Fishes

Microsatellite markers were used to investigate the reproductive behavior of the damselfish Abudefduf sordidus at Johnston Atoll, Central Pacific Ocean. Genetic results indicated that ten males maintained guardianship over their nest territories for up to nine nest cycles during a 3.5 month period. Genotypes of 1025 offspring sampled from 68 nests (composed of 129 clutches) were consistent with 95% of the offspring being sired by the guardian male. Offspring lacking paternal alleles at two or more loci were found in 19 clutches, indicating that reproductive parasitism and subsequent alloparental care occurred. Reconstructed maternal genotypes allowed the identification of a minimum of 74 different females that spawned with these ten territorial males. Males were polygynous, mating with multiple females within and between cycles. Genetic data from nests, which consisted of up to four clutches during a reproductive cycle, indicated that each clutch usually had only one maternal contri...

Viral haemorrhagic septicaemia virus (VHSV) has, in recent decades, been isolated from an increasing number of free-living marine fish species. So far, it has been isolated from at least 48 fish species from the northern hemisphere, including North America, Asia and Europe, and fifteen different species including herring, sprat, cod, Norway pout and flatfish from northern European waters. The high number of VHSV isolations from the Baltic Sea, Kattegat, Skagerrak, the North Sea and waters around Scotland indicate that the virus is endemic in these waters. The VHSV isolates originating from wild marine fish show no to low pathogenicity to rainbow trout and Atlantic salmon, although several are pathogenic for turbot. Marine VHSV isolates are so far serologically indistinguishable from freshwater isolates. Genotyping based on VHSV G- and N-genes reveals four groups indicating the geographical origin of the isolates, with one group representing traditional European freshwater isolates and isolates of north European marine origin, a second group of marine isolates from the Baltic Sea, a third group of isolates from the North Sea, and a group representing North American isolates. Examples of possible transfer of virus from free-living marine fish to farmed fish are discussed, as are measures to prevent introduction of VHSV from the marine environment to aquaculture.

The Citarum River in West Java is the largest water supplier to the Saguling Dam, which plays a major role in electric power generation for the entire Java Island and is used for the aquaculture of marketed fish. To elucidate the extent of degradation in water quality and its causes in the Upper Citarum watershed, physical, chemical and biological parameters for water samples collected from various sites were analyzed. The results demonstrate large site-to-site variations in water qualities and pollutant loads derived from various human activities such as agriculture, cattle raising and the textile industry. To halt worsening conditions of the Citarum watershed, integrated mitigation efforts should be made, taking biophysical pollution mechanisms and local socioeconomic conditions into account.

Organochlorine chemical residues and elemental contaminants were measured in northern pike (Esox lucius), longnose sucker (Catostomus catostomus), and burbot (Lota lota) from 10 sites in the Yukon River Basin (YRB) during 2002. Contaminant concentrations were compared to historical YRB data and to toxicity thresholds for fish and piscivorous wildlife from the scientific literature. A risk analysis was conducted to screen for potential hazards to piscivorous wildlife for contaminants that exceeded literature-based toxicity thresholds. Concentrations of total DDT (sum of p,p¢-homologs; 1.09-13.6 ng/g), total chlordane (0.67-7.5 ng/g), dieldrin (<0.16-0.6 ng/g), toxaphene (<11-34 ng/g), total PCBs (<20-87 ng/g), TCDD-EQ (£1.7 pg/g), arsenic (0.03-1.95 lg/g), cadmium (<0.02-0.12 lg/g), copper (0.41-1.49 lg/g), and lead (<0.21-0.27 lg/g) did not exceed toxicity thresholds for growth and reproduction in YRB fish. Concentrations of mercury (0.08-0.65 lg/g), selenium (0.23-0.85 lg/g), and zinc (11-56 lg/g) exceeded toxicity thresholds in one or more samples and were included in the risk analysis for piscivorous wildlife. No effect hazard concentrations (NEHCs) and low effect hazard concentrations (LEHCs), derived from literaturebased toxicity reference values and avian and mammalian life history parameters, were calculated for mercury, selenium, and zinc. Mercury concentrations in YRB fish exceeded the NEHCs for all bird and small mammal models, which indicated that mercury concentrations in fish may represent a risk to piscivorous wildlife throughout the YRB. Low risk to piscivorous wildlife was associated with selenium and zinc concentrations in YRB fish. Selenium and zinc concentrations exceeded the NEHCs and LEHCs for only the small bird model. These results indicate that mercury should continue to be monitored and assessed in Alaskan fish and wildlife.

