Species interact and exploit one another for a number of reasons, including transportation, shelter or nutrition such as in parasitic relationships. Parasitism is an important aspect in life and is common in all taxonomic groups. Parasites are often host-specific and can be endoparasites or ectoparasites. The phylum Platyhelminthes includes the class Monogenea or monogenetic parasitic flukes. Monogeneans are mainly parasitic in fish but the family Polystomatidae, also commonly referred to as polystomes, are found on the skin and gills of the Australian lungfish, tadpole gills, kidneys and urinary bladders of frogs, gills and skin of salamanders, cloaca and phalodeum of caecileans, on the eye, in the nose, mouth or urinary bladder of freshwater turtles and on the eye of the hippopotamus. Polystomes have a cosmopolitan distribution, and are found on all hospitable continents. Polystome species were first discovered in the 1758. Between 1961 and 1980 French researchers focussed on Central and West Africa and described a large number of parasites. Polystome discovery has steadily decreased in the last 30 years, however despite this, new species are still being discovered annually. The list of currently known polystomes is most likely only a small portion of the species that exists. Wherever scientists searched for polystomes, new species were discovered. The current distribution of polystomes is not at all a true reflection of their global distribution but merely an indication of research effort. Monogenean flatworms exhibit many variations in the morphology of the intestinal tract. These parasites display two distinct diets, where one group mainly feeds on blood while the other mainly feeds on mucus and epithelial tissues. Thus the feeding habits and other factors such as the shape of the caeca, the presence/absence and number of medial and lateral diverticula as well as anastomosis may play a role in the morphology of the intestinal tract, which can be used as a classification tool to classify polystome species into specific genera. The three aims of the study were to:  Conduct a literature study to compile a species list and source of information on all valid polystome taxa.  Review the intestine shape of all polystomes and evaluate it as a taxonomic characteristic.  Conduct a species description of a new North American chelonian polystome belonging to the genus Polystomoides. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2015

Species interact and exploit one another for a number of reasons, including transportation, shelter or nutrition such as in parasitic relationships. Parasitism is an important aspect in life and is common in all taxonomic groups. Parasites are often host-specific and can be endoparasites or ectoparasites. The phylum Platyhelminthes includes the class Monogenea or monogenetic parasitic flukes. Monogeneans are mainly parasitic in fish but the family Polystomatidae, also commonly referred to as polystomes, are found on the skin and gills of the Australian lungfish, tadpole gills, kidneys and urinary bladders of frogs, gills and skin of salamanders, cloaca and phalodeum of caecileans, on the eye, in the nose, mouth or urinary bladder of freshwater turtles and on the eye of the hippopotamus. Polystomes have a cosmopolitan distribution, and are found on all hospitable continents. Polystome species were first discovered in the 1758. Between 1961 and 1980 French researchers focussed on Central and West Africa and described a large number of parasites. Polystome discovery has steadily decreased in the last 30 years, however despite this, new species are still being discovered annually. The list of currently known polystomes is most likely only a small portion of the species that exists. Wherever scientists searched for polystomes, new species were discovered. The current distribution of polystomes is not at all a true reflection of their global distribution but merely an indication of research effort. Monogenean flatworms exhibit many variations in the morphology of the intestinal tract. These parasites display two distinct diets, where one group mainly feeds on blood while the other mainly feeds on mucus and epithelial tissues. Thus the feeding habits and other factors such as the shape of the caeca, the presence/absence and number of medial and lateral diverticula as well as anastomosis may play a role in the morphology of the intestinal tract, which can be used as a classification tool to classify polystome species into specific genera. The three aims of the study were to:  Conduct a literature study to compile a species list and source of information on all valid polystome taxa.  Review the intestine shape of all polystomes and evaluate it as a taxonomic characteristic.  Conduct a species description of a new North American chelonian polystome belonging to the genus Polystomoides. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2015

