Study on Carapace Width Growth Band Counts Relationship of Orange Mud Crab, Scylla olivacea (Herbst, 1796) from Terengganu Coastal Waters, Malaysia

• Published in: Pakistan journal of biological sciences Vol. 20; no. 3; pp. 140 - 146
• Main Authors: Hasyima Is, N., Amin Safwa, A., Fairuz Foz, N., Megat, F.H., Muhd Farou, H., Kamaruddin, S.A., Ikhwanuddi, M., Ambak, M.A.
• Format: Journal Article
• Language: English
• Published: Pakistan 2017
• Subjects: Animal Shells - growth & development; Animals; Brachyura - growth & development; Environmental Monitoring - methods; Linear Models; Malaysia; Molting; Time Factors; gastric mill; Scylla olivacea; conservation; crustaceans; carapace width; growth; growth band counts; Mud crab; age
• ISSN: 1028-8880
• DOI: 10.3923/pjbs.2017.140.146

Orange mud crab Scylla olivacea is one of the most important fisheries resources. A new development in ageing technique of crustaceans has been introduced. The detection of growth band deposited in hard structure of gastric mill in the cardiac stomach are found retained after moulting process can be used as age indicator and growth estimation. This study was carried out to determine the comparison between carapace width and growth band count of S. olivacea in Malaysia. Samples were collected from Setiu Wetlands, Terengganu, Malaysia from February until August, 2016. Samples were categorized based on their morphological measurements. The mesocardiac and zygocardiac ossicles in the gastric mill of S. olivacea was dissected out and preserved in solutions and underwent a cross sectioning process. A total of 76 of wild S. olivacea ranging from 6.56 to 12.84 cm in carapace width were analysed. The growth band counts were examined for each individual and ranging from 1 to 3 band counts. A positive linear relation was observed between CW and GBC with r2 = 0.5178, p<0.01. Overall, there was a strong, positive correlation between CW and GBC. Increase in CW were correlated with increases in GBC respectively for this species. Therefore, the carapace width, growth band counts and body weight can be used to improve data on growth, recruitment, maturation and mortality. Thus, this study would able to improve new ageing technique and contribute greatly to improve the conservation and management of S. olivacea in Setiu Wetlands, Terengganu, Malaysia.