We report the construction of a genome-wide fish metabolic network model, MetaFishNet, and its application to analyzing high throughput gene expression data. This model is a stepping stone to broader applications of fish systems biology, for example by guiding study design through comparison with human metabolism and the integration of multiple data types. MetaFishNet resources, including a pathway enrichment analysis tool, are accessible at http://metafishnet.appspot.com.

The South American lungfish, Lepidosiren paradoxa inhabits seasonal environments in the Central Amazon and Paraná-Paraguay basins that undergo significant oscillations in temperature throughout the year. They rely on different gas exchange organs, such as gills and skin for aquatic gas exchange while their truly bilateral lungs are responsible for aerial gas exchange; however, there are no data available on the individual contributions of the skin and the gills to total aquatic gas exchange in L. paradoxa. Thus, in the present study we quantify the relative contributions of skin and gills on total aquatic gas exchange during warm (35°C) and cold exposure (20°C) in addition to the effects of aerial and aquatic hypercarbia on aquatic gas exchange and gill ventilation rate (fG; 25°C), respectively. Elevated temperature (35°C) caused a significant increase in the contribution of cutaneous (from 0.61±0.13 to 1.34±0.26ml. STPD.h(-1)kg(-1)) and branchial (from 0.54±0.17 to 1.73±0.53ml. STP...

The pathogenic oomycete Aphanomyces invadans is the primary etiological agent in ulcerative mycosis, an ulcerative skin disease caused by a fungus-like agent of wild and cultured fish. We developed sensitive PCR and fluorescent peptide nucleic acid in situ hybridization (FISH) assays to detect A. invadans. Laboratory-challenged killifish (Fundulus heteroclitus) were first tested to optimize and validate the assays. Skin ulcers of Atlantic menhaden (Brevoortia tyrannus) from populations found in the Pamlico and Neuse River estuaries in North Carolina were then surveyed. Results from both assays indicated that all of the lesioned menhaden (n = 50) collected in September 2004 were positive for A. invadans. Neither the FISH assay nor the PCR assay cross-reacted with other closely related oomycetes. These results provided strong evidence that A. invadans is the primary oomycete pathogen in ulcerative mycosis and demonstrated the utility of the assays. The FISH assay is the first molecula...

Sarcoplasmic reticulum (SR), Ca *+ + Mg *+-ATPase, and Ca *+-ioncphore were obtained from white rabbit skeletal muscles. Methylmercury inhibited the Ca *+ + Mg*+-ATPase an d Ca**-transport but had no effect on the Ca*+ionophore. Mercuric chloride inhibited all three functions (i.e., ATPase, transport and ionophoric activity). The mechanism of HgC12 inhibition of the Ca*+ionophore was by competition with Ca*+ for Ca*'-ionophoric site whereas its inhibition of the enzyme ar,d Ca*+-transport was due to the blockage of essential sulfhydryl (-SH) groups. Ca*' + Mg*+-ATPase and Ca*+-transport were more sensitive to methylmercury than to HgC12. Acetylcholine receptor (AChR) was obtained for the electric organ of T.

