RESUMO
The catshark genus Holohalaelurus Fowler is currently represented by five species distributed off the southern and eastern parts of the African coast. Very few parasitological records exist for any of these five species, representing a significant knowledge gap. We report the first monogenean species from the bathydemersal species Holohalaelurus regani (Gilchrist): a new species of Microbothriidae Price, 1936, Leptomicrobothrium holohalaelure n. sp. from the dorsal skin surface, and a new species of Hexabothriidae Price, 1942 representing a new genus, Scyliorhinocotyle narvaezae n. gen., n. sp., from the gill lamellae. Both monogenean records represent the first for any member of the catshark genus Holohalaelurus. Previously we focused on the identification of monogenean taxa of emerging veterinary importance for public aquaria. We now begin a focused effort to document a generally unexplored monogenean biodiversity from diverse marine habitats off South Africa.
Assuntos
Elasmobrânquios/parasitologia , Trematódeos/classificação , África Austral , Animais , Especificidade da Espécie , Trematódeos/anatomia & histologiaRESUMO
Thirteen species of sea lice (family Caligidae) are reported from a range of elasmobranch and actinopterygian fishes caught off South Africa or obtained from public aquaria in South Africa. Two new species of Caligus Müller, 1785 are described: C. linearis n. sp. from Pomatomus saltatrix (Linnaeus) and C. tumulus n. sp. from Chrysoblephus cristiceps (Valenciennes). A supplementary description is provided for both sexes of Caligus tetrodontis Barnard, 1948 taken from Amblyrhynchotes honckenii (Bloch) and previous records of this parasite from South African fishes are critically reviewed. It is concluded that Caligus material from Arothron hispidus Linnaeus was previously misidentified as C. tetrodontis and is in urgent need of re-examination. Morphological and molecular observations on Caligus furcisetifer Redkar, Rangnekar & Murti, 1949 indicate that this copepod is phenotypically and genetically identical to Lepeophtheirus natalensis Kensley & Grindley, 1973, and the latter becomes a junior subjective synonym of C. furcisetifer. We include new geographical distribution records for Caligus longipedis Bassett-Smith, 1898, C. rufimaculatus Wilson, 1905 and Lepeophtheirus spinifer Kirtisinghe, 1937, extending into South African waters, as well as both new distribution and host records for Alebion gracilis Wilson, 1905, Caligus dakari van Beneden, 1892 and Lepeophtheirus acutus Heegaard, 1943. The molecular analysis confirmed the monophyly of the genus Caligus. The South African species of Caligus did not cluster together, but the two included South African species of Lepeophtheirus were recovered as sister taxa.
Assuntos
Copépodes/classificação , Elasmobrânquios/parasitologia , Peixes/parasitologia , Distribuição Animal , Animais , Copépodes/anatomia & histologia , África do Sul , Especificidade da EspécieRESUMO
Species of Anoplodiscus Sonsino, 1890 were previously only known from host members of Sparidae. A new species, Anoplodiscus hutsonae n. sp. is proposed for museum specimens originally collected from species of Scolopsis Cuvier (Nemipteridae) off Heron Island and Lizard Island, Australia. Additionally, Anoplodiscus tai Ogawa, 1994 is synonymised with Anoplodiscus cirrusspiralis Roubal, Armitage & Rohde, 1983 due to a lack of support for differential characters, and Anoplodiscus richiardii is considered a species inquirenda. Anoplodiscus cirrusspiralis causes visible lesions on the skin and fins of its host, and may also contribute to poor food conversion rates in sparid aquaculture. Anoplodiscus cirrusspiralis has been recorded from cultured sparids in Australia, Japan, South Africa, and South Korea, and was implicated as a disease agent in fish from the former two countries. However, the discovery of A. cirrusspiralis on Chrysoblephus gibbiceps (Valenciennes), Ch. laticeps (Valenciennes) and Cymatoceps nasutus (Castelnau) in South Africa, ?Pagrus major (Temminck & Schlegel) in South Korea, and P. auratus (Forster) in Australia, New Zealand and Japan suggests that this species may have a wide distribution and low host-specificity within the Sparidae. In South Africa, A. cirrusspiralis was first encountered on a morbid C. nasutus and Ch. gibbiceps from two public aquaria in 2009 (Two Oceans Aquarium, Cape Town and uShaka Sea World, Durban, respectively). Additional material was collected from C. laticeps kept at an abalone farm in Hermanus that originated from Struisbaai on the South African south coast. Anoplodiscus cirrusspiralis is redescribed from the South African specimens. This is the first record of a member of Anoplodiscidae Tagliani, 1912 from Africa.
