Thesis (PhD)--Macquarie University, School of Biological Sciences, 1999. / "July 1998" Bibliography: leaves 321-360.

Lipase was partially purified from the viscera of grey mullet ( Mugil cephalus) by ammonium sulfate fractionation, simultaneous desalting, and concentration via ultrafiltration and then affinity chromatography on EAH-Sepharose 4B. The partially purified extract was characterized using p-nitrophenyl palmitate (rho-NPP) as substrate. Grey mullet lipase was active within the pH range of 7-10, with an optimum pH of 8.0, and was stable from pH 4-10. The enzyme was active within the temperature range of 20°C and 60°C, and exhibited an optimum for the hydrolysis of rho-NPP at 50°C. The enzyme was stable between 10-50°C, beyond which it lost activity progressively. At 50°C there was ca. 50% residual activity after 60 min incubation. However at 60°C, there was 22%, 20% and 0% remaining activity after 10, 30 and 60 min incubation respectively. Based on the temperature activity data, the activation energy for the hydrolysis of rho-NPP was calculated as 1.94 kcal/mol (8.15 kJ/mol). / The rho-nitrophenyl esters of medium to long chain fatty acid (C10-C16) served as good substrates with the order of ease of hydrolysis as; rho-NP-palmitate > rho-NP-myristate > rho-NP-caprate > rho-NP-caproate > rho-NP-butyrate > rho-NP-acetate. The Km' and Vmax for the hydrolysis of rho-NPP were 0.22 mM and 20 mumol min-1 mg-1 , respectively. The hydrolytic activity of the lipase was enhanced by Mg2+, Mn2+, NaN3, and EDTA, but strongly inhibited by Hg2+, and Cu2+. PMSF (1 mM), Ca2+ (1 mM and 10 mM) had no effect on grey mullet lipase activity. Lower concentrations (25-10% v/v) of water-miscible organic solvents (dimethyl sulfoxide, dimethyl formamide, iso-propanol, and methanol) had negligible effect on the activity of the lipase while higher concentrations (>50% v/v) completely inhibited the enzyme. The grey mullet lipase was remarkably stable in water-immiscible organic solvents (benzene, toluene, hexane, heptane, and isooctane). The water-immiscible solvents also activated the enzyme with hexane giving the most activation. Lower concentrations of trihydroxylated bile salts (sodium taurocholate, and sodium cholate) were more potent activators than the dihydroxylated bile salt (sodium deoxycholate). Sodium dodecyl sulfate at 1 mM, and Tween 80RTM at 1% had 6% and 12% stimulatory effect on the activity of the enzyme respectively, while 1% and 0.5% Triton RTM X-100 caused 67% and 40% inhibition, respectively.

