Zobaer Masum, Mohammad Abu Naeem, Syduzzaman, Md. Rakeb‑Ul Islam,
Md Asaduzzaman, Mohammed Shariful Azam, Benoy Kumar Barman, and
Abdullah‑Al Mamun
Abstract
Mud crab (Scylla olivacea) aquaculture has traditionally depended on capturing and fattening
wild juveniles, which has contributed to declining populations in Bangladesh.
To address this issue, broodstocks were collected from offshore and estuary regions and
transported to a private hatchery to establish a mass seed production system. Seasonal
maturation rates were highest in summer (52.08%), followed by late autumn (42.30%),
pre-autumn (30.12%), and monsoon (26.11%). Offshore broodstock had a higher spawning
rate than estuarine broodstock (71.42% vs. 30.95%), with those weighing over 300 g
exhibiting the highest spawning rate (51.51 ± 17.40%). Seasonality influenced the mean
number of zoea-1 larvae production from brood crab in the following decreasing order:
summer (0.77 ± 0.40) > Pre-autumn (0.72 ± 0.15) > late-autumn (0.71 ± 0.25) > monsoon
(0.16 ± 0.06). Zoea (Z) rearing was conducted in two MT tanks using artemia nauplii and
shrimp larval feed. The highest mortality occurred during the transitions from zoea-5 to
megalopa (77.55%) and from megalopa to crablet (84.02%), followed by the mid-stages
(Z3–Z4, Z4–Z5) and the early zoeal stages (Z1–Z2, Z2–Z3). Larvae took 24–31 days to
reach the first stage. Of the 42 trials, only 8 successfully completed the entire cycle. The
most successful batch (SB4) had a survival rate of 3.17%, which could potentially increase
to 11.0% with decreasing stocking density (15 megalopa/L to 3.75 megalopa/L). SWOT
analysis suggests improving feed quality, addressing hatchery constraints, and maintaining
ideal environmental conditions are among the main challenges. A well-structured hatchery
with standardized procedures can enhance large-scale S. olivacea seed production, supporting
sustainable aquaculture and Bangladesh’s blue economy.
Keywords Mud crab · Scylla olivacea · Hatchery · Larvae rearing · SWOT analysis · Blue
economy