A5054606599- Aquaculture Nutrition and Growth
- Marine Bivalve and Aquaculture Studies
- Fish Ecology and Management Studies
- Fish Biology and Ecology Studies
- Echinoderm biology and ecology
- Aquatic life and conservation
- Marine and fisheries research
- Aquaculture disease management and microbiota
- Identification and Quantification in Food
- Marine and coastal plant biology
- Marine and coastal ecosystems
- Fish biology, ecology, and behavior
- Animal Nutrition and Health
- Molecular Biology Techniques and Applications
- Aquatic Ecosystems and Biodiversity
- Aquatic Ecosystems and Phytoplankton Dynamics
- Cephalopods and Marine Biology
- Coastal and Marine Dynamics
- Marine Biology and Environmental Chemistry
- Meat and Animal Product Quality
- Comparative Animal Anatomy Studies
- Coastal wetland ecosystem dynamics
- Marine Sponges and Natural Products
- Genetic and phenotypic traits in livestock
- Agriculture and Biological Studies
University of Fort Hare
2014-2024
South African Institute for Aquatic Biodiversity
2022-2024
National Research Foundation
2023
Rhodes University
1998-2011
Abstract Probiotics for aquaculture are generally only selected by their ability to produce antimicrobial metabolites; however, attachment intestinal mucus is important in order remain within the gut of its host. Five candidate probiotics (AP1–AP5), isolated from clownfish, Amphiprion percula (Lacepéde), were examined attach fish and compete with two pathogens, Aeromonas hydrophila Vibrio alginolyticus . Two different radioactive isotopes used quantify competition between pathogens...
The selection of probiotics for aquaculture is usually based on their antagonism towards pathogens. However, other criteria such as growth, attachment to intestinal mucus and production beneficial compounds should also be considered. We suggest a protocol the isolation potential probiotic bacteria in vitro growth characteristics propose ranking index (RI) screen probionts. that lag period doubling time are most important comparison curves, hence RI (t(d)) (lambda) obtained from profile each...
The reuse of aquaculture waste to produce valuable sea cucumber biomass promises reduce environmental impacts and increase incomes. This study aimed assess the suitability potential from abalone farming as feed for warty Neostichopus grammatus infer bioremediation effects feeding. Four diets: waste, fermented algae (sea lettuce Ulva lacinulata) mixed with sand (U+S), pelleted feed, sand, were fed N. under controlled conditions 6 wk. Sea cucumbers exhibited a significantly higher (p <...
This gonad enhancement study investigates the effect of different fresh and formulated feeds feeding regimes on growth quality wild-collected adult sea urchin, Tripneustes gratilla, under farm conditions for over 18 weeks. In first 12 weeks (phase 1), urchins were fed Ulva rigida (U); a 50:50 mixture U. Gracilaria gracilis (UG); G. (G) diet 20U (containing 20% rigida), in final 6 2) study, was changed to feed (20U diet). By end phase 1, produced gonads (50.72 ± 5.4 g) that significantly...
South Africa is in the process of developing a National Freshwater (Inland) Wild Capture Fisheries Policy. A properly focused research strategy essential to guide policy development process, and thus dedicated 'Inland Fisheries' workshop was convened by African Society for Aquatic Scientists June 2018 update further develop list priority knowledge requirements inland fisheries country. The main themes that emerged during were developed contextualised as ten questions. These were: (1) What...
The possible links between river flow, zooplankton abundance and the responses of zooplanktivorous fishes to physico‐chemical food resource changes are assessed. To this end, seasonal abundance, distribution diet estuarine round‐herring Gilchristella aestuaria Cape silverside Atherina breviceps were studied in Kariega Estuary. Spatio‐temporal differences determined for selected variables, fish distribution. Results indicated that, following a flood event winter (>30 m 3 s −1 ), altered...
Water temperature and the presence of sand substrate are considered critical environmental factors affecting growth cultured sea cucumbers. This study investigated effects water temperatures or absence in tanks on N. grammatus fed an equal ration abalone waste for eight weeks. Sea cucumbers with a mean weight 8.34 g were used study. The treatments Ambient + (A S), without (A-S), Cold (C Cold-water (C–S). cold/constant was 16°C representative winter conditions while ambient/fluctuating...
Abstract The integrated multitrophic aquaculture (IMTA) of sea cucumber and abalone has been proposed as a potential bioremediation tool that stimulates increased growth. This study assessed the role stocking density frequency tank cleaning in IMTA on growth, water, sludge bioremediation. was conducted for 16 weeks made four treatments replicates; cocultured with (low density—27: 1 g [abalone (ab): (sc)]) tanks cleaned once week (L1); density) twice (L2); (high density—15:1 [ab:sc]) (H1)...
