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PhD (Science with environmental Sciences), North-West University, Potchefstroom Campus Parasites contribute substantially to global biodiversity. Similarly, parasites of aquatic species have a vast unexplored diversity, and in recent years received increasing attention, contributing to the global aim of scientists to catalogue the entirety of the world’s biodiversity. Simultaneously, it became apparent that the diversity of parasites, as well as their assemblages within ecosystems, represent a complex interconnectivity of various components of an ecosystem and is not solely a reflection of the diversity or presence and absence of species. These macro- and microscopic organisms contribute to the dynamics of interactions between humans, the environment, and the hosts within said environments. Thus, leading to the present study that investigated diversity of the pan-African distributed sharptooth catfish, Clarias gariepinus (Burchell) in several geographic regions within southern Africa that is greatly underrepresented in parasitological data. This study provides an overview on the validity and biogeography of the more than 107 metazoan parasite species currently known from C. gariepinus, and the number of listed digenean species known from this host is amended from 34 to 36. Furthermore, 44 parasitic species across the major taxonomic groups (Monogenea, Digenea, Cestoda, Nematoda and Crustacea) representing 12 orders and 19 families were recorded from various localities in southern Africa during this study. Of these, eight species are novel to the parasite fauna of C. gariepinus, 33 taxa are already known, and three species utilised the sharptooth catfish as paratenic host. Community assemblages were distinct across all sampled populations, and diversity and abundance [species richness (S)] varied greatly, with highest diversity recorded in the Upper Zambezi River system: Barotse floodplain (S = 31) and Kabompo River (S = 15) in Zambia, while catfish from the Lower Phongolo River and floodplain (S = 17) harboured the most diverse parasitic community in South Africa compared to the lower diversity found from populations in the Boskop Dam (BS) (S = 14), Vaal River (VR) (S = 13), Sand River (SR) (S = 10), Riet River (RR) (S = 9) and Gariep Dam (GD) (S = 8) on the Orange-Vaal River system. The parasite diversity and abundances from two translocated populations, one in the Great Fish River (GFR) (S = 9) and Riviersonderend River (RSE) (S = 7) were similar, however community assemblages were distinct. The GFR populations shared a similar community assemblage compared to its source population from GD, while RSE had a distinct community assemblage. The resilience of 12 parasitic species is confirmed, in their persistence upon co-introduction into novel environments, and provided support for the enemy release hypothesis on loss of native parasites upon entering a new environment. Two alien invasive species, Argulus japonicus Thiele, 1900 and Schyzocotyle acheilognathi (Yamaguti, 1934) were also found to parasitise C. gariepinus. The former in GD, while S. acheilognathi most probably spilled back to the translocated C. gariepinus in RSE from another alien invasive, Cyprinus carpio, already present in the system. Furthermore, a novel parasitic copepod species, Ergasilus sp. A was found on the gills of both translocated populations and suggests a spillback event from an unknown native host to the introduced C. gariepinus in GFR and RSE. The complexity and tolerance of parasitic taxa were illustrated in the absence of complex life cycle species from some native distribution populations, but presence in translocated populations, indicating that the ecosystems where they occur support similar host (intermediate or definitive) assemblages or that the parasites can adapt to a new host-parasite system in a novel environment. Finally, the responses of parasitic taxa to functional host traits and their environment (unimpacted or impacted), as well as inverse responses to increased elements, or in the case of positive responses to Au, Fe, Co, Hg, Sn and Se by respective taxa, indicate that the effect of pollutants on different organisms in aquatic environments is more complex than linking a generalised concept of pollution to species (intermediate and definitive hosts) absence or presence, or increased morbidity. Doctoral

