Water Fish Research Articles

Temporal of reef fish communities in the coastal water of Krueng Raya, Aceh Besar Regency, Indonesia

Krueng Raya waters have a big potency on coral reef fish; However, there was no study was conducted to document this biodiversity. This data are crucial for the conservation plan. Therefore, the objective of the study was to examine the community structure of reef fish in the Krueng Raya coastal waters, Mesjid Raya Subdistrict, Aceh Besar, Indonesia. The sampling was conducted from January 2014 to December 2016. The data were collected at three stations by the Visual Census method with a depth of 3-4 meters. The research found the average amount of reef fish was 1743 individuals that were consisted of 93 species and comprised of 26 families. The Families dominating were Pomacentridae, Acanthuridae, Chaetodontidae, and Labridae. The distribution level of reef fish individually was influenced by the environmental conditions of the coral reef ecosystem. The severe condition of the coral ecosystem in the Krueng Raya coastal waters was caused by two factors. Firstly, fishing activities of the locals and tourists who deliberately stepping on the coral colonies and using unfriendly tools to catch the fish (speargun). Another factor was the occurrence of coral bleaching in 2016, of which almost 80% of the coral ecosystem in the Krueng Raya coastal waters was exposed to this phenomenon (bleaching).Keywords: Reef Fish, Acanthurida, Communities Structure, Krueng Raya

Mobile Chinese students navigating between fields: (Trans)forming habitus in transnational articulation programmes?

Transnational articulation programmes are one way China is attempting to advance its higher education (HE) system. We report a study of twelve Chinese students’ experiences in two China-Australia 2 + 2 articulation programmes. In our analysis of semi-structured interviews, we use Bourdieu’s concepts of field and habitus to understand the impact on the habitus of the students. We report the experiences of the Chinese students in the HE sub-field in Australia. Students were like fish in water with the logics of practice of Chinese HE. In the new sub-field of HE in Australia, their habitus was out of place. This field/habitus mismatch created a field-habitus dissonance that can be productive of change to the habitus. Some in the study strategised to overcome this field-habitus mismatch and to adjust to the logics of the new field. We designate this emergent habitus as an in-between, diasporic cosmopolitan habitus, while others were able to ‘compartmentalise’ the demands of the new field, indicating durability of habitus.

수온변화에 따른 해수내 VHSV(Viral Hemorrhagic Septicemia Virus)의 생존능 분석

Viral hemorrhagic septicemia (VHS) is a serious viral disease that infects the olive flounder in South Korea. The Korean aquaculture industry experienced an economic loss caused by the high infectivity and mortality. Wastewater is a factor in transferring infections to wild and cultured fish in waters near infected aquaculture farms. In this study, we analyzed the stability of the VHS virus in sterilized seawater depending on the water temperature. The VHS virus maintained infectivity for 8 days and was detected using quantitative polymerase chain reaction after 10 days of inoculation to sterilized seawater at low temperatures. On the other hand, at high temperatures, the virus maintained infectivity for 4 days and was detected for 7 days. These results may contribute to basic data for epidemiological studies.

Using DNA Barcodes to Aid the Identification of Larval Fishes in Tropical Estuarine Waters (Malacca Straits, Malaysia).

Larval descriptions of tropical marine and coastal fishes are very few, and this taxonomic problem is further exacerbated by the high diversity of fish species in these waters. Nonetheless, accurate larval identification in ecological and early life history studies of larval fishes is crucial for fishery management and habitat protection. The present study aimed to evaluate the usefulness of DNA barcodes to support larval fish identification since conventional dichotomous keys based on morphological traits are not efficient due to the lack of larval traits and the rapid morphological changes during ontogeny. Our molecular analysis uncovered a total of 48 taxa (21 families) from the larval samples collected from the Klang Strait waters encompassing both spawning and nursery grounds of marine and estuarine fishes. Thirty-two (67%) of the larval taxa were identified at the species level, two taxa (4%) at the genus level, and 14 taxa (29%) at family level. The relatively low rate of species-level identification is not necessarily due to the DNA barcoding method per se, but a general lack of reference sequences for speciose and non- commercial fish families such as Gobiidae, Blenniidae, and Callionymidae. Larval morphology remains important in species diagnoses when molecular matches are ambiguous. A lower ethanol percentage (50%) for larva preservation is also useful to keep the body of larvae intact for morphological identification, and to preserve DNA for subsequent molecular analyses. The 10% Chelex resin used to extract DNA is also cost- effective for long term monitoring of larval fishes. Hence, the DNA barcoding method is an effective and easy way to aid the identification of estuarine larval fishes at the species level.

