher in spring and summer seasons as compared with autumn and winter. Besides, as the fishes become aged, the amount of the said index increases in a manner that the gradient of it in the years to maturity is less than the maturity time and thereafter. Sexual maturity stages in different months are directly related to Gonadosomatic index, and increase as the age increases. The sexual ratio of male fishes to the female fishes in terms of number is plus one prior to maturity; about one at the time of maturity and minus after maturity. In general the frequency of male fishes as compared with female fishes in all group ages is approximately two times. The fecundity mean, and the diameter and the rate of eggs will substantially increase, as the Gonadosomatic index rises. The maturity age in the male fishes is 3 to 4 years and in female fishes is 4 to 5 years. The spawning of this species in rivers occurs repeatedly and in different time intervals, and do not take place once (Asyncronous). The Gastrosomatic index is directly related to index of fullness and will decrease, as the age increases. The index of fullness is relatively the months of April and May. The underlying reason is the need of the fishes to energy for reproduction. As the spawning time commences, the index of fullness moves down and the downward direction continues. After spa g mg and reduction of the volume of energy in the body, the index of fullness rises, and it will be substantially high until the beginning of fall. In fall and winter as it gets cold, the index of fullness moves downward and the body fat deposits are used. A correlation is shown between the changes in vacuity index and fullness indices. This means that as the fullness index rises, the vacuity index decreases, and vice versa. The Hepatosomatic index prior to the reproduction is at the highest amount and after spawning is at the lowest. No correlation is observed between the fullness and Hepatosomatic indices. In other words reproduction is an inherent and instinct originated matter; and its cycle goes on, alternately and in an orderly manner, upon completion of germinal cells, even when it coincides with reduction or stoppage of somatic cell growth. The rising trend of Hepatosomatic starts in August and will continue until the next July. The volume of fat around digestive tract is severely reduced in early spring and this trend will reach its apex in summer season. In the cold seasons, i.e. the fall and winter, the accumulation of fat around digestive tract increases. Consequently, a meaningful and inverse relation is observed between index of fullness, also the progress of sexual maturity stages and the volume of fat.