In order to assess the condition of heavy metal pollution in the Yellow River, Lanzhou section, China, and to quantify heavy metal (copper, lead, zinc, and cadmium) contents in tissues (liver, kidney, gills, and muscles) of two fish species (Triplophysa pappenheimi and Gobio hwanghensis), levels of these four metals in the water body, sediment, and tissues of the two fish were measured using inductively coupled plasmaatomic emission spectrometry. The metal levels from this study were compared with the threshold values in the guidelines of water, sediment, and food given by the National Environmental Protection Agency of China, the National Oceanic and Atmospheric Administration of America, and the National Standards Management Department of China. We found the mean concentrations of Cu, Pb, Zn, and Cd in THE water body, sediment, and muscles of two fish species were far below the values in guidelines. We also found that the type of metals present and their concentrations varied in different tissues and species. The results suggested that (1) Cu, Pb, Zn, and Cd did not contaminate the aquatic ecosystem severely and did not threaten the safety of human consumption in the Yellow River, Lanzhou section, and (2) organs that are sensitive to accumulating heavy metals may be useful to develop bioindicators for monitoring metal contamination. Considering environmental variables, further study is necessary before deciding which fish species or tissue could be the ideal bioindicators for aquatic pollution.

Channichthyid icefishes of Antarctica are unique among adult vertebrates. All icefish species lack hemoglobin and red blood cells in their circulating blood. All icefishes examined to date also lack the intracellular oxygen-binding protein myoglobin (Mb) in their oxidative skeletal muscles. However, some icefish species do express Mb in their heart ventricles. It is unknown whether Mb in those species in which it is present represents an evolutionary relic or has functional significance. To address this problem, we compared mechanical performance of isolated, perfused hearts from two species of icefish in which Mb is either present (Chionodraco rastrospinosus) or is absent (Chaenocephalus aceratus). Hearts were challenged with increasing afterload (2.5-4.0 kPa) under conditions of defined basal flow (approximately 100 ml.min-1.kg-1), in both the presence and absence of 5 mM sodium nitrite, a Mb poison. Unlike hearts from C. aceratus, which were unable to maintain a constant cardiac ...

ObjectiveDespite widespread concern over exploitation of the European Union&#39;s fish stocks, dietary guidelines in the UK continue to recommend two portions of fish per week. The present study sought to investigate whether health and/or sustainability are motivating factors when purchasing and consuming fish and whether there are sociodemographic trends.DesignA structured, self-completion postal questionnaire exploring consumers’ attitudes towards purchasing fish, their dietary intake, stated purchasing behaviour and sociodemographic information.SettingNottinghamshire, UK.SubjectsAdults from 842 households randomly selected from the electoral register.ResultsOver half of the participants (57·0 %) were aware of the health benefits of fish consumption and reported health as a primary motivator for purchasing fish; however, only 26·8 % actively sought to purchase fish from a sustainable source (e.g. Marine Stewardship Council (MSC) certified fish). Only 30·6 % of participants met cur...

The poorly developed visual system of the electric catfish was studied with silver-degeneration methods. Retinal projections were entirely contralaterat to the hypothalamic optic nucleus, the lateral geniculate nucleus, the dorsomedial optic nucleus, the pretectal nuclei including the cortical nucleus, and the optic tectum. The small size and lack of differentiation of the visual system in the electric catfish suggest a relatively small role for this sensory system in this species.

Studies were conducted from May, 1993 to April, 1995 to determine the changing patterns of infection by the liver fluke, Clonorchis sinensis, among residents and fish hosts in Kyongbuk Province. The infection rate among residents was 7.7% by stool examination. The rate in males (11.3%) was significantly higher than females (4.1%). Positive rate of intradermal test was 27.6% in the same population. The special type of a simple catalytic model was applied for the analysis of intradermal positive reactors by age and sex, and the equation was y = 0.4776 (1 - e-0.0375t) for males and, y = 0.2085 (1 - e-0.0138t) for females. Analysis of stool examination data by two-stage catalytic model revealed y = 0.025 (e-0.00471 - e-0.0235t). The annual Clonorchis infection rate was 4.7 per 1,000 susceptibles and the annual loss rate was 23.5 per 1,000 infected. The frequency distribution by the eggs per gram (EPG) was calculated as well as the cumulative percentages of positives. The regression equa...