Identification of Antibacterial Molecule(s) from Animals Living in Polluted Environments.

Snakes feed on germ-infested rodents, while water monitor lizards thrive on rotten matter in unhygienic conditions. We hypothesize that such creatures survive the assault of superbugs and are able to fend off disease by producing antimicrobial substances. In this study, we investigated the potential antibacterial activity of sera/lysates of animals living in polluted environments. Snake (Reticulatus malayanus), rats (Rattus rattus), water monitor lizard (Varanus salvator), frog (Lithobates catesbeianus), fish (Oreochromis mossambicus), chicken (Gallus gallus domesticus), and pigeon (Columba livia) were dissected and their organ lysates/sera were collected. Crude extracts were tested for bactericidal effects against neuropathogenic E. coli K1, methicillin-resistant Staphylococcus aureus (MRSA), Streptococcus pyogenes, Pseudomonas aeruginosa, Bacillus cereus and Klebsiella pneumoniae. To determine whether lysates/sera protect human cells against bacterialmediated damage, cytotoxicity assays were performed by measuring lactate dehydrogenase release as an indicator of cell death. Lysates/sera were partially characterized using heat-treatment and pronasetreatment and peptide sequences were determined using the Liquid Chromatography Mass Spectrometry (LC-MS). Snake and water monitor lizard sera exhibited potent broad-spectrum bactericidal effects against all bacteria tested. Heat inactivation and pronase-treatment inhibited bactericidal effects indicating that activity is heat-labile and pronase-sensitive suggesting that active molecules are proteinaceous in nature. LCMS analyses revealed the molecular identities of peptides. The results revealed that python that feeds on germ-infested rodents and water monitor lizards that feed on rotten organic waste possess antibacterial activity in a heat-sensitive manner and several peptides were identified. We hope that the discovery of antibacterial activity in the sera of animals living in polluted environments will stimulate research in finding antibacterial agents from unusual sources as this has the potential for the development of novel strategies in the control of infectious diseases.

Bioaccumulation of Pesticides in Aquatic System of Edku Lake, Egypt: An Approach for Risk Associated With Fish Consumption

Monitoring of some organochlorines (OCs) and organophosphorus (OP) pesticide residues in Edku Lake during 2015-2016 have been determined in water, sediment and Tilapia fish to find out the extent of pesticides contamination and bioaccumulation into the lake. Pesticide residues were determined using gas chromatography equipped with appropriate detectors. The mean residues of ∑BHC, ∑DDT, total OCs, and OPs in water samples were 68.43, 14.17, 118.3 and 138.46 ppb, respectively. The corresponding residues in sediments were 8343.26, 5307.59, 21402.83 and 267.66 ppb, respectively. In fish muscles, the mean residues of ∑BHC, ∑DDT, methoxychlor and total OCs were 2513.56, 1916.85, 46175.05, and 57592.40 ppb, respectively. The corresponding values in fish gills were 3565.44, 16014.96, 13182.44, 35645.15 and 3318.10 ppb, respectively. Sum of BHC and DDT were the mostly detected in muscle samples accounting for 1593.60 and 916.53 ppb, respectively. Regarding bioaccumulation of examined pesticides, bioconcentration factor (BCF) was estimated to be in range 7.96-40701.50 for water/muscle ratio of OCs. In case of BCF for water/gills, the values ranged from 16.72 to 237090.17. BCF values obtained from ratio sediment/muscle or sediment/gills not exceeded than 100. These concepts indicate that OCs induced bioaccumulation in fish tissues may attributed to predicted risks associated with this kind of consumption. All findings represent concept that, Edku Lake represents reservoir of all pollutants coming from north governorates e.g. El-Behira.