Macrogyrodactylus clarii Gussev, 1961 Figs. 2A–C, 3A,D (i); Table 4 T y p e h o s t: Clarias sp. (Siluriformes: Clariidae). T y p e l o c a l i t y: Lake Awasa, Ethiopia. O t h e r r e c o r d s: Clarias gariepinus: Egypt – El-Naggar and Serag (1987), El-Naggar (1993), Hagras et al. (1995, 1999), El-Naggar et al. (1997, 2001a,b, 2004a,b, 2016, 2017, 2019, 2020), El-Naggar and Cable (2007), Arafa et al. (2009, 2012), Radwan et al. (2009), El-Seify et al. (2011), Mashalay et al. (2019); Ethiopia – Gussev (1961), Beletew et al. (2016); Ghana – Paperna (1969, 1979); Kenya – Barson et al. (2010); Nigeria – Obiekezie and Ajah (1994), Eyo et al. (2015); South Africa – Khalil and Mashego (1998), Olivier et al. (2009), Madanire-Moyo et al. (2010, 2012), Matla (2012), Mahlatji (2014); Uganda – Paperna (1979); Zimbabwe – Barson et al. (2008, 2010), Madanire-Moyo and Barson (2010). Clarias anguillaris (Linnaeus); Nigeria – Shotter (1980). L o c a l i t i e s (p r e s e n t s t u d y): SouthAfrica: KuShokwe Pan, Ndumo Game Reserve, KwaZulu-Natal Province; Zambia: Barotse floodplain, Zambezi River, Northwestern Province. S i t e o f i n f e c t i o n: Skin and gills. Vo u c h e r m a t e r i a l: Twenty-three voucher specimens deposited in NMB (Coll. Nos. P 800–809, 820–822). R e p r e s e n t a t i v e D N A s e q u e n c e s: 710–753 bp long sequences of the ITS1-5.8S-ITS2 region of the rRNA gene of four isolates (GenBank accession numbers: MZ869846, MZ869850, MZ869847, MZ869849). Hologenophores: NMB (P 824–827). S p e c i m e n s s t u d i e d: n = 48 (KuShokwe Pan, South Africa - SA); n = 25 (Barotse floodplain, Zambia - ZM). I n f e c t i o n r a t e: KuShokwe Pan (SA): Prevalence (P) of 80% and intensity of infection (IF) 1–12; Barotse floodplain (ZM) P = 64%, IF = 1–4. Morphological observations (measurements provided in Table 4): Morphology of haptoral sclerites conform to description of Gussev (1961) and redescription of El-Naggar and Serag (1987). Individuals armed with 16 marginal hooks, two positioned in anterolateral lobes, 14 in posterior edge of haptor. Basal part of sickle has small indentation near anterior end of base, anterior end of sickle base thin, sharply rounded. Base of sickle rounded with slight curvature on distal side into slender sickle blade curving inward and tapering into a fine, sharp point that stops in line with anterior end of sickle base (see Figs. 2B, 3D (i)). Hamulus complex consisting of a pair of robust hamuli with curvature into point, sharp inward curved root, small dorsal bar consisting of two articulating sclerites, Y-shaped ventral bar with short anterolateral processes and long posterior central arm. Two narrow rod-like sclerites (R1 and R2) accompany ventral bar (Figs. 2A–C, 3A). Cirrus observed in 24 (SA) and 11 (ZM) specimens studied, each armed with 13–15 small spines and one large spine (Fig. 2C). Abbreviations: KY – Kenya; SN – Senegal; SA – South Africa; ZM – Zambia; n – number of specimens studied. Remarks. The dimensions of the hamulus (total length and length of the shaft, root and point) from specimens studied from NGR (SA) and Barotse floodplain (ZM) (Table 4) are similar to those of specimens from the Middle Letaba Dam (SA) and localities in Kenya and Egypt (El-Naggar and Serag 1987, Khalil and Mashego 1998, Barson et al. 2010). Dimensions obtained for the dorsal bar in the present study do not deviate from the ranges found in other studies. Marginal hook size also conforms to previously recorded measurements. The marginal hook sickle morphology is identical to that illustrated for M. clarii specimens collected from Zimbabwe and M. clarii × Macrogyrodactylus heterobranchii from Kenya (see Barson et al. 2010). Gussev (1961) and El-Naggar and Serag (1987) reported 16 and 12 cirrus spines, with one large spine in their descriptions, respectively. Additionally, this study provides details on the morphology of the sickle, which was not described by Gussev (1961) and El-Naggar and Serag (1987). Comparative measurements are presented in Table 4.