The UV photolysis of the aromatic amino acid, tryptophan (Trp), in the Ca2+-binding protein, cod parvalbumin, type 111, was studied using electron paramagnetic resonance (EPR) spectroscopy in the temperature range 4-80 K. For the Ca2+-bound protein, irradiation with UV light (250-400 nm) resulted in the generation of atomic hydrogen with a hyperfine splitting of 50.9 mT, whereas in the Ca2+-free form, where the Trp is exposed to solvent, the trapped atomic hydrogen was not in evidence. In the same spectra, the radical signal in the g = 2.00 region could be detected. The line shape of the Ca2+bound form is similar to the EPR line shape obtained for Trp in micellar systems. In contrast, the EPR line shape for the Ca2+-free form is essentially featureless up to 80 K. The EPR spectra of the photoproducts of Trp and the nature of the photoreactions are therefore sensitive to the environment of Trp within the protein.

SUMMARY In tetrapods, arginine vasopressin and its counterpart, arginine vasotocin(AVT), are involved in renal water conservation through vascular V1a-type and tubular V2-type receptors, and only the former has thus far been cloned in fish. We successfully cloned the V1a-type and V2-type AVT receptor from the kidney of the African lungfish, Protopterus annectens, and the deduced amino acid sequences exhibited high homology with amphibian V1a- and V2-type receptors, respectively. Functional analysis showed that AVT addition to CHO cells transfected with lungfish V1a-type receptor increased[Ca2+]i in a concentration-dependent manner, whereas CHO cells transfected with lungfish V2-type receptor responded with cAMP accumulation after AVT stimulation. Lungfish V2-type receptor mRNA was strongly expressed in the heart and kidney, while V1a-type receptor mRNA was ubiquitously expressed in all the tissues examined. In the kidney,immunohistochemistry using a specific antibody to lungfish V2-...

Sarcoplasmic reticulum (SR) participates in the contraction and relaxation of cardiac muscle by a Ca 2+induced Ca 2+ release mechanism and an ATP-dependent resequestration process, respectively. Ryanodine-sensitive Ca 2+ efflux channels are confined to the junctional and corbular SR, while thapsigargin-and cyclopiazonic-acidinhibitable Ca 2+ -pumping ATPase molecules are localized both in junctional and in nonjunctional SR . The significance of SR in the contraction-relaxation cycle of cardiac muscle varies greatly among different vertebrate classes, among different species within the same phylogenetic group and during the ontogenetic development of an individual. The SR is well developed in mammalian and avian cardiac myocytes, where it is thought to be the major source and sink of the activator Ca 2+ . In ectothermic vertebrates, such as lizards, frogs and fishes, and in newborn mammals, cardiac SR is relatively sparse, and contraction and relaxation are more directly dependent on sarcolemmal Ca 2+ fluxes Vornanen, 1996a,b).

Aims:  The development and evaluation of a protocol based on polymerase chain reaction (PCR) and nucleic acid hybridization techniques for the specific detection of lymphocystis disease virus (LCDV) in several marine fish species.Methods and Results:  The pair of primers for PCR, OBL3 and OBL4, was designed based on published nucleotide sequence (LCDV-1) and amplifies a fragment within the major capsid protein. The sensitivity was evaluated using DNA from purified viral particles, as well as from cells inoculated with several viral concentrations. The PCR combined with slot blot was the most sensitive methodology, detecting 2·5 ng of viral DNA. Using this methodology LCDV was detected at 5 days postinoculation from SAF-1 cells initially inoculated with 10−5 TCID50 ml−1. The combination of PCR with membrane hybridization has also been proved to be adequate to detect LCDV from apparently healthy carriers by means of caudal fin sample analysis. This asymptomatic infection was also demonstrated by classical virological methods (cell culture and immunoblot).Conclusions:  The protocol described in this study allows the specific detection of LCDV, both in cell cultures and in fin homogenates from asymptomatic fish.Significance and Impact of the Study:  The detection of asymptomatic carriers by a rapid molecular method using caudal fin sampling, which does not imply animal killing, could be an important tool to control epizootics caused by LCDV, as fish could be analysed before their introduction and/or mobilization in farm facilities.

