Embrionary development of Strombus pugilis (Mesogastropoda : Strombidae) in the laboratory

Stages from oviposition to veliger hatching are described for Strombus pugi lis under laboratory conditions. Two egg masses from Playa Seyba, Mexico, ( 20 degrees 45' N, 91 degrees 45' W) were used (three sub-samples per mass). Each sub-sample was immersed in a 1 l container at 29 +/- 1 degreesC. This description is based on stages known from Strombus gigas, which include nu mber of: fertilized eggs, morulae, gastrulae, trochophore larvae with slow movements, larvae with primordium foot, lar vae with eyes, larvae with stat ocyst and veliger larvae. Eggs with first division appeared five hours afte r oviposition in the three replicates of each mass, although in greatest nu mber in one of the egg masses. Trochophore larvae with slow movements appea r after 50-54 hours and veligers hatch after 90 hours.