Truter, Marliese, Acosta, Aline A., Weyl, Olaf L. F., Smit, and Nico J. (2021): Novel distribution records and molecular data for species of Macrogyrodactylus Malmberg, 1957 (Monogenea: Gyrodactylidae) from Clarias gariepinus (Burchell) (Siluriformes: Clariidae) in southern Africa. Folia Parasitologica (027) 68: 1-14, DOI: 10.14411/fp.2021.027, URL: http://dx.doi.org/10.14411/fp.2021.027

Macrogyrodactylus congolensis (Prudhoe, 1957) Yamaguti, 1963 Figs. 2D–F, 3B,D (ii); Table 5 S y n o n y m: Neogyrodactylus congolensis Prudhoe, 1957 T y p e h o s t: Clarias gariepinus (Burchell) (Siluriformes: Clariidae). T y p e l o c a l i t y: Lake Upemba (Lualaba River), Democratic Republic of the Congo. O t h e r r e c o r d s: Clarias gariepinus: Egypt – El-Naggar et al. (1999, 2001a,b, 2004b, 2007, 2017, 2019), Hagras et al. (1999), Arafa (2000, 2011), Arafa et al. (2003, 2013, 2014), Mashalay et al. (2019); Democratic Republic of the Congo – Prudhoe (1957), Vanhove et al. (2018); Kenya – Barson et al. (2010); South Africa – Khalil and Mashego (1998), Madanire-Moyo et al. (2010, 2012); Uganda – Thurston (1970), Akoll et al. (2012). Clarias anguillaris: Senegal – Přikrylová and Gelnar (2008), Barson et al. (2010). L o c a l i t i e s (p r e s e n t s t u d y): South Africa: Vaal River, North West Province and Usuthu River, Ndumo Game Reserve (NGR), KwaZulu-Natal Province; Zambia: Barotse floodplain, Zambezi River, Northwestern Province, Kabompo River, Northern Province. S i t e o f i n f e s t a t i o n: Skin and gills. Vo u c h e r m a t e r i a l: Nineteen voucher specimens deposited in, NMB P 812–817, 823. R e p r e s e n t a t i v e D N A s e q u e n c e: 696 bp long sequence of the ITS1-5.8S-ITS2 region of the rRNA gene of one isolate. GenBank accession number: MZ869848. Hologenophore, NMB P 828. S p e c i m e n s s t u d i e d: n = 25 (Vaal River, SA), n = 2 (Usuthu River, SA), n = 1 (Barotse floodplain, ZM), n = 1 (Kabompo River, ZM). I n f e c t i o n r a t e: Usuthu River (SA): P = 3%, IF = 1; Vaal River (SA): P = 33%, IF = 1–109; Barotse floodplain (ZM): P = 6%, IF = 1; Kabompo River (ZM): P = 50%, IF = 1. Abbreviations: SA – South Africa; ZI – Zimbabwe; ZM – Zambia; n – number of specimens studied. Morphological observations (measurements provided in Table 5): Morphology of haptoral sclerites similar to illustrations provided in description of Prudhoe (1957). Hamulus complex of M. congolensis large in size, has slender hamuli less sharply curved into point and root, armed with 16 marginal hooks. Marginal hook sickle robust, with noticeable curvature in base near anterior end of sickle. Anterior end of sickle base rounded and convex, with indentation on distal side as it joins sickle blade that is short, curved inward tapering into a fine point and stops before the proximal end of sickle base (Figs. 2E, 3D (ii)). Hamuli complex has small uniform dorsal bar, wider than long, Y-shaped ventral bar with long anterolateral processes, and short posterior central arm. Two narrow rod-like sclerites accompany ventral bar (Figs. 2D–F, 3B). Cirrus observed in one specimen from the Usuthu River (SA) and Barotse floodplain (ZM), respectively, and 17 individuals from the Vaal River (SA), each armed with 18–20 small spines and one large spine (Fig. 2F). Remarks. The dimensions of the hamulus (total length and the length of the shaft, root and point) from specimens studied from the Vaal and Usuthu rivers (SA) and the Kabompo River and Barotse floodplain (ZM) are similar in size to specimens from the Middle Letaba Dam and Lake Turkana in Kenya (Khalil and Mashego 1998, Barson et al. 2010). Macrogyrodactylus congolensis specimens from Senegal seems to have smaller hamuli compared to the present and other studies (see Přikrylová and Gelnar 2008). Dimensions obtained for the undivided dorsal bar in the present study do not deviate from the ranges found in other studies. Marginal hook measurements are also in accordance with previously recorded measurements (see Table 5). The morphology of the marginal hook sickle conforms to those illustrated for M. congolensis from Kenya (see Barson et al. 2010). Prudhoe (1957) reported fewer cirrus spines (15), with one large spine in his description of M. congolensis. Details on the morphology of the marginal hooks were not provided in the description of Prudhoe (1957), which are added in the present study. Comparative measurements are presented in Table 5.

