Aquaculture Research. 2020;00:1–18. wileyonlinelibrary.com/journal/are | 1 © 2020 John Wiley & Sons Ltd
Received: 11 December 2019
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Revised: 18 February 2020
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Accepted: 28 February 2020
DOI: 10.1111/are.14598
ORIGINAL ARTICLE
Evaluation of limb autotomy as a promising strategy to improve
production performances of mud crab (Scylla olivacea) in the
soft-shell farming system
Mohammad Redwanur Rahman
1
| Md. Asaduzzaman
1
| Md. Mahiuddin Zahangir
1
|
SM Rashadul Islam
1
| Sk Ahmad-Al Nahid
1
| Durin Akter Jahan
2
| Yahia Mahmud
2
|
Mohammed Nurul Absar Khan
1
1
Faculty of Fisheries, Chattogram Veterinary
and Animal Sciences University, Chattogram,
Bangladesh
2
Bangladesh Fisheries Research Institute,
Mymensingh, Bangladesh
Correspondence
Md. Asaduzzaman, Faculty of Fisheries,
Chattogram Veterinary and Animal Sciences
University, Chattogram-4225, Bangladesh.
Email: a_zamanbau@yahoo.com
Funding information
Bangladesh Fisheries Research Institute,
Grant/Award Number: 54324-36
Abstract
Soft-shell crab, a newly moulted crab having non-calcified and hydrated soft exo-
skeleton, farming has been increasing tremendously in recent years throughout the
world due to its high market price and consumer preferences. However, high aggres-
siveness and cannibalistic behaviour of mud crab limit its culture to an individual
chamber system which ultimately makes the soft-shell mud crab farming space and
labour-intensive. Therefore, the aim of this study was to improve the efficiency of
soft-shell crab production by autotomy of the claw and/or walking legs to reduce
the moulting duration and intensify the culture system through double stocking in
the existing individual chamber culture system. To achieve our objectives, a series of
experiment were conducted at both indoor and on-farm levels by removing the claw
and/or walking legs of Scylla olivacea for two consecutive moulting cycles. Results
showed that both claw ablation significantly ( p < .01) shortened the moulting dura-
tion and increased the carapace width, weight gain, specific growth rate, feeding ef-
ficiency and yield parameter compared to the non-ablated crabs more prominently at
1st moulting than the 2nd moulting in both indoor and on-farm trials. Ablation of all
walking legs while keeping the claw intact did not significantly influence ( p > .05) the
moulting duration and carapace width, but significantly ( p < .01) improved the spe-
cific growth rate, weight gain, feeding efficiency and yield parameters at 1st moult-
ing compared to the non-ablation and unilateral three walking leg ablation groups.
However, ablation of all appendages (both claw and walking legs) showed significant
( p < .01) improvements of carapace width, weight gain, specific growth rate, feeding
efficiency and yield parameters, and shortened the moulting duration up to 23 days
from 34 days during 1st moulting and up to 27 days from 40 days at 2nd moulting.
The survivals of different autotomized mud crabs were statistically non-significant
( p > .05) to the non-autotomized crabs in various indoor and on-farm trials. Besides
improving the production performances, ablation of bilateral claw and all append-
ages allowed to double the stocking density in the existing individual chamber-based
soft-shell crab farming that enhanced the production about threefold higher than