Proceedings A Study of Parastes of Three Imported Ornamental Fishes Conducted in Limpopo Province, South Africa † Linda Prince Lukhele The Department of Biodiversity, School of Molecular and Life Sciences, Faculty of Science and Agriculture, University of Limpopo, South Africa; [email protected] † Presented at the 1st International Electronic Conference on Biological Diversity, Ecology and Evolution, 15- 31 March 2021; Available online: https://bdee2021.sciforum.net/. Abstract: Invasive alien species pose a significant threat to biodiversity in the area where they have been introduced. In South Africa, most of ornamental fishes sold are imported from other countries. The parasites of alien species can be transported along with their hosts and become co-invasive. An invasive parasite from Asia, Camallanus cotti was reported in Africa for the first time in the year 2017 from the guppy, an ornamental fish which established a feral population. This is proof that orna- mental fish may introduce alien parasites. Three ornamental fish species were imported (Red rain- bowfish, pearl gourami and clown loach) from Indonesia. Standard methods were used for the dis- section of fish, examination, fixation and preservation of parasites. The prevalence and mean inten- sity of different parasites of each fish species were determined and they were identified to genus and species level where possible. Nematodes (Camallanus cotti and Procamallanus sp), cestodes (Ne- ogryporhynchus cheilancristrotus and Dendrouterina herodiae), a copepod (Lernaea cyprinacea) and mon- ogeneans were found from the imported fishes. Two new species of monogeneans (here named Ancyrocephalidae sp. 1 and Ancyrocephalidae sp. 2) not belonging to any established genus were discovered. Cestodes were only found from pearl gourami and the copepod from red rainbowfish. The clown loach had no parasites. Red rainbowfish had the highest prevalence and mean intensity for mongeneans and nematodes. Keywords: Ornamental fishes; alien species; parasite; new species; South Africa Citation: Lukhele, L.P. A Study of Parastes of Three Imported Ornamental Fishes Conducted in Limpopo Province, South Africa. Proceedings 2021, 68, x. 1. Introduction https://doi.org/10.3390/xxxxx 1.1. Background Information Invasive alien species pose a significant threat to biodiversity in the area where they Published: date have been introduced (Goyal 2005). There’s international trading of above a billion orna- mental fish consisting of more than 4000 freshwater and 1400 marine species each year Publisher’s Note: MDPI stays neu- (Whittington and Chong 2007). In a review by Ellender and Weyl (2014) on non-native tral with regard to jurisdictional claims in published maps and institu- freshwater fish introductions in South Africa, a list was established whereby there was a tional affiliations. total of 55 fishes that have been introduced into new environments in South Africa, with 27 of those being alien. Ellender and Weyl (2014) also emphasised that the co-introduction of parasites is a serious threat to native fish communities in South Africa. Introduction of these parasites (through trading of ornamental fish) may lead to a decrease in native fish Copyright: © 2021 by the authors. diversity in South Africa, possibly through eventual extinction of native fish species. Submitted for possible open access Translocation of freshwater fish into non-native regions affects the native life found publication under the terms and there (Smith et al. 2017) and the trading of ornamental fish species is considered to be an conditions of the Creative Commons important pathway through which alien parasites can be introduced to native fish species Attribution (CC BY) license (Gozlan et al. 2010). According to Bruton and Van As (1986), “The major vectors for intro- (http://creativecommons.org/licenses ductions of non-native fishes in South Africa were primarily associated with recreational /by/4.0/). Proceedings 2021, 68, x. https://doi.org/10.3390/xxxxx www.mdpi.com/journal/proceedings Proceedings 2021, 68, x FOR PEER REVIEW 2 of 18 angling, aquaculture, conservation translocations, ornamental fish trade, inter-basin wa- ter transfer schemes (IBTs) and bio-control”. There are other factors that lead to the intro- duction of non-native fish species (and with them their parasites) in South Africa, with ornamental fish trading being one of the main factors. 