Today De Jong announced it has successfully bred the Blue Spotted Jawfish for the first time. A excerpt from the new March/April edition of Coral Magazine has been published revealing some of the breeding details written by Head Scientist Tom Verhoeven. Below are select quotations from the Coral Magazine post which can be read here.
“At De Jong Aquaculture, we are proud to announce a groundbreaking achievement: the first successful captive breeding of Opistognathus rosenblatti, commonly known as the Blue-spotted Jawfish. This milestone not only highlights our commitment to advancing marine aquaculture but also marks a significant step toward the conservation of this captivating species.
The Blue-spotted Jawfish is celebrated for its vibrant blue spots and intriguing burrowing behaviors, making it a sought-after addition to the aquarium trade. Native to the cooler waters of the Gulf of California, this species is both ecologically and commercially valuable. First described in 1991, O. rosenblatti honors ichthyologist Richard H. Rosenblatt. Its electric blue spots on a yellow or orange body, paired with its “froggy” large eyes, make it a visual delight. During the breeding season, males undergo dramatic color changes, with their front halves turning white and their tails darkening to black. These fascinating traits, combined with its intricate courtship rituals tied to lunar cycles, make this species a marvel of marine biodiversity.
Breeding O. rosenblatti required meticulous attention to its unique environmental and behavioral needs. Contrary to common belief, this species thrives in warmer, tropical water conditions during its spawning phase, despite its association with cooler waters. In captivity, replicating its natural habitat was critical, including providing a deep sandy substrate for burrow construction. These burrows are not only shelters but also key to their reproductive behavior. The fish exhibit fascinating nightly rituals, such as sealing their burrows with fragments of coral for protection. During courtship, males perform elaborate displays, darting into the water column to attract mates.
Spawning involves careful interactions between males and females, with eggs fertilized and guarded within the burrows. Eggs hatch after 7–12 days, releasing larvae that are attracted to light and can be collected with light traps. The larvae, heavily pigmented and fully developed at hatching, required enriched live feeds such as rotifers and copepods to support their rapid growth. Transitioning to Artemia nauplii and providing “green water” conditions further ensured their survival.
By Day 21 DPH, larvae underwent metamorphosis, developing their juvenile coloration. Early sand introduction was crucial for their health and development, emphasizing the importance of replicating natural conditions. As juveniles grew to 4–6 cm, they displayed exceptional resilience and vitality, readily accepting frozen and pellet foods. Unlike wild-caught specimens, they showed no signs of health issues, solidifying the case for tank-bred alternatives.
The successful breeding of O. rosenblatti is a major leap forward for marine aquaculture, proving that even highly specialized species can thrive in captivity with the right care. This achievement reflects our dedication to sustainability, conservation, and scientific innovation. We look forward to sharing all the details in a future article, where we will dive deeper into the breeding of this beautiful and unique species.
We extend our gratitude to the entire De Jong Aquaculture team for their dedication and hard work in making this project a success. Special thanks to Jaimy, whose photography beautifully captures the essence of this remarkable species. By sharing our findings, we hope to inspire further efforts in sustainable marine aquaculture, paving the way for the breeding of other challenging species. Together, we can advance conservation and protect the wonders of the marine world, one species at a time.”
This marks a paramount achievement in aquaculture which will help fuel the sustainability of the hobby and hopefully some day bring commercial scale blue spotted jawfish to market.