Correlates of Waterbody Characteristics and the Occurrence or Diversity of Larval Amphibians in Central Ontario, Canada.

Watershed acidification and poor water quality can deleteriously affect amphibian populations. Between 1990 and 2008, we sampled 333 small, permanent (inundated year round) waterbodies that drain forested areas in the Algoma, Muskoka and Sudbury regions of central Ontario, Canada to determine whether water chemistry parameters, fish presence, and waterbody area and depth predict amphibian presence or diversity. Amphibians were present in some low-pH waterbodies, contrasting earlier studies, and generally water chemistry was not a strong indicator of amphibian presence or diversity in central Ontario. We suspect that other biotic and abiotic factors have a stronger effect on amphibian presence, and that the relationships between chemical and physical attributes and amphibian presence are complex. Future research should focus on long-term habitat change in central Ontario waterbodies to determine how watershed degradation has affected amphibians.

Water Pollution, Fish Migration and the Plight of Fish Famers: A Biblical-Contextual Analysis

The relationship between unethical activities in the water zones and fish migration in ancient Israel and contemporary Rivers State (R/S) cannot be overemphasized. This study focused on the linkage between unethical activities and fish migration in ancient Israel and especially, contemporary R/S of Nigeria. This work utilised the Historical-Grammatical method for analysis of Biblical text of Hosea 4:3c and survey method for gathering of data from 583 respondents in R/S. The data collated were subjected to Simple Percentage Ratings and Content analyses. Accordingly, findings revealed that in Hosea 4:1-2, dysfunctional community relationships ( w e ’en-chesed ) manifested in destructive activities ( pārats ), while Hosea 4:3c echoed the attendant consequences as fish migration owing to excessive fishing motivated by greed. Similarly, in Rivers State, the unethical use of chemical and explosive as fishing gear was attested to by 89.4% of the Residents. Equally, a whopping 84.9% of the respondents believed that there was a reduction in the amount of fish brought home from fishing activities due to recent use of chemicals and explosives as part of fishing strategies. Residents from fresh water zone applied gammalin20 while those of saline water zone used dynamite as fishing techniques. This resulted in non-selective mortal damage, which left water sources stinking after two days. Thus, was detrimental to the economic life of families that depended on fishing for livelihood. Therefore, the role of residents and the government remains imperative for the environmental remediation in Rivers State as this will ameliorate the economic downturn of fish farmers. Keywords: gammalin20/dynamite, fishing strategies, fish migration, coastal rivers state, family livelihood, hosea 4:3c DOI : 10.7176/JEES/9-9-04 Publication date :September 30 th 2019

Seasonal assessment of some heavy metal pollution and Metallothionein gene expression in cultured Oreochromis niloticus

