Trypsin enzyme
activity during larval development of Litopenaeus vannamei (Boone)
fed on live feeds
A.C. Puello-Cruz, R.S. Sangha, D.A. Jones, L. Le Vay-2002
Aquaculture
Research, 33(5):
333-338
Abstract:
Larval stages of the Pacific white
shrimp, Litopenaeus vannamei (Boone) were fed standard live diets of
mixed microalgae from the first to the third protozoea (PZ1 to PZ3),
followed by Artemia nauplii until post-larvae 1 (PL1). Trypsin enzyme
activity for each larval stage was determined using N-α-p-toluenesulphonyl-l-arginine
methyl ester (TAME) as a substrate. Results were expressed as enzyme content
to assess ontogenetic changes during larval development. Tissue trypsin
content (IU µg-1 DW for each larval stage) was significantly highest at the PZ1
stage and declined through subsequent stages to PL1. This contrasts with
previously observed patterns of trypsin development in Litopenaeus
setiferus (Linnaeus) and other penaeid genera, which exhibit a peak in
trypsin activity at the third protozoea/first mysis (PZ3/M1) larval stage. Litopenaeus
vannamei larvae transferred to a diet of Artemia at the beginning
of the second protozoea (PZ2) stage were significantly heavier on reaching
the first mysis stage (M1) than those fed algae, while survival was not
significantly different between treatments. At both PZ2 and PZ3 stages,
trypsin content in larvae feeding on Artemia was significantly lower
than in those feeding on algae. The rapid decline in trypsin content from
PZ1 and the flexible enzyme response from PZ2 suggest that L. vannamei
is physiologically adapted to transfer to a more carnivorous diet during the
mid-protozoeal stages.
(Centro de Investigación en Alimentación y Desarrollo, A.C. (C.I.A.D),
Unidad Mazatlán en Acuicultura y Manejo Ambiental, Apdo. Postal
711, C.P. 82010, Mazatlán, Sinaloa, México. E-mail: puello@victoria.ciad.mx)