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Thomas Hecht - One of the best experts on this subject based on the ideXlab platform.
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Intercohort cannibalism and post‐partum behaviour of juvenile swordtail Xiphophorus helleri Heckel (Pisces: Poeciliidae)
Aquaculture Research, 2008Co-Authors: Clifford L. W. Jones, Horst Kaiser, Thomas HechtAbstract:Newborn (i.e. neonate) swordtail Xiphophorus helleri Heckel attempted to escape cannibalization attempts in a downward direction more frequently than in any other direction. The downward escape response is likely to be anti-predator behaviour. In addition, neonates were often able to escape cannibalization at the time of birth, despite no previous exposure to predators, which suggests that this anti-predator behaviour is innate. However, neonates at the time of birth were more vulnerable to cannibalism than older juveniles, which supports the hypothesis that anti-predator behaviour is, at least in part, further developed as a result of previous experience (i.e. learning).
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intercohort cannibalism and post partum behaviour of juvenile swordtail Xiphophorus helleri heckel pisces poeciliidae
Aquaculture Research, 2008Co-Authors: Clifford L. W. Jones, H Kaiser, Thomas HechtAbstract:Newborn (i.e. neonate) swordtail Xiphophorus helleri Heckel attempted to escape cannibalization attempts in a downward direction more frequently than in any other direction. The downward escape response is likely to be anti-predator behaviour. In addition, neonates were often able to escape cannibalization at the time of birth, despite no previous exposure to predators, which suggests that this anti-predator behaviour is innate. However, neonates at the time of birth were more vulnerable to cannibalism than older juveniles, which supports the hypothesis that anti-predator behaviour is, at least in part, further developed as a result of previous experience (i.e. learning).
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intercohort cannibalism and parturition associated behaviour of adult swordtail Xiphophorus helleri heckel pisces poeciliidae
Aquaculture Research, 2007Co-Authors: Clifford L. W. Jones, H Kaiser, Thomas HechtAbstract:The post-parturition behavioural patterns of adult Xiphophorus helleri (Heckel) were described and quantified by recording their duration and/or frequency in glass tanks. All births occurred in the dark. Female behaviour might increase the chance of newborn juvenile survival: at the top of the tank, where juveniles are more vulnerable to predation, the females gave birth in the artificial refuge, while no parturition took place in the refuge at the bottom. Birth-giving females were no less cannibalistic than males and other females. There was a reduction in cannibalism and the frequency of secondary attacks with time, even though the number of juveniles in the tank continued to increase due to ongoing parturition. Most adults were found at the bottom of the water column during the first 500 min of parturition, after which they were distributed equally in the water column. The movement of adults, away from the bottom and consequently away from the juveniles corresponded with an increase in feeding on alternative food and a reduction in cannibalism. Thus, cannibalism in swordtail might be opportunistic predation.
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Intercohort cannibalism and parturition‐associated behaviour of adult swordtail, Xiphophorus helleri Heckel (Pisces: Poeciliidae)
Aquaculture Research, 2007Co-Authors: Clifford L. W. Jones, Horst Kaiser, Thomas HechtAbstract:The post-parturition behavioural patterns of adult Xiphophorus helleri (Heckel) were described and quantified by recording their duration and/or frequency in glass tanks. All births occurred in the dark. Female behaviour might increase the chance of newborn juvenile survival: at the top of the tank, where juveniles are more vulnerable to predation, the females gave birth in the artificial refuge, while no parturition took place in the refuge at the bottom. Birth-giving females were no less cannibalistic than males and other females. There was a reduction in cannibalism and the frequency of secondary attacks with time, even though the number of juveniles in the tank continued to increase due to ongoing parturition. Most adults were found at the bottom of the water column during the first 500 min of parturition, after which they were distributed equally in the water column. The movement of adults, away from the bottom and consequently away from the juveniles corresponded with an increase in feeding on alternative food and a reduction in cannibalism. Thus, cannibalism in swordtail might be opportunistic predation.