Made available in DSpace on 2016-04-28T20:15:33Z (GMT). No. of bitstreams: 1 2009 - Patricia Barizon Cepeda.pdf: 4456439 bytes, checksum: 76acf89f6f60c2d403100e8366a812b4 (MD5) Previous issue date: 2009-02-18 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / A new genus and five new species of dactylogyrid monogeneans were described from the gills of Brachyplatystoma filamentosum (Pimelodidae). The fishes were collected from the Araguaia river, State of Mato Grosso, Brazil. The new genus is characterized by a combination of characters which included gonads tandem, germarium ovate or elongate, anterior to testis, copulatory organ J shaped or curved and accessory piece non-articulated or articulated, prostatic reservoir is ovate when observed, vagina sinistro-marginal, sclerotized or not, haptor subhexagonal with shank simple and similar hooks. Characteristics of the new genus resembles Demidospermus Suriano, 1983, Aphanoblastella Kritsky, Mendoza-Franco e Scholz, 2000, Pseudovancleaveus Fran?a, Issac, Pavanelli e Takemoto, 2003, Unibarra Suriano e Incorvaia, 1995 and Unilatus Mizelle e Kritsky, 1967. Morphological differences among the five new species are based on: Genus n., sp. n. 1 possessing ventral bar slightly curved and dorsal bar straight, both with the large ends; accessory piece slightly curved, nonarticulated; copulatory organ shaped-J with ornamentation. Genus n., sp. n. 2 possessing ventral bar slightly curved and dorsal bar straight with ends slightly curved; vagina sclerotized; copulatory organ shaped-J; accessory piece with two lobes, articulated and prostatic reservoir present. Genus n., sp. n. 3 present peduncle elongate; ventral bar slightly curved with a small prominence in the antero-median region, dorsal bar elongate, with ends slightly curved; accessory piece curved, articulated; copulatory organ curved with ornamentation. Genus n., sp. n. 4 possessing ventral bar slightly curved, with a small prominence in the antero-median region and dorsal bar straight, both with large ends; accessory piece curved with large proximal end; copulatory organ shape-J with ornamentation. Genus n., sp. n. 5 possessing peduncle elongate; ventral, dorsal bar slightly curved, dorsal bar present a prominence in the antero-median region; vagina sclerotized; accessory piece articulated, irregular and copulatory organ shaped-J; prostatic reservoir present. / Como resultado do estudo taxon?mico dos parasitos de br?nquias de Brachyplatystoma filamentosum (Pimelodidae) provenientes do rio Araguaia, Mato Grosso, Brasil, um novo g?nero (Gen. n..) de Dactylogyridae (Monogenea) ? proposto e cinco esp?cies novas (Gen. n., sp. n. 1, 2, 3, 4 e 5) foram descritas. O g?nero novo est? caracterizado por uma combina??o de caracteres que inclui: g?nadas n?o superpostas, germ?rio pr?-testicular alongado ou oval, ?rg?o copulat?rio masculino em forma de J ou curvo, pe?a acess?ria articulada ou n?o, reservat?rio prost?tico oval quando presente, vagina sinistro-marginal esclerotizada ou n?o, haptor subhexagonal com sete pares de ganchos similares entre si. As caracter?sticas que definem o g?nero novo sugerem semelhan?as morfol?gicas com Demidospermus Suriano, 1983, Aphanoblastella Kritsky, Mendoza-Franco e Scholz, 2000, Pseudovancleaveus Fran?a, Issac, Pavanelli e Takemoto, 2003, Unibarra Suriano e Incorvaia, 1995 e Unilatus Mizelle e Kritsky, 1967. As diferen?as morfol?gicas entre as cinco esp?cies do g?nero novo s?o: G?nero n., sp. n. 1 possui barra ventral ligeiramente curva e barra dorsal reta, ambas com extremidades alargadas; apresenta pe?a acess?ria ligeiramente curva, n?o articulada; ?rg?o copulat?rio em forma de J com ornamenta??o; aus?ncia de reservat?rio prost?tico. G?nero n. sp. n. 2. possui barra ventral ligeiramente curva e barra dorsal reta com extremidades ligeiramente curvas; presen?a de vagina esclerotizada; org?o copulat?rio em forma de J; pe?a acess?ria bilobada, articulada e presen?a de reservat?rio prost?tico. G?nero n. sp. n. 3 apresenta o ped?nculo longo; possui barra ventral ligeiramente curva com pequena proemin?ncia na regi?o antero-mediana; barra dorsal reta, alongada, com extremidades ligeiramente curvas; pe?a acess?ria curva, articulada e ?rg?o copulat?rio curvo, com ornamenta??o. G?nero n., sp. n. 4 apresenta barra ventral ligeiramente curva com pequena proemin?ncia na regi?o antero-mediana e barra dorsal reta, ambas com extremidades alargadas; pe?a acess?ria curva com a extremidade proximal mais larga; ?rg?o copulat?rio em forma de J, com ornamenta??o. G?nero n., sp. n. 5 possui o ped?nculo largo; barra ventral quase reta e barra dorsal ligeiramente curva com pequena proemin?ncia na regi?o anteromediana; vagina esclerotizada; pe?a acess?ria articulada e irregular e ?rg?o copulat?rio apresenta forma de J, presen?a de reservat?rio prost?tico. Estes s?o os primeiros registros de monogen?ticos parasitando B. filamentosum.

