Richard D. Moccia

Seasonal changes in the quality of rainbow trout (Salmo gairdneri) semen:effect of a delay in stripping on spermatocrit, motility, volume and seminal plasma constituents.

Abstract Seasonal changes in ejaculate characteristics were monitored for groups of male rainbow trout ( Salmo gairdneri ) which were stripped weekly, beginning at various periods after the onset of the spermiation cycle. The duration of stripping varied from 14 to 28 weeks for the different groups, and the minimum duration of milt release was longer for groups in which semen collections wewe begun earlier in the season. A delay in initiating milt collections caused an increase in volume, or an increase in volume and spermatocrit at first collection. A delay of 14 weeks before stripping resulted in the release of 98.3% of their seasonal output of spermatozoa over the first 2 months of stripping, while the control group released only 34.7%, and groups in which stripping was initiated 3,6 or 10 weeks later released 63.7%, 64.5% and 67.5%, respectively. The control group released a mean of 416.3 × 10 9 spermatozoa per fish in 85.9 ml of semen during the season, while groups initiated 3, 6, 10 or 14 weeks later released 445.7 × 10 9 in 119.8 ml, 330.8 × 10 9 in 133.4 ml, 297.2 × 10 9 in 50.1 ml and 96.5 × 10 9 in 24.9 ml, respectively. Spermatocrit, motility and seminal plasma ion concentrations declined as the season progressed, but volume was independent of time. Late in the season both motility and seminal plasma ion concentrations were highest in groups which were stripped the fewest times. Motility was lower in samples with low spermatocrits or large volumes.

The Chemical Composition of Settleable Solid Fish Waste (Manure) from Commercial Rainbow Trout Farms in Ontario, Canada

Abstract The chemical composition of settleable faecal fish waste was determined from fresh manure samples collected at 12 commercial farms growing rainbow trout Oncorhynchus mykiss in Ontario, Canada. The manure samples from the commercial farms averaged 2.83% nitrogen (N), 2.54% phosphorus (P), 0.10% potassium (K), 6.99% calcium (Ca), and 0.53% magnesium (Mg) on a dry-weight basis. The concentrations of the metals, arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), iron (Fe), mercury (Hg), manganese (Mn), nickel (Ni), lead (Pb), selenium (Se), and zinc (Zn) were also measured. Mean concentrations of these metals ranged from 0.05 mg/kg for Hg to 1,942 mg/kg for Fe. Fresh fish manure has similar levels of N, P, Ca, and Mg, and lower levels of K when compared to manure from beef, dairy cattle, poultry and swine. Fish manure tended to have a higher content of Mn, Cd, Cr, Pb, Fe, and Zn than most other livestock manures, but had lower levels of As, Se, Co, and Ni. The copper (Cu) content of fish manure ...

Use of Chemotherapeuties on Trout Farms in Ontario

Abstract A personal-interview survey was conducted to determine the frequency of and reasons for chemotherapeutic treatments on Ontario trout farms during 1990. Sixty-two farmers, producing 91 % of Ontarios farmed trout, participated in the survey. Farmers had most often received advice on treatments from other farmers. The number of treatment regimes administered during a production cycle ranged from zero (5% of farms) to more than nine; the median on user farms was 2.3 treatment regimes. Chloramine-T and formalin were the most commonly used chemicals (they were used on 66 and 53% of the farms, respectively). Preventive treatments accounted for 67% of all treatment regime initiations; initial therapeutic treatments, primarily for gill diseases, accounted for 22% and repeat treatments accounted for 11%. At least some 2-10-cm fish were treated on most farms. Fish in increasingly larger size ranges were treated for therapeutic purposes on progressively fewer farms; prophylactic treatment, however, appeared...

