title: Physiological, cellular and biochemical thermal stress response of intertidal shrimps with different vertical distributions: Palaemon elegans and Palaemon serratus.
abstract: The ability to cope with high temperature variations is a critical factor in intertidal communities. Two species of intertidal rocky shore shrimps (Palaemon sp.) with different vertical distributions were collected from the Portuguese coast in order to test if they were differentially sensitive to thermal stress. Three distinct levels of biological organization (organismal, biochemical, and cellular) were surveyed. The shrimp were exposed to a constant rate of temperature increase of 1°C x h(-1), starting at 20°C until reaching the CTMax (critical thermal maximum). During heat stress, two biomarkers of protein damage were quantified in the muscle via enzyme-linked immunosorbent assays: heat shock proteins HSP70 (hsp70/hsc70) and total ubiquitin. Muscle histopathological alterations caused by temperature were also evaluated. CTMax values were not significantly different between the congeners (P. elegans 33.4 ± 0.5 °C; P. serratus 33.0 ± 0.5 °C). Biomarker levels did not increase along the temperature trial, but P. elegans (higher intertidal) showed higher amounts of HSP70 and total ubiquitin than P. serratus (lower intertidal). HSP70 and total ubiquitin levels showed a positive significant correlation in both species, suggesting that their association is important in thermal tolerance. Histopathological observations of muscle tissue in P. serratus showed no gross alterations due to temperature but did show localized atrophy of muscle fibers at CTMax. In P. elegans, alterations occurred at a larger scale, showing multiple foci of atrophic muscular fascicles caused by necrotic or autolytic processes. In conclusion, Palaemon congeners displayed different responses to stress at a cellular level, with P. elegans having greater biomarker levels and histopathological alterations.
authors.affiliation: UCIBIO-REQUIMTE, Departamento de Química, Centro de Química Fina e Biotecnologia, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal. Electronic address: dianabmar@gmail.com.
authors.forename: Diana
authors.initials: D
authors.lastname: Madeira
authors.affiliation: Centro de Oceanografia, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal; MARE - Marine and Environmental Sciences Centre, Faculdade de Ciências da Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Mendonça
authors.affiliation: Centro de Oceanografia, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal; MARE - Marine and Environmental Sciences Centre, Faculdade de Ciências da Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal.
authors.forename: Marta
authors.initials: M
authors.lastname: Dias
authors.affiliation: Centro de Oceanografia, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal; MARE - Marine and Environmental Sciences Centre, Faculdade de Ciências da Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal.
authors.forename: Joana
authors.initials: J
authors.lastname: Roma
authors.affiliation: MARE - Marine and Environmental Sciences Centre, Faculdade de Ciências da Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal; IMAR-Instituto do Mar, Departamento de Ciências e Engenharia do Ambiente, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.
authors.forename: Pedro M
authors.initials: PM
authors.lastname: Costa
authors.affiliation: UCIBIO-REQUIMTE, Departamento de Química, Centro de Química Fina e Biotecnologia, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.
authors.forename: Miguel
authors.initials: M
authors.lastname: Larguinho
authors.affiliation: Centro de Oceanografia, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal; MARE - Marine and Environmental Sciences Centre, Faculdade de Ciências da Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal.
authors.forename: Catarina
authors.initials: C
authors.lastname: Vinagre
authors.affiliation: UCIBIO-REQUIMTE, Departamento de Química, Centro de Química Fina e Biotecnologia, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.
authors.forename: Mário S
authors.initials: MS
authors.lastname: Diniz
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D017753:Ecosystem; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D018869:Heat-Shock Response / Q000502:physiology*; D009132:Muscles / Q000378:metabolism / Q000473:pathology; D033541:Palaemonidae / Q000502:physiology*; D013045:Species Specificity; D013696:Temperature; D025801:Ubiquitin / Q000378:metabolism
chemical_list: D015415:Biomarkers; D018840:HSP70 Heat-Shock Proteins; D025801:Ubiquitin
keywords: CTMax; Crustacean; Heat stress; Histopathological changes; Hsp70; Ubiquitin