Made available in DSpace on 2016-04-28T20:16:28Z (GMT). No. of bitstreams: 1 2009 - Vanessa Doro Abdallah.pdf: 3833672 bytes, checksum: 322601a1d1e2505642c0eda34de72fd6 (MD5) Previous issue date: 2009-02-19 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Between the period from August 2005 to August 2007 were collected and analyzed 565 specimens belonging to 20 species from the Guandu River, near the dam of water treatment station (WTS) (22 ? 48 ' 32 "S, 43 ? 37'35" W), State of Rio de Janeiro, to study the biodiversity of the monogeneans from Guandu river, considering the strategic importance of this river in the State of Rio de Janeiro. Of the 20 fish species studied in this work, 13 were parasitized by monogeneans. All monogeneans were found parasitizing the gills of the hosts. A total of 24 species of monogenean were found, with 18 belonging to the family Dactylogyridae Bychowsky, 1933, four belonging to the family Gyrodactylidae Van Beneden and Hesse, 1863 and two belonging to the family Diplectanidae Monticelli, 1903. Fish belonging to the families Auchenipteridae, Cichlidae, Heptapteridae, Mugilidae and Pimelodidae were parasitized by only monogenean family Dactylogyridae. The family Centropomidae was parasitized by only monogenean belonging to the family Diplectanidae. The fishes of the families Anostomidae, Characidae and Loricariidae were parasitized by monogeneans belonging to the families Dactylogyridae and Gyrodactylidae. In this work are described six new species of monogeneans, being one species of Jainus, four species of Ligophorus and one species of Rhabdosynochus, respectively parasitizing Leporinus copelandii Steindachner, 1875, Mugil liza Valenciennes, 1836 and Centropomus undecimalis (Bloch, 1792). In this study were made 12 new records of hosts and 21 new records of locality. Key words: Between the period from August 2005 to August 2007 were collected and analyzed 565 specimens belonging to 20 species from the Guandu River, near the dam of water treatment station (WTS) (22 ? 48 ' 32 "S, 43 ? 37'35" W), State of Rio de Janeiro, to study the biodiversity of the monogeneans from Guandu river, considering the strategic importance of this river in the State of Rio de Janeiro. Of the 20 fish species studied in this work, 13 were parasitized by monogeneans. All monogeneans were found parasitizing the gills of the hosts. A total of 24 species of monogenean were found, with 18 belonging to the family Dactylogyridae Bychowsky, 1933, four belonging to the family Gyrodactylidae Van Beneden and Hesse, 1863 and two belonging to the family Diplectanidae Monticelli, 1903. Fish belonging to the families Auchenipteridae, Cichlidae, Heptapteridae, Mugilidae and Pimelodidae were parasitized by only monogenean family Dactylogyridae. The family Centropomidae was parasitized by only monogenean belonging to the family Diplectanidae. The fishes of the families Anostomidae, Characidae and Loricariidae were parasitized by monogeneans belonging to the families Dactylogyridae and Gyrodactylidae. In this work are described six new species of monogeneans, being one species of Jainus, four species of Ligophorus and one species of Rhabdosynochus, respectively parasitizing Leporinus copelandii Steindachner, 1875, Mugil liza Valenciennes, 1836 and Centropomus undecimalis (Bloch, 1792). In this study were made 12 new records of hosts and 21 new records of locality. / Entre o per?odo de agosto de 2005 a agosto de 2007 foram coletados e analisados 565 esp?cimes de peixes, pertencentes a vinte esp?cies, provenientes do Rio Guandu, pr?ximo ? barragem da Esta??o de tratamento de ?gua (ETA) (22?48 32 S, 43?37 35 W), Estado do Rio de Janeiro, com o objetivo de obter um maior conhecimento da biodiversidade dos monogen?ticos do Rio Guandu e fazer um estudo taxon?mico dos mesmos, em fun??o da import?ncia estrat?gica deste rio no Estado do Rio de Janeiro. Das 20 esp?cies de peixes estudadas no presente trabalho, 13 estavam parasitadas por monogen?ticos. Todos os monogen?ticos encontrados estavam parasitando as br?nquias dos hospedeiros. Um total de 24 esp?cies de monogen?ticos foram encontradas, sendo 18 pertencentes ? fam?lia Dactylogyridae