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Filial Cannibalism in the Swordtail Xiphophorus helleri (Poeciliidae)
Aquarium Sciences and Conservation, 1998Co-Authors: Clifford L. W. Jones, H Kaiser, G.a. Webb, Thomas HechtAbstract:To understand behaviour during filial cannibalism in swordtails (Xiphophorus helleri), the parturition behaviour of eight individually kept females was recorded on videotape. Three levels of female activity (low, medium and high) were quantified by measuring the duration of each. Four additional behavioural events (non-cannibalistic feeding, as well as the birth, attack and cannibalism of juveniles) were quantified by determining the frequency of each. Females gave birth most frequently at a low level of activity and at this level of activity they most often gave birth at the top of the tank. Of all the attacks by females on the young, 84.4% occurred in the light. Most attacks were recorded at the bottom of the tank and 84.0% of all cannibalism occurred at the bottom. Cannibalism was most successful at the bottom of the tank with a cannibalism:attack ratio of 1:2.2 and least successful in the middle where no cannibalism was recorded. In the light, females spent more time at the top of the tank, whereas in the dark they spent more time at the bottom. It was suggested that the rate of cannibalism might be reduced if parts of the tank were kept constantly dark and if females were restricted from reaching those areas in the tank where the frequency of cannibalism was highest, namely the top and the bottom of the tank. Experimental designs and working hypotheses for future studies are discussed.
Hinrich Rahmann - One of the best experts on this subject based on the ideXlab platform.
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NADPH-diaphorase reactivity in the Mauthner cells of the swordtail fish, Xiphophorus helleri
Neuroscience letters, 1996Co-Authors: Ralf Anken, Ingeborg Sorger, Dirk Bremen, Hinrich RahmannAbstract:The presence of nicotinamide adenine dinucleotide phosphate-diaphorase (NADPHDH) in fixed tissue was histochemically demonstrated in the Mauthner cells of the teleost fish Xiphophorus helleri. This is the first detection of the enzyme in these giant neurons (which are restricted to fishes and amphibians) of a gnathostomate vertebrate. NADPHDH reactivity in fixed tissue is thought to reflect the activity of nitric oxide synthase. Thus, nitric oxide, a gaseous intercellular messenger, is probably synthesized in the Mauthner cells.
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Notes on the organization of the rostral diencephalon of the Atherinomorph Swordtail-Fish Xiphophorus helleri
Annals of anatomy = Anatomischer Anzeiger : official organ of the Anatomische Gesellschaft, 1995Co-Authors: Ralf Anken, Hinrich RahmannAbstract:Summary By using conventional histological methods, the nuclear organization of the rostral diencephalon of the swordtail-fish, Xiphophorus helleri (Poecilidae, Atherinomorpha, Teleostei) was analyzed and compared with those from other teleost species. The subdivisions of the entopeduncular region, especially in their relative position and cytoarchitectonic structure, reveal clear differences between the various teleost orders. A new nucleus, the lateral entopeduncular nuclear area (leNA), found within this region, is described.
Fang Zhan-qiang - One of the best experts on this subject based on the ideXlab platform.
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Observation on the Microstructure and Ultrastructure of the Testels in Swordtail(Xiphophorus helleri)
Journal of South China Normal University, 2012Co-Authors: Fang Zhan-qiangAbstract:The microstructure and ultrastructure of the spermatogenesis in Swordtail(Xiphophorus helleri) were studied with microscope and transmission electron microscope.The results showed that the adult's spermary likes two trabs,Its internal structure is of a small pipe type.The generated cells of each bursula in spermary grow at equal pace.From spermatogeny to spermium,the bursula moves gradually from caecum in canoula to central,and the generative cells grow gradually.The spermatogenesis of Xiphophorus helleri needs go through several phases,such as spermiogonium,primary spermatocyte,second spermatocyte,spermatid,spermiogenesis and mature spermium.The spermium consists of head,midportion and tail.
