UNAIR NEWS – One of fisheries commodities with economic and potential value at present is blue swimming crab. In the past 10 years, this commodity ranks fourth in the total export of fishery products in Indonesia after tuna, shrimp and seaweed, with a value of up to USD 200 million.
The processed blue swimming crab is widely exported to the American, Australian, Japanese and European Union markets. Furthermore, processed crab meat also has a by-product in the form of shells or carapace with high selling value.
Explained by Dr. Kismiyati., Ir., M.Si., one of the lecturers of Faculty of Fisheries and Marine UNAIR, blue swimming crab ( Portunus pelagicus ) is a type of crab that lives in the sea. This species is usually found in shallow coastal areas, especially in western Pacific Ocean waters.
“Blue swimming crab is a type of crab that is loved by consumers because of its meat delicacy, even in coastal areas there are special dishes made from these crabs. This is not only happening in Indonesia, but also in our neighboring country Malaysia, ” she added.
Despite being considered a potential product, the crab has a problem that needs to be anticipated, the presence of parasites. It inspired Dr. Kismiyati., Ir., M.Si., with the team to study the blue swimming crab’s distribution and types of parasites.
“The parasites that often attack the crab are from the ectoparasites or parasites that attack the external organs of the crab, that of the Octolasmis sp. to be precise,” said Kismiyati.
She added, Octolasmis sp. is included in the crustaceae group that has been identified to have a body size of about 0.01-0.15 cm. Also, these parasites can be seen without instrument, most of them are found on each sheet of gills or sometimes attached to the inner shell.
Research conducted in the coastal area of Kuala Terengganu, Malaysia, used 13 blue swimming crab samples and found 4 types (species) Octolasmis sp. ; Octolasmis angulata , Octolasmis warwickii , Octolasmis lowei and Octolasmis tridens . The distribution of ectoparasites was more common in crab gills (57.70%) than in other parts (42.30%). It happens because of the presence of water currents on the surface of the body of the crab, so that ectoparasites prefer to stick to the gills which are protected from water currents.
“The economic effects caused by ectoparasitic infections in fishing and crab farming activities can be in the form of population reduction, weight reduction and consumer rejection due to morphological changes. While the physiological loss is disrupted growth and decreased quality of meat in the crab, ” she concluded. (*)
Author: Bastian Ragas
Editor: Nuri Hermawan
Source : Marina, H., Fazrul, H., Kismiyati., Sri, S., & Ihwan, M. Z. (2019). Occurrence of Pedunculate Barnacle, Octolasmis spp. in Blue Swimming Crab, Portunus pelagicus. Jurnal Ilmiah Perikanan dan Kelautan, 11(1):1–8. http://doi.org/10.20473/jipk.v11i1.10635.