The pathology of chronic erosive dermatopathy in Murray cod, Maccullochella peelii peelii (Mitchell)

Abstract

Chronic erosive dermatopathy (CED) is a disease of intensively farmed Murray cod in Australia that has been reported in association with the use of groundwater (mechanically extracted from shallow boreholes) supplies. CED results in focal ulceration of the skin overlying sensory canals of the head and flanks. Trials were conducted at an affected fish farm to study the development of the condition, both in Murray cod and in goldfish, and also to assess the reported recovery of lesions when affected fish were transferred to river water. Grossly, lesions began after 2-3 weeks with degeneration of tissue at the periphery of pores communicating with the sensory canals. Widening of these pores along the axis of the canals resulted from a loss of tissue covering the canal. Histopathologically, hyperplasia of the canal epithelial lining was seen after 3 weeks in borehole water and subsequent necrosis and sloughing of this tissue resulted in the loss of the canal roof. Canal regeneration occurred when fish were transferred from borehole water into river water. The lack of lesions in other organs and the pattern of lesion development support exposure to waterborne factors as the most likely aetiology.

Lateral line depigmentation (LLD) in channel catfish, Ictalurus punctatus (Rafinesque)

“…However, there was no evidence presented that the virus caused LLD. In addition, neither we, Blasiola (1989), nor Baily et al. (2005) found any evidence that an infectious agent was responsible for the LLD lesion.…”

“…The gross lesion we observed in channel catfish is identical to that observed in a ‘disease’ that has been most often referred to as ‘head and lateral line erosion’ or HLLE. HLLE most commonly affects certain tropical freshwater and marine aquarium fish of the families Anabantidae, Belontidae, Cichlidae, Acanthuridae and Pomacentridae (Gratzek 1988), but a grossly identical lesion has also been observed in some food fish (Möller & Anders 1986; Baily et al. 2005).…”

Cytochemical characterisation of the leucocytes and thrombocytes from Murray cod (Maccullochella peelii peelii, Mitchell)

“…Cytochemistry is also effective in analysing a range of disease states that affect immune cell function [19]. Therefore, the cytochemical approaches utilised here may also have useful applications to studying the diseases affecting this species, such as chronic erosive dermatopathy [32]. …”

Pathological obstacles of newly-introduced fish species in Mediterranean mariculture: a review

“…Other pathology A pathological condition resembling chronic erosive dermatopathy recently described in Murray cod (Maccullochella peelii peelii) (Baily et al 2005) was often observed in juvenile sharpsnout sea breams, groupers and meagre reared in borehole water (Katharios, lab observations). The disease which has not yet been described in the literature affects 100% of the population and is not associated with mortalities.…”