Letters to Nature

Nature 402, 173-176 (11 November 1999) | doi:10.1038/46023; Received 12 May 1999; Accepted 20 August 1999

The insidious effect of diatoms on copepod reproduction

A. Miralto1, G. Barone2, G. Romano1, S. A. Poulet3, A. Ianora1, G. L. Russo4, I. Buttino1, G. Mazzarella4, M. Laabir1, M. Cabrini5 & M. G. Giacobbe6

  1. Stazione Zoologica "A. Dohrn", Villa Comunale, 80121 Naples, Italy
  2. Dipartimento di Chimica Organica e Biologica, Università di Napoli "Federico II", Via Mezzocannone 16, 80134 Naples, Italy
  3. Station Biologique de Roscoff, CNRS, Place Georges Teissier, 29682 Roscoff, France
  4. Istituto di Scienze dell'Alimentazione, CNR, 83100 Avellino, Italy
  5. Laboratorio di Biologia Marina, Via August Piccard 54, 34040 Trieste, Italy
  6. Istituto Sperimentale Talassografico CNR, Via San Ranieri 86, 98122 Messina, Italy

Correspondence to: A. Miralto1 Correspondence and request for materials should be addressed to A.M. (e-mail: Email: miralto@alpha.szn.it).

The productive regions of the ocean are characterized by seasonal blooms of phytoplankton which are generally dominated by diatoms. This algal class has, therefore, traditionally been regarded as providing the bulk of the food that sustains the marine food chain to top consumers and important fisheries. However, this beneficial role has recently been questioned on the basis of laboratory studies showing that although dominant zooplankton grazers such as copepods feed extensively on diatoms, the hatching success of eggs thus produced is seriously impaired1. Here we present evidence from the field showing that the hatching success of wild copepods feeding on a diatom-dominated bloom is also heavily compromised, with only 12% of the eggs hatching compared with 90% in post-bloom conditions. We report on the structure of the three aldehydes isolated from diatoms that are responsible for this biological activity, and show that these compounds arrest embryonic development in copepod and sea urchin bioassays and have antiproliferative and apoptotic effects on human carcinoma cells.