Potential influence of phytoplankton density on doliolaria and pentactula appearances in sandfish hatcheries
Todinanahary, G.G.B.; Fohy, N.; Andriatsialonana, C.; Eeckhaut, I. (2018). Potential influence of phytoplankton density on doliolaria and pentactula appearances in sandfish hatcheries. SPC Beche-de-mer Information Bulletin 38: 60-63
In: SPC Beche-de-mer Information Bulletin. Secretariat of the Pacific Community: Noumea. ISSN 1095-4943, meer
|   |
| Auteurs | | Top |
- Todinanahary, G.G.B., meer
- Fohy, N.
- Andriatsialonana, C.
- Eeckhaut, I., meer
|
|
|
| Abstract |
The present study reports on the influence of phytoplankton food density on the time of appearance of doliolaria and pentactula. 72 h-old auricularia of Holothuria scabra were used at the beginning of the experiment. Two different food concentrations were used during the larval rearing: ~1500 cells mL-1 day-1 (F1) and ~120 cells mL-1 day-1 (F2). Results show that doliolaria appears significantly – ca 7 days – earlier with F1. Pentactula appears from 22 ± 6.6 days with F1, while with F2 they appear after 29.8 ± 9.3 days, but the difference is not significant. The results suggest that when the sea water is saturated with food (as in F1), the density of auricularia does not affect the larval life span (time of appearance of doliolaria). With low food concentration (as in F2), when the larval density is high, the quantity of food in the medium remains low, suggesting that food competition occurs between the larvae and slows down their development into doliolaria and pentactula. |
|