Exposure to contaminants in Great Lakes fish has been linked to impaired neuropsychological functioning in children, but neurological function of exposed adults has not been evaluated. This report describes a cross-sectional analysis of the effects of PCB/DDE exposure from contaminated fish on fine motor function in older adults. The subjects were 50-90-year-old Michigan residents who were members of a previously established study cohort. Fisheaters ate 24 lbs or more of sport-caught Lake Michigan fish/year at the time they were originally recruited in 1980-1982. Age-and sex-matched nonfisheaters ate 6 or fewer lbs/year. Outcome measures were scores on the Static Motor Steadiness Test (SMST) and Grooved Pegboard Test (GPT). PCB/DDE exposure was determined through serum analyses performed at the time of recruitment into the present study in 1993-1995. Because of the high correlation between serum PCB and DDE levels in this sample (Spearman r ‫؍‬ 0.64, P < 0.0001), the effects of the two contaminants were assessed jointly using a single derived exposure variable: Low ‫؍‬ both PCB and DDE at or below the medians of their respective distributions, intermediate ‫؍‬ PCB and/or DDE in the third quartile, and high ‫؍‬ PCB and/or DDE in the upper quartile. In unadjusted analyses, high exposure to PCBs/DDE was associated with significantly poorer performance on the GPT (P ‫؍‬ 0.03). However, in the multiple regression model, age and gender emerged as the most significant factors affecting GPT scores, and exposure to PCB/DDE was not significant. Performance on the SMST was not related to PCB/DDE exposure in initial unadjusted analyses, but performance with the dominant hand was marginally (P ‫؍‬ 0.052) associated with exposure in the final model. Scores on the SMST improved slightly as PCB/DDE exposure increased. A similar trend was not observed for the nondominant hand (P ‫؍‬ 0.46). These findings suggest that PCB/DDE exposure from Great Lakes fish has not significantly impaired hand steadiness or visual-motor coordination in this sample of older adults.

In mammals, the orexigenic and anorexigenic neuronal systems are morphologically and functionally connected, forming an interconnected network in the hypothalamus to govern food intake and body weight. However, there are relatively few studies on the brain control of feeding behavior in fish. Recent studies using mammalian neuropeptides or fish homologs of mammalian neuropeptides indicate that brain orexigenic signal molecules include neuropeptide Y, orexins, galanin and b-endorphin, whereas brain anorexigenic signal molecules include cholecystokinin, bombesin, corticotropin-releasing factor, cocaine-and amphetamine-regulated transcript, and serotonin. Tachykinins may also have an anorectic action in fish. The brain hypothalamic area is associated with regulation of food intake, while sites outside the hypothalamus are also involved in this function. There is correlation between short-term changes in serum growth hormone levels and feeding behavior, although possible mechanisms integrating these functions remain to be defined.

We have initiated a genetic analysis of the zebrafish visual system to identify novel molecules involved in vertebrate retinal function. Zebrafish are highly visual; they have four types of cones as well as rod photoreceptors, making it possible to study both rod and cone-mediated visual responses. To identify visual mutants, optokinetic responses of mutagenized larvae are measured in a three-generation screen for recessive mutations. By measuring visual behavior our genetic screen has been targeted towards identifying mutants that do not have gross morphological abnormalities. The electroretinogram (ERG) of optokinetic-defective mutants is recorded and their retinas are examined histologically to localize defects to the retina. In this report, we summarize our screening results and ERG and histological analyses of the five morphologically normal mutants we have analyzed to date. Additionally, the more detailed characterization of a red-blind mutant that we have isolated is summariz...