The induction of a radiation-induced bystander effect in fish transcends taxonomic group and trophic level

Abstract Purpose: To extend the investigations of bystander effect induction in fish of the same species as the irradiated fish, to bystander effect induction between fish species and between trophic levels. Materials and methods: To investigate interspecies bystander effect induction, zebrafish and medaka were irradiated with a 0.5 Gy X-ray dose and then swum with non-irradiated fish of the same and opposite species. To investigate trophic level bystander effect induction, California blackworms were irradiated with the same X-ray dose and then fed to non-irradiated rainbow trout. Results: Reductions in clonogenic survival of the HPV-G (non-transformed human keratinocytes, immortalized with the human papilloma virus) reporter cell line, treated with tissue explant media, revealed that zebrafish and medaka induced a pro-apoptotic bystander effect in the other species and that, in trout, the normally anti-apoptotic effect caused by the consumption of non-irradiated blackworms was significantly reduced or lost if the blackworms had been irradiated. Conclusions: These results are the first to show that a radiation- induced bystander effect can transcend taxonomic group and trophic level in fish. This provides further evidence that bystander signals are widespread and conserved and may be transmitted through an ecosystem, as well as between individuals of the same species.

Irradiation of rainbow trout at early life stages results in trans-generational effects including the induction of a bystander effect in non-irradiated fish

The bystander effect, a non-targeted effect (NTE) of radiation, which describes the response by non-irradiated organisms to signals emitted by irradiated organisms, has been documented in a number of fish species. However transgenerational effects of radiation (including NTE) have yet to be studied in fish. Therefore rainbow trout, which were irradiated as eggs at 48h after fertilisation, eyed eggs, yolk sac larvae or first feeders, were bred to generate a F1 generation and these F1 fish were bred to generate a F2 generation. F1 and F2 fish were swam with non-irradiated bystander fish. Media from explants of F1 eyed eggs, F1 one year old fish gill and F1 two year old fish gill and spleen samples, and F2 two year old gill and spleen samples, as well as from bystander eggs/fish, was used to treat a reporter cell line, which was then assayed for changes in cellular survival/growth. The results were complex and dependent on irradiation history, age (in the case of the F1 generation), and were tissue specific. For example, irradiation of one parent often resulted in effects not seen with irradiation of both parents. This suggests that, unlike mammals, in certain circumstances maternal and paternal irradiation may be equally important. This study also showed that trout can induce a bystander effect 2 generations after irradiation, which further emphasises the importance of the bystander effect in aquatic radiobiology. Given the complex community structure in aquatic ecosystems, these results may have significant implications for environmental radiological protection.

Exposure to acute levels of waterborne aluminium modifies the legacy of early life stage irradiation, including the communication of radiation-induced bystander signals, in adult rainbow trout

Abstract Purpose: To determine if the legacy of early life stage irradiation seen in rainbow trout is modified in adult fish by acute exposure to waterborne aluminium (Al). Methods: Two-year-old trout which had been irradiated as either eggs 48 h after fertilization, eyed eggs, yolk sac larvae or as first feeders, were exposed to 100 or 200 μg l−1 Al. These fish were then paired with untreated fish. Gill and skin samples from both the irradiated and Al-exposed, and the untreated bystander fish, were then assayed for the production of toxic or pro-death signals, using the HPV-G reporter cell line. Results: Depending on the life stage, irradiated and the tissue assayed acute Al exposure modified both the radiation legacy, and the radiation-induced bystander effect in untreated fish, either by reducing reporter cell survival or increasing reporter cell growth. Conclusions: The effects of early irradiation and adult Al exposure were complex but clearly demonstrated that both the direct radiation effects and the communication of a radiation-induced bystander effect can be modified by a second environmental stressor.

Dietary live yeast and increased water temperature influence the gut microbiota of rainbow trout

The objective was to determine the effects of dietary substitution of fishmeal (FM) with live yeast and increasing water temperature on the diversity and composition of gut microbiota in rainbow trout.