BackgroundThe present study was planned to estimate the heavy metal concentrations in water samples and fish tissue residue (liver and muscle) of cultured Oreochromis niloticus as well as metallothionein (MT) gene expression in fish liver. Fish samples were collected from different private fish cultures in Kafr El-Sheikh governorate during April 2018–April 2019 in order to assess the public health risks associated with consuming cultured fish. Therefore, we investigated the concentrations of four metal elements (cadmium [Cd], copper [Cu], lead [Pb], and zinc [Zn]) in both fish tissues (muscle and liver) and water samples during the four seasons. Other water parameters (pH value, chemical oxygen demand, dissolved oxygen, alkalinity, total hardness, ammonia, and nitrite) were also determined.ResultsNH3 values were above recommended limits mostly along the year. The trend of metal mean contents found in the fish were in decreasing order of Zn > Cu > Pb > Cd, and the liver showed greater accumulation than muscle. The highest amounts of metals accumulated in fish liver and muscle were recorded in winter and autumn, respectively, while the lowest amount was recorded in summer. Regarding fish muscle which is the edible part consumed by human, the concentration of studied metals was within the safe limits for seafood except for Pb. MT showed a significant high level in response to metals accumulated in fish liver. A positive correlation occurred between MT levels and Cu and Pb concentrations across different seasons.ConclusionIn conclusion, MT expression levels seem to be sensitive to the heavy metals in natural habitats making it a powerful biomarker of heavy metals pollution in fish cultures. In addition, cultured fish in this study could be unfit for human consumption due to a high level of Pb in the edible part of fish. Therefore, greater attention should be set to Pb sources accumulated in cultured fish in Kafr El-Sheikh governorate.

Ex vivo and in vivo effects of arsenite on GST and ABCC2 activity and expression in the middle intestine of the rainbow trout Oncorhynchus mykiss

In fish of freshwaters environments, the accumulation and toxic effects of arsenite (AsIII) can be attenuated by detoxification proteins such as GST and ABCC transporters. We studied the effects of AsIII on the middle intestine of O. mykiss in ex-vivo and in vivo/ex vivo assays. For the ex vivo assays, we measured the transport rate of the ABCC substrate DNP-SG and GST activity in intestinal strips and everted sacs. AsIII inhibited DNP-SG transport in a concentration-dependent manner, specifically when we applied it on the basolateral side. GST activity increased when we applied a maximum concentration of AsIII. For the in vivo/ex vivo assays, we kept fish in water with or without 7.7 μmol L−1 of AsIII for 48 h. Then, we measured DNP-SG transport rate, GST activity, and PP1 activity in intestine strips during one hour. For PP1 activity, we incubated the strips with or without microcystin-LR (MCLR), a toxin excreted through ABCC2 proteins. We also analyzed Abcc2 and Gst-π mRNA expression in intestine and liver tissue. In the group exposed in vivo to AsIII, DNP-SG transport rate and GST activity were higher and the effect of MCLR over PP1 activity was attenuated. AsIII significantly induced only Abcc2 mRNA expression in both middle intestine and liver. Our results suggest that, in the middle intestine of O. mykiss, AsIII is absorbed mainly at the basolateral side of the enterocytes, excreted to the lumen by ABCC2 transporters, and is capable of modulating Abcc2 mRNA expression by a transcriptional mechanism.

Heavy metals concentration and histopathological profile of some commercial fish species at Makoko Slum Neighbourhood Environment, Lagos, Nigeria

Potentially harmful substances such as pesticides, heavy metals, and hydro chemicals are often released into the aquatic environment. The objective of the present study was to assess the concentration of lead, copper, cadmium, chromium, and nickel in water samples from two different points (Mid-stream and downstream), also determine the levelsof Lead, Zinc, Manganese and copper in four commercially important fish species, Pseudotolithus senegalensis (croaker fish) and Ethmalosa fimbriata (bonga), Oreochromis mossambicus (Tilapia fish) and Bagrus bayad (silver catfish) from Makoko water body, Yaba, Lagos, Nigeria. Histopathological profile of the fish species selected was also examined. The results were compared to the World Health Organization (WHO) acceptable limit.The concentrations of the heavy metals were analyzed using Perkin Atomic Absorption Spectrophotometer (AAS). Pseudotholithus senegalensishad 3.01±0.02, 2.41±0.02, 3.48±0.01, 1.04±0.10 mg kg-1as the mean concentration of lead, zinc, manganese, and copper respectively, while E. fimbriatahad 1.06±0.02, 2.41±0.02, 4.14±0.01, 1.04±0.10 mg kg-1,O. mossambicushad 2.09±0.02, 3.11±0.04, 2.48±0.02, 0.62±0.01 mg kg-1and B. bayadhad 1.53±0.12, 3.61±0.05, 2.44±0.03, 0.66±0.01 mg kg-1 as the mean concentration of these metals in the tissues of these fishes. The concentrations of heavy metals were higher in the gills compared to other organs. The mean concentration of each heavy metal were varied significantly (p0.05) depending on the species of fish. In the histological analysis of the tissues, there was vacuolation of hepatocytes, inflammation, and necrosis. In the muscle, there was a mild lesion, necrosis, inflammation, and cellular degenerations. But the level of tissue and organ degeneration is more severe in the gills. The study showed that some levels of these metals were within the permissible recommended allowed limit for human consumption. It is concluded that Makoko Lagoon water body and fishes are heavily contaminated with heavy metals.

