First report of the myxozoan parasite Myxobolus episquamalis infecting grey mullet (Mugil cephalus) from New Zealand

Abstract

Primary Industries, New Zealand, received a report of a grey mullet (Mugil cephalus) presenting reddish-white granular lesions across its body. Gross pathological examination revealed cyst-like lesions on the distal portion of the scales and proximal part of the fins. Giemsa-stained wet preparations of these lesions presumptively identified spores as Myxobolus sp. DNA sequencing of the 18S rRNA gene further identified these spores as Myxobolus episquamalis. This is the first report of Myxobolus episquamalis infecting M. cephalus from New Zealand.

Aquatic disease in New Zealand: synthesis and future directions

“…There is information on the parasites of eels because they were identified as an aquaculture species in the mid-1970s (Hine 1978); see also for snapper (Sharples and Evans 1995a, 1995b, 1995c, 1995d) and kingfish (Sharp et al 2003). Parasites can increase mortality rates (Cranfield et al 2005), reduce flesh quality and marketability (Diggles 2003;Lane et al 2015), reduce fecundity (Howell 1967), incur extra costs through treatments (Sharp et al 2004), and in the case of OIE-notifiable diseases, affect international trade (http://www.stuff.co.nz/business/industries/10542544/Canada-bans-NZ-live-mussel-exports-after-parasite-find). Marine mammals are not commercial in the sense of wild capture fisheries or aquaculture production, instead they support ecotourism and people value their existence.…”

“…A core function of Biosecurity New Zealand is to investigate and diagnose aquatic diseases. Consequently, detections are often reported (Lane et al 2015;Brosnahan et al 2017b), but host-parasite interactions are rarely investigated because government agencies are limited in their research scope. Benefits in operational research between government and research providers have been exemplified in terrestrial disease events such as the New Zealand Veterinary Journal (2016) Special Issue vol.…”

“…Baseline health surveys supplemented by passive observations of diseased animals, such as Microsporidia Myospora metanephrops detected in New Zealand scampi Metanephrops challengeri (Stentiford et al 2010) and Thelohania sp. in kōura Paranephrops planifrons (Jones 1980), fungal lesions in pāua Haliotis iris (Grindley et al 1998), the Myxozoa parasite Myxobolus equisquamalis in grey mullet Mugil cephalus (Lane et al 2015) and others (Diggles 2003), allow for the assessment of changes in disease prevalence and intensity more easily and quickly.…”