Nick King

Broodstock conditioning of New Zealand geoduck (Panopea zelandica) within different temperature and feeding ration regimes

Two-year-old New Zealand geoducks (Panopea zelandica) were conditioned within combinations of three water temperatures (7–8, 11–12 and 16–17 °C) and three feeding rations (10,000, 50,000 and 100,000 cells mL−1 of Chaetoceros mulleri and Isochrysis galbana) for 73 days. Similar percent matured and dry condition index values were observed among temperatures. However, significantly higher dry gonadosomatic indices (GSIdw) were recorded at 8 and 12 °C. Although no difference was detected in percentage of spawned individuals and connective tissue occupation indices, a higher percent matured were recorded when fed 10,000 and 50,000 cells mL−1. A reference group conditioned in pond water became matured 2 months later than the other nine experimental groups, but GSIdw were similar. To maximise reproductive output, we suggest that 2-year-old P. zelandica may be conditioned in pond water for a month and then in 8 or 12 °C seawater with 50,000 cells mL−1.

Enabling and driving aquaculture growth in New Zealand through innovation

Aquaculture is currently the world’s fastest growing food sector, and is well placed to meet the growing demands for aquatic food. Around 50% of the global fish and seaweed food supply is cultivated, amounting to about 68 million tonnes and worth US

Practical Fertilization Procedure and Embryonic Development of the New Zealand Geoduck Clam (Panopea Zelandica)

106 billion in 2008 (Bostock et al. 2010). Based on population growth estimates, it is anticipated that an additional 40 million tonnes of aquatic food will be required by 2030 (FAO 2006). Aquaculture production is developing, ex‐ panding and intensifying rapidly throughout the world with a strong focus on new species and improvement of systems and practices. The importance of food security is increasing, both from a food safety perspective and in terms of supply volume consistency. Rapid growth in the global middle class has increased demand for high quality aquatic food products. International markets clearly show strong preference towards countries with reliable and high quality track records, and targeted efforts to reduce environmental impacts and increase sus‐ tainability. New Zealand is well placed in this endeavour, with a reputation for eco-friendly production practices and strict quality assurance programmes, especially for shellfish. Currently, we are at a critical point in New Zealand’s economic development. The New Zealand Government, through the aquaculture strategy and action plan (MPI 2012), has recognised the huge eco‐ nomic potential of aquaculture exports, and is com‐ mitted to developing this industry to annual sales of NZ

Greenshell™ Mussels: A Review of Veterinary Trials and Future Research Directions

1 billion by 2025. This potential, together with recent changes in the resource management and aquaculture laws, have opened doors and op‐ portunities for growth in seafood production and management of cultivated aquatic resources. Of particular interest will be the development of new high value species, such as abalone, geoduck, flat oysters, trout, kingfish and eels, and value-added products through strong investment in research and innovation. The papers in this special issue highlight the wide scope of current research for new and existing species, and some key biotechnological advances currently underway in New Zealand. While there is a diverse range of species investigated, including abalone, oysters, sea cucumbers, geoduck, crayfish, eels and finfish, we have attempted to organise the contributions to the special issue into five subheadings: larval development; reproduction; farming and production; nutrition and health; and molecular and genetic tools. The increasing reliance on hatchery-produced shellfish seed has faced numerous production challenges that centre on insufficient understanding of larval developmental processes and requirements. Alfaro et al. (2014) placed attention on neurophysiological responses to chemical stimulation during larval development of the abalone,Haliotis iris, with a view to improving larval production processes. Suneja et al. (2014) focused on improving cryopreservation techniques of Pacific oyster (Crassostrea gigas) larvae to increase reliability and flexibility of hatchery-reared oyster larvae. A key step across aquaculture production is the availability of a dependable parental stock or broodstock to maintain a consistent seed resource. In the case of the Chilean flat oyster (Ostrea chilensis), Alipia et al. (2014) developed a cost-effective, noninvasive method to evaluate reproductive state that would increase security of gamete production. To support the newly developing geoduck (Panopea zelandica) industry, Le et al. (2014) exposed twoyear old individuals to different temperature and feeding regimes to improve gonadal condition and gamete production. New Zealand Journal of Marine and Freshwater Research, 2014 Vol. 48, No. 3, 311–313, http://dx.doi.org/10.1080/00288330.2014.933115

Cryopreservation of sperm of the Pacific oyster (Crassostrea gigas): development of a practical method for commercial spat production

Cultivation of the geoduck Panopea zelandica (Quoy & Gaimard, 1835) requires knowledge on embryonic development to produce spat in hatcheries. This study investigated the development of P. zelandica embryos at 15°C and 35 ppt and the optimal sperm:egg ratios for fertilization under hatchery conditions. Panopea zelandica broodstock were induced to spawn by serotonin injection. Sperm and eggs were collected and fertilization was conducted at sperm:egg ratios of: 50:1, 100:1, 500:1, 1000:1 and 10,000:1 over 40 min. The optimal sperm:egg ratio was Panopea zelandica eggs (~80 μm diameter) developed the first and second polar bodies within 15–20 and 50–55 min post-fertilization, respectively. The blastula appeared at ~8 hpf, including the X R and X L cells and the presumptive shell field depression. Gastrulation occurred at 12–18 hpf with organic material apparent at the shell field depression. The mid-stage trochophore, which appeared at around 35 hpf had an apical plate with an apical tuft. The shell field spread to form the periostracum, which expanded and folded into right and left segments covering the late trochophore. The early D-stage veliger appeared at 45 hpf with the soft body being enclosed by two valves and the appearance of the velum. These observations will serve as the basis for future analyses of P. zelandica embryogenesis and for optimization of commercial production of D-veliger larvae.

Optimising the delivery of the key dietary diatom Chaetoceros calcitrans to intensively cultured Greenshell™ mussel larvae, Perna canaliculus

The therapeutic benefits of Greenshell™ mussel (GSM; Perna canaliculus) preparations have been studied using in vitro test systems, animal models, and human clinical trials focusing mainly on anti-inflammatory and anti-arthritic effects. Activity is thought to be linked to key active ingredients that include omega-3 polyunsaturated fatty acids, a variety of carotenoids and other bioactive compounds. In this paper, we review the studies that have been undertaken in dogs, cats, and horses, and outline new research directions in shellfish breeding and high-value nutrition research programmes targeted at enhancing the efficacy of mussel and algal extracts. The addition of GSM to animal diets has alleviated feline degenerative joint disease and arthritis symptoms, and chronic orthopaedic pain in dogs. In horses, GSM extracts decreased the severity of lameness and joint pain and provided improved joint flexion in limbs with lameness attributed to osteoarthritis. Future research in this area should focus on elucidating the key active ingredients in order to link concentrations of these active ingredients with their pharmacokinetics and therapeutic effects. This would enable consistent and improved efficacy from GSM-based products for the purpose of improved animal health.