The complete ontogeny and postlarval growth of Modiolus capax are described for the first time. Spawning was easily achieved by a gradual increase in water temperature (1°C/h) from 26°C to 31–32°C after exposing the breeders to air for 6 h. The veliger stage (103 ± 8 μm) was reached 23–24 h after fertilization and the low umbo stage (165 ± 9 μm) on the fifth day of culture; growth thereafter was temperature-dependent. At 28.5 ± 0.5°C, competent pediveligers (275 μm) were first observed on the tenth day of culture and on the twelfth day at 26.5 ± 0.5°C, but survival was twice (42%) that obtained at 28.5°C. Most larvae settled between 290 and 310 μm; metamorphosis took 3–4 days. For settlement, several suspended artificial substrata were tested; ropes of twisted anchovy fishing nets captured the larger percentage. However, the use of a downwelling system was the most efficient strategy for the settlement of M. capax over artificial substratum. After metamorphosis, the shell hinge slowly moved toward a more posterior position, and at 440 μm the disconch had adventitious serrated hairs. Seed growth was exponential and temperature-dependent. At 28.0 ± 0.5°C, growth ranged from 26–127 μm day−1, and from 24–63 μm day−1 at 24.8 ± 1.7°C. In both cases, survivorship from pediveliger to seed was approximately 80%.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.
Vol. 26 • No. 4