Bychowsky, 1933, quatro pertencentes ? fam?lia Gyrodactylidae Van Beneden e Hesse, 1863 e duas pertencentes ? fam?lia Diplectanidae Monticelli, 1903. Os peixes pertencentes ?s fam?lias Auchenipteridae, Cichlidae, Heptapteridae, Mugilidae e Pimelodidae foram parasitados exclusivamente por monogen?ticos da fam?lia Dactylogyridae. As esp?cies da fam?lia Centropomidae foram parasitadas somente por monogen?ticos pertencentes ? fam?lia Diplectanidae. As esp?cies estudadas das fam?lias Anostomidae, Characidae e Loricariidae foram parasitadas pelos monogen?ticos das fam?lias Dactylogyridae e Gyrodactylidae. No presente trabalho est?o sendo descritas seis esp?cies novas de monogen?ticos, sendo uma esp?cie de Jainus, quatro esp?cies de Ligophorus e uma esp?cie de Rhabdosynochus, parasitando respectivamente Leporinus copelandii Steindachner, 1875, Mugil liza Valenciennes, 1836 e Centropomus undecimalis (Bloch, 1792). No presente trabalho foram realizados 12 novos registros de hospedeiros e 21 novos registros de localidade.

Japanese yellowtail Seriola quinqueradiata has been commercially farmed in Japan since the 1940s. In comparison, sea-cage farming of yellowtail kingfish Seriola lalandi in Australia is still developing, with commercial production commencing in 1998. In Australia, S. lalandi is parasitised by Zeuxapta seriolae and Benedenia seriolae. In Japan, S. quinqueradiata is parasitised by Heteraxine heterocerca and B. seriolae. These monogeneans affect industries in both countries and management of these parasites is required to prevent impacts on fish health and commercial losses. I investigated efficacy (% reduction of mean parasite abundance) for orally administered praziquantel, fenbendzole and oxfendazole against Z. seriolae and B. seriolae on S. lalandi and the efficacy of orally administered praziquantel and febantel against H. heterocerca and B. seriolae on S. quinqueradiata. Medications were administered to fish by surface coating feed pellets or via direct intubation of the stomach. Seriola lalandi administered fenbendazole and oxfendazole by surface coating of feed had lower abundance of the gill parasite Z. seriolae. Seriola quinqueradiata intubated with febantel had lower abundance of the gill parasite H. heterocerca. Neither fenbendazole nor oxfendazole administered to S. lalandi in Australia, nor febantel administered to S. quinqueradiata in Japan resulted in a lower abundance of the skin parasite B. seriolae. Praziquantel was first administered to S. lalandi by surface coating of feed. Fish rejected medicated feed, suggesting praziquantel affected its palatability. Fish treated with feed medicated with praziquantel had fewer Z. seriolae and B. seriolae than untreated fish. Praziquantel administered to S. lalandi by intubation allowed a more accurate dose to be tested without differential feeding or reduced palatability obstructing results, and resulted in fewer Z. seriolae (99.5-100 % reduction) and B. seriolae (91 – 97.7 % reduction). Intubated praziquantel also led to fewer recruitment life stages of Z. seriolae and B. seriolae, even at low doses, but did not completely eliminate them from S. lalandi. Praziquantel administered to S. lalandi alone and combined with cimetidine had high efficacy (>99%) against Z. seriolae. In comparison, praziquantel administered alone resulted in fewer B. seriolae (68.3 – 69.7 % reduction) than the same doses of praziquantel combined with cimetidine (36.9 – 40.9 % reduction). A 90.4 -100% reduction in H. heterocerca was achieved when praziquantel was administered by intubation to S. quinqueradiata in Japan but there was only a 22-77.8 % reduction in B. seriolae. The dose of PZQ (150 mg kg⁻¹ body weight day⁻¹ for 3 days) on the label of a commercially available product used to treat B. seriolae in Japanese aquaculture resulted in a 50.9% reduction against B. seriolae, but completely eliminated H. heterocerca. In trials against Z. seriolae and B. seriolae on S. lalandi in South Australia, I also screened 27 other anthelmintics and antiparasitics from the chemical groups: amprolium derivatives, benzimidazoles, benzyl ureas, diphosphate salts, imidazothiazoles, macrocyclic lactones, nitromidazoles, organophosphates, piperazines, salicylanilides, substituted phenols and tetrahydropyrimidines. Of these, only the benzimidazole, albendazole, was effective against Z. seriolae and none appeared to have an effect against B. seriolae. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1459172 / Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, 2010