Methylmercury (MeHg) is a bioaccumulable toxin in the trophic chain and a powerful neurotoxin during fetal and child development. Consumption of contaminated fish and shellfish is a principal environmental source of MeHg exposure. This study was designed to assess the Hg and estimated MeHg intake in vulnerable groups of the Murcia region, a Mediterranean part of Spain, compared with international regulations. A validated food frequency questionnaire was used to assess seafood consumptions in 320 children younger than 10 years, 301 women of childbearing age, and 537 pregnant women. Hg concentrations were measured in the most consumed fish products by cold vapor generation-atomic fluorescence spectrometry. The weekly intake of MeHg (μg/kg bw/week) was 2.60 (95% CI=2.10-3.10) in children 1-5 years, 2.65 (95% CI=2.26-3.03) in children 6-10 years, 0.98 (95% CI= 0.89-1.07) in women of childbearing age, and 0.88 (95% CI=0.81-0.95) in pregnant women. The main exposure to MeHg, especially in young children, is related to intake of bluefin tuna and swordfish. Fifty-four percent of children aged 1-10 years, 10% of pregnant women, and 15% of women of childbearing age exceed the Joint Expert Committee on Food Additives provisional tolerable weekly intake of MeHg. In the Murcia region, where fish is a central component of the diet, the focus should be on educating vulnerable populations to reorient fish consumption in order

Fish communities and habitat structures were evaluated by underwater visual censuses a rocky location impacted by thermal discharge (I) and at two control locations, one in a Sargassum bed (C1) and the other in a rocky shore with higher structural complexity (C2). Habitat indicators and fish communities exhibited significant differences between the impacted and control locations, with the impacted one

A highly practical two-tier approach involving a screening and a confirmatory method was set up to efficiently test histamine in fish products in the frame of official controls. After their validation, the routine management of the two procedures was simplified as far as possible ensuring a strict quality data control and maximizing the cost-effectiveness. Accordingly five hundred and ninety batches of fish products (3129 determinations) sampled from the Italian authorities were successfully analyzed over a four year period (2008-2012). Only a small percentage of analysed batches (4.9%) was judged non-compliant. The examination of irregular cases (fish species, processing technology and storage practices) suggests important considerations in order to minimise the histamine risk for consumers.

This paper presents an overview of the significance of the use of molecular biomarkers as diagnostic and prognostic tools for marine pollution monitoring. In order to assess the impact of highly persistent pollutants such as polychlorinated biphenyls (PCB), polychlorinated dibenzo-dioxins (PCDD), polychlorinated dibenzo-furans (PCDF), polynuclear aromatic hydrocarbons (PAH), tributyltin (TBT) and other toxic metals on the marine ecosystem a suite of biomarkers are being extensively used worldwide. Among the various types of biomarkers, the following have received special attention: cytochrome P4501A induction, DNA integrity, acetylcholinesterase activity and metallothionein induction. These biomarkers are being used to evaluate exposure of various species of sentinel marine organisms (e.g. mussels, clams, oysters, snails, fishes, etc.) to and the effect of various contaminants (organic xenobiotics and metals) using different molecular approaches [biochemical assays, enzyme linked immuno-sorbent assays (ELISA), spectrophotometric, fluorometric measurement, differential pulsed polarography, liquid chromatography, atomic absorption spectrometry]. The induction of the biotransformation enzyme, cytochrome P4501A in fishes (Callionymus lyra, Limanda limanda, Serranus sp., Mullus barbatus) and mussels (Dreissena polymorpha) by various xenobiotic contaminants such as PCBs, PAHs, PCDs is used as a biomarker of exposure to such organic pollutants. The induction of cytochrome P4501A is involved in chemical carcinogenesis through catalysis of the covalent bonding of organic contaminants to a DNA strand leading to formation of DNA adduct. Measurement of the induction of cytochrome P4501A in terms of EROD (7-ethoxy resorufin O-deethylase) activity is successfully used as a potential biomarker of exposure to xenobiotic contaminants in marine pollution monitoring. In order to assess the impact of neurotoxic compounds on marine environment the evaluation of acetylcholinesterase activity in marine organisms is used as a biomarker of exposure to neurotoxic agents such as organophosphorus, carbamate pesticides etc. Metallothioneins (MTs) are induced by toxic metals such as Cd, Hg, and Cu by chelation through cysteine residues and are used in both vertebrates and invertebrates as a biomarker of metal exposure. The measurement of the levels of DNA integrity in marine organisms such as Sea stars (Asterias rubens) from the North Sea and the marine snails (Planaxis sulcatus) from the Arabian Sea along the Goa coast exposed to environmental xenobiotic contaminants clearly indicated the extent and the nature of pollution at the sampling sites along coastal environment.

