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Macbeth G.M.,Khan Research Laboratories | Palmer P.J.,Bribie Island Research Center
Aquaculture | Year: 2011

Rapid genetic gains for growth in barramundi (Lates calcarifer) appear achievable by starting a breeding programme using foundation stock from progeny tested broodstock. The potential gains of this novel breeding design were investigated using biologically feasible scenarios tested with computer simulation models. The design involves the production of a large number of full-sib families using artificial mating which are compared in common growout conditions. The estimated breeding values of their paternal parents are calculated using a binomial probit analysis to assess their suitability as foundation broodstock. The programme can theoretically yield faster rates of genetic gain compared to other breeding programmes for aquaculture species. Assuming a heritability of 0.25 for growth, foundation broodstock evaluated in two years had breeding values for faster growth ranging from 21% to 51% depending on the genetic diversity of stock under evaluation. As a comparison it will take between nine and twenty-two years to identify broodstock with similar breeding values in a contemporary barramundi breeding programme. © 2011. Source

Slattery S.L.,Innovative Food Technologies | Palmer P.J.,Bribie Island Research Center
Journal of Aquatic Food Product Technology | Year: 2014

The marketing of organically labeled prawns is predominately in a cooked or raw frozen form to avoid the development of melanosis (black spot). Certification for organic status prohibits the use of any added chemicals. The application of 60% CO2/40%N2 modified atmosphere to chilled (raw) prawns using two species of prawn was investigated for the ability to control black spot formation. Sensory assessment and microbiological counts were used to determine the end of product shelf life. Modified atmosphere packaged (MAP) prawns exhibited no melanosis for up to 16 days. The high quality life was retained for 12 days; shelf life of 16 days, according to standard microbiological criteria, was achieved, which is more than twice previously reported for non-MAP prawns. Results suggest MAP may be an effective method for the marketing of organically grown prawns as well as those produced by conventional prawn aquaculture without application of the normal chemicals used to prevent black spot. Copyright © 2014 Crown Copyright. Source

Hoskin M.L.,University of Queensland | Hutchison M.J.,Bribie Island Research Center | Barnes A.C.,University of Queensland | Ovenden J.R.,University of Queensland | Pope L.C.,University of Queensland
Marine and Freshwater Research | Year: 2015

When releasing captive-bred animals into wild populations, it is essential to maintain the capacity for adaptation and resilience by minimising the effect on population genetic diversity. Populations of the jungle perch (Kuhlia rupestris) have become reduced or locally extinct along the Queensland coast; thus, captive breeding of K. rupestris for restocking is presently underway. Currently, multiple individuals are placed in a tank to produce larvae, yet the number of adults contributing to larval production is unknown. We performed a power analysis on pre-existing microsatellite loci to determine the minimum number of loci and larvae required to achieve accurate assignment of parentage. These loci were then used to determine the number of contributing participants during a series of four spawning events through the summer breeding season in 2012-2013. Not all fish contributed to larval production and no relationship was found between male body size and parentage success. In most cases, there was a high skew of offspring to one mating pair (62% was the average contribution of the most successful pair per tank). This has significant implications for the aquaculture, restocking and conservation of K. rupestris. Source

Leland J.C.,Australian Department of Primary Industries and Fisheries | Leland J.C.,Southern Cross University of Australia | Butcher P.A.,Australian Department of Primary Industries and Fisheries | Broadhurst M.K.,Australian Department of Primary Industries and Fisheries | And 2 more authors.
Fisheries Research | Year: 2013

Large numbers of Sagmariasus verreauxi are trapped and hand collected in Australia, but discarded due to size and quota restrictions, and under the unevaluated assumption of few impacts. To test the validity of enforced discarding, trapped and hand-collected S. verreauxi (49-143. mm carapace length - CL) were examined for external damage, placed into cages, transferred to aquaria and monitored (with controls) over three months. Haemolymph was non-repetitively sampled immediately and at one, three, and seven days to quantify stress. Most trapped (64%) and hand-collected (79%) specimens were undersized (<104. mm CL), with the latter method yielding broader ranges of sizes and moult stages. Within-trap Octopus tetricus predation caused the only mortalities (3.3%). Hand collection resulted in much greater antennae and pereopod loss than trapping (53 vs. 4%) but, compared to controls, both methods evoked benign physiological responses that resolved within a week. While most wounded S. verreauxi regenerated all or some missing appendages post-moult, their mean CLs were less than those from intact conspecifics. Simple strategies, including larger mesh sizes, and/or installing modifications to reduce bycatch in traps, careful hand collection, and appropriate release techniques might minimise impacts (including predation) to unwanted S. verreauxi, and help to control stock exploitation. © 2012 Elsevier B.V. Source

Moran D.,Lund University | Smith C.K.,NIWA - National Institute of Water and Atmospheric Research | Lee P.S.,Bribie Island Research Center | Pether S.J.,NIWA - National Institute of Water and Atmospheric Research
Aquatic Biology | Year: 2011

A study was undertaken to measure the effects of conspecific density on the growth, mortality and deformity rate of yellowtail kingfish Seriola lalandi Valenciennes during the first feeding period. Newly hatched larvae were stocked in replicate tanks at initial densities of 40, 60 and 100 ind. l-1 until 30 d post-hatch (DPH). Live prey was administered at frequent intervals in an effort to maintain absolute prey density for all treatments. There was a negative relationship between conspecific density and mean individual length during the first half of the trial, which was attributed to food depletion between supplementary feedings at higher conspecific densities. The effect size (partial eta-squared) of conspecific density decreased considerably during the trial, to the point where the initial stocking density had no discernible effect on cohort growth or mortality rate. The apparent morphological deformity rate ranged from 17 to 32%, but did not differ between treatments. Jaw malformations were the most commonly observed deformity (12 to 30%). The weights of juveniles at the end of the trial were log-normally distributed, with some disproportionately large individuals skewing the weight distributions. There was substantial variation in mortality between and within treatments (74 to 97%), and the conspecific densities of each replicate at 30 DPH did not reflect the relative ordering of the initial treatments. Median individual weight was highly correlated with mortality and weight variance, and the positive skewness of populations decreased as mortality increased. Both trends indicated a strong population size-structuring mechanism. Given the controlled experimental conditions the size-structuring mechanism was not predation or cannibalism. Differential feeding success and an unidentified size-specific mortality agent are hypothesized to be the mechanisms by which mortality was able to strongly influence population size distributions. © Inter-Research 2011. Source

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