Assuntos
Especificidade de Hospedeiro , Perciformes/parasitologia , Trematódeos/classificação , Animais , Austrália , Pele/parasitologia , África do Sul , Especificidade da Espécie , Trematódeos/anatomia & histologiaRESUMO
Rajonchocotyle Cerfontaine, 1899, species are blood-feeding parasites on the gills of rajiforms. Eight species are considered valid, the most recent of which was described just after World War II. Many of the original descriptions of Rajonchocotyle species are limited in diagnostic value, and comparative museum material is scanty. The genus requires revision, and in support thereof, we provide detailed redescriptions for Rajonchocotyle albaCerfontaine, 1899, from the type host Rostroraja alba (Lacepède, 1803) and Rajonchocotyle emarginata (Olsson, 1876), Sproston, 1946, from 2 new host records, Raja straeleni Poll, 1951, and Leucoraja wallacei (Hulley, 1970), from South Africa, a new locality record. The generic diagnosis for Rajonchocotyle is amended to include greater details of the male reproductive system and confirms Paul Cerfontaine's and Nora Sproston's historic observations of the morphology of the male copulatory organ consisting of a separate proximal seminal vesicle and a distal cirrus. The lectotype of Rajonchocotyle kenojeiYamaguti, 1938, is assigned, and a comprehensive Rajonchocotyle-host species list is provided, highlighting species records that require further verification, and the purported global host range of R. emarginata is discussed.
Assuntos
Rajidae , Trematódeos , Animais , Masculino , África do Sul , Rajidae/parasitologia , Brânquias/parasitologia , Especificidade de HospedeiroRESUMO
Many hexabothriid genera require renewed taxonomic attention to provide additional detailed comparative data from new material to resolve existing species quandaries. Our current study describes and provides additional museum material for three hexabothriid species from three genera from South Africa: Erpocotyle catenulata (Guberlet), which is confirmed as a valid species, Heteronchocotyle gymnurae Neifar, Euzet and Ben Hassine, and Hypanocotyle bullardi Chero, Cruces, Sáez, Carolina, Camargo, Portes Santos and Luque. Evidence of these three hexabothriid species from South Africa suggests that hexabothriids have more globally widespread distributions, and that they are less host-specific than previously considered. A detailed summary of hexabothriids reported from the triakid hosts, Galeorhinus galeus and Mustelus mustelus is provided, and the host-specificity of hexabothriids is discussed.
Assuntos
Especificidade de Hospedeiro , Trematódeos , Animais , Rajidae , África do Sul , Trematódeos/classificação , Trematódeos/fisiologiaRESUMO
Detection of pathogens, parasites, and other symbionts in environmental samples via eDNA/eRNA (collectively eNA) is an increasingly important source of information about their occurrence and activity. There is great potential for using such detections as a proxy for infection of host organisms in connected habitats, for pathogen monitoring and surveillance, and for early warning systems for disease. However, many factors require consideration, and appropriate methods developed and verified, in order that eNA detections can be reliably interpreted and adopted for surveillance and assessment of disease risk, and potentially inclusion in international standards, such as the World Organisation for Animal Health guidelines. Disease manifestation results from host-symbiont-environment interactions between hosts, demanding a multifactorial approach to interpretation of eNA signals.
Assuntos
DNA Ambiental , Parasitos , Animais , Parasitos/genética , DNA Ambiental/genética , RNA , Ecologia , Ecossistema , Monitoramento AmbientalRESUMO
Abalone Haliotis midae exhibiting typical clinical signs of tubercle mycosis were discovered in South African culture facilities in 2006, posing a significant threat to the industry. The fungus responsible for the outbreak was identified as a Peronosporomycete, Halioticida noduliformans. Currently, histopathology and gross observation are used to diagnose this disease, but these 2 methods are neither rapid nor sensitive enough to provide accurate and reliable diagnosis. Real-time quantitative PCR (qPCR) is a rapid and reliable method for the detection and quantification of a variety of pathogens, so therefore we aimed to develop a qPCR assay for species-specific detection and quantification of H. noduliformans. Effective extraction of H. noduliformans genomic DNA from laboratory grown cultures, as well as from spiked abalone tissues, was accomplished by grinding samples using a pellet pestle followed by heat lysis in the presence of Chelax-100 beads. A set of oligonucleotide primers was designed to specifically amplify H. noduliformans DNA in the large subunit (LSU) rRNA gene, and tested for cross-reactivity to DNA extracted from related and non-related fungi isolated from seaweeds, crustaceans and healthy abalone; no cross-amplification was detected. When performing PCR assays in an abalone tissue matrix, an environment designed to be a non-sterile simulation of environmental conditions, no amplification occurred in the negative controls. The qPCR assay sensitivity was determined to be approximately 0.28 pg of fungal DNA (~2.3 spores) in a 25 µl reaction volume. Our qPCR technique will be useful for monitoring and quantifying H. noduliformans for the surveillance and management of abalone tubercle mycosis in South Africa.