Although the majority of teleost fishes possess a fused lower jaw (or mandible), some lineages have acquired a secondary joint in the lower jaw, termed the intramandibular joint (IMJ). The IMJ is a new module that formed within the already exceptionally complex teleost head, and disarticulation of two bony elements of the mandible potentially creates a &quot;double-jointed&quot; jaw. The apparent independent acquisition of this new functional module in divergent lineages raises a suite of questions. (1) How many teleostean lineages contain IMJ-bearing species? (2) Does the IMJ serve the same purpose in all teleosts? (3) Is the IMJ associated with altered feeding kinematics? (4) Do IMJ-bearing fishes experience trade-offs in other aspects of feeding performance? (5) Is the IMJ used to procure prey that are otherwise unavailable? The IMJ is probably under-reported, but has been documented in at least 10 lineages within the Teleostei. Across diverse IMJ-bearing lineages, this secondary...

Antifreeze glycoproteins (AFGPs), found in the blood of polar fish at concentrations as high as 35 g/liter, are known to prevent ice crystal growth and depress the freezing temperature of the blood. Previously, Rubinsky et al. [Rubinsky, B., Mattioli, M., Arav, A., Barboni, B. & Fletcher, G. L. (1992) Am. J. Physiol. 262, R542

Currently, the lipid content of fish feeds includes high amounts of terrestrial vegetable oils, rich in n-6 fatty acids and poor in n-3 fatty acids. Sinking organic matter in the shape of fragmented pellets and fish faeces could be ingested by the surrounding fauna attracted to the submerged structures of aquaculture facilities or living in natural benthic habitats. Fatty acids contained in feed pellets were used as trophic markers to shed light on the assimilation and incorporation of aquaculture wastes by the invertebrate fauna associated to sea-cages. Eighteen macroinvertebrate species, and zooplankton, seaweeds and sediments were collected from two fish farms, one of which (control) had not been used as such for two years. This study demonstrates that macroinvertebrate fauna present in fouling can take up sinking organic matter from farms. Further research should be directed at assessing the potential implications of aquaculture production for the surrounding ecosystem.

The authors examined the relation between fish consumption during pregnancy and fetal growth among 44,824 women from the Danish National Birth Cohort (1996)(1997)(1998)(1999)(2000)(2001)(2002). They evaluated the associations between consumption of total fish, fatty fish, and lean fish in midpregnancy and birth weight, birth length, and head circumference among singleton full-term infants. Fish consumption was ascertained by food frequency questionnaire. The birth of infants classified below the 10th percentile for gestational age and gender was significantly increased among women who consumed more than 60 g of fish per day, as compared with women who consumed 5 g or less per day. Adjusted odds ratios were 1.24 (95% confidence interval (CI): 1.03, 1.49) for birth weight and 1.21 (95% CI: 1.01, 1.43) for head circumference. The adjusted odds ratio was borderline significant for birth length (odds ratio ¼ 1.20, 95% CI: 1.00, 1.45). These increases in risk were followed by small decreases in average values for these growth measures. Furthermore, the inverse association for total fish consumption could be explained by consumption of fatty fish, while no association was found for lean fish. These results indicate that consumption of fatty fish, a known route of exposure to persistent organic pollutants, could be associated with reduced fetal growth.

Cardiac muscle M-band structures in several mammals (guinea pig, rabbit, rat and cow) and also from three teleosts (plaice, cap and roach), have been studied using electron microscopy and image processing. Axial structure seen in negatively stained isolated myofibrils or negatively stained cryo-sections shows the presence of five strong M-bridge lines (M6, M4, M1, M4' and M6') except in the case of the teleost M-bands in which the central M-line (MI) is absent, giving a four-line M-band. The M4 (M4') lines are consistently strong in all muscles, supporting the suggestion that bridges at this position are important for the structural integrity of the A-band myosin filament lattice. Across the vertebrate kingdom, cardiac M-band ultrastructure appears to correlate roughly with heartbeat frequency, just as in skeletal muscles it correlates with contraction speed, reinforcing the suggestion that some M-band components may have a significant physiological role. Apart from rat heart, which is relatively fast and has a conventional five-line M-band with M1 and M4 approximately equal, the rabbit, guinea pig and beef heart M-bands form a new 1 + 4 class; M1 is relatively very much stronger than M4.

