Spawning, Larval Development, and Juvenile Rearing of White Teatfish Holothuria fuscogilva in the Hatchery in the Philippines

Abstract

The significant exploitation of the high-value white teatfish, Holothuria fuscogilva, has raised global concerns about the species' wild populations. Aquaculture technology development may potentially restore dwindling stocks; however, it remains to be established in the Philippines. This study reported the first successful mass production of H. fuscogilva in the Philippines. The broodstock was collected on two occasions from Tubajon, Laguindingan, Misamis Oriental (May and June 2020). All broodstock survived with no evisceration in 30 min (27.8–35.2 ̊C) of transport to the hatchery. Broodstock was induced to spawn using spawning techniques adopted from those of Agudo (2006) with modification in three events (July, August, and December 2020). However, successful spawning only occurred when the temperature was reduced by 7 ̊C (extreme cold shock).H. fuscogilva produced 3.4 million eggs in three spawning inductions at > 88% fertilization rate. The eggs hatched 2–3 d post-fertilization. Generally, the embryonic development of H. fuscogilva was radial holoblastic, and the larval development had the same pattern as other sea cucumber species. The auricularia stage was observed at Days 4–27, followed by the doliolaria stage at Days 28–32, and pentactula stage at 33–39 d post-fertilization. An average of 1.1% of the fertilized eggs proceeded to the juvenile stage at 40–45 d post-fertilization. Over 4 mo, juveniles grew at 0.03 ± 0.002 g d–1. This is the first documentation of the larval development of H. fuscogilva and the first production of the juvenile stage in the Philippines, where 15,000 juveniles are being grown in the hatchery for future broodstock.