Assuntos
Fungos/isolamento & purificação , Moluscos/microbiologia , Reação em Cadeia da Polimerase em Tempo Real/métodos , Animais , DNA Fúngico/classificação , DNA Fúngico/genética , Fungos/classificação , Sensibilidade e Especificidade , Especificidade da EspécieRESUMO
Gyrodactylus molweni sp. n. is described from the body surface and fins of the South African mullet, Chelon richardsonii (Smith, 1846) collected from Table Bay Harbour, Cape Town and is compared to five other Gyrodactylus species described from grey mullets globally namely G. zhukovi Ling, 1963 and G. mugili Zhukov, 1970 from Planiliza haematocheila (Temminck and Schlegel, 1845); G. mugelus Rawson, 1973 from Mugil cephalus L.; G. curemae Conroy and Conroy, 1985 from Mugil curema Valenciennes, 1836 and G. xiamenensis Zang,Yang and Liu, 2001 from Planiliza macrolepis (Smith, 1846). Morphologically, G. molweni sp. n. has prominent ventral bar processes that near cover the hamulus roots, marginal sickles with large rhomboid heels, slender shafts and fine points that extend beyond the sickle toes. Gyrodactylus molweni sp. n. can, however, be readily differentiated: G. mugili and G. xiamenensis have ventral bars with small ventral processes; G. zhukovi has marginal hooks sickles with slender shafts and proportionately short points and open-faced blades; G. mugelus possesses marginal hook sickles with deep, rounded heels, forward slanting shafts and an angular, square line to the inner face of the blades. Although the length of the marginal hooks of G. curemae are similar to G. molweni sp. n., their hamuli are double the size. A GenBank BlastN search with the 931 bp sequence covering ITS1, 5.8S and ITS2 gave no close hits; the nearest species for which sequences are available is G. nipponensis Ogawa and Egusa, 1978 (identity 96.56%, 899/931 bp). The proposal of G. molweni sp. n. as a new species, therefore, is well supported by both the molecular and morphological analyses presented herein. This Gyrodactylus species is the first to be described from C. richardsonii and only the second Gyrodactylus species to be described from the marine environment off the African continent.
RESUMO
Gyrodactylus eyipayipi sp. n. is described from the skin, gills, flute and male brood pouch of captive specimens of the greater pipefish Syngnathus acus L., collected for and maintained at the Two Oceans Aquarium in Cape Town, South Africa. It is the first marine Gyrodactylus species reported from the African continent. The new species is compared to the three known Gyrodactylus species affecting syngnathiform hosts (G. pisculentus Williams, Kritsky, Dunnigan, Lash et Klein, 2008, G. shorti Holliman, 1963, and G. syngnathi Appleby, 1996). Although all four species have similar-sized and shaped attachment hooks with some overlap, separation of the species is possible using marginal hook morphology. The marginal hooks of G. eyipayipi measure (mean) 30 pm in total length and are larger than those of the three other species (mean, 24-28 tm). Gyrodactylus eyipayipi can also be discriminated based on differences in the shape of the marginal hook sickle notably by its long sickle point which extends far beyond the toe, its blunt rounded toe and, by the approximate rectangular shape to the base of the sickle. By comparison, the sloping toe regions of G. pisculentus and G. syngnathi give the sickle bases an approximately triangular shape, whilst the short sickle point and open aperture to the sickles of G. shorti allow for their discrimination from G. eyipayipi.
Assuntos
Platelmintos/anatomia & histologia , Platelmintos/classificação , Smegmamorpha/parasitologia , Animais , Feminino , Doenças dos Peixes/epidemiologia , Doenças dos Peixes/parasitologia , Masculino , Doenças Parasitárias em Animais/epidemiologia , Doenças Parasitárias em Animais/parasitologia , África do Sul/epidemiologia , Especificidade da EspécieRESUMO
Neoechinorhynchus (Neoechinorhynchus) dorsovaginatus n. sp. (Acanthocephala: Neoechinorhynchidae) is described from the dusky kob, Argyrosomus japonicus (Temminck & Schlegel) from the southern coast of South Africa in the Breede River Estuary. Like four other species of Neoechinorhynchus Stiles & Hassall, 1905, N. (N.) africanus Troncy, 1969, N. (N.) johnii Yamaguti, 1939, N. topseyi Podder, 1937 and N. (N.) tylosuri Yamaguti, 1939, the new species has a very long, slender body, cylindrical testes and cement-gland, anterior proboscis hooks much longer than the middle or posterior hooks, and a long neck. The new species is the only species of Neoechinorynchus having an antero-dorsal hump just posterior to the neck and a specialised vaginal sphincter and a gonopore on the dorsal side. It is closest to N. (N.) johnii, but is distinguished from it by: the size of the trunk, proboscis, anterior proboscis hooks, neck, and the posterior testis in relation to the cement-gland; the shape of cerebral ganglion and proboscis hook root; and the number of giant nuclei in the cement-gland.
Assuntos
Acantocéfalos/anatomia & histologia , Perciformes/parasitologia , Acantocéfalos/classificação , Animais , Masculino , Reto/parasitologia , Rios , Estações do Ano , África do SulRESUMO
A new species of Gyrodactylus von Nordmann, 1832 and the first monogenean reported from Botswana is described from the cichlid Pseudocrenilabrus philander philander, bringing the number of gyrodactylids described from the African Continent to 18. Gyrodactylus thlapi n. sp. can be readily discriminated from the other described species almost exclusively by the shape of its hamuli, which have short roots and large, elongate ventral bar attachment points with the dorsal bar attachment point, demarcating the junction between the hamulus shaft and the root, positioned at the anterior terminus of the attachment plane. The marginal hooks of G. thlapi n. sp., which most closely resemble those of G. groschafti Ergens, 1973, are compared and discussed.