Marine Biology

, Volume 137, Issue 3, pp 453–461

Susceptibility to oxidative stress of the Mediterranean demosponge Petrosia ficiformis : role of endosymbionts and solar irradiance

  • F. Regoli
  • C. Cerrano
  • E. Chierici
  • S. Bompadre
  • G. Bavestrello

DOI: 10.1007/s002270000369

Cite this article as:
Regoli, F., Cerrano, C., Chierici, E. et al. Marine Biology (2000) 137: 453. doi:10.1007/s002270000369

Abstract

 The effects of elevated pO2 and irradiance as inducers of prooxidant conditions have been investigated in the Mediterranean demosponge Petrosia ficiformis (Poiret, 1789). This species lives symbiotically with the autotrophic cyanobacterium Aphanocapsa feldmanni, the abundance of which is controlled by the intensity of light irradiance. In the presence of symbionts, tissues of P. ficiformis were characterized by a general enhancement of antioxidant defenses as compared to aposymbiotic specimens. The main differences included higher activities of several antioxidant enzymes and a greater capability to neutralize various forms of oxyradicals, as indicated by the total oxyradical scavenging capacity (TOSC) assay. Elevated pO2, more than light, appeared to be the primary factor inducing prooxidant pressure in the Mediterranean sponge; in fact, irrespective of the solar irradiance experienced by the sponge, symbiotic specimens showed comparable activities of antioxidant enzymes and a similar scavenging capacity towards various reactive oxygen species. However, the potential toxicity of photodynamic production of reactive oxygen species was demonstrated in organisms from more irradiated sites, as the levels of antioxidant defenses were lowered in the outer layer of the sponge. The role of enhanced antioxidant defenses in protecting symbiotic specimens, also from oxyradical-mediated toxicity of light exposure, was supported by translocation experiments; aposymbiotic sponges did not survive when moved to conditions of elevated solar irradiance, while no effects were observed in symbiotic specimens if translocated and/or deprived of symbionts.

Copyright information

© Springer-Verlag Berlin Heidelberg 2000

Authors and Affiliations

  • F. Regoli
    • 1
  • C. Cerrano
    • 2
  • E. Chierici
    • 1
  • S. Bompadre
    • 3
  • G. Bavestrello
    • 4
  1. 1.Istituto di Biologia e Genetica, Università di Ancona, Via Ranieri Monte D'Ago, 60100 Ancona, Italy Tel.: +39-071-2204613; Fax: +39-071-2204609 e-mail: regoli@popcsi.unian.itIT
  2. 2.Dipartimento per lo Studio del Territorio e delle sue Risorse, Università di Genova, Via Balbi 5, 16126 Genova, ItalyIT
  3. 3.Istituto di Scienze Biomediche, Università di Ancona, Via Brecce Bianche, 60100 Ancona, ItalyIT
  4. 4.Istituto di Scienze del Mare, Università di Ancona, Via Brecce Bianche, 60100 Ancona, ItalyIT