1.2. Purpose of Study 1.2.1. Problem Statement Invasive alien species are recognised as one of the main factors threating native spe- cies worldwide (Kathiresan et al. 2005). In South Africa, most of ornamental fishes sold are imported from other countries (Mount et al. 2001). This means that South Africa re- ceive alien species from different countries, which may be a threat to South Africa’s native fish species when released into nature. The parasites of alien species can be transported along with their hosts and become co-invasive (Lymbery et al. 2014). An invasive parasite from Asia, Camallanus cotti Fujita 1927 was reported in Africa for the first time in the year 2017 from an ornamental fish, Poecillia reticulata Peters, 1859 collected from Komati River and from several pet shops in South Africa (Tavakol et al. 2017). It is thus evident that ornamental fish may introduce alien parasites. The potential impacts of parasites switch- ing from the host they were introduced with to a new native host have been well docu- mented (Adlard et al. 2015). In South Africa there are a limited number of studies done on ornamental fish parasites (Mount et al. 2001, Tavakol et al. 2017), therefore the assumption that importing ornamental fishes from different countries brings along with their parasites needs more studies to be substantiated. 1.2.2. Aim The aim of the project was to study the parasite diversity of three ornamental fish species bought from importers to South Africa. 1.2.3. Objectives The objectives of the study were to: i. determine the prevalence and mean intensity of different parasites of each fish spe- cies examined ii. identify the parasites to genus level and where possible to species level 2. Material and Methods 2.1. Sampling of Fish The fishes were obtained using a well-established importing company, WCB Imports, Midrand. Fish species were selected from the supplier’s list and the following species from the Aquazone in Indonesia were received: Red rainbowfish, Glossolepis incisus Weber, 1907; pearl gourami, Trichopodus leerii (Bleeker, 1852) and clown loach, Chromobotia macracanthus (Bleeker, 1852). Due to the fact that we needed to examine the fish before they receive any treatment for parasites or diseases, the fishes were collected directly at the OR Tambo International Airport, Johannesburg upon the cargo aircraft landing. A number of 21 red rainbowfish, 15 pearl gourami and 15 clown loaches were received in the middle of Octo- ber 2020. Fish Hosts. Glossolepsis incisus is known as red rainbowfish and belonging to Melanotaeniidae family. It is endemic to Indonesia’s lake, Sentani in Irian Jaya (Siby et al. 2017). It is the “Type species” for the genus Glossolepsis with currently nine species (Eschmeyer et al. 2012). It is characterised by bright colours and small body size (Alien 1980). It takes be- tween 5 and 7 days for their eggs to hatch (Kadarini et al. 2013). It can survive a pH range Proceedings 2021, 68, x FOR PEER REVIEW 3 of 18 of 7.6–8.2 and temperatures between 29 and 30 degree Celsius (Allen 1991). They can grow to a maximum length of 12 cm (Allen 1991). Figure 1. Glossolepsis incisus. Chromobotia macranthus, known as clown loach, belongs to the family Botiidae, and is the only member of the genus Chromobotia. The clown loach is endemic to Indonesia in the rivers of the islands Borneo and Sumatra (Kottelat et al. 1995) and it is considered as a major species on international market of ornamental freshwater fish (Legendre et al. 2012). It is characterised by attractive colour patterns, with three wide bars running across their orange-reddish body. They can grow to a maximum length of 30.5 cm and commence their breeding at the beginning of rainy seasons in fast flowing streams (Kottelat 2004; Legendre et al. 2012). Figure 2. Chromobotia macracanthus. Trichopodus leeri, commonly known as pearl gourami, belongs to the family Osphronemidae and it is native to Southeast Asia (Roberts 1989). Pearl gouramis are air breathing and directly undergo gas exchange with the atmosphere (Graham 2005). Its ac- cessory air breathing organs include the skin, gas bladder and the digestive tract (Huang et al. 2008). They can grow to a maximum length of 12 cm and can survive temperatures between 24 and 28 degrees Celsius and a pH between 6 and 8 (Roberts 1989). Proceedings 2021, 68, x FOR PEER REVIEW 4 of 18 Figure 3. Trichopodus leeri. 2.2. Fish Handling Prior to the arrival of the fishes, tanks were prepared and the water was let to stand to let chlorine evaporate, and all the tanks were set to a temperature of 24 degree Celsius. Upon their arrival, the fishes were acclimatised to the water in the glass tanks, following the protocol provided by the importing company. A pH and a temperature reading were taken for each of the water bags as well as for each tank. Then water was added to each bag with water from the glass tank that had the closest pH and temperature readings. The bag was opened and about 30% of water was removed from the bag and replaced with water from the selected glass tank. The bags were re-oxygenated using air pumps, re- sealed, and then allowed to float in its chosen glass tanks for 20 min. This procedure was repeated twice. After floating of the bags, the fishes were gently released into the glass tanks. Fish were kept in the tank for less than 24 h before dissections commenced.