Japanese yellowtail Seriola quinqueradiata has been commercially farmed in Japan since the 1940s. In comparison, sea-cage farming of yellowtail kingfish Seriola lalandi in Australia is still developing, with commercial production commencing in 1998. In Australia, S. lalandi is parasitised by Zeuxapta seriolae and Benedenia seriolae. In Japan, S. quinqueradiata is parasitised by Heteraxine heterocerca and B. seriolae. These monogeneans affect industries in both countries and management of these parasites is required to prevent impacts on fish health and commercial losses. I investigated efficacy (% reduction of mean parasite abundance) for orally administered praziquantel, fenbendzole and oxfendazole against Z. seriolae and B. seriolae on S. lalandi and the efficacy of orally administered praziquantel and febantel against H. heterocerca and B. seriolae on S. quinqueradiata. Medications were administered to fish by surface coating feed pellets or via direct intubation of the stomach. Seriola lalandi administered fenbendazole and oxfendazole by surface coating of feed had lower abundance of the gill parasite Z. seriolae. Seriola quinqueradiata intubated with febantel had lower abundance of the gill parasite H. heterocerca. Neither fenbendazole nor oxfendazole administered to S. lalandi in Australia, nor febantel administered to S. quinqueradiata in Japan resulted in a lower abundance of the skin parasite B. seriolae. Praziquantel was first administered to S. lalandi by surface coating of feed. Fish rejected medicated feed, suggesting praziquantel affected its palatability. Fish treated with feed medicated with praziquantel had fewer Z. seriolae and B. seriolae than untreated fish. Praziquantel administered to S. lalandi by intubation allowed a more accurate dose to be tested without differential feeding or reduced palatability obstructing results, and resulted in fewer Z. seriolae (99.5-100 % reduction) and B. seriolae (91 – 97.7 % reduction). Intubated praziquantel also led to fewer recruitment life stages of Z. seriolae and B. seriolae, even at low doses, but did not completely eliminate them from S. lalandi. Praziquantel administered to S. lalandi alone and combined with cimetidine had high efficacy (>99%) against Z. seriolae. In comparison, praziquantel administered alone resulted in fewer B. seriolae (68.3 – 69.7 % reduction) than the same doses of praziquantel combined with cimetidine (36.9 – 40.9 % reduction). A 90.4 -100% reduction in H. heterocerca was achieved when praziquantel was administered by intubation to S. quinqueradiata in Japan but there was only a 22-77.8 % reduction in B. seriolae. The dose of PZQ (150 mg kg⁻¹ body weight day⁻¹ for 3 days) on the label of a commercially available product used to treat B. seriolae in Japanese aquaculture resulted in a 50.9% reduction against B. seriolae, but completely eliminated H. heterocerca. In trials against Z. seriolae and B. seriolae on S. lalandi in South Australia, I also screened 27 other anthelmintics and antiparasitics from the chemical groups: amprolium derivatives, benzimidazoles, benzyl ureas, diphosphate salts, imidazothiazoles, macrocyclic lactones, nitromidazoles, organophosphates, piperazines, salicylanilides, substituted phenols and tetrahydropyrimidines. Of these, only the benzimidazole, albendazole, was effective against Z. seriolae and none appeared to have an effect against B. seriolae. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1459172 / Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, 2010

