Abstract:
Increased harvest pressure and local harvesters’ intensifying collection have led to a critical de
cline in Holothuria scabra populations in Sri Lanka. Aquaculture provides a practical solution to reduce
the overexploitation of sea cucumbers. In Sri Lanka, juvenile post-release survival and growth performance
have been scarce. Therefore, this study aims to evaluate the growth performance and percentage of survival
of juveniles under different feed treatments along with control setups. The present study was conducted
at Suganth Seafood (Pvt) Ltd, Kakkaitheevu, Jaffna. Juveniles (2–3g) were selected randomly from the
hatchery and stocked in indoor nursery tanks (120L). Three replicate tanks were maintained for each treat
ment (T1, T2, T3) and the control, with a stocking density of 20 juveniles per tank. Varying ratios of
three types of seaweeds and sea mud were utilized in feed preparation as follows: Sargassum crassifolium :
Gracilaria salicornia : Kappaphycus alvarizii : sea mud in T1 = 4:3:2:1, T2 = 2:4:3:1, T3 = 3:2:4:1, and
in the control, sea mud alone (100%) was utilized. Growth performances were evaluated by measuring total
body weight, total body length, growth rate, along with survival rate and food conversion ratio. Although all
seaweed-based feeds supported 100% survival with moderate growth, the feed containing a higher proportion
(40%) of Kappaphycus alvarizii (T3) produced significantly higher growth performance compared to the
other treatments (T1 and T2). This was observed in mean weight (14.72 ± 0.39g, p < 0.05), mean length
(5.48 ± 0.18cm, p < 0.05), and growth rate (0.39 ± 0.01g/day, p < 0.05). Interestingly, the control setup
showed the lowest growth performance. Statistically, there was a significant difference among treatments
(p < 0.05), and the K. alvarizii (40%) showed improved growth performance among indoor nursery systems.
Therefore, this study suggests that indoor culture using seaweed-based feeds such as Kappaphycus alvarizii
seems to be a stable and effective approach for post-release hatchery juveniles in sea cucumber culture.
