Early identification of mushy Halibut syndrome with hyperspectral image analysis

The ‘jellied’ or ‘mushy’ condition of fish in the North Atlantic and North Pacific fisheries: Characteristics, causes and consequences

“…2 ). In American plaice, Dover sole, sablefish and Greenland halibut, affected musculature is more white or opalescent compared to normal [ 10 , 11 , 18 , 19 , 21 ], while that of affected Pacific halibut has a more translucent appearance [ 14 ]. Apart from a small number of Kudoa clupeidae cysts found in Dover sole [ 20 ], no studies report visible cysts or pseudocysts.…”

“…Units depicted as in original studies. Author and year Fish species Sample size ‘Jellied’/normal Water content ‘Jellied’/normal Fat content ‘Jellied’/normal Protein content ‘Jellied’/normal Ash content ‘Jellied’/normal Ortega, Ofstad et al [ 11 ] Greenland halibut L 8/8 0.996/0.993 a 4.3 e−3 /6.9 e−3 a – – Ortega, Lindberg et al [ 10 ] Greenland halibut L 12/11 78.63%/74.99% 7.6%/10.88% 12.54%/14.10% 1.14%/1.03% Widera and Madler [ 13 ] Greenland halibut F 3/3 – – 34.9%/39.14% – Widera [ 12 ] Greenland halibut F 3/3 – 2.43%/11.62% – – Karinen et al [ 16 ] Sablefish N 115/64 726.1 mg/g/720.7 mg/g 148.1 mg/g/132.6 mg/g 118.2 mg/g/136.8 mg/g 10.3 mg/g/10.6 mg/g Templeman and Andrews [ 21 ] American plaice F 108/165 b 79.01–93.0%/...…”

“…Other dietary imbalances may be relevant to look into, such as essential fatty acid deficiency, which can cause symptoms similar to vitamin E and selenium deficiency [ 116 ]. Hyperspectral and chemical analysis point to a decreased fat and protein content of ‘mushy’ Greenland halibut [ 10 , 11 ]. Previous studies have found the level of both fatty acids and essential amino acids to be lower in ‘gelatinous’ Greenland halibut compared to unaffected fish, and the composition to differ considerably [ 12 , 13 ].…”

“…In peer-reviewed studies and grey literature, affected fish products exhibit myodegenerative changes without signs of parasitic infection. This includes reports of ‘gelatinous’ or ‘mushy’ Greenland halibut ( Reinhardtius hippoglossoides ) [ [10] , [11] , [12] , [13] ], ‘mushy halibut syndrome’ in Pacific halibut ( Hippoglossus stenolepis ) [ 14 , 15 ], ‘soft flesh’ in sablefish ( Anoplopoma fimbria ) [ [16] , [17] , [18] ] and the ‘jellied condition’ in American Plaice ( Hippoglossoides platessoides ) and Dover sole ( Microstomus pacificus ) [ [19] , [20] , [21] , [22] , [23] ]. Fish appear to be affected at capture, and may be recognized by experienced fishermen [ 16 , 21 ].…”

“…sp.) American plaice ( Hippoglossoides platessoides ) [ 21 , 22 ] No causative agent identified – possibly reproductive strategy, environmental factors or nutritional deficiency Arrowtooth flounder ( Atheresthes stomias ) [ 39 , 40 ] Parasitic (Kudoa thyrsites) Atlantic lumpfish ( Cyclopterus lumpus ) [ 41 ] Parasitic (Kudoa islandica) Atlantic mackerel ( Scomber scombrus ) [ [42] , [43] , [44] , [45] ] Parasitic (Kudoa thyrsites) Atlantic wolffish ( Anarhichas lupus ) [ 41 ] Parasitic (Kudoa islandica) Broad flounder ( Paralichthys squamilentus ) [ 46 ] No causative agent identified Dover sole ( Microstomus pacificus ) [ 19 , 20 , 23 , 47 ] No causative agent identified – possibly reproductive strategy or environmental factors Greenland halibut ( Reinhardtius hippoglossoides ) [ [10] , [11] , [12] , [13] ] No causative agent identified – possibly nutritional deficiency or myodegenerative disease Hoki ( Macruronus novaezelandaie ) [ 48 ] Nutritional deficiency Mahi mahi ( Coryphaena hippurus ) [ 36 ] Parasitic (Kudoa thyrsites) Olive flounder ( Paralichthys olivaceus) ...…”