Study of Corrosion Efficiency of Mild Steel Using Commercial Liquid Additives for Fish in Natural Water

This work is devoted to examine the effectiveness of the different commercial liquid additives for fish (sweet corn and molasses) on corrosion of mild steel in natural water by different methods (gravimetric and potentiostatic polarization) at room temperature. The corrosion tests were employed to evaluate corrosion rate (CR) and inhibition efficiency (IE %). The maximum inhibition efficiency was obtained for the inhibitor type molasses of 90.00% by gravimetric method for a period of 3 hours and over 31 % by potentiostatic polarization method. It was found that the commercial liquid additives acted as a good inhibitors for the tested environment. Furthermore, the corroded metal was observed by metallographic microscope.

Happy Like a Fish in Water? The Role of Personality–Situation Fit for Momentary Happiness in Social Interactions across the Adult Lifespan

Growing research on personality–relationship dynamics demonstrates that people's personality and their (enjoyment of) social relationships are closely intertwined. Using experience sampling data from 136 adults (aged 18–89 years) who reported on more than 50 000 social interactions, we zoom into everyday real–world social interactions to examine how Big Five personality traits and social context characteristics shape people's happiness in social encounters across the adult lifespan. Results revealed that interactions that were social (vs. task–oriented) and with close (vs. less close) others were associated with higher momentary happiness as were higher levels of the target person's extraversion, agreeableness, and conscientiousness, and lower neuroticism. Of the 10 personality × situation interactions tested, only one reached significance (with p = .041): Individuals with higher levels of neuroticism benefitted more from interactions with friends than did individuals low in neuroticism. The role of social context characteristics for momentary happiness changed with age, but the role of personality or personality × social context did not, suggesting that personality effects on happiness in social context manifest in similar ways across the adult lifespan. We discuss implications for personality–situation research and the understanding of affective dynamics in everyday social interactions. © 2019 European Association of Personality Psychology

DNA barcoding of commercially important snapper species (Lutjaniformes; Lutjanidae; Lutjanus) from Visakhapatnam, Central Eastern coast of India

Snappers are commercially important fishes in Indian waters, currently belonging to the order Lutjaniformes, family Lutjanidae. Generally, recognizing species of Lutjanus is a challenging task not only because of overlapping morphological characters, such as shapes, size groups, or colour patterns, but also based on the definition of the species concept or the definition of the threshold for speciation. In India there has not been any updated and accurate study of the genus so far. Besides, identification of the group based on ecological aspects and DNA barcoding tools were confined to limited laboratories. In the present study, ten species of snappers were identified from samples obtained from the major fish landing centres in the Visakhapatnam, Central Eastern coast of India. Snapper species were identified using COI (Cytochrome oxidase I) sequences for DNA barcoding. The validity of the conjecture species-level taxonomy based on COI is assisted with high equivalence search (98–100%) both in BOLD and BLAST, well-distributed genetic distance values.