D.Phil. (Zoology) / Fish parasites may cause disease and lead to commercial losses. In order to construct practical management systems to mitigate or manage potential adverse effects, information on basic biological variables is required. Compared to the number of internationally published papers on the subject, little is known about the monogenean parasite fauna of South African fishes. Monogeneans are largely ectoparasitic, thin, flattened, host- and site specific parasites with a simple life cycle involving a single host (often a fish). They range in size between 0.3 mm and 20 mm and are mostly bilaterally symmetrical with the body subdivided into a number of regions. Attachment organs are a necessary feature both anteriorly and posteriorly, with the morphology of the prominent posterior attachment organ (opisthaptor) highly variable between genera. It may contain suckers, clamps or large hooks (anchors) as well as marginal hooks. In some genera anchors (one to two pairs) are associated with spikes or accessory sclerites and are supported by a connecting bar. All these structures, together with the sclerotized male copulatory organ, are of taxonomic significance....

Trygonorrhina fasciata (Rhinobatidae) specimens naturally infected by three monogenean species were captured and maintained in marine aquaria to promote a continuous parasite load. Monogenean eggs recovered from aquaria provided larvae for descriptions and life history experiments. I describe the adult, larva and post-larval development of a new species of hexabothriid, Branchotenthes octohamatus, from the gills. This is the first monogenean larva described with only eight hooklets. This character may be useful to help resolve problematic relationships within the Hexabothriidae and offers insight into more general hypotheses about relationships within the Monogenea. I also redescribe the adult of Calicotyle australis (Monocotylidae) from the cloaca and describe the larva. The number and arrangement of larval ciliated epidermal cells and sensilla was revealed using silver nitrate. I redescribe Pseudoleptobothrium aptychotremae (Microbothriidae) adults from the skin of T. fasciata, representing a new host and locality record. Larval anatomy and post-larval development are also documented. The presence of six needle-like spicules in the larval haptor is confirmed, supporting an earlier theory that spicules are ancestral vestiges. My studies revealed three different egg hatching, host finding strategies and larval ‘types’. Branchotenthes octohamatus has a ‘sit-and-wait’ strategy, entirely dependent on mechanical disturbance to stimulate eggs to hatch. Larvae are unciliated, cannot swim, lack pigmented eyespots and show no photo-response but may survive for more than two days after hatching at 22ºC. In contrast, eggs of C. australis hatch spontaneously with a strong diurnal rhythm in the first few hours of daylight when exposed to a LD12:12 illumination regime. Larvae are ciliated and can swim, have pigmented eyespots, are photo-positive and can remain active and survive for up to 24 h after hatching at 22ºC. Eggs of P. aptychotremae may have a ‘bet-hedging’ strategy. Some eggs hatch spontaneously and rhythmically in an LD12:12 regime during the last few hours of daylight but their low hatching success rate suggests that other eggs may require a different cue provided by the host. Larvae are ciliated, can swim, lack pigmented eyespots, show no photo-response and remain active for only a few hours at 22ºC. Experiments using the fluorescent dye, 5(6)-carboxyfluorescein diacetate N-succinimidyl ester (CFSE) revealed B. octohamatus on gills of T. fasciata within 30 min of exposure to the host. This provides strong evidence that larvae invade the gills directly via the host’s inhalant respiratory current and do not migrate after initial attachment elsewhere. Five rhinobatid species (Aptychotrema vincentiana, T. fasciata, Trygonorrhina sp. A, A. rostrata and Rhinobatos typus), with overlapping distributions spanning west, south and east Australian coastal waters were surveyed for monogeneans at four locations between Fremantle, Western Australia and Stradbroke Island, Queensland. Genetic homogeneity, using the mitochrondrial gene Cytochrome b (cytb) and the nuclear marker, Elongation factor-1 alpha (EF1a), was observed for all Branchotenthes and Calicotyle specimens irrespective of collection locality or rhinobatid species. Genetic homogeneity was observed for Pseudoleptobothrium specimens collected in western and southern Australia. However, local genetic heterogeneity was apparent among Pseudoleptobothrium specimens collected from two sympatric host species in New South Wales. Analyses revealed a highly divergent clade, indicating a morphologically cryptic, ancestral species. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1323070 / Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, 2008