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OBSERVATION ON THE HISTOLOGY AND ULTRASTRUCTURE OF THE KIDNEY IN Xiphophorus helleri
Journal of South China Normal University, 2011Co-Authors: Fang Zhan-qiangAbstract:Histology and ultrastructure of the kidney in Swordtails(Xiphophorus helleri) were studied with microscope and transmission electron microscope.Similar to other teleost,the mesonephros was consisted of renal corpuscle and renal tubules.Renal corpuscles were interspersed in the kidney.The renal tubules were composed of the neck tubule,first and second proximal tubule,distal tubule and the collecting tubule.Lymphoid tissues,including Lymphocyte,Monocyte and Melano-macrophage,were differentiated in the kidney under electron microscope.As a multifunction organ,the characteristic of structure and ultrastructure of the kidney in fish were also discussed in this paper.
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Development of ELISA for Detecting Xiphophorus helleri Vitellogenin
Research of Environmental Sciences, 2007Co-Authors: Wen Ru-shu, Fang Zhan-qiangAbstract:An indirect competitive enzyme-linked immunosorbent assay(ELISA) was established for detecting vitellogenin(Vtg) in the whole body homogenate(WBH) of male swordtail fish(Xiphophorus helleri).This technique was developed with antiserum of lipovitellin(Lv)resistance as antibody and Vtg as antigen.The results indicated that the working range was 32.5～(2 000)(ng/mL);the sensitivity was 7.8(ng/mL);intra-assay and inter-assay coefficients of variation were 5.094% and 5.540% respectively.The technique shows good linearity and repeatability in standard curve.WBH of male swordtail fish sample can be checked in one same coated well and different coated wells to develop screening of environmental estrogen.The results also indicated that the WBH from 50(μg/L) 17β estradiol treated with 21 days male had Vtg obviously,and that of 10(μg/L) had too,but that of 1(μg/L) had not yet(P/N was less than 2.1).
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Induction of Vitellogenin by 17-Estradiol in Swordtail Fish (Xiphophorus helleri)
2007Co-Authors: Wen Ru-shu, Fang Zhan-qiangAbstract:Objective To explore if induction of vitellogenin(Vtg) by 17β-estradiol in male swordtail fish(Xiphophorus helleri) can be used as a valid biomarker for environmental risk assessment(ERA).Methods\ Vtg was purified from whole body homogenate(WBH) of estradiol-17β treated(10 μg/mL ambient freshwater for 21 days) male swordtail fish by gel filtration(Sephacryl S-300) and anion exchange chromatography(Q Sepharose),respectively.Results\ Vtg appeared to exist as a homotrimer of approximately 540×10~3 in native polyacrylamide gel electrophoresis(PAGE).Vtg was characterized as a phospholipoglycoprotein by native PAGE and staining of gels for phosphorus with methyl green,for lipids with Sudan black B,and for carbohydrates with periodic acid-Schiff reagent.It also indicated that the purified proteins resembled the Vtg in other teleost species,and therefore reasonably identified as swordtail fish Vtg.Conclusion\ The results indicated that Vtg in male swordtail fish could be considered as a valid biomarker for environmental risk assessment(ERA).