"July 1998" / Thesis (PhD)--Macquarie University, School of Biological Sciences, 1999. / Bibliography: leaves 321-360. / Introduction -- Musculoskeletal anatomy of Mugil cephalus -- A phylogenetic analysis of the Indo-Pacific mullets -- Description of the genera and species of Indo-Pacific mullet -- References. / Systematic, phylogeny and geographical distribution of Mugilidae in Indo-Pacific and Australian waters was reviewed, using morphological and osteological data. The original description, and synonymies, of all genera and species were compiled, and the extant type specimens in the Australian Museum, Queensland Museum, Western Australian Museum, British Museum of Natural History, Paris Museum of Natural History, Amsterdam, and Leiden Museums of Natural History were examined. Specimens of 11 species were collected from 50 coastal sites of Australia between Cairns (Queensland), to Port Elliston (South Australia), and Tasmania. Species that could not be collected were borrowed from the above mentioned museums. Thirty nine genera of mullets have been described worldwide of which 18 genera were recognised as valid in this study and a new genus 'ParamugiV is described. Mullets are most speciose in Indo-Pacific and this research suggests that 27 species (excluding Mugil brousssonetii Valenciennes, 1836), belonging to 14 genera are found in this region. -- The osteology and musculature of Mugil cephalus, as representative of Mugilidae is described. Distinguishing osteological characters within the group are defined. Osteology is a useful discriminant between genera and, in combination with morphometries and meristics, establishes useful criteria for the identification of these fishes. -- Phylogenetic analysis of data was performed using PAUP (Phylogenetic Analysis Using Parsimony) computer software. Keys for identification of genera and species of Indo-Pacific mullets are developed and description of different genera and species are given following the hierarchy of relationships among them on the cladogram. The genera of Cestraeus and Aldrichetta represent the plesimorphic (primitive) subfamily of Agonostominae in Indo-Pacific. Mugilinae containing the other Indo-Pacific mullets is apomorphic (advanced). The cladogram of phylogenetic analysis suggests that Myxus elongatus and Trachystoma petardi are the most plesiomorphic members of the subfamily Mugilinae and sister group to other Indo-Pacific species. Osteology and morphology of alimentary canal of Gracilimugil argenteus also supports the superficial differences of this genus from Liza, and the cladogram separates it as a distinct lineage following Trachystoma, and more primitive compared to the rest of Indo-Pacific mullets. Osteology also strongly suggests that Gracilimugil ramsayii is a junior synonym of Gracilimugil argenteus. The cladogram also separates Ellochelon vaigiensis as a distinct lineage which is plesiomorphic to Liza and the rest of derived Indo-Pacific mullets. Valamugil georgii and Liza parmata display some morphological features different from diagnostic characters for Mugil, Valamugil and Liza. The autapomorphic character states of distinct morphology of maxilla, articular, palatine and lachrymal plus ctenoid scales without membranous hind margin, and lack of pectoral axillary scale grouped them as a distinct lineage in the cladogram and sister-group to Liza. 'Paramugil' a new genus is erected for 'MugiV parmatus and 'Mugil' georgii. The genera Crenimugil and Valamugil are sister-groups, and except morphology of mouth do not reveal any significant differences. -- Twenty species of mullets belonging to twelve genera are found in Australian waters. Species Trachystoma petardi, Myxus elongatus, Gracilimugil argenteus, and Paramugil georgii, are restricted only to Australian waters. Trachystoma petardi is confined to freshwater rivers of north New South Wales to south Queensland. Myxus elongatus inhabits in temperate waters of Australia, Lord Howe Island and Norfolk Island. Gracilimugil argenteus is limited to southern coasts of Australia from Cardwell in Queensland to Geraldton in Western Australia and Paramugil georgii is confined to temperate and tropical coastal waters of Australia. Aldrichtta forsteri is restricted to temperate waters of Australia and New Zealand. The most diversity in Australian mullets is observed in tropical waters of north Queensland, Northern Territory and north Western Australia. Liza macrolepis occurs in the waters of north and north-east Australia. There is no record of Neomyxus leuciscus, Cestraeus spp., Liza affinis, Valamugil speigleri and Valamugil perusii in Australian Waters. / Mode of access: World Wide Web. / xiii, 397 leaves ill

No description available.

