{"id":{"repo_id":"cape-town","oai_identifier":"oai:open.uct.ac.za:11427/21850"},"canonical_url":"https://search.dev.ndltd.org/etd/cape-town/oai:open.uct.ac.za:11427/21850","repository":{"repo_id":"cape-town","name":"University of Cape Town","base_url":"https://open.uct.ac.za/oai/request"},"display":{"title":"Aspects of the sensitivity of juvenile Jasus lalandii and decapod excitable tissue to the water soluble fraction of crude oil","abstract":"1. A flow-through aquarium facility, for testing the toxicity of the water-soluble fraction (WSF) of crude oil is described. 2. The 24 hour median lethal concentration (LC50) of WSF of crude oil for 2 to 3 year old (30 - 45 mm cephalothorax length) juvenile Jasus lalandii ranged from 3,7 to 5,9 mg l⁻¹. 3. Behavioural experiments appear to provide a quick and convenient approach for estimating the relative toxicity of the WSF of crude oil. 4. The major effect of the WSF of crude oil on Jasus heart beat rate was bradycardia. Furthermore, the greater the initial exposure concentration the sooner the heart beat frequency decreased. 5. Exposure of Jasus muscle fibres to the WSF of crude oil resulted in a shift of the resting membrane potential of those fibres in a hyperpolarising direction. Preliminary investigations into the level of excitability of decapod neurons after exposure to the WSF, indicated a rapid increase, followed by a decrease in excitability, to a level below that of unexposed tissue. 6. Recommendations are made as to how the findings of this study could be applied to enhance the sensitivity of toxicity bioassays.","abstract_html":"1. A flow-through aquarium facility, for testing the toxicity of the water-soluble fraction (WSF) of crude oil is described. 2. The 24 hour median lethal concentration (LC50) of WSF of crude oil for 2 to 3 year old (30 - 45 mm cephalothorax length) juvenile Jasus lalandii ranged from 3,7 to 5,9 mg l⁻¹. 3. Behavioural experiments appear to provide a quick and convenient approach for estimating the relative toxicity of the WSF of crude oil. 4. The major effect of the WSF of crude oil on Jasus heart beat rate was bradycardia. Furthermore, the greater the initial exposure concentration the sooner the heart beat frequency decreased. 5. Exposure of Jasus muscle fibres to the WSF of crude oil resulted in a shift of the resting membrane potential of those fibres in a hyperpolarising direction. Preliminary investigations into the level of excitability of decapod neurons after exposure to the WSF, indicated a rapid increase, followed by a decrease in excitability, to a level below that of unexposed tissue. 6. Recommendations are made as to how the findings of this study could be applied to enhance the sensitivity of toxicity bioassays.","abstract_has_math":false,"creators":["Lipschitz, Steven Richard"],"institution":"Department of Biological Sciences","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Brown, Alec C"],"committee_chairs":[],"committee_members":[],"year":1983,"date_issued":"1983","date_published":"1983","updated_at":"2026-07-22T22:23:44Z","subjects":[],"languages":["eng"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/11427/21850","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Brown, Alec C"]},{"key":"dc:creator","label":"Author","values":["Lipschitz, Steven Richard"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2016-09-20T12:35:02Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2016-09-20T12:35:02Z"]},{"key":"dc:date.issued","label":"Date","values":["1983"]},{"key":"dc:publisher.department","label":"Dc Publisher Department","values":["Department of Biological Sciences"]},{"key":"dc:publisher.institution","label":"Dc Publisher Institution","values":["University of Cape Town"]},{"key":"dc:type","label":"Dc Type","values":["Master Thesis"]},{"key":"dc:type.qualificationlevel","label":"Dc Type Qualificationlevel","values":["Masters"]},{"key":"dc:type.qualificationname","label":"Dc Type Qualificationname","values":["MSc"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["eng"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/11427/21850"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Bibliography: pages 110-125."]},{"key":"dc:description.abstract","label":"Abstract","values":["1. A flow-through aquarium facility, for testing the toxicity of the water-soluble fraction (WSF) of crude oil is described. 2. The 24 hour median lethal concentration (LC50) of WSF of crude oil for 2 to 3 year old (30 - 45 mm cephalothorax length) juvenile Jasus lalandii ranged from 3,7 to 5,9 mg l⁻¹. 3. Behavioural experiments appear to provide a quick and convenient approach for estimating the relative toxicity of the WSF of crude oil. 4. The major effect of the WSF of crude oil on Jasus heart beat rate was bradycardia. Furthermore, the greater the initial exposure concentration the sooner the heart beat frequency decreased. 5. Exposure of Jasus muscle fibres to the WSF of crude oil resulted in a shift of the resting membrane potential of those fibres in a hyperpolarising direction. Preliminary investigations into the level of excitability of decapod neurons after exposure to the WSF, indicated a rapid increase, followed by a decrease in excitability, to a level below that of unexposed tissue. 6. Recommendations are made as to how the findings of this study could be applied to enhance the sensitivity of toxicity bioassays."]},{"key":"dc:title","label":"Title","values":["Aspects of the sensitivity of juvenile Jasus lalandii and decapod excitable tissue to the water soluble fraction of crude oil"]}]}],"canonical_facts":{"dc:contributor.advisor":["Brown, Alec C"],"dc:creator":["Lipschitz, Steven Richard"],"dc:date.accessioned":["2016-09-20T12:35:02Z"],"dc:date.available":["2016-09-20T12:35:02Z"],"dc:date.issued":["1983"],"dc:description":["Bibliography: pages 110-125."],"dc:description.abstract":["1. A flow-through aquarium facility, for testing the toxicity of the water-soluble fraction (WSF) of crude oil is described. 2. The 24 hour median lethal concentration (LC50) of WSF of crude oil for 2 to 3 year old (30 - 45 mm cephalothorax length) juvenile Jasus lalandii ranged from 3,7 to 5,9 mg l⁻¹. 3. Behavioural experiments appear to provide a quick and convenient approach for estimating the relative toxicity of the WSF of crude oil. 4. The major effect of the WSF of crude oil on Jasus heart beat rate was bradycardia. Furthermore, the greater the initial exposure concentration the sooner the heart beat frequency decreased. 5. Exposure of Jasus muscle fibres to the WSF of crude oil resulted in a shift of the resting membrane potential of those fibres in a hyperpolarising direction. Preliminary investigations into the level of excitability of decapod neurons after exposure to the WSF, indicated a rapid increase, followed by a decrease in excitability, to a level below that of unexposed tissue. 6. Recommendations are made as to how the findings of this study could be applied to enhance the sensitivity of toxicity bioassays."],"dc:identifier.uri":["http://hdl.handle.net/11427/21850"],"dc:language.iso":["eng"],"dc:publisher.department":["Department of Biological Sciences"],"dc:publisher.institution":["University of Cape Town"],"dc:title":["Aspects of the sensitivity of juvenile Jasus lalandii and decapod excitable tissue to the water soluble fraction of crude oil"],"dc:type":["Master Thesis"],"dc:type.qualificationlevel":["Masters"],"dc:type.qualificationname":["MSc"]},"updated_at":"2026-07-22T22:23:44Z"}