Into the future: Donkergat Military Training Area and the Langebaan Ramsar site

Militaries need natural areas for offensive and defensive combat-readiness programmes. Here soldiers, war machinery and munitions are employed to prepare forces to execute warfighting tactics. Integration of environmental considerations into military activities is a growing global challenge. This study is based on a qualitative approach underpinned by an extensive literature review. The potential for the contribution of the military to a sensitive and diminishing wetland on the West Coast of South Africa (SA) is addressed. Donkergat Military Training Area (DMTA) in the Western Cape province, SA, provides diverse, seaborne training and warfighting facilities for the South African Special Forces (SASF), a specialist branch of the South African National Defence Force (SANDF). This facility borders the Atlantic Ocean and Langebaan Lagoon, a Ramsar site (no. 398). One of only 15 island ecosystems on the southern African coastline, lies within the boundaries of the area. Saldanha Bay was identified as an economic development node by the national government. The 4 Special Forces Regiment (4 SFR) is thus obliged to contribute to the conservation of these environmental assets. Industrial development includes Operation Phakisa by the Department of Agriculture, Forestry and Fisheries (DAFF) that envisages expanded aquaculture practices in Saldanha Bay. Developers of fish and bivalve farms are allowed up-scaling aquaculture operations. These result in the loss of ecological attributes of the Langebaan Lagoon Wetland system. In the study, we recommend that parts of DMTA should be incorporated in the Ramsar definition for the Langebaan Lagoon Wetland system. Ecosystem indicators monitoring bird life, water and sediment quality, fish and rocky intertidal macrofauna in the DMTA waters should be intensified. The DMTA as a benchmark ecosystem in the Saldanha Bay area will facilitate environmentally sound planning amidst recent developments. Integrating sections of the Langebaan Lagoon that is part of the DMTA into the existing internationally recognised wetland area, the military can contribute significantly to wetland conservation. Management of these areas should be formulated in a Military Integrated Environmental Management (MIEM) plan by incorporating international guidelines.

The Effect of Difference Temperature on Cortisol, Glucose and Glycogen level of Uceng Fish (Nemacheilus fasciatus)

Nemacheilus is one of the genera of freshwater fish. The existence of Uceng fish ( Nemacheilus fasciatus ) in public waters is increasingly rare. Changes in water temperature in the maintenance medium will affect the physiological processes of fish. The purpose of this study was to analyze physiological responses (blood glucose levels, cortisol, and glycogen hormones) of Ucen g Fish ( N. fasciatus ) which were incubated at different temperatures and find out the initial time of Uceng fish adaptation to its new environment. Total of 200 fish were collected from wild catches in the Lekso River, Blitar. Fish tissue collection was carried out to test the profile of glucose, cortisol, and glycogen. The research activities at this stage were carried out by raising the Uceng fish from nature to a cultivation container in an aquarium of size 50 x 30 x 30 cm that given the different temperatures (20°C, 24°C, 28°C and 32°C), and each aquarium is filled with 10 Uceng fish and will be kept for 14 days. ELISA method was used to quantify the parameter. The result of this study showed highest peak of cortisol levels and blood glucose levels was achieved in the treatment of 24°C on the 10 th day and the lowest in the treatment temperature of 28°C on the 6 th day. The highest glycogen peak was reached at 32°C on day 10 and the lowest peak was reached at 28°C on day 2. We conclude that temperature affects the physiological response (cortisol, blood glucose, and glycogen) of Uceng fish ( N. fasciatus ). High levels of cortisol and blood glucose indicate stressful fish. Keywords: Fish, Nemacheilus fasciatus, Physiological, Temperature, Uceng.