The present study focused on using food wastes and feed supplements, e.g. enzymes (bromelain and papain), baker’s yeast and Traditional Chinese Medicines (TCMs) for rearing freshwater fish (grass carp and grey mullet) in Hong Kong. Different types of food wastes, e.g. meats, bones, cereals, fruits and vegetables were collected from local hotels, mixed in different ratios and processed into feed pellets for feeding trials. The cereal dominant food waste feed (FW A) was more suitable for grass carp and grey mullet, with the best growth performance (e.g. feed conversion ratio (FCR), specific growth rate (SGR)) and higher protein digestibility (in grass carp), compared to FW B and FW C which contained higher proportions of meat products. The NBT (Nitroblue Tetrazolium) activities in blood and plasma protein levels were decreased in the grass carp, cultured with food waste feeds without any supplements, compared to the commercial feed, Jinfeng®, 613 formulation (Control). Upgrading FW A by the addition of 1% and 2% mixtures of bromelain and papain significantly increased the feed protein solubility and subsequent to growth (SGR and relative weight gain (RWG)) and feed utilization (e.g. apparent net protein utilization (ANPU), protein efficiency ratio (PER)) in both fish species. The protein and feed utilizations by grass carp were also promoted by the yeast supplements with the optimal dose of 2.5% yeast (S. cerevisiae) added to FW A upgraded by enzymes. This showed that yeast could further enhance nutrient utilization contained in feeds after addition of bromelain and papain. The in vitro study on the grass carp’s plasma treated with TCM extracts also showed that TCM extracts could stimulate plasma bactericidal activity (on Aeromonas hydrophila), possibly through enhancing plasma complement activity. The formulation with Radix scutellaria, Rhizoma coptidis, Herba andrographis and Radix sophorae flavescentis in the ratio of 1:1:2:3 was more effective in enhancing plasma bactericidal activity than single TCM extracts. Besides, R. coptidis and R. scutellaria possessed the strongest antimicrobial activity (in vitro) on fish pathogens (such as A. hydrophila, Lactococcus garvieae and Vibrio cholerae) among the 17 tested TCMs. In addition, TCMs were less likely for developing drug resistant pathogens than antibiotics. Grass carp immunity (NBT activity in blood, plasma bactericidal activity and total immunoglobulin level) was boosted by the addition of TCM formulation and baker’s yeast (S. cerevisiae). The disease resistance to pathogen (A. hydrophila) was also enhanced, with significantly lower mortalities observed in groups feeding with TCM (1 and 2% for 21 to 28 days) and baker’s yeast (2.5 and 5% for 28-56 days). The uses of yeast and TCMs led to positive effects on growth, immunity and disease resistance to pathogens in fish, but the effects (grass carp) were less effectual when both were supplemented in feed. The combined use of both supplements may impair the effects of TCM formulation or yeast in the modulation of gut mircoflora, and upset the balance of beneficial microbial communities. The present study demonstrated the feasibility of using feed supplements (TCM and baker’s yeast) to enhance fish immunity and enzymes upgraded food waste feeds for rearing fish, for the development of a more sustainable aquaculture in Hong Kong.

Thesis (M.Sc. (Zoology & Entomology)) - Rhodes University, 2009.

Orientador: Marlene Tiduko Ueta / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-19T08:04:24Z (GMT). No. of bitstreams: 1 Namba_ThalesKodi_M.pdf: 808082 bytes, checksum: 323221cbe3d59207547b2b04abbf693b (MD5) Previous issue date: 2011 / Resumo: globalização da cultura oriental e o aumento do consumo de pescado cru evidenciaram alguns problemas, entre eles doenças causadas por parasitas. Existe grande incidência de Ascocotyle sp. em peixes mugilídeos, muito utilizados na alimentação humana em diversas partes do mundo. O estudo teve como objetivos verificar a presença de metacercárias de trematódeos Heterophyidae em peixes mugilídeos comercializados no município de Iguape/SP; estabelecer a prevalência e densidade de metacercárias em peixes capturados em praia e rio; estabelecer correlação entre metacercárias e morfometria dos peixes; constatar o hábito alimentar da população do município de Iguape/SP em relação ao consumo do pescado e a eventual ocorrência de zoonose. Foram coletados 120 peixes, 60 tainhas Mugil liza e 60 paratis Mugil curema, sendo 30 de cada espécie capturados em praia e outros 30, em rio. Foram anotados os dados biométricos dos peixes e, após a necropsia, 5g de "pool de vísceras" e de musculatura de cada espécime foram fragmentados e homogeneizados para extração e contagem de metacercárias. M. liza mediram 45,6 ± 4,8 cm, com peso de 860,6 ± 228,4g, M. curema mediram 36,2 ± 2,4 cm, com 448,5 ± 127,8g de peso. As metacercárias, identificadas como Ascocotyle sp., estavam presentes em todos os exemplares de peixes. A prevalência de metacercárias não mostrou diferenças em relação ao sexo dos peixes. A densidade de metacercárias foi maior nas vísceras do que na musculatura para as duas espécies de peixes e maior em M. liza. Em M. curema a densidade de larvas nas vísceras foi significativamente maior em exemplares capturados em rios. Os testes de correlação de Pearson mostraram valores muito baixos entre prevalência e densidade de metacercárias e dados biométricos dos peixes. Residentes no município, pesquisados para levantamento do hábito alimentar, relataram consumir peixes, frequentemente tainhas, na maioria assados ou cozidos. Um total de 3,2% das pessoas pesquisadas relataram consumir peixe cru / Abstract: The world spread of oriental culture and the common use of fish which is not cooked showed some problems related to them like diseases caused by parasites. There is a great incidence of Ascocotyle sp. parasites in mullets fishes, which are part of human culinary spread all over world. The aim of the present study is to estimate the presence of trematode Heterophyidae metacercariae among mullets fishes commercialized at Iguape city; to evaluate the prevalence and density of metacercariae among fishes from the sea and river; to stablish the inter-relation between the presence of metacercariae and the fishes morphometry; to ascertain food habits among people from Iguape city and relate food fish habits to zoonosis occurrence. 120 fishes were select, 60 Mugil liza and 60 Mugil curema, half of each species from the sea and the other half from the river. All fishes biometrical data have been score and, pos-mortem, 5g of visceral pool and muscular tissue from each sample have been fragmented and homogeneized in order to stablish the presence and amount of metacercariae. M. liza were 45,6 ± 4,8 cm length and 860,6 ± 228,4g weigth; M. curema were 36,2 ± 2,4 cm length and 448,5 ± 127,8g weigth. Metacercariae identified as Ascocotyle were present in all fishes. There were no differences for prevalence between fishes sex. The major concentration of metacercariae samples have been identified in visceral organs when compared to muscular tissue of both fish species and much greater at visceral organs from M. liza. Larval visceral concentration of M. curema was significantly high among river species. Pearson correlation tests did not show close association between metacercariae prevalence/density and biometrial fish data. People from Iguape city use to eat grilled or cooked mullet. Total of 3,2% of people consume raw fish / Mestrado / Parasitologia / Mestre em Parasitologia

