Summary

Closing the life cycle of Black Jewfish (Protonibea diacanthus): a new candidate for aquaculture in northern Australia.

Black Jewfish aquaculture is in the early stages of development, with three batches of juveniles successfully produced at the Darwin Aquaculture Centre (DAC) in the Northern Territory.

Initial bottlenecks identified include handling stress, low larval survival, and cannibalism during early juvenile stages. This project aims to address the following key research questions:

1. What factors are critical to improving rearing procedures for Black Jewfish?
2. Are Black Jewfish a suitable species for aquaculture?

To answer these questions, the project team will undertake a series of trials to determine optimum growing procedures for Black Jewfish in aquaculture systems.

This requires access to high-quality, fertilised Black Jewfish eggs, which is a limiting factor with current broodstock holding systems at the DAC. The addition of new broodstock (adult) housing capacity will increase availability of sexually mature fish and therefore fertilised eggs, enabling two annual spawns, around the Black Jewfish natural spawning season, to undertake larval rearing, nursery, grow-out and broodstock handling trials, targeted at developing and refining rearing protocols for Black Jewfish.

Key areas of working include:

• Larval rearing trials focused on optimising nutrition, weaning, and water quality to improve survival rates.
• Nursery trials aimed at reducing cannibalism and handling stress.
• Grow-out trials conducted on farms to assess and refine handling and feeding techniques.
• Broodstock focused on animal handling for gonad assessment.

As hatchery-produced fish reach harvest size, they will be assessed for end-product quality and marketability. This will contribute to the project’s primary objective: to assess the feasibility of Black Jewfish for commercial aquaculture and produce the first hatchery manual for production.

Expected outcomes

The expected outcomes of the project are:

• A series of publications describing the development of Black Jewfish and the results of trials aimed at determining optimal rearing procedures for this species in aquaculture systems.
• Improved growth and survival rates of Black Jewfish.
• Hatchery production of commercial-scale batches of Black Jewfish fingerlings.
• Increased capacity and capability of commercial project partners through hands-on experience with Black Jewfish farming during grow-out trials.
• Greater confidence among industry investors and proponents.
• A comprehensive market analysis for Black Jewfish aquaculture.

The project will have a significant impact on aquaculture stakeholders in northern Australia by providing practical, instructional information on how to successfully grow Black Jewfish in a commercial setting.

The ability for farmers to sell market sized Black Jewfish has the potential to stimulate market demand for the species and contribute valuable insights into expected profitability for both new and established participants in the industry.