Trygonorrhina fasciata (Rhinobatidae) specimens naturally infected by three monogenean species were captured and maintained in marine aquaria to promote a continuous parasite load. Monogenean eggs recovered from aquaria provided larvae for descriptions and life history experiments. I describe the adult, larva and post-larval development of a new species of hexabothriid, Branchotenthes octohamatus, from the gills. This is the first monogenean larva described with only eight hooklets. This character may be useful to help resolve problematic relationships within the Hexabothriidae and offers insight into more general hypotheses about relationships within the Monogenea. I also redescribe the adult of Calicotyle australis (Monocotylidae) from the cloaca and describe the larva. The number and arrangement of larval ciliated epidermal cells and sensilla was revealed using silver nitrate. I redescribe Pseudoleptobothrium aptychotremae (Microbothriidae) adults from the skin of T. fasciata, representing a new host and locality record. Larval anatomy and post-larval development are also documented. The presence of six needle-like spicules in the larval haptor is confirmed, supporting an earlier theory that spicules are ancestral vestiges. My studies revealed three different egg hatching, host finding strategies and larval ‘types’. Branchotenthes octohamatus has a ‘sit-and-wait’ strategy, entirely dependent on mechanical disturbance to stimulate eggs to hatch. Larvae are unciliated, cannot swim, lack pigmented eyespots and show no photo-response but may survive for more than two days after hatching at 22ºC. In contrast, eggs of C. australis hatch spontaneously with a strong diurnal rhythm in the first few hours of daylight when exposed to a LD12:12 illumination regime. Larvae are ciliated and can swim, have pigmented eyespots, are photo-positive and can remain active and survive for up to 24 h after hatching at 22ºC. Eggs of P. aptychotremae may have a ‘bet-hedging’ strategy. Some eggs hatch spontaneously and rhythmically in an LD12:12 regime during the last few hours of daylight but their low hatching success rate suggests that other eggs may require a different cue provided by the host. Larvae are ciliated, can swim, lack pigmented eyespots, show no photo-response and remain active for only a few hours at 22ºC. Experiments using the fluorescent dye, 5(6)-carboxyfluorescein diacetate N-succinimidyl ester (CFSE) revealed B. octohamatus on gills of T. fasciata within 30 min of exposure to the host. This provides strong evidence that larvae invade the gills directly via the host’s inhalant respiratory current and do not migrate after initial attachment elsewhere. Five rhinobatid species (Aptychotrema vincentiana, T. fasciata, Trygonorrhina sp. A, A. rostrata and Rhinobatos typus), with overlapping distributions spanning west, south and east Australian coastal waters were surveyed for monogeneans at four locations between Fremantle, Western Australia and Stradbroke Island, Queensland. Genetic homogeneity, using the mitochrondrial gene Cytochrome b (cytb) and the nuclear marker, Elongation factor-1 alpha (EF1a), was observed for all Branchotenthes and Calicotyle specimens irrespective of collection locality or rhinobatid species. Genetic homogeneity was observed for Pseudoleptobothrium specimens collected in western and southern Australia. However, local genetic heterogeneity was apparent among Pseudoleptobothrium specimens collected from two sympatric host species in New South Wales. Analyses revealed a highly divergent clade, indicating a morphologically cryptic, ancestral species. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1323070 / Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, 2008