Van As, L. L.Christison, K. W.Van As, J. G.Mogorosi, Lefetlho Katlego2019-07-022019-07-022019-01http://hdl.handle.net/11660/9962English: Inland aquaculture has started to receive increased interest in South Africa and indeed the Free State Province. This is a means to diversify agriculture production, the creation of jobs and contributing towards food security. Sharptooth catfish/baber Clarias gariepinus, common carp Cyprinus carpio and rainbow trout Oncorhyncus mykiss have been identified as commercially viable species in the Free State, although the latter species was not collected during the current study. Parasitological data was collected from the above mentioned host species as well as other species of interest from impoundments in the Free State. Under aquaculture conditions susceptible hosts are usually in close proximity, for intensive culture thereby facilitating the transmission and establishment of parasites and diseases. As such, parasites and diseases of fish are regarded as significant constraints to the development of inland aquaculture in the province. The present study was a disease and parasite survey of commercially important fishes of the Free State Province. Herein we qualitatively assess the risk to sustainable development of a fresh water aquaculture industry based on parasitic data collected from field surveys in the Free State Province carried out over a period of two years 2013 and 2014 and parasitic data collected from the Agricultural Technology Demonstration Centre in Gariep Dam during 2016. The taxa collected included; the alien parasitic crustaceans Lernaea cyprinacea and Argulus japonicus; monogeneans Quadriacanthus aegypticus, Dactylogyrus sp 1 and Dactylogyrus sp 2.; the alien cestode, Schyzocotyle acheilognathi; peritrich ciliophorans Trichodina centrostrigeata, Tripartiella lechridens as well as the alien species Trichodina nigra and Trichodinella epizootica. Although some of the above species have been shown to cause mass mortalities of fish hosts both in the wild and in aquaculture, during the current study mortalities as a direct result of parasite infestations/infections were not encountered. The study found that parasites and diseases can indeed be constraints to aquaculture development in the province, coupled with factors such as access to markets, profits and economic value of the species being farmed.Afrikaans: Binnelandse akwakultuur is besig om toenemende belangstelling in Suid-Afrika te toon veral in die Vrystaat Provinsie. Dit word gedoen om landbouproduksie te diversifiseer, werkskepping te bevorder en om tot voedselsekuriteit by te dra. Die skerptandbaber Clarias gariepinus, gewone karp Cyprinus carpio, en reënboogforel Oncorhyncus mykiss is as kommersiële lewensvatbare spesies in die Vrystaat geïdentifiseer, alhoewel laasgenoemde spesie nie tydens die studie versamel is nie. Parasitologiese data is van bogenoemde gasheerspesies versamel, asook van ander visspesies van belang, in damme in die Vrystaat. Onder intensiewe akwakultuurtoestande is vatbare gasheerspesies gewoonlik in kontak met mekaar, wat die oordrag en vestiging van parasiete en siektes vergemaklik. As gevolg van die kwesbaarheid van visse vir parasiete en siektes onder akwakultuur omstandighede, word dit as ‘n beduidende beperking in die ontwikkeling van binnelandse akwakultuur in die provinsie beskou. Die huidige studie was 'n siekte- en parasietopname van kommersieel belangrike visspesies in die Vrystaatse Provinsie. In die studie is die parasitiese data wat versamel was van visse in Vrystaat damme oor ‘n periode van twee jaar (2013-2014), asook data van die Landbou Tegnologie Demonstrasie Sentrum in Gariep Dam, gebruik om die risiko’s te identifiseer wat die akwakultuurontwikkeling kan benadeel. Die spesies wat versamel was sluit die volgende in: uitheemse parasitiese krustaseë Lernaea cyprinacea en Argulus japonicus; verteenwoordigers van die Monogenea Quadriacanthus aegypticus, Dactylogyrus sp 1 en Dactylogyrus sp 2.; die uitheemse lintwurm Schyzocotyle acheilognathi; peritrich siliate Trichodina centrostrigeata, Tripartiella lechridens asook die uitheemse Trichodina nigra en Trichodinella epizootica. Alhoewel sommige van bogenoemde spesies al grootskaalse vissterftes in natuurlike asook akwakultuur omstandighede veroorsaak het, was daar tydens die studie geen vissterftes opgemerk as gevolg van direkte parasietinfeksies nie. Die studie het bevind dat parasiete en siektes inderdaad beperkings kan inhou vir ontwikkeling van akwakultuur in die provinsie, asook faktore soos die beskikbaarheid van ’n mark, winsgrens en ekonomiese waarde van die spesies wat geteel word.enDissertation (M.Sc. (Zoology))--University of the Free State, 2019AquacultureParasitic crustaceansMonogeneansCestodesCiliophoransDissertationUniversity of the Free State