ANALYSIS OF THE GROWTH RATE AND MOULTING FREQUENCY OF MUD CRAB (Scylla serrata) UNDER DIFFERENT REARING SUBSTRATES

Abstract

Mud crab (Scylla serrata) is a high-value fishery commodity, but the success of its culture is
still influenced by growth and moulting processes. This study aimed to analyze the effects of
different rearing substrates on the growth rate, moulting frequency, and moulting time of mud
crab. The study was conducted at the Dakota Crab Culture Facility, Mataram City, and the
Aquaculture Environment Laboratory, Aquaculture Study Program, University of Mataram.
An experimental method was used with two treatments, namely P1, a beach sand substrate, and
P2, a beach sand substrate with the addition of mangrove leaves. Rearing was carried out in
crab boxes connected to a Recirculating Aquaculture System (RAS). The main parameters
included moulting frequency, moulting time, absolute weight gain, absolute length growth,
Specific Growth Rate (SGR), and Survival Rate (SR). The data were analyzed using a two
sample t-test assuming unequal variances at the 5% level. The results showed that substrate
differences had no significant effect on any parameter (p>0.05). Descriptively, treatment P2
produced a higher moulting frequency of 0.500±0.534 times/day than P1 at 0.375±0.517
times/day. Moulting time in P2 was also slightly faster, at 38.00±16.4 days, whereas P1 was
39.67±11.3 days. Thus, the combination of beach sand and mangrove leaves tended to be better
for moulting frequency and moulting time, but the differences were not statistically significant.
Keywords: Growth; Mangrove Leaves; Moulting; Moulting Time; Mud Crab; Substrate