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Acute Response of the Estuarine Crab Eurypanopeus Depressus to Salinity and Desiccation Stress

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Date Issued:
2007
Abstract/Description:
An understanding of how organisms survive in oyster-reef habitat gives clues as to how they will respond to watershed alterations caused by humans. All estuarine environments experience natural salinity fluctuations, but anthropogenic activities have seriously altered salinity regimes in many areas. The changing tide in the shallow environment of the oyster reef means inhabitants risk exposure and desiccation, yet the reefs support rich communities. Population distribution, osmoregulatory and desiccation physiology and a generic basis for tolerance of extreme environments were investigated in the flatback mud crab Eurypanopeus depressus, a dominant species on oyster reefs in Southwest Florida. An analysis of abundance, biomass and size along a salinity gradient showed that although this species can survive extreme salinities, it is most common in moderate environments. In laboratory experiments, E. depressus hyper-osmoregulated in dilute salinities and conformed in concentrated salinities, achieving stable haemolymph osmotic concentration in less than 24 h. Water loss tolerance and the effect of desiccation on osmoregulatory abilities were also investigated. Eurypanopeus depressus, displayed average tolerance to water loss compared with other crustaceans and does not appear to be able to osmoregulate in air. Also, two distinct partial gene sequences from the peroxiredoxin antioxidant enzyme family were cloned from E. depressus. One of the cloned sequences is 465 bp in length and exhibits over 80% sequence homology with peroxiredoxins found in other arthropods and mammals. With further refinement of extraction techniques, peroxiredoxin gene expression in this intertidal crab could be used as a biomarker reflecting stress caused by environmental conditions.
Title: Acute Response of the Estuarine Crab Eurypanopeus Depressus to Salinity and Desiccation Stress.
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Name(s): Van Horn, Julie, author
Type of Resource: text
Genre: Thesis
Issuance: single unit
Date Issued: 2007
Physical Form: bound thesis
Extent: 98 pgs.
Language(s): English
eng
Abstract/Description: An understanding of how organisms survive in oyster-reef habitat gives clues as to how they will respond to watershed alterations caused by humans. All estuarine environments experience natural salinity fluctuations, but anthropogenic activities have seriously altered salinity regimes in many areas. The changing tide in the shallow environment of the oyster reef means inhabitants risk exposure and desiccation, yet the reefs support rich communities. Population distribution, osmoregulatory and desiccation physiology and a generic basis for tolerance of extreme environments were investigated in the flatback mud crab Eurypanopeus depressus, a dominant species on oyster reefs in Southwest Florida. An analysis of abundance, biomass and size along a salinity gradient showed that although this species can survive extreme salinities, it is most common in moderate environments. In laboratory experiments, E. depressus hyper-osmoregulated in dilute salinities and conformed in concentrated salinities, achieving stable haemolymph osmotic concentration in less than 24 h. Water loss tolerance and the effect of desiccation on osmoregulatory abilities were also investigated. Eurypanopeus depressus, displayed average tolerance to water loss compared with other crustaceans and does not appear to be able to osmoregulate in air. Also, two distinct partial gene sequences from the peroxiredoxin antioxidant enzyme family were cloned from E. depressus. One of the cloned sequences is 465 bp in length and exhibits over 80% sequence homology with peroxiredoxins found in other arthropods and mammals. With further refinement of extraction techniques, peroxiredoxin gene expression in this intertidal crab could be used as a biomarker reflecting stress caused by environmental conditions.
Identifier: fgcu_ETD_0417 (IID)
Note(s): Degree Awarded: Master of Science
Department: College of Arts & Sciences
Subject(s): Oyster-reef habitat
mud crab
Southwest Florida
curstaceans
Persistent Link to This Record: http://purl.flvc.org/fgcu/fd/fgcu_ETD_0417
Use and Reproduction: Creator holds copyright.
Use and Reproduction: http://rightsstatements.org/vocab/InC/1.0/
Host Institution: FGCU