eCite Digital Repository

The use of image analysis techniques for the study of muscle melanisation in sand flathead (Platycephalus bassensis)


Ooi, CK and Lewis, T and Nowak, B and Lyle, J and Haddy, J, The use of image analysis techniques for the study of muscle melanisation in sand flathead (Platycephalus bassensis), Environmental Pollution, 292 Article 118360. ISSN 0269-7491 (2022) [Refereed Article]

Copyright Statement

2021 Elsevier Ltd

DOI: doi:10.1016/j.envpol.2021.118360


Muscle melanisation in sand flathead is visible as black spots in the normally white flesh of fish. It is widespread in Tasmania, including at the Tamar Estuary, with increasing frequency of reporting by recreational fishers. The phenomenon is more prevalent in areas impacted by heavy metal pollution and has been linked to heavy metal accumulation. In this study, image processing software ImageJ was employed to study the phenomenon and to establish an objective rating system. A longitudinal profile plot was used to study the greying of the fillet. The degree of melanisation was rated based on the percentage surface area melanised on the surface and in transverse sections of fillets. A muscle melanisation scoring system for sand flathead was established based on visual interpretation using the macroscopic melanisation scoring criteria: melanisation scores 0 = <0.5%, 1 = 0.55%, 2 = 520%, and 3 = >20% (% = melanised surface area in proportion to the whole fillet). A refined image analysis technique was developed to quantify the percentage of melanised muscle surface area and the muscle melanisation scoring system was statistically validated. Sand flathead fillet with higher melanisation score was shown to be linked to increased intensity of greyness and greater numbers and size of black spots on the surface of fillets and within the flesh. The greying and black spots were primarily concentrated at the anterior region of fillet and around the dorsal vertebrae zone on transverse section of fillets. Overall, findings from this study established the use of image analysis techniques to validate visual inspection and to give a standardised and objective method to determine the degree of melanisation in sand flathead. As muscle melanisation appears to be linked to heavy metal pollution, the standardised scoring system would facilitate future research for environmental pollution and monitoring purposes.

Item Details

Item Type:Refereed Article
Keywords:melanisation, black spot, fish muscle, sand flathead, melanisation scoring system, image analysis
Research Division:Agricultural, Veterinary and Food Sciences
Research Group:Fisheries sciences
Research Field:Fisheries sciences not elsewhere classified
Objective Division:Animal Production and Animal Primary Products
Objective Group:Fisheries - wild caught
Objective Field:Fisheries - wild caught not elsewhere classified
UTAS Author:Ooi, CK (Mr CK Ooi)
UTAS Author:Lewis, T (Associate Professor Trevor Lewis)
UTAS Author:Nowak, B (Professor Barbara Nowak)
UTAS Author:Lyle, J (Associate Professor Jeremy Lyle)
UTAS Author:Haddy, J (Dr James Haddy)
ID Code:153173
Year Published:2022
Deposited By:Chemistry
Deposited On:2022-09-11
Last Modified:2022-10-12

Repository Staff Only: item control page