Macrogyrodactylus karibae Douëllou et Chishawa, 1995 Figs. 2G–I, 3C,D (iii); Table 6 T y p e h o s t: Clarias gariepinus (Burchell) (Siluriformes: Clariidae). Ty p e l o c a l i t y: Lake Kariba, Zimbabwe. O t h e r r e c o r d s: Clarias gariepinus. South Africa – Khalil and Mashego (1998), Olivier et al. (2009), Matla (2012); Zimbabwe – Douëllou and Chishawa (1995), Barson et al. (2008, 2010). L o c a l i t i e s (p r e s e n t s t u d y): SouthAfrica: KuShokwe Pan and Usuthu River, Ndumo Game Reserve, KwaZulu-Natal Province; Zambia: Barotse floodplain, Zambezi River, Northwestern Province. S i t e o f i n f e c t i o n: Skin and gills. Abbreviations: IC –Iceland, KY – Kenya, M. – Macrogyrodactylus, SN – Senegal, SA – South Africa, ZI – Zimbabwe, ZM – Zambia. Vo u c h e r m a t e r i a l: Four voucher specimens deposited in, NMB P 818–821. R e p r e s e n t a t i v e D N A s e q u e n c e s: 715–741 bp long sequence of the ITS1-5.8S-ITS2 region of the rRNA gene of two isolates. GenBank accession numbers: MZ869845, MZ869851. Hologenophore, NMB P 829. S p e c i m e n s s t u d i e d: n = 8 (KuShokwe Pan, SA), n = 1 (Usuthu River, SA), n = 2 (Barotse floodplain, ZM). I n f e c t i o n r a t e: KuShokwe Pan (SA): P = 20%, IF = 1–2; Usuthu River (SA): P = 66%, IF = 1; Barotse floodplain (ZM) P = 6%, IF = 1. Morphological observations (measurements provided in Table 6): General morphology of the haptoral sclerites is similar to the description of Douëllou and Chishawa (1995). Marginal hook sickle blade slender and inwardly curved point, distal side slightly convex as it joins sickle blade. Base of sickle presents noticeable curvature toward anterior end of sickle, has a convex distal side with an indentation as it joins sickle blade that sharply curve inward, tapering into a sharp point that stops before proximal side of sickle base; proximal side of sickle base curved. Cirrus observed in two specimens from KuShokwe Pan (SA) and Barotse floodplain (ZM), respectively, armed with 15 small spines and one large spine (Fig. 2I). Remarks. Macrogyrodactylus karibae can be easily distinguished from M. congolensis in having a ventral bar with short anterolateral processes and a short central arm. It can also be distinguished from M. clarii in having slender hamuli that is sharply curved into the point and root and in having a single uniform dorsal bar, wider than long (see Figs. 2G–H, 3C). Additionally, M. karibae presents a curved proximal side of sickle base, opposed to the absence of a curved appearance in M. clarii and M. congolensis (Fig. 2H and Fig. 3D (iii)). Dimensions for the hamuli (total length, point, shaft and root length) for specimens in the present study from NGR (SA) and Barotse floodplain (ZM) are within the ranges reported for the same species from other localities in southern Africa (Table 6) (Douëllou and Chishawa 1995, Khalil and Mashego 1998, Barson et al. 2010). The size of the dorsal and ventral bars is within the size ranges previously reported. The marginal hook size and morphology are comparable to previously reported data, specimens from NGR seem to have a slightly larger marginal hook sickle than previously reported. In the description and re-evaluation of M. karibae, Douëllou and Chishawa (1995) and Khalil and Mashego (1998) did not provide details on the morphology of the marginal hooks, which are provided in the present study. Comparative measurements are presented in Table 6.