Tissue-specific effects of acute aluminium exposure on the radiation-induced bystander effect in rainbow trout (Oncorhynchus mykiss, Walbaum)

Purpose: To investigate if aluminium (Al) modifies the rainbow trout response to radiation exposure and/or the induction of a radiation-induced bystander effect. Methods: Rainbow trout were exposed to 100 or 200 μg l−1 Al (for 3 h), a 0.5 Gy X-ray dose or Al followed immediately by irradiation. The exposed fish were then swum with completely untreated bystander fish. A human reporter cell clonogenic assay was used to determine whether Al exposure modified the effects of irradiation on the skin and gills from directly exposed fish and also the radiation-induced bystander effect in untreated fish. Results: Al exposure did not modify the response to direct irradiation by the skin, or the gill. Al did not modify the bystander effect in the skin. However Al did modify the bystander effect in the gill. Gills of bystander fish swum with fish exposed to 200 μg l−1 Al, followed by irradiation, caused a greater reduction in HPV-G cell survival than was caused by irradiation only. Interestingly Al exposure only also caused a bystander effect (reduced HPV-G survival) in the gill. Conclusion: This study shows that, in a multiple stressor scenario, the communication of radiation-induced stress signals is modified on a tissue-specific basis by acute Al exposure. Aside from the implications this has for radiological protection this response may also have potential for environmental monitoring where detection of the bystander effect could act as an indicator of radiation exposure when direct exposure responses are not evident.

Fiber-optic spectrophotometry of raw, smoked and baked Arctic charr (Salvetinus alpinus)

Abstract In the subjective evaluation of carotenoid coloration in market-size Arctic charr, scores for external skin color were correlated negatively with scores for the internal musculature (r = −0.65, P

Irradiation of rainbow trout at early life stages results in a proteomic legacy in adult gills. Part B; the effect of a second radiation dose, after one year, on the proteomic responses in the irradiated and non-irradiated bystander fish

&NA; This study extends the investigation of the legacy effects of exposure to a single radiation dose at one of four early life stages, in adult rainbow trout (Part A), by examining the effects of a second identical dose after one year; i.e. egg 48 h after fertilisation (48 h egg) + 1 year, eyed egg + 1 year, yolk sac larvae (YSL) + 1 year and first feeder + 1 year. This included the induction of a bystander effect in non‐irradiated trout which had swam with the irradiated fish. The second radiation dose negated any beneficial proteomic responses following early life stage irradiation only, particularly irradiation of 48 h eggs and eyed eggs (Part A). Instead the responses after early life stage + 1 year irradiation are consistently associated with tumorigenesis, cancer progression, or are otherwise damaging: upregulation of alpha‐globin 1 (YSL + 1 year and first feeders + 1 year) and downregulation of histone H1, type II keratin, malate dehydrogenase 2–2, Na/K ATPase alpha subunit isoform 1b, nucleoside diphosphate kinase (48 h egg + 1 year), electron transfer flavoprotein subunit alpha (eyed egg + 1 year), 60 S ribosomal protein L30 (YSL + 1 year) and haemoglobin subunit beta‐4 (first feeder + 1 year). Most significantly the second radiation dose also negated the overwhelmingly beneficial bystander effect proteomic responses induced by trout irradiated at an early life stage only (Part A). Instead the bystander effect proteomic changes induced by trout irradiated at an early life stage and again at 1 year have been associated with uncertain, with respect to tumorigenesis, or detrimental effects; upregulation of alpha‐globin 1 (YSL + 1 year and first feeder + 1 year) and downregulation of malate dehydrogenase 2–2, nucleoside diphosphate kinase (48 h egg + 1 year), transferrin precursor (eyed egg + 1 year), 60 S ribosomal protein L30 (YSL + 1 year) and serine / threonine‐protein phosphatase 2 A 65 kDa (first feeder + 1 year). This difference between the bystander effect induced proteomic changes following early life stage irradiation only and early life stage + 1 year irradiation may indicate a fundamental change in the non‐targeted effects of radiation following multiple exposure to radiation. HighlightsThe effects of a 2nd radiation dose at one year were investigated.The bystander effect proteomic responses in non‐irradiated fish were investigated.The effects of a 2nd radiation dose differed to those of early life irradiation only.Proteomic responses of irradiated fish indicated tumorigenesis or cancer progression.Bystander effect proteomic responses were tumorigenic, detrimental or uncertain. Abbreviations: HPV‐G: human papilloma virus – G; LCMS: liquid chromatography–mass spectrometry; PPP2R2A: serine / threonine protein phosphatase 2A; YSL: yolk sac larvae.