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Primary Culture of Swordtail Fish(Xiphophorus helleri) Hepatocytes
Chinese Journal of Comparative Medicine, 2006Co-Authors: Fang Zhan-qiangAbstract:Objective To study the primary culture methods of hepatocytes of swordtail fish(Xiphophorus helleri).Methods\ Hepatocytes were isolated by digestion with pancreatin and mechanical separation.The growth effect of hepatocytes cultured in William's E(William's Medium E),DMEM and DMEM/F12(Serum-free medium) was compared.Results\ ⑴ With mechanical separation method,hepatocytes could normally grow in all the mediums of William's E(William's Medium E),DMEM,DMEM/F12(Serum-free medium) at the temperature 25℃ ～ 28℃,pH7.3 in a shortterm.The best growth of hepatocytes was in William's E,followed by culture in DMEM,and least in DMEM/F12.⑵ With digestion with pancreatin,the average yield of hepatocytes was(6.4±1.7)×10~6 cell/g liver tissue,and the average viability was(85±6)%.The rate of cell adherence was not more than 20% at 24 h.Conclusion\ The results indicated that the average yield,the average viability and the rate of cell adherence of hepatocytes isolated by digestion method with pancreatin was lower.However,hepatocytes culture obtained by mechanical separation method could grow well and deos not need rigorous conditions,and can well satisfy the requirement of toxicological experiments.It also indicated that the William's Medium E is a preferred medium for the primary culture of Xiphophorus helleri hepatocytes.
Clifford L. W. Jones - One of the best experts on this subject based on the ideXlab platform.
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Intercohort cannibalism and post‐partum behaviour of juvenile swordtail Xiphophorus helleri Heckel (Pisces: Poeciliidae)
Aquaculture Research, 2008Co-Authors: Clifford L. W. Jones, Horst Kaiser, Thomas HechtAbstract:Newborn (i.e. neonate) swordtail Xiphophorus helleri Heckel attempted to escape cannibalization attempts in a downward direction more frequently than in any other direction. The downward escape response is likely to be anti-predator behaviour. In addition, neonates were often able to escape cannibalization at the time of birth, despite no previous exposure to predators, which suggests that this anti-predator behaviour is innate. However, neonates at the time of birth were more vulnerable to cannibalism than older juveniles, which supports the hypothesis that anti-predator behaviour is, at least in part, further developed as a result of previous experience (i.e. learning).
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intercohort cannibalism and post partum behaviour of juvenile swordtail Xiphophorus helleri heckel pisces poeciliidae
Aquaculture Research, 2008Co-Authors: Clifford L. W. Jones, H Kaiser, Thomas HechtAbstract:Newborn (i.e. neonate) swordtail Xiphophorus helleri Heckel attempted to escape cannibalization attempts in a downward direction more frequently than in any other direction. The downward escape response is likely to be anti-predator behaviour. In addition, neonates were often able to escape cannibalization at the time of birth, despite no previous exposure to predators, which suggests that this anti-predator behaviour is innate. However, neonates at the time of birth were more vulnerable to cannibalism than older juveniles, which supports the hypothesis that anti-predator behaviour is, at least in part, further developed as a result of previous experience (i.e. learning).
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intercohort cannibalism and parturition associated behaviour of adult swordtail Xiphophorus helleri heckel pisces poeciliidae
Aquaculture Research, 2007Co-Authors: Clifford L. W. Jones, H Kaiser, Thomas HechtAbstract:The post-parturition behavioural patterns of adult Xiphophorus helleri (Heckel) were described and quantified by recording their duration and/or frequency in glass tanks. All births occurred in the dark. Female behaviour might increase the chance of newborn juvenile survival: at the top of the tank, where juveniles are more vulnerable to predation, the females gave birth in the artificial refuge, while no parturition took place in the refuge at the bottom. Birth-giving females were no less cannibalistic than males and other females. There was a reduction in cannibalism and the frequency of secondary attacks with time, even though the number of juveniles in the tank continued to increase due to ongoing parturition. Most adults were found at the bottom of the water column during the first 500 min of parturition, after which they were distributed equally in the water column. The movement of adults, away from the bottom and consequently away from the juveniles corresponded with an increase in feeding on alternative food and a reduction in cannibalism. Thus, cannibalism in swordtail might be opportunistic predation.