Largemouth bass, Micropterus salmoides (Lacepéde, 1802) were sampled from three provinces (Eastern Cape EC, North West NWP and KwaZulu-Natal KZN) in South Africa to assess for parasite diversity and community composition. Morphological evaluation of the sampled parasite specimens provided evidence for the first record of five monogeneans from the family Ancyrocephalidae: Clavunculus bursatus (Mueller, 1963), Onchocleidus dispar (Mueller, 1936), Onchocleidus furcatus (Mueller, 1937), Onchocleidus principalis (Mizelle, 1936) and Syncleithrium fusiformis (Mueller, 1934) from the African continent. Community composition differed between localities. Clavunculus bursatus were only sampled from the EC and KZN, O. dispar and O. principalis were only sampled from the EC, O. furcatus was only sampled from the NWP and KZN localities and S. fusiformis only from KZN. Prevalence was 100% at all localities. Data from this study support the enemy release hypothesis as many of the parasites reported from the native range of M. salmoides were not collected., Graphical abstract Image 1, Highlights • Report on the parasite diversity of invasive Micropterus salmoides in South Africa. • First identification of co-introduced Ancyrocephalidae monogeneans into South Africa. • Enemy release supported: lower parasite diversity in South African Micropterus salmoides. • Potential for spillover to natives exists and needs to be investigated.

Four species of previously known nematodes from the family Camallanidae were found from different hosts in South Africa: Batrachocamallanus xenopodis from the frog Xenopus muelleri, Paracamallanus cyathopharynx and Procamallanus pseudolaeviconchus from the catfish Clarias gariepinus and Spirocamallanus daleneae from the catfish Synodontis zambezensis. In the material collected from various marine fishes, several specimens of nematodes from the genus Camallanus clearly differed from all previously known species. Based on morphological differences these specimens are assigned to a new species, C. sodwanaensis. Molecular data of 18S and 28S rDNA and COI sequences are provided for the collected species and a phylogenetic analyses based on 28S gene fragmets are presented., Graphical abstract Image 1, Highlights • Five species of Camallanidae nematodes found from different hosts in South Africa. • Camallanus sodwanaensis n. sp. is the first species from marine fish in Southern Africa. • Molecular data of 18S and 28SrDNA and COI sequences provided for found species. • Phylogenetic analyses based on 28S gene fragmets is performed.

Freshwater biodiversity is under constant threat from a range of anthropogenic stressors. Using South Africa’s Phongolo River and floodplain (PRF) as a study case, the aim of this chapter is to provide an overview of the conservation and management of freshwater biodiversity in a highly diverse subtropical ecosystem. The PRF is the largest floodplain system in South Africa which is severely threatened by irregularly controlled flood releases from a large upstream dam, prolonged drought, deteriorating water quality, organic pollutants and the increasing dependence of the local communities. Based on a decade of survey of the PRF conducted from 2010 to 2020, this chapter highlights the current diversity of aquatic organisms (invertebrates, fishes, frogs and their parasitic fauna), followed by an overview of their biological and physical stressors. The current challenges in the management of the aquatic biodiversity of this region and a way forward to conservation strategies are also addressed in this chapter.