The effects of temperature on growth, food-conversion ratio (FCR) and feeding intensity juvenile dusky kob Argyrosomus japonicus (23.7±2.6 g fish−1) were assessed over the range 17.5–28.5 °C in a 42-day growth trial. Growth increased with increasing up to an optimum after which it declined. Specific rates 2.05% 1.2% day−1 for fastest (25.3 °C) slowest (17.5 treatments respectively. Food-conversion peaked at lower than growth. Optimal (0.72 kg gain−1) least efficient (1.40 FCR found 21.7 17.5...
South African juvenile dusky kob Argyrosomus japonicus are more abundant in turbid estuaries than clear marine-dominated estuaries. Turbidity can reduce light penetration into the water and create an environment different from that experienced by fish under culture conditions mechanically filtered water. In order to optimize rearing of this species, effects intensity (23–315 lx) feeding method (restricted ration vs. apparent satiation) on growth food conversion ratio (FCR) A. were assessed a...
In this study, we purified and characterized bioflocculant from a mixed culture of three marine bacteria (Cobetia sp. OAUIFE, Bacillus MAYA, Gilbert with accession number JF799092, JF799093, HQ537128, respectively) isolated the sediment sample Algoa Bay South Africa. The consortium showed high flocculation river water, brewery wastewater, dairy resultant flocculating activities 96.4%, 93.7%, 82.2%, respectively. applicability for removing turbidity reducing chemical oxygen demand (COD) these...
Abstract As part of the evaluation new aquaculture species, effect environmental factors on growth, food conversion ratio and survival should be tested. In this study silver kob, Argyrosomus inodorus, were reared for 98 days at three salinities, 15, 25, 35, an average water temperature 18 °C. Fish fed to satiation twice daily. There no differences between treatments in mass gain, feed ratio, feeding intensity (% body d−1), blood osmolality, or survival. During first 84 there was also...
South African abalone Haliotis midae farms utilise large volumes of seawater (c. 500–1 500 l s–1) and produce relatively dilute effluents that are potentially suitable for the integrated culture other species. To test this hypothesis, a marine finfish, silver kob Argyrosomus inodorus, detritivorous polychaete, bloodworm Arenicola loveni loveni, were cultured in farm effluent results compared to controls reared unused seawater. The fed nutritionally complete pelleted diet whereas placed...
Abstract Temperature, feeding frequency and intensity are important determinants of fish growth in aquaculture. As part a research development programme to optimise husbandry techniques for new mariculture species, the dusky kob, Argyrosomus japonicus, this study tested effect four strategies on growth, food conversion ratio (FCR), condition factor, size distribution commercially species. Treatments included restricted ration distributed over three daily feedings, apparent satiation either...
This study aimed to investigate the feeding behaviour (particularly gut fullness and evacuation, preying on rotifers preference in water column) of calanoid copepod, Pseudodiaptomus hessei, as a potential live feed species for aquaculture. Fed starved, male female P. hessei were fed (Brachionus plicatilis) presence absence microalgae 24 hr. Starved copepods consumed more (11.31 ± 1.01, individual rotifers) than (8.06 while number was similar when or starved. Gut evacuation determined by two...
Dusky kob or mulloway Argyrosomus japonicus is a potential aquaculture candidate, but data on growth of this species in South Africa are missing. To determine the effect crowding density (kg m−3) growth, survival and food conversion ratio, juvenile dusky were reared at constant densities 10, 30 50 kg m−3. Both flow index fish within treatment kept 33 (m3 water h−1)−1. There no significant differences quality, between treatments, suggesting that can be using range conditions tested. During...
Abstract Reducing the time to settlement and metamorphosis of abalone larvae is critical for ensuring that settle within seeding site ocean ranching or increase production in hatcheries. This study investigated effect biological (planktonic Nitzschia sp.) chemical (potassium chloride) cues inducing Haliotis midae on diatom‐coated plastic sheets. Larvae were exposed different concentrations KCl (10–20 mM), with being highest at 10 mM first 20 h. Settlement a combined treatment 24 h was...
A nontoxic method that results in distinct and persistent marks Haliotis midae juveniles is fundamental for field-based studies, abalone ranching, stock enhancement programs. Developed (6 days after fertilization) H. larvae were batch-tagged with 25 50 mg L−1 of calcein xylenol orange 24 48 h to determine the effect on survival, settlement, persistence mark shell. Epifluorescence was detected shell spire tagged either or immediately staining (t0) visible 51 when experiment terminated....
The use of action cameras for underwater video sampling provides a non-harmful alternative monitoring endangered and threatened fish populations in clear headwater streams. Here, we examine the baited remote systems (BRUVS) vulnerable species streams Cederberg Wilderness Area, South Africa. We tested whether baits (bread Marmite™) increased number individuals recorded comparison to un-baited BRUVS. Overall, baiting recorded, with bread outperforming Marmite™. Numbers varied notably among...