STUDI BUKAAN MULUT LARVA KERAPU SUNU PLECTROPOMUS LEOPARDUS DAN KESESUAIAN UKURAN PAKAN ALAMI

Abstract

Data on the mouth gap of coral trout grouper Plectropomus leopardus larvae is vital on selecting their suitable live feed during its larval rearing. Therefore, this study was aimed to determine the mouth gap of the larvae as well as to evaluate the compatibility of its live feed. P. leopardus larvae were reared for 30 days and fed on trochophore since day-2 (D-2), rotifers started on D-3, copepods nauplii on D-4, and Artemia nauplii which started on D-20. A minimum of 30 larvae and each type of the live feed were sampled, photographed, and measured for their size. Mouth gap of the larvae increased slowly from D-3 (113.33±29.85 µm) to D-7 (144.65±23.99 µm), but rose significantly to 263.67±44.57 µm on D-10, 470.94±123.86 µm and 719.73±103.39 µm on D-20 and D-30, respectively. Results showed that trochophore had small size, and were suitable for the larvae. The screened rotifers had an average length of 121.94±17.21 µm and width of 93.65±13.32 µm. It is important to note that only 34.14% (14/41) of the rotifers revealed length under the mouth gap of D-3 larvae. The mean length and width of copepods nauplii were 354.40 ± 44.83 µm and 237.77 ± 33.42 µm indicated that this size was much higher than the mouth gap of D-4 larvae. Artemia nauplii showed an average length of 541.23±88.56 µm and width of 408.62±68.25 µm implied that D-20 larvae could not prey from the lateral side, but they can prey from the anterior part of Artemia nauplii. We suggested that the compatibility concept should be adopted in P. leopardus larval rearing to increase live feed predation by the larvae.