Recent Studies on Spawning, Embryonic Development, and Hatching in the Cephalopoda

Cephalopods are exclusively marine molluscs and should be included among the organisms that are of general interest to marine biologists. As to experimental embryology, Naef has already stressed the suitability of cephalopod embryos for experimental work. The whole body of information accumulated in this field during the past half century since Naef published his monograph was reviewed by Marthy. This field of research is clearly underrated by many developmental biologists who could profit by the topological simplicity of the blastulation pattern in cephalopods, which contrasts with the spiralian mode of other molluscs. Questions raised by comparative/evolutionary embryology, following the tradition of descriptive developmental morphology, are truly stimulating to the field of experimental embryology, and vice versa. However, experimental studies are generally possible with only a limited number of models, which, in the case of cephalopods, appear to be embryos of medium to small size. On the other hand, some of the most intriguing questions in cephalopod biology are related to those forms that produce eggs of extremely large size. This chapter gives a brief overview of these recent studies placing them in the chronological sequence of embryogenesis. Studies covering early stages of embryonic development as well as later ones will be cited at least once in the section dealing with the earliest stage considered. Most of these investigations ultimately rest on the basic work by Naef

Molluscs and echinoderms aquaculture: biological aspects, current status, technical progress and future perspectives for the most promising species in Italy

Shellfish aquaculture is a widespread activity in the Italian peninsula. However, only two bivalve species are mainly cultured along the coastline of that country: the Mediterranean mussel <em>Mytilus galloprovincialis</em> and the Manila clam <em>Venerupis philippinarum</em> (<em>Ruditapes philippinarum</em>). By contrast, just a few other mollusc species of commercial interest are scarcely reared at a small-scale level. After analysing the current status of Italian shellfish production, this paper reports and discusses the potential for culturing several different invertebrate species <em>[i.e</em>., the European flat oyster <em>Ostrea edulis</em>, the grooved carpet shell <em>Venerupis decussata</em> (<em>Ruditapes decussatus)</em>, the razor clams <em>Ensis minor</em> and <em>Solen marginatus,</em> the cephalopod <em>Octopus vulgaris</em>, and the purple sea urchin <em>Paracentrotus lividus</em>] in this country. In addition, a detailed overview of the progress made in aquacultural techniques for these species in the Mediterranean basin is presented, highlighting the most relevant bottlenecks and the way forward to shift from the experimental to the aquaculture phase. Finally, an outlook of the main economic and environmental benefits arising from these shellfish culture practices is also given