97,528 research outputs found
Review of "A Gentle Bunyip: The Athol Gill Story"
No full textAthol Gill was one of the most controversial Australian theologians of recent decades. This review looks at Harold Pidwell's biography "A Gentle Bunyip: The Athol Gill Story", and raises some questions about the radical discipleship movement in Australia
Gill disease in barramundi (Lates calcarifer)
Get PDFDisease is a major impediment to world aquaculture, amplified by the increase of the intensity of aquaculture relieving pressure from over depleted wild stocks, but with intensity brings disease and particularly disease of the fragile gill organ, exposed directly to the water environment. There is little literature on barramundi biology and the various forms of culture impacting on health, particularly the gill and much research is required in gaining a further understanding of this popular eating fish.
The light microscope is a pivotal tool with cytology and histology mandatory in assessing gill health. The gill biopsy should be considered part of a clinical examination as the water medium surrounding the gill and on the gill contains often fragile organisms that would otherwise be lost in fixation for histology alone, but easily viewed with cytology. Barramundi are easily anaesthetised and recovered like many terrestrials and gill re-growth is rapid, healing within days. Biopsies should be viewed unstained with and without phase contrast and then stained and reviewed, recognizing some ectoparasites maybe lost with anaesthetic agents and stains. The sacrificing of the fish after a live gill biopsy is necessary with histology and microbiology our major tools for diagnostics, with no other non invasive methods readily available as for terrestrials. Every year many new water organisms related to aquaculture are described in the literature and the finding of novel and new organisms makes the veterinary examination of the live fish exciting yet imperative.
A major concern is the gill pathogens found in wild barramundi were similar to those found in culture. For example the prevalence of the parasite Henneguya a Myxosporidean was 90% in sea cages 60 km offshore from Darwin in the Bathurst Island river system and 66% for ponded fish with water drawn from the Darwin Elizabeth river, compared to 33% infected in the wild habitat of the Mary river system close to Darwin by road. However the bacterial disease Epitheliocystis had a prevalence of 66% in the sea cages and 18% of similarly sized fish in the Mary river system, yet nil found in the pond farm, but in this case sample numbers were restricted. Consequently the surveillance for new fish pathogens and monitoring for existing pathogens in the wild ecosystems and aquaculture facilities is necessary and must include the macro and micro flora and fauna surrounding such facilities as they are potentially affected from aquaculture waste streams. The sustainability of aquaculture in open water culture must be considered with great concern for many reasons, but disease by its nature could overwhelm a species and other aquatic life quickly disseminated in a dynamic water medium.
Freshwater culture of barramundi has problems with off flavour and disease, particularly recirculating aquaculture systems due to undercapitalization and possibly at this stage with existing type farms not suited for the culture of barramundi with one farm having all fish sampled diagnosed with systemic bacteraemia and gill Epitheliocystis. Commonly fish sampled from freshwater culture had suffered pathological changes to the gill, particularly hyperplasia indicating the fish are continually affected by issues of water quality and disease.
Pond culture appeared to control gill disease issues by affording lower stocking rates, high water exchanges from a river within metres, fallow and the flavour of the fish similar to wild catch or sea cage culture, when purged in brackish water. The decreased environmental and ecosystem risks, coupled with the pond farmer reporting good profits with a simple form of culture, also suitable for intensification is a success story for barramundi production for today and the future
Primary cultured cells as sensitive in vitro model for assessment of toxicants-comparison to hepatocytes and gill epithelia
No full textIn an effort to develop cultured cell models for toxicity screening and environmental biomonitoring, we compared primary cultured gill epithelia and hepatocytes from freshwater tilapia (Oreochromis niloticus) to assess their sensitivity to AhR agonist toxicants. Epithelia were cultured on permeable supports (terephthalate membranes, "filters") and bathed on the apical with waterborne toxicants (pseudo in vivo asymmetrical culture conditions). Hepatocytes were cultured in multi-well plates and exposed to toxicants in culture medium. Cytochrome P4501A (measured as 7-Ethoxyresorufin-O-deethylase, EROD) was selected as a biomarker. For cultured gill epithelia, the integrity of the epithelia remained unchanged on exposure to model toxicants, such as 1,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), benzo(a)pyrene B[a]P, polychlorinated biphenyl (PCB) mixture (Aroclor 1254), and polybrominated diphenyl ether (PBDE) mixture (DE71). A good concentration-dependent response of EROD activity was clearly observed in both cultured gill epithelia and hepatocytes. The time-course response of EROD was measured as early as 3 h, and was maximal after 6 h of exposure to TCDD, B [alp and Aroclor 1254. The estimated 6 h EC50 for TCDD, B [a]P, and Aroclor 1254 was 1.2x10(-9), 5.7x10(-8) and 6.6x10(-6) M. For the cultured hepatocytes, time-course study showed that a significant induction of EROD took place at 18 h, and the maximal induction of EROD was observed at 24 h after exposure. The estimated 24 It EC50 for TCDD, B[a]P, and Aroclor 1254 was 1.4x10(-9), 8.1x10(-8) and 7.3x10(-6) M. There was no induction or inhibition of EROD in DE71 exposure to both gill epithelia and hepatocytes. The results show that cultured gill epithelia more rapidly induce EROD and are slightly more sensitive than cultured hepatocytes, and could be used as a rapid and sensitive tool for screening chemicals and monitoring environmental AhR agonist toxicants. (c) 2006 Elsevier B.V. All rights reserved.In an effort to develop cultured cell models for toxicity screening and environmental biomonitoring, we compared primary cultured gill epithelia and hepatocytes from freshwater tilapia (Oreochromis niloticus) to assess their sensitivity to AhR agonist toxicants. Epithelia were cultured on permeable supports (terephthalate membranes, "filters") and bathed on the apical with waterborne toxicants (pseudo in vivo asymmetrical culture conditions). Hepatocytes were cultured in multi-well plates and exposed to toxicants in culture medium. Cytochrome P4501A (measured as 7-Ethoxyresorufin-O-deethylase, EROD) was selected as a biomarker. For cultured gill epithelia, the integrity of the epithelia remained unchanged on exposure to model toxicants, such as 1,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), benzo(a)pyrene B[a]P, polychlorinated biphenyl (PCB) mixture (Aroclor 1254), and polybrominated diphenyl ether (PBDE) mixture (DE71). A good concentration-dependent response of EROD activity was clearly observed in both cultured gill epithelia and hepatocytes. The time-course response of EROD was measured as early as 3 h, and was maximal after 6 h of exposure to TCDD, B [alp and Aroclor 1254. The estimated 6 h EC50 for TCDD, B [a]P, and Aroclor 1254 was 1.2x10(-9), 5.7x10(-8) and 6.6x10(-6) M. For the cultured hepatocytes, time-course study showed that a significant induction of EROD took place at 18 h, and the maximal induction of EROD was observed at 24 h after exposure. The estimated 24 It EC50 for TCDD, B[a]P, and Aroclor 1254 was 1.4x10(-9), 8.1x10(-8) and 7.3x10(-6) M. There was no induction or inhibition of EROD in DE71 exposure to both gill epithelia and hepatocytes. The results show that cultured gill epithelia more rapidly induce EROD and are slightly more sensitive than cultured hepatocytes, and could be used as a rapid and sensitive tool for screening chemicals and monitoring environmental AhR agonist toxicants. (c) 2006 Elsevier B.V. All rights reserved
A novel computerized real effort task based on sliders
Get PDFIn this note, we present a novel computerized real effort task based on moving sliders across a screen which overcomes many of the drawbacks of existing real effort tasks. The task was first developed and used by us in Gill and Prowse (forthcoming). We outline the design of our \slider task", describe its advantages compared to existing real effort tasks and provide a statistical analysis of the behavior of subjects undertaking the task. We believe that the task will prove valuable to researchers in designing future real effort experiments, and to this end we provide z-Tree code and guidance to assist researchers wishing to implement the slider task
Detection of QTL with effects on osmoregulation capacities in the rainbow trout (Oncorhynchus mykiss)
Get PDFBackground
There is increasing evidence that the ability to adapt to seawater in teleost fish is modulated by genetic factors. Most studies have involved the comparison of species or strains and little is known about the genetic architecture of the trait. To address this question, we searched for
QTL affecting osmoregulation capacities after transfer to saline water in a nonmigratory captive-bred population of rainbow trout.
Results
A QTL design (5 full-sib families, about 200 F2 progeny each) was produced from a cross between F0 grand-parents previously selected during two generations for a high or a low cortisol response after a standardized confinement stress. When fish were about 18 months old (204 g body weight), individual progeny were submitted to two successive hyper-osmotic challenges (30g of salt/L) at a 14 d interval. Plasma chloride and sodium concentrations were
recorded 24h after each transfer. After the second challenge, fish were sacrificed and gill index (weight of total gill arches corrected for body weight) was recorded. The genome scan was performed using 200 microsatellites and 88 SNP markers. Unitrait and multitrait QTL analyses evidenced a total of 15 and 7 different QTL (P<0.10) for plasma ion concentrations and gill index respectively. Among the most significant QTL, three affected concentrations of both chloride and sodium during both challenges, two were specific to either chloride or
sodium concentrations, three QTL were specific to gill index, and three affected both gill index and ionic concentrations in plasma. Altogether, allelic effects were consistent for QTL affecting chloride and sodium concentrations but inconsistent for QTL affecting ionic
concentrations and gill morphology. There was no systematic lineage effect (grand-parental origin of QTL alleles) on the recorded traits.