Animal products like milk and meat are often found to be contaminated with residues of persistent pesticides and other toxic substances. The major source of entry of these compounds to animal body is the contaminated feed and fodder. So, unless the residues are managed at this stage, it is very difficult to prevent contamination in milk and meat. Therefore, the status of residue level of most persistent organochlorinated pesticides (OCP) in feed and fodder should be monitored regularly. The frequency of occurrence and contamination levels of OCP residues in different kinds of animal concentrate feed and straw samples collected from Bundelkhand region of India were determined. Out of 533 total samples, 301 i.e. 56.47% samples were positive containing residues of different OCPs like hexachlorocyclohexane (HCH) isomers, dichlorodiphenyltrichloroethane (DDT) complex, endosulfan and dicofol. Among different HCH isomers, the mean concentration of β-HCH was highest, and total HCH varied from 0.01 to 0.306 mg kg −1 . In case of DDT complex, i.e. DDD, DDE and DDT, the concentration ranged between 0.016 and 0.118 mg kg −1 and the pp | isomers were more frequently encountered than their op | counterparts. Endosulfan was also found in some samples in concentration ranging from 0.009 to 0.237 mg/kg, but dicofol could be recorded in very few samples. Although feed samples were found to contain OC residues, after comparing their levels in positive samples with the limiting values of respective pesticides, only very few were found to exceed the threshold level. Otherwise, they were mostly within safe limits.

Acid neutralizing capacity (ANC) is the parameter most commonly used as chemical indicator for fish response to acidification. Empirical relationships between fish status of surface waters and ANC have been documented earlier. ANC is commonly calculated as the difference between base cations (wBCxswCa xqwMg xqwN xqwK x) and OAA OAA organic carbon (mg C L ), and CDs10.2 is charge density of the organic matter (meqymg C), based on literature y1 data from Swedish lakes. ANC gives significant lower values of ANC in order to achieve equal fish status OAA compared with the traditional ANC calculation. Using ANC the humic conditions in lakes are better taken into OAA account. This may also help explain observations of higher ANC needed to have reproducing fish populations in lakes with higher TOC concentrations. ᮊ

Theoretical and laboratory studies generally show that ectotherm performance increases with temperature to an optimum, and subsequently declines. Several physiological mechanisms probably shape thermal performance curves, but responses of free-ranging animals to temperature variation will represent a compromise between these mechanisms and ecological constraints. Thermal performance data from wild animals balancing physiology and ecology are rare, and this represents a hindrance for predicting population impacts of future temperature change. We used internally implanted accelerometers near the middle of a species&#39; geographical distribution and gill-net catch data near the species&#39; latitudinal extremes to quantify temperature-related activity levels of a wild predatory fish (Platycephalus fuscus). We examined our data in…

Biomarkers are widely used to measure environmental impacts on marine species. For many biomarkers, it is not clear how the signal levels relate to effects on the whole organism. This paper shows how species sensitivity distributions (SSDs) can be applied to evaluate multiple biomarker responses in species assemblages. To our knowledge, the present study compared for the first time SSDs based on biomarker response levels for marine species to a SSD for whole-organism responses. The comparison indicates that for exposure to dispersed oil in the marine environment, the selected biomarkers were, on average, 35-to 50-fold more sensitive than the whole-organism effect. At the 5% hazardous concentration derived from the SSD for whole-organism effects, which is a conservative threshold level, the potentially affected fraction of species showing biomarker response corresponds to approximately 80%. Variation in species sensitivity, expressed either as biomarker or as whole-organism response levels, were similar. Although uncertainties exist, the link between biomarkers and risk assessment presented here provides a preliminary guideline for deciding when biomarker responses likely are hazardous and, therefore, require further investigation.