Protozoea

Protozoea

 

one of the larval stages in the development of decapod Crustacea. The protozoean stage usually occurs in the egg; a free-floating protozoea is characteristic of a few primitive shrimp. The protozoea has a segmented thorax, an unsegmented abdomen, a cephalothoracic shell, and a pair of compound sessile eyes. After ecdysis, the protozoea passes into the next larval stage, the zoea.

References in periodicals archive ?
Three isotrypsins were detected from protozoea to postlarvae, and particularly in the midgut gland of adults.
Next, the shrimp mature to protozoea stage during which time they develop antennal locomotion and begin free swimming.
Initially, nauplii utilize yolk granules within their body as food and subsequently feeding on microalgae begins at the protozoea stage [70].
Chymotrypsin showed a significantly lower activity in protozoea 3, a peak of activity between postlarvae 1 and 10, and a decrease in the following postlarval stages (Table 3).
Early larval stages (protozoea and myses) migrate vertically in a diel cycle and there is no cross-shelf displacement during the first 15 days of development.
and Penaeus aztecus Ives larvae fed Artemia beginning at the protozoea two substage versus the mysis-one substage.
Among the recorded taxa, 27.8% were very frequent (Table 1), especially the protozoea of Lucifer faxoni and Acetes americanus with 91.7% each, followed by zoea of Pinnixa sp.
All the known members of the family Penaeidae have a similar life cycle: planktonic larval stages; including nauplius, protozoea, mysis, and postlarva; followed by juvenile and adult stages (Dall et al.