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Metadata
Title
bioecologie des hippocampes dans le lagon du grand recif de toliara essai d’elevage experimental des hippocampes, des syngnathes et des amphiprions de l’ocean indien et/ou de la mediterranee
Authors
LANDY SOAMBOLA Amelie
Research Topic
Abstract
Observations and samplings of the Hippocampus were carried out in the lagoon of the Great Reef of Toliara,
during 2006 to 2008, on the three inventoried species of Hippocampus: Hippocampus borboniensis H. fuscus
and H. histrix. H. borboniensis and H. fuscus were recruited respectively with an average overall length of 5,8
cm and 5,7 cm corresponding to the age of 3 and 2 months. The first maturity take place with an average overall
length of 6,1 cm at the 8 months age of for H. borboniensis and 5,58 cm at the 8 months age and half for H.
fuscus. Two parameters of growth obtained are 15,7 cm for L∞ and 0,6 yearly for K at H. borboniensis and
12,2 cm for L∞ and 1 yearly for K at H. fuscus. Longevity was estimated at 5,48 years for H. borboniensis
against 3,22 years for H. fuscus. Thus, the results of the studies gave the informations on the bioecology of these
three species which run of the dangers of overexploitation. So strategies of management were proposed in
opposition to these dangers.
Moreover, experimental breeding of " H. borboniensis ", the " Amphiprion ocellaris " and " Syngnathus typhle
rondeleti " were the subject of our study in the laboratory within the Institute Halieutic of the Marine Science
(IH.SM of the University of Toliara, Madagascar), of the Aquarium of the Réunion, the EBMR and the Institute
Oceanographic Paul Ricard. (I.O.P.R) in France. The optimum conditions for breeding of the local species of H.
borbonienis were met at an average temperature of water 23°C and a density from 3 to 7 individuals /l. So the
new born from 1,2 cm got to the size of 6,22 cm at the 2 months age and a size at the first spawning of 10 cm.
The optimum conditions for breeding of Amphiprion ocellaris of the Indian Ocean was obtained at a
temperature of water 25°C and an density of 13 individuals /l. Indeed, the larvae arrived at commercial size after
3 months of captivity. As for the Syngnathus, at the optimum condition for breeding of temperature of 21,9 °C
and density of 0,26 individuals /l, the new born were arrived at the juvenile stage after 4 to 9 weeks. The results
of the experimental breeding are encouraging with a fairly high survival rate of survival for the three studied
species. These fish breeding of aquarium were coupled with the control of planktonic cultures like the
phytoplankton represented by Chlorella sp , zooplanctons them by Brachionus s, Artémