The venom of certain jellyfish has long been known to be potentially fatal to humans, but it is o... more The venom of certain jellyfish has long been known to be potentially fatal to humans, but it is only recently that details of the proteomes of these fascinating creatures are emerging. The molecular contents of the nematocysts from several jellyfish species have now been analyzed using proteomic MS approaches and include the analysis of Chironex fleckeri, one of the most venomous jellyfish known. These studies suggest that some species contain toxins related to peptides and proteins found in other venomous creatures. The detailed characterization of jellyfish venom is likely to provide insight into the diversification of toxins and might be a valuable resource in drug design.
Cnidarian venoms produce a wide spectrum of envenoming syndromes in humans ranging from minor loc... more Cnidarian venoms produce a wide spectrum of envenoming syndromes in humans ranging from minor local irritation to death. Here, the effects of Chironex fleckeri, Chiropsalmus sp., and Carybdea xaymacana venoms on ventricular myocyte cytosolic Ca2+, haemolysis and Artemia sp. lethality are compared for the first time. All three venoms caused a large, irreversible elevation of cytosolic Ca2+ in myocytes as measured using the Ca2+ sensitive fluorescent probe Indo-1. The L-type Ca2+ channel antagonist verapamil had no effect on Ca2+ influx whilst La3+, a non-specific channel and pore blocker, inhibited the effect. Haemolytic activity was observed for all venoms, with C. xaymacana venom displaying the greatest activity. These activities are consistent with the presence of a pore-forming toxin existing in the venoms which has been demonstrated by transmission electron microscopy in the case of C. fleckeri. The venom of C. fleckeri was found to be more lethal against Artemia sp. than the venom of the other species, consistent with the order of known human toxicities. This suggests that the observed lytic effects may not underlie the lethal effects of the venom, and raises the question of how such potent activities are dealt with by envenomed humans.
[Extract] As their common name implies, adult green lacewings are green, with four clear wings. A... more [Extract] As their common name implies, adult green lacewings are green, with four clear wings. Adult female lacewings live for 3-4 weeks and lay up to 600 eggs. Each egg sits on the end of a slender stalk, which elevates it from the ground and decreases the chances of predation by ants. The eggs take approximately 4 days to hatch. Larvae increase in size from 1 mm at first emergence up to 8 mm just before they pupate. They have small spines on their backs upon which they impale the remains of prey. This provides a form of camouflage and allows the larvae to appear inconspicuous among the prey. It is also believed to reduce cannibalism between larvae.
We thank Yanagihara and Chen for their comments and for the opportunity to further the discussion... more We thank Yanagihara and Chen for their comments and for the opportunity to further the discussion. Our statistician has re-examined (and reanalysed) these data, and we have supplied our data to an independent statistician (who supported our subsequent re-analysis) and are more than willing to supply these data to the journal editors should they feel this is necessary. Furthermore, the manuscript was independently reviewed by two reviewers who expressed no concern over our analysis. We are confident of our results. Yanagihara and Chen have incorrectly assumed that the errors displayed in Figure 2 are SEM. These errors represent the 95% confidence limits (CL) and as such their arguments are invalid. Furthermore, they outline that no statistical significance was provided for the specific W4 vs. W3 comparison. Although no specific statistics were displayed in the article, we do outline that LSD post hoc analysis was conducted and the means and 95% CL (as signified in Figure 2) that were significantly different were listed. This analysis showed that the percentage of venom discharged after the application of voltage (W2) and after the application of vinegar (W4) were significantly different from one another and both were significantly higher than either the initial before-voltage percentage (W1) or after the third washing (W3) after voltage application. It is further suggested that the samples used (W1 to W4) are internally matched samples and hence ANOVA is inappropriate. They suggest that a simple t-test would give different results. To alleviate their concerns, we have reanalysed the data using a paired t-test, comparing the level of protein present after the third washing (W3) since voltage was applied to the tentacle and the amount of protein present after vinegar was applied (W4). We paired each sample with itself (which effectively removes the issues surrounding analysis of internally matched samples). This analysis showed that the difference between the matched pairs was significant (t = 8.938, df = 2, P = 0.012). We further reanalysed these data comparing the mean protein expression after vinegar application (W4) to a standard value (23.2%) which was the mean percentage found after three washings (W3) post voltage application. Once again, the difference was found to be significant (t = 6.012, df = 2, P = 0.027). We would argue, however, that the use of t-tests, as suggested by Yanagihara and Chen, is inappropriate owing to a possible non-normal distribution of the data. To address this, we further analysed these data using a non-parametric median test to a binomial distribution for data collected after the third washing (W3) post voltage application and data collected after the application of vinegar (W4). We used a one-sample median test to a binomial. This statistical test is non-parametric as no assumption is made about the form of the population distribution except that it is continuous. This analysis once again revealed a significant difference between the treatments (Zb = 1.73, P = 0.04) and, as such, the amount of protein after vinegar application is greater than after the washing protocol; that is, the application of vinegar increases the amount of venom expressed. Finally, we have reanalysed our data using a Friedman's test (as suggested by another independent biostatistician consulted by the Editor) and once more found that the application of vinegar increased the presence of toxin (Χ2 = 9.0, df = 3, P = 0.029). We thank Yanagihara and Chen for pointing out an issue of the degrees of freedom listed. We realize there was a transcription error that was not identified by the authors within the proofs. Where it reads (F = 77.123x82), it should read (F = 77.123x8). Yanagihara and Chen have also expressed concerns about the press releases associated with this paper. We were contacted by the media as a result of the article's abstract release and the cover page of this journal for March 2014 with the heading "Does vinegar make box jellyfish stings worse?" Our sole press release (in response to the above) stated our findings and suggested a review of the current guidelines, as we do in the article. We do not have control over what the media publishes. We would point out that in every interview conducted by the authors, it was explicitly stated that first aid for cubozoan envenomings in Australia should continue to follow the ARC guidelines unless…
Although Chironex fleckeri and Carukia barnesi cause significant human envenomation, research int... more Although Chironex fleckeri and Carukia barnesi cause significant human envenomation, research into their effects in human models or human cells has been limited. In this in vitro study we have presented data that shows that although C. fleckeri is highly cytotoxic to human cardiac and skeletal muscle cells, C. barnesi is not cytotoxic at all concentrations tested to both cardiac and skeletal muscles cells. We also demonstrate that in vitro C. fleckeri venom cardiocytotoxic activity is significantly attenuated when heated to 44 °C for 20 min. There is a similar attenuation with skeletal cells at 46 °C.
Safety considerations for researchers shape ecological research approaches in dangerous aquatic e... more Safety considerations for researchers shape ecological research approaches in dangerous aquatic environments. A series of recent studies has demonstrated that the moray Gymnothorax polyuranodon (Family Muraenidae) occupies freshwater in the adult phase. However, its potential use of tidal habitat remains largely unexplored, due partly to the challenges of performing underwater research within estuarine crocodile territories. In September 2017, opportunistic snorkel-based observations revealed individuals of this species occupying lairs at an upper tidal creek site during low tide (under freshwater conditions). This provided an opportunity to tailor field-based measurements of the salinity tolerance of this species a fortnight later during a more substantial high tide. Specifically, remote underwater video, snorkel and above-water observations of morays, combined with salinity measurements, reveal that G. polyuranodon is capable of tolerating salinity of at least 14.4 for several hours and can inhabit salinity of 19 for a period of several minutes. This finding, when viewed in synergy with other relevant studies of G. polyuranodon, indicates that the species is either catadromous or amphidromous or capable of either strategy.
Found in the waters off northern Australia, the box jellyfish Chironex fleckeri is not the only m... more Found in the waters off northern Australia, the box jellyfish Chironex fleckeri is not the only marine invertebrate to use venom, but it is the possessor of arguably the most lethal venom in the world.
The dive behaviour undertaken by gravid green turtles, Chelonia mydas, during a part of their int... more The dive behaviour undertaken by gravid green turtles, Chelonia mydas, during a part of their inter-nesting period (11-14 d) while offshore from Raine Island, was investigated. Five Time Depth Recorders (TDRs) were deployed on turtles returning to the sea following either an unsuccessful or a successful nesting attempt. Because the fringing reef immediately adjacent to Raine Island slopes precipitously to meet the sea floor at depths of 200-300 m (Aus Chart 836), this cay presents an ideal location to investigate the dive behaviour of C. mydas in a deep-water inter-nesting habitat.
[Extract] The ischnurid scorpion Liocheles karschii (Keyserling, 1855) is known from New Guinea a... more [Extract] The ischnurid scorpion Liocheles karschii (Keyserling, 1855) is known from New Guinea and adjacent islands. In Australia the species is reported only from islands of Torres Strait (Koch, 1977), but in December 1990 many specimens were observed in boulder caves in Black Mountain, 20k S of Cooktown, NE Queensland. A female specimen was collected from the Black Mountain caves and has been deposited in the Museum of Tropical Queensland, Townsville QMS105138).
Modern, intensified aquaculture typically involves three production phases; hatchery, nursery, an... more Modern, intensified aquaculture typically involves three production phases; hatchery, nursery, and grow-out. For redclaw crayfish aquaculture however, such delineation has been ill-defined. Farming of redclaw was initiated based on the putative beneficial physical and biological attributes of the species, which suggested production methods would be relatively simple. The simple approach proved to be inefficient and only partially effective, which hindered industry development. Hatchery technology now exists to supply seed stock for grow-out, but hatchery production is variable, and the performance of hatchery reared juveniles is inconsistent. A nursery phase has been proposed between hatchery production and grow-out of approximately 3 weeks duration, sufficient to allow 2 or more moults. An important primary parameter in the proposed nursery phase is the thermal regime that will support optimum survival and growth. This study quantified the effect of temperature on the growth and su...
Sawfishes are among the most threatened families of marine fishes and are susceptible to incident... more Sawfishes are among the most threatened families of marine fishes and are susceptible to incidental capture in net fisheries. Since bycatch reduction devices currently used in trawl fisheries are not effective at reducing sawfish catches, new methods to minimise sawfish bycatch are needed. Ideally, these should affect sawfish behaviour and prevent contact with the fishing gear. We tested the effects of electric fields on sawfish behaviour to assess the potential of electric pulses in mitigating sawfish bycatch. Experiments were conducted in a tank where 2 electrodes were suspended in the water column, connected to a pulse generator, and placed across the swimming path of sawfish. Two largetooth sawfish Pristis pristis were tested in control conditions, in the presence of a baseline pulse, and of 5 variations of that pulse where 1 parameter (polarity, voltage, frequency, pulse shape, pulse duration) was altered at a time. Conditional inference trees were used to identify the effects ...
The venom of certain jellyfish has long been known to be potentially fatal to humans, but it is o... more The venom of certain jellyfish has long been known to be potentially fatal to humans, but it is only recently that details of the proteomes of these fascinating creatures are emerging. The molecular contents of the nematocysts from several jellyfish species have now been analyzed using proteomic MS approaches and include the analysis of Chironex fleckeri, one of the most venomous jellyfish known. These studies suggest that some species contain toxins related to peptides and proteins found in other venomous creatures. The detailed characterization of jellyfish venom is likely to provide insight into the diversification of toxins and might be a valuable resource in drug design.
Cnidarian venoms produce a wide spectrum of envenoming syndromes in humans ranging from minor loc... more Cnidarian venoms produce a wide spectrum of envenoming syndromes in humans ranging from minor local irritation to death. Here, the effects of Chironex fleckeri, Chiropsalmus sp., and Carybdea xaymacana venoms on ventricular myocyte cytosolic Ca2+, haemolysis and Artemia sp. lethality are compared for the first time. All three venoms caused a large, irreversible elevation of cytosolic Ca2+ in myocytes as measured using the Ca2+ sensitive fluorescent probe Indo-1. The L-type Ca2+ channel antagonist verapamil had no effect on Ca2+ influx whilst La3+, a non-specific channel and pore blocker, inhibited the effect. Haemolytic activity was observed for all venoms, with C. xaymacana venom displaying the greatest activity. These activities are consistent with the presence of a pore-forming toxin existing in the venoms which has been demonstrated by transmission electron microscopy in the case of C. fleckeri. The venom of C. fleckeri was found to be more lethal against Artemia sp. than the venom of the other species, consistent with the order of known human toxicities. This suggests that the observed lytic effects may not underlie the lethal effects of the venom, and raises the question of how such potent activities are dealt with by envenomed humans.
[Extract] As their common name implies, adult green lacewings are green, with four clear wings. A... more [Extract] As their common name implies, adult green lacewings are green, with four clear wings. Adult female lacewings live for 3-4 weeks and lay up to 600 eggs. Each egg sits on the end of a slender stalk, which elevates it from the ground and decreases the chances of predation by ants. The eggs take approximately 4 days to hatch. Larvae increase in size from 1 mm at first emergence up to 8 mm just before they pupate. They have small spines on their backs upon which they impale the remains of prey. This provides a form of camouflage and allows the larvae to appear inconspicuous among the prey. It is also believed to reduce cannibalism between larvae.
We thank Yanagihara and Chen for their comments and for the opportunity to further the discussion... more We thank Yanagihara and Chen for their comments and for the opportunity to further the discussion. Our statistician has re-examined (and reanalysed) these data, and we have supplied our data to an independent statistician (who supported our subsequent re-analysis) and are more than willing to supply these data to the journal editors should they feel this is necessary. Furthermore, the manuscript was independently reviewed by two reviewers who expressed no concern over our analysis. We are confident of our results. Yanagihara and Chen have incorrectly assumed that the errors displayed in Figure 2 are SEM. These errors represent the 95% confidence limits (CL) and as such their arguments are invalid. Furthermore, they outline that no statistical significance was provided for the specific W4 vs. W3 comparison. Although no specific statistics were displayed in the article, we do outline that LSD post hoc analysis was conducted and the means and 95% CL (as signified in Figure 2) that were significantly different were listed. This analysis showed that the percentage of venom discharged after the application of voltage (W2) and after the application of vinegar (W4) were significantly different from one another and both were significantly higher than either the initial before-voltage percentage (W1) or after the third washing (W3) after voltage application. It is further suggested that the samples used (W1 to W4) are internally matched samples and hence ANOVA is inappropriate. They suggest that a simple t-test would give different results. To alleviate their concerns, we have reanalysed the data using a paired t-test, comparing the level of protein present after the third washing (W3) since voltage was applied to the tentacle and the amount of protein present after vinegar was applied (W4). We paired each sample with itself (which effectively removes the issues surrounding analysis of internally matched samples). This analysis showed that the difference between the matched pairs was significant (t = 8.938, df = 2, P = 0.012). We further reanalysed these data comparing the mean protein expression after vinegar application (W4) to a standard value (23.2%) which was the mean percentage found after three washings (W3) post voltage application. Once again, the difference was found to be significant (t = 6.012, df = 2, P = 0.027). We would argue, however, that the use of t-tests, as suggested by Yanagihara and Chen, is inappropriate owing to a possible non-normal distribution of the data. To address this, we further analysed these data using a non-parametric median test to a binomial distribution for data collected after the third washing (W3) post voltage application and data collected after the application of vinegar (W4). We used a one-sample median test to a binomial. This statistical test is non-parametric as no assumption is made about the form of the population distribution except that it is continuous. This analysis once again revealed a significant difference between the treatments (Zb = 1.73, P = 0.04) and, as such, the amount of protein after vinegar application is greater than after the washing protocol; that is, the application of vinegar increases the amount of venom expressed. Finally, we have reanalysed our data using a Friedman's test (as suggested by another independent biostatistician consulted by the Editor) and once more found that the application of vinegar increased the presence of toxin (Χ2 = 9.0, df = 3, P = 0.029). We thank Yanagihara and Chen for pointing out an issue of the degrees of freedom listed. We realize there was a transcription error that was not identified by the authors within the proofs. Where it reads (F = 77.123x82), it should read (F = 77.123x8). Yanagihara and Chen have also expressed concerns about the press releases associated with this paper. We were contacted by the media as a result of the article's abstract release and the cover page of this journal for March 2014 with the heading "Does vinegar make box jellyfish stings worse?" Our sole press release (in response to the above) stated our findings and suggested a review of the current guidelines, as we do in the article. We do not have control over what the media publishes. We would point out that in every interview conducted by the authors, it was explicitly stated that first aid for cubozoan envenomings in Australia should continue to follow the ARC guidelines unless…
Although Chironex fleckeri and Carukia barnesi cause significant human envenomation, research int... more Although Chironex fleckeri and Carukia barnesi cause significant human envenomation, research into their effects in human models or human cells has been limited. In this in vitro study we have presented data that shows that although C. fleckeri is highly cytotoxic to human cardiac and skeletal muscle cells, C. barnesi is not cytotoxic at all concentrations tested to both cardiac and skeletal muscles cells. We also demonstrate that in vitro C. fleckeri venom cardiocytotoxic activity is significantly attenuated when heated to 44 °C for 20 min. There is a similar attenuation with skeletal cells at 46 °C.
Safety considerations for researchers shape ecological research approaches in dangerous aquatic e... more Safety considerations for researchers shape ecological research approaches in dangerous aquatic environments. A series of recent studies has demonstrated that the moray Gymnothorax polyuranodon (Family Muraenidae) occupies freshwater in the adult phase. However, its potential use of tidal habitat remains largely unexplored, due partly to the challenges of performing underwater research within estuarine crocodile territories. In September 2017, opportunistic snorkel-based observations revealed individuals of this species occupying lairs at an upper tidal creek site during low tide (under freshwater conditions). This provided an opportunity to tailor field-based measurements of the salinity tolerance of this species a fortnight later during a more substantial high tide. Specifically, remote underwater video, snorkel and above-water observations of morays, combined with salinity measurements, reveal that G. polyuranodon is capable of tolerating salinity of at least 14.4 for several hours and can inhabit salinity of 19 for a period of several minutes. This finding, when viewed in synergy with other relevant studies of G. polyuranodon, indicates that the species is either catadromous or amphidromous or capable of either strategy.
Found in the waters off northern Australia, the box jellyfish Chironex fleckeri is not the only m... more Found in the waters off northern Australia, the box jellyfish Chironex fleckeri is not the only marine invertebrate to use venom, but it is the possessor of arguably the most lethal venom in the world.
The dive behaviour undertaken by gravid green turtles, Chelonia mydas, during a part of their int... more The dive behaviour undertaken by gravid green turtles, Chelonia mydas, during a part of their inter-nesting period (11-14 d) while offshore from Raine Island, was investigated. Five Time Depth Recorders (TDRs) were deployed on turtles returning to the sea following either an unsuccessful or a successful nesting attempt. Because the fringing reef immediately adjacent to Raine Island slopes precipitously to meet the sea floor at depths of 200-300 m (Aus Chart 836), this cay presents an ideal location to investigate the dive behaviour of C. mydas in a deep-water inter-nesting habitat.
[Extract] The ischnurid scorpion Liocheles karschii (Keyserling, 1855) is known from New Guinea a... more [Extract] The ischnurid scorpion Liocheles karschii (Keyserling, 1855) is known from New Guinea and adjacent islands. In Australia the species is reported only from islands of Torres Strait (Koch, 1977), but in December 1990 many specimens were observed in boulder caves in Black Mountain, 20k S of Cooktown, NE Queensland. A female specimen was collected from the Black Mountain caves and has been deposited in the Museum of Tropical Queensland, Townsville QMS105138).
Modern, intensified aquaculture typically involves three production phases; hatchery, nursery, an... more Modern, intensified aquaculture typically involves three production phases; hatchery, nursery, and grow-out. For redclaw crayfish aquaculture however, such delineation has been ill-defined. Farming of redclaw was initiated based on the putative beneficial physical and biological attributes of the species, which suggested production methods would be relatively simple. The simple approach proved to be inefficient and only partially effective, which hindered industry development. Hatchery technology now exists to supply seed stock for grow-out, but hatchery production is variable, and the performance of hatchery reared juveniles is inconsistent. A nursery phase has been proposed between hatchery production and grow-out of approximately 3 weeks duration, sufficient to allow 2 or more moults. An important primary parameter in the proposed nursery phase is the thermal regime that will support optimum survival and growth. This study quantified the effect of temperature on the growth and su...
Sawfishes are among the most threatened families of marine fishes and are susceptible to incident... more Sawfishes are among the most threatened families of marine fishes and are susceptible to incidental capture in net fisheries. Since bycatch reduction devices currently used in trawl fisheries are not effective at reducing sawfish catches, new methods to minimise sawfish bycatch are needed. Ideally, these should affect sawfish behaviour and prevent contact with the fishing gear. We tested the effects of electric fields on sawfish behaviour to assess the potential of electric pulses in mitigating sawfish bycatch. Experiments were conducted in a tank where 2 electrodes were suspended in the water column, connected to a pulse generator, and placed across the swimming path of sawfish. Two largetooth sawfish Pristis pristis were tested in control conditions, in the presence of a baseline pulse, and of 5 variations of that pulse where 1 parameter (polarity, voltage, frequency, pulse shape, pulse duration) was altered at a time. Conditional inference trees were used to identify the effects ...
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Papers by Jamie Seymour