Abnormal chromosome assessment of snakehead fish (Channa striata) affected by heavy metals from a reservoir near an industrial factory

ABSTRACT This study aimed to investigate nine heavy metal concentrations (As, Cd, Cr, Pb, Cu, Fe, Zn, Mn and Ni) in water, sediment and snakehead fish (Channa striata) and to identify abnormal chromosomes in C. striata from a reservoir near an industrial factory and a reference area. Heavy metal concentrations were measured by inductively coupled plasma optical emission spectrometry (ICP-OES). The metal concentrations in the water, sediment and C. striata samples did not exceed the standard limit of Thailand, except for Cr concentrations, which exceeded water quality standards. The concentrations of Cd, Fe, Mn and Ni in C. striata samples between the reservoir and the reference area were significantly different (p < 0.05). The diploid chromosome number of C. striata from both areas was (2n = 42). Eight types of abnormal chromosomes were identified and classified as a single-chromatid gap, a single-chromatid break, centric fragmentation, a centric gap (CG), fragmentation, deletion, single-chromatid decomposition and iso-arm fragmentation. The most frequent abnormal chromosome in the samples was CG. The percentages of abnormal chromosomes in the C. striata samples from the reservoir near the industrial factory and the reference area were significantly different (p < 0.05) at 8.44 and 1.20, respectively.

Fecundity of diploid and triploid Carassius gibelio (Bloch, 1782) females

Fecundity of diploid and triploid Carassius gibelio (Bloch, 1782) females

A Soviet Miracle: On Translating The Order of Things. An interview with introduction by Elena Smirnova

This conversation with the philosopher and translator Natalia Avtonomova deals with how Michel Foucault’s seminal work the Order of things: An Archaeology of the Human Sciences came to be translated into Russian and published in 1977. Those who backed its publication, the officials who were involved with it, and the editors of the book are all singled out. Ms. Avtonomova emphasizes how exceptional this publication was as an intellectual and editorial feat. Even though the text was skeptical about Marxism (e.g. asserting that Marxism is “like a fish in water” in the context of 19th century thought but “has nothing to breathe” in any other environment), the book was published completely unabridged, albeit with editorial notes commenting on sensitive passages. Moreover, the book appeared during the period of stagnation when Russian translations of works by modern Western philosophers, especially those with an ideological ax to grind, simply did not exist as part of the Soviet intellectual scene. The interview further tackles the reception of French structuralism by Soviet scholars in structure and systems studies. Natalia Avtonomova also discusses her book Philosophical Issues of Structural Analysis in the Humanities that was published at the same time as the translation of Foucault, recounts the difficulties in getting it published, and describes the status of the translator in Soviet Russia. Another topic is her correspondence with Foucault in the late 1970s that turned mostly on his attitude toward the events of May 1968. The interview also sheds light on some distinctive features in the current Russian attitude toward Foucault’s work and on the prospects for a new revised edition of the Order of things in Russian

Evidence of a hydraulically challenging reach serving as a barrier for the upstream migration of infection-burdened adult steelhead.

Anadromous fishes such as steelhead trout, Oncorhynchus mykiss, are exposed to a suite of infectious agents and migratory challenges during their freshwater migrations. We assessed infectious agent load and richness and immune system gene expression in gill tissue of Bulkley River (British Columbia, CA) steelhead captured at and upstream of a migratory barrier to evaluate whether infectious burdens impacted migration success. We further considered the potential influences of water temperature, sex and fish size on host infectious agents and transcription profiles. There were eight infectious agents detected in steelhead gill tissue, with high prevalence of the bacteria Candidatus Branchiomonas cysticola (80%) and Flavobacterium psychrophilum (95%) and the microparasite Sphaerothecum destruens (53%). Fish sampled at the falls had significantly greater relative loads of Ca. B. cysticola and F. psychrophilum, higher infectious agent richness and differential gene expression compared to fish captured upstream. Flavobacterium psychrophilum was only associated with immune gene expression (particularly humoral immunity) of fish sampled at the falls, while water temperature was positively correlated with genes involved in the complement system, metabolic stress and oxidative stress for fish captured upstream. This work highlights interesting differences in agent-host interactions across fisheries and suggests that hydraulic barriers may reduce the passage of fish with the heaviest infectious agent burdens, emphasizing the selective role of areas of difficult passage. Further, this work expands our knowledge of infectious agent prevalence in wild salmonids and provides insight into the relationships between infectious agents and host physiology.