Enzymatic activity
Trypsin specific activity was detected as early as 1 dph (0.80±
0.16 mU/mg protein), when larvae measured 2.5±0.02 mm total length
and 0.51±0.001 mg wet weight, and increased gradually during the
following days, but most notably after the initial exogenous feeding,
between 4 and 5 dph, until 14 dph (5.84±0.20 mU/mg protein). After
this time, trypsin activity decreased until 18 dph, before increasing at
24 dph and again at 32 dph (9.75±0.36 mU/mg protein), and then
decreased until the experiment was concluded at 40 dph (Fig. 2A).
The specific activity of chymotrypsin was detected at 1 dph (7.21±
1.29mU×10−4/mg protein). Maximum activity (15.92±1.02 mU×
10−4/mg protein) was measured 2 days after weaning from Artemia
nauplii to a microdiet, at 18 dph. Chymotrypsin activity then decreased
until 20 dph and remained constant thereafter (Fig. 2B).
The specific activity of leucine aminopeptidase was detected at
1 dph (1.31±0.05 mU×10−3/mg protein), and it increased continuously
until 18 dph (15.91±0.40 mU×10−4/mg protein). This
increase was followed by a steady decline until 20 dph, when the
activity increased again until 28 dph (Fig. 2C).