Conclusions
For the first time, genomic loci associated with effects on major physiological components of osmotic adaptation to seawater in a nonmigratory fish were revealed. The results pave the way for further deciphering of the complex regulatory mechanisms underlying seawater adaptation
and genes involved in osmoregulatory physiology in rainbow trout and other euryhaline fishes
Plectranthias cruentus Gill & Roberts
No full textPlectranthias cruentus Gill & Roberts Figure 15–16; Tables 1–16, 22 Common name: Bloody Perchlet Plectranthias sp. C.— Williams et al. 2006: appendix 8: 29 (colour photo of holotype).— Clark & Roberts 2008: 51, fig. 18 (colour photo of holotype). Plectranthias cruentus Gill & Roberts 2020: 561, figs 1–2 (type locality, off Balls Pyramid, Lord Howe Rise, Australia). Diagnosis. The following combination of characters distinguishes P. cruentus from all known congeners: dorsal rays X,16–17, fifth or sixth spine longest; pectoral rays 13, at least some middle rays branched, upper 5 or more unbranched; predorsal scales extending forward only to supratemporal commissure. Its live coloration is also distinctive: dorsal and lateral body bright orange, becoming yellow-orange ventrally, crossed by narrow, red-edged pink oblique bars, which also extend along base of anal fin; posterior part of caudal peduncle with broad orange-red bar, caudal fin yellow. Remarks. The description in Gill & Roberts (2020) is compatible with methods used herein. They described P. cruentus from the holotype and three paratypes from Lord Howe Island and vicinity, but tentatively identified a (non-type) specimen from off Moreton Bay, Queensland as conspecific. Further material is needed to verify the species’ occurrence in mainland Australian waters. Gill & Roberts provided a colour photograph of the holotype, which has been also reproduced by Williams et al. (2006) and Clark & Roberts (2008). We provide a photo of the preserved holotype (Figure 15). Morphometric data are provided in Table 22. Material examined. Australia. AMS I.12854, 43.0 mm SL (paratype), Lord Howe Island, P. R. Pedley, 1913; AMS I.35797-007, 37.4 mm SL, Queensland, off Point Lookout, Stradbroke Island, 27°27.37′S, 153°39′E, 77 m (stated depth 42 fathoms), W.F. Ponder, RANS Kimbla, 29 Mar 1969; AMS I.42725-007, 57.3 mm SL (holotype), NMNZ P.039081, 52.7 mm SL (paratype), NMNZ P.061156, 44.4 mm SL (paratype), Lord Howe Island, off Balls Pyramid, 31°49.11′S, 159°20.14′E, 86–89 m, Sherman sled, R. V. Tangaroa, 22 May 2003 (TAN 0308 /061).Published as part of Gill, Anthony C., Pogonoski, John J., Moore, Glenn I. & Johnson, Jeffrey W., 2021, Review of Australian species of Plectranthias Bleeker and Selenanthias Tanaka (Teleostei: Serranidae: Anthiadinae), with descriptions of four new species, pp. 1-116 in Zootaxa 4918 (1) on page 51, DOI: 10.11646/zootaxa.4918.1.1, http://zenodo.org/record/447192
Measurements of the branchial sieve of sardine (Sardinops sagax ocellatus) from the west and south coasts of southern Africa
No full textIncludes abstract.Includes bibliographical references (p. 40-46).Branchial sieves of southern African sardine (Sardinops sagax ocellatus) were collected from three geographical regions along the southern African coast: Namibia, the south coast and the west coast of South Africa. Sardine from Namibia represented the northern Benguela upwelling ecosystem while sardine from the west and south coasts of South Africa represented the southern Benguela upwelling ecosystem. Morphometric measurements (gill arch length and gill raker spacing) and counts (number of gill rakers) of branchial sieves on the left side of the first gill arch were taken to determine whether the sardine from these regions have different branchial sieve structures
Notarius Gill