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Intercohort cannibalism and parturition‐associated behaviour of adult swordtail, Xiphophorus helleri Heckel (Pisces: Poeciliidae)
Aquaculture Research, 2007Co-Authors: Clifford L. W. Jones, Horst Kaiser, Thomas HechtAbstract:The post-parturition behavioural patterns of adult Xiphophorus helleri (Heckel) were described and quantified by recording their duration and/or frequency in glass tanks. All births occurred in the dark. Female behaviour might increase the chance of newborn juvenile survival: at the top of the tank, where juveniles are more vulnerable to predation, the females gave birth in the artificial refuge, while no parturition took place in the refuge at the bottom. Birth-giving females were no less cannibalistic than males and other females. There was a reduction in cannibalism and the frequency of secondary attacks with time, even though the number of juveniles in the tank continued to increase due to ongoing parturition. Most adults were found at the bottom of the water column during the first 500 min of parturition, after which they were distributed equally in the water column. The movement of adults, away from the bottom and consequently away from the juveniles corresponded with an increase in feeding on alternative food and a reduction in cannibalism. Thus, cannibalism in swordtail might be opportunistic predation.
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Filial Cannibalism in the Swordtail Xiphophorus helleri (Poeciliidae)
Aquarium Sciences and Conservation, 1998Co-Authors: Clifford L. W. Jones, H Kaiser, G.a. Webb, Thomas HechtAbstract:To understand behaviour during filial cannibalism in swordtails (Xiphophorus helleri), the parturition behaviour of eight individually kept females was recorded on videotape. Three levels of female activity (low, medium and high) were quantified by measuring the duration of each. Four additional behavioural events (non-cannibalistic feeding, as well as the birth, attack and cannibalism of juveniles) were quantified by determining the frequency of each. Females gave birth most frequently at a low level of activity and at this level of activity they most often gave birth at the top of the tank. Of all the attacks by females on the young, 84.4% occurred in the light. Most attacks were recorded at the bottom of the tank and 84.0% of all cannibalism occurred at the bottom. Cannibalism was most successful at the bottom of the tank with a cannibalism:attack ratio of 1:2.2 and least successful in the middle where no cannibalism was recorded. In the light, females spent more time at the top of the tank, whereas in the dark they spent more time at the bottom. It was suggested that the rate of cannibalism might be reduced if parts of the tank were kept constantly dark and if females were restricted from reaching those areas in the tank where the frequency of cannibalism was highest, namely the top and the bottom of the tank. Experimental designs and working hypotheses for future studies are discussed.
Jin-hwa Kim - One of the best experts on this subject based on the ideXlab platform.
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Effects of nonylphenol, bisphenol A, and their mixture on the viviparous swordtail fish (Xiphophorus helleri).
Environmental toxicology and chemistry, 2001Co-Authors: Hyeong-il Kwak, Mi-ok Bae, Moon-han Lee, Yong-soon Lee, Bum-joon Lee, Kyung-sun Kang, Chanhee Chae, Ha-jung Sung, Jin-sup Shin, Jin-hwa KimAbstract:A number of fish species have been used for studies on endocrine disrupting chemicals (EDCs). However, despite the widespread use of oviparous fish, relatively little attention has been given to viviparous species. This study investigated the effects of EDCs in a viviparous fish and examined the possible usefulness of the fish as an alternative model for the studies on EDCs. Swordtails (Xiphophorus helleri) were exposed to nonylphenol (NP), bisphenol A (BPA), and their mixture. Both short-term (3-d) and relatively long-term (60-d) exposures were carried out using adult male and 30-d-old juvenile fish, respectively. Following the short-term exposure, both NP and BPA caused vitellogenin mRNA expression. Flow cytometric analysis and terminal deoxynucleotidyl transferase assay on the testes of treated fish indicated reproductive damage. Histopathological analysis found degenerative and necrotic cells in seminiferous tubules following the exposure to 100 ppb NP. The testes with lesions were also associated with highly suppressed spermatogenesis. Following the long-term exposure, both NP and BPA exposures significantly affected the growth of swordtails. In all cases, the results showed that the mixture was always more potent than a single chemical and that swordtail fish can be a useful model for the study of endocrine disruptors.