The spatial and temporal patterns in the ichthyofaunal community composition and structure in Taylor’s salt marsh and adjacent eelgrass beds (Zostera capensis) in the Kariega Estuary, was investigated every two months between May 2006 and March 2007. Total ichthyofaunal abundances and biomass in the salt marsh ranged between 0.55 and 21.7 ind.10m-2 and between 0.03 and 1.9 g.wwt.10m⁻², respectively. There were no significant spatial patterns in the values evident (P > 0.05 in all cases) although seasonal trends were marked, with highest values consistently recorded during the warmer summer months. Investigations into the community structure showed that the ichthyofaunal community within salt marsh was composed almost exclusively of juveniles of estuarine dependant (category II) species, mainly juvenile Mugilidae (<20mm SL) that comprised up to 83% of all fish sampled. Hierarchical cluster analysis and multidimensional scaling did not identify any distinct spatial patterns in the ichthyofaunal community within the salt marsh. The absence of any spatial patterns in the community structure could be related to the absence of any significant spatial patterns in the physico-chemical (temperature, salinity and dissolved oxygen concentrations) and biological (water column and microphytobenthic algal concentrations) variables within the salt marsh (P > 0.05 in all cases). Temporal shifts in the ichthyofaunal community structure within the salt marsh were, however, evident largely reflecting the breeding cycles of individual species within the sub-region. Within the adjacent eelgrass beds, total ichthyofaunal abundances and biomass ranged between 8.4 and 49.4 ind.10m⁻² and between 2.9 and 94.5 g.wwt.10m⁻², respectively. Once again there were no distinct spatial patterns in the abundance and biomass values evident although seasonal patterns were marked. In contrast to the salt marsh, within the in the eelgrass community, there were a large number of adult individuals recorded. Again category II species, the estuarine dependent species, were numerically and gravimetrically dominant. The dominance of category II species reflects the marine dominance of Kariega Estuary. The remaining estuarine utilisation categories did not contribute significantly to abundance or standing stock totals. Hierarchical cluster analysis showed that the salt marsh and eelgrass beds represented two distinct habitats within the Kariega Estuary. Within the salt marsh, the family Mugilidae were numerically dominant contributing 83% of the total catch. Within the eelgrass beds, the sparid, Rhabdosargus holubi and representatives of the family Gobidae contributed 36.3% and 33.9% respectively to the total catch. Estuaries with a wide range of microhabitats have been demonstrated to support a more diverse ichthyofaunal community. Shallow water habitats in general are important areas for juvenile fish within estuaries. Taylor’s salt marsh provides an alternative shallow water habitat, occupied by a distinct ichthyofaunal community composition, with increased food availability and decreased predation pressure, for a wide range of fish species.