No full text[[Notarius Gill]] The amphiamerican sea catfish genus Notarius Gill was recently revised by Betancur-R. and Acero P. (2004). Notarius includes at least 14 species, with seven distributed in the eastern Pacific (EP). The monophyly of the genus is strongly supported by molecular evidence obtained from the sequences of five mitochondrial genes and one nuclear gene [3900 base pairs (bp)] (Betancur-R., 2003; Betancur-R. and Acero P., 2004). This claim was not supported by Kailola (2004), who placed the species of Notarius sensu Betancur-R. and Acero P. (2004) in the genera Hemiarius Bleeker, Ariopsis Gill, Aspistor Jordan & Evermann, and Sciades Müller & Troschel, as well as two species recognized as incertae sedis (Table 1). It is noteworthy, however, that none of the species assigned by Betancur-R. and Acero P. (2004) in Notarius were included in Kailola (2004)’s phylogenetic analysis. Marceniuk and Ferraris (2003), based on the results of Marceniuk’s (2003) unpublished dissertation, also proposed a different classification scheme for New World ariids, placing most of the species of Notarius sensu Betancur-R. and Acero P. (2004) in Notarius (only four species), Aspistor, Arius Valenciennes, and Hexanematichthys Bleeker (Table 1). In summary, despite the recent efforts to resolve the taxonomy of the Ariidae, its generic nomenclature is still unstable.Published as part of Ricardo Betancur-R. & Arturo Acero P., 2006, A new species of Notarius (Siluriformes: Ariidae) from the Colombian Pacific., pp. 47-59 in Zootaxa 1249 on page 4
Natural mineral particles are cytotoxic to rainbow trout gill epithelial cells in vitro
Get PDFWorldwide increases in fluvial fine sediment are a threat to aquatic animal health. Fluvial fine sediment is always a mixture of particles whose mineralogical composition differs depending on the sediment source and catchment area geology.Nonetheless, whether particle impact in aquatic organisms differs between mineral species remains to be investigated. This study applied an in vitro approach to evaluate cytotoxicity and uptake of four common fluvial mineral particles (quartz, feldspar, mica, and kaolin; concentrations: 10, 50, 250 mg L21) in the rainbow trout epithelial gill cell line RTgill-W1. Cells were exposed for 24, 48, 72, and 96 h. Cytotoxicity assays for cell membrane integrity (propidium iodide assay), oxidative stress (H2DCF-DA assay), and metabolic activity (MTT assay) were applied. These assays were complemented with cellcounts and transmission electron microscopy. Regardless of mineral species, particles #2 mm in diameter were taken up by the cells, suggesting that particles of all mineral species came into contact and interacted with the cells. Not all particles, however, caused strong cytotoxicity: Among all assays the tectosilicates quartz and feldspar caused sporadic maximum changes of 0.8–1.2-fold compared to controls. In contrast, cytotoxicity of the clay particles was distinctly stronger and even differed between the two particle types: mica induced concentration-dependent increases in free radicals, with consistent1.6–1.8-fold-changes at the 250 mg L21 concentration, and a dilated endoplasmic reticulum. Kaolin caused concentrationdependent increases in cell membrane damage, with consistent 1.3–1.6-fold increases at the 250 mg L21 concentration. All effects occurred in the presence or absence of 10% fetal bovine serum. Cell numbers per se were marginally affected. Results indicate that (i.) natural mineral particles can be cytotoxic to gill epithelial cells, (ii.) their cytotoxic potential differs between mineral species, with clay particles being more cytotoxic, and (iii.) some clays might induce effects comparable to engineered nanoparticles
The Folio: F. C. C. Magazine
No full textEditorial. pp. 1-3; Poetry-To the Old Site Building. pp. 3; Gill, P. S.-Article-Cosmic Rays. pp. 4-7; Jagadish Goyle-The Last Command. pp. 8-10; Kashyap, L.-Article-Bacon as an Essayist. pp. 10-17; Sharma, O. P.-Article-Man's Conflict with Nature. pp. 18; Saran Singh-Article-My Idea of a Happy Life. pp. 19-20; Des Raj Gupta-Poetry-Friendship. pp. 20; Story-Donna E Mobile-A Melo Drama. pp. 20-22; Sawhney, B.-Article-Future of Poetry. pp. 22-23; News and Notes. pp. 25-27; Correspondence. pp. 27-28; Narindra, B. L.-An Adventure. pp. 29-30; Three Old Formanites with the Indian Troops in Egypt. pp. 30-33; [Hindi]. 18 p.; Punjabi Kiyari [Punjabi]. 8 p.; The Folio [Urdu]. 24 p.New Site Buildings. before page 1; Dr. P. S. Gill. The Late Miss Grace Mason. Mr B. L. Narindra. before page 2
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