Larval release and settlement of the marine sponge Hymeniacidon perlevis (Porifera, Demospongiae) under controlled laboratory conditions

The insufficient supply of wild sponge biomass, i.e., "the supply problem," critically limits the development of sponge-derived bioactive natural products and other applications. Intensive aquaculture of sponges through artificial seed rearing may provide an alternative sustainable supply of sponge biomass. To develop the technology of sponge aquaculture, protocols for artificial seed production need to be established. To understand larval release and settlement under artificial controlled environments, a model marine sponge Hymeniacidon perlevis was investigated under controlled laboratory conditions. The larval release of H. perlevis is an asynchronous event in the laboratory-controlled environment Sponge explants attached on substrata release 5 times more larvae than unattached sponge explants. Over the course of 12 days of release, the mean release rate was 7.2 larvae g(-1) wet sponge day(-1) for attached sponges. Over the course of 7 days of release for unattached sponges, the mean release rate was 2.6 larvae g(-1) wet sponge day(-1). Light (6000 lx) stimulated the sponges to release more larvae than did dark incubation. The highest number of sponge larvae (195.8 larvae g(-1) wet sponge) was released at 18 degrees C, while only 48 and 51.7 larvae g(-1) wet sponge were released at 14 degrees C and 25 degrees C, respectively. Larval settlement was favored in dark condition. The highest percentage of larvae settled at 22 degrees C, among all temperatures tested. (C) 2009 Elsevier B.V. All rights reserved.