From March to September, cuttlefish lay eggs on natural substrata (tubes of
polychaetes, Zostera leaves, algae) and also on artificial surfaces (cuttl
etraps, ropes, branches). In Morbihan Bay, during this period, between 18 a
nd 40 million eggs are laid on cuttletraps. From March to May, fishermen em
pty traps every two days. They stack the traps on a pontoon-bridge before f
urther use, and so a great quantity of eggs are destroyed. The objective of
this study is provide artificial substrata (similar to natural surface) to
compensate for significant loss of eggs. The artificial surfaces, in the f
orm of floating ropes, are well adapted to the hydrodynamics of Morbihan Ba
y. The characteristics of the ropes best suited for egg laying are a diamet
er about 8 mm and a length between 30 and 90 cm with a preference for 50 cm
. The number of eggs per surface is estimated at 2200, and the surfaces sho
uld be easy to manipulate by fishermen. (C) 1998 Elsevier Science B.V. All
rights reserved.