Pathogens and parasites of the black-striped pipefish (Syngnathus abaster) from the Tunis North Lake, Tunisia

Abstract

The black-striped pipefish, Syngnathus abaster member of the Syngnathidae family, is a small species occurring in either brackish or fresh waters associated with vegetated habitats, few data are known about the anomalies that encounter the species in coastal lagoons and estuaries. A survey of S. abaster from the Tunis north lagoon (Tunisia), where the species occurs and breeds among vegetation, was conducted during 2007-2011, a multitude of anomalies were observed in external bodies and guts of some specimens of S.abaster and were suspected to be related to parasitic infections. The parasitic analysis were made in 2011 and revealed the presence of a number of visible cysts in the epidermis, musculature and intestine. A focussed histological study of the fish revealed the presence of microsporidian infections in the epidermis, musculature and the intestine. In addition, a coccidian infection of the intestine and a systemic digenean infection were noted. Pathology associated with the myotrophic microsporidian consisted mainly of pressure atrophy and disruption of affected muscles, whilst the gut-dwelling microsporidian infection may have affect absorption rates. Other infections were considered relatively benign. The results are discussed in relation to the general ecology of the host. In conclusion, it is suggested in this study to assess the health status of S. abaster in the lagoon using more data about the impact of such infections on the fish behaviour and to study the transmission of the parasites in this area to commercial fish.