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Transmission electron microscopy (TEM) images of sections through the anterior part of the oncosphere of Tetracampos ciliotheca. a Section showing the syncytial ciliated inner envelope bearing on its surface bulb-like microvilli and numerous cilia and part of the oncosphere surrounded by the oncospheral membrane. b The oncospheral tegument underline by a layer of somatic muscles attached to the basal lamina by electron dense areas of muscle attachment zones. c Binucleated subtegumental cell representing tegumental perikaryon. d Peripheral part of the oncosphere showing peripherally situated somatic cells, somatic musculature and the oncospheral hooks. e Section through the oncospheral region with the hooks and their musculature and zones of hook muscle attachments. Inset: cross section through the hook composed of three layers of different electron densities. f Section through the oncospheral hooks, hook muscles and nerve processes. BSC binucleated subtegumental cell, C cilia, GER granular endoplasmic reticulum, H hooks, HM hook musculature, Mt mitochondria, N nucleus, n nucleolus, MAZ muscle attachment zones, NP nerve processes, OM oncospheral membrane, OT oncospheral tegument, SC somatic cell, SM somatic musculature. Scale bars: a, e, Inset, f 1 μm, b 0.2 μm, d 2 μm, c 0.3 μm
Source publication
Transmission electron microscopy (TEM) was used to study the ultrastructure of the uterus and egg morphology in the enigmatic bothriocephalidean tapeworm Tetracampos ciliotheca. The uterine wall, underlain by well-developed muscle bundles, consists of a syncytial epithelium which is characterized by the abundance of free ribosomes, mitochondria and...
Citations
... The necessary permits (HO 09/03/17-125 NW; HO 20/02/18-057 NW, North West Province, Department of Rural, Environmental and Agricultural Development) and ethical clearance (NWU-00282-17-A5) for collecting and euthanizing fishes were obtained prior to sampling. Fish were collected using multifilament gill nets and fyke nets (SOP No. NWU-00274-17-A5), identified a priori using Skelton (2001), and subsequently euthanized by means of percussive stunning followed by pithing (SOP No. NWU-00267-17-A5) as in Erasmus et al. (2019) and Yoneva et al. (2020). Fishes were dissected and screened for endoparasites, and the parasites were collected for identification following the procedures described by Scholz et al. (2018). ...
Due to the increasing consumption of platinum (Pt), especially in automobile exhaust catalysts, environmental concentrations of Pt are of emerging concern worldwide. Limited information exists on environmental concentrations, particularly in Pt mining regions, while South Africa is the world’s main supplier of Pt. Moreover, other metals are also released as by-products of Pt mining, which might also cause environmental concern. Certain fish parasite taxa have the ability to accumulate metals orders of magnitude higher than their hosts and can be used to reliably detect metals with naturally low abundance. Studies on Pt accumulation in parasite-host systems are limited. Therefore, the aims of the present study were (1) to determine the accumulation of a variety of metals (cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), platinum (Pt), and zinc (Zn)) in helminth fish parasites compared with their hosts from a reference site and an impoundment impacted by Pt mining activities; (2) to assess whether there is a difference between bioaccumulation of metals in infected and uninfected hosts, as well as between hosts with different infection intensities; and (3) to compare the biomarker responses (acetylcholine esterase activity (AChE), metallothionein content (MT), catalase activity (CAT), reduced glutathione content (GSH), malondialdehyde content (MDA), protein carbonyls induction (PC), superoxide dismutase activity (SOD), and cellular energy allocation (CEA)) between infected and uninfected hosts. The cestode Atractolytocestus huronensis accumulated significantly higher concentrations of Cr, Ni, and Pt than their host Cyprinus carpio, while the nematode Contracaecum sp. accumulated significantly higher concentrations of Pt and Zn than their host Clarias gariepinus. Infected fish showed lower metal concentrations compared to uninfected fish, while the parasites had no significant effects on their hosts’ biomarker responses. The parasites demonstrated the bioavailability of metals derived from Pt mining activities and their ability to resist its toxic effects. Thus, these parasites are promising sensitive accumulation indicators for Cr, Ni, Pb, and Pt contaminations from Pt mining activities.
One of the most widely distributed African freshwater fish is the African sharptooth catfish Clarias gariepinus (Burchell) that is naturally distributed in 8 of the 10 ichthyofaunal regions of this continent. Clarias gariepinus is a highly valued and cheap staple to local communities and an ideal aquaculture species. Consequently, interest in the parasitic communities of C. gariepinus has increased as parasites may accidentally be ingested by humans when eating uncooked fish or can be introduced into culture systems through fish stocks supplied from local rivers which affect yield, growth, and marketability. This review provides an overview of the ∼107 metazoan parasite species known to parasitise C. gariepinus in Africa and their general life cycles, morphology, paratenic and post-cyclic infections, and the biogeography and validity of records are discussed. A brief overview is included on the application of some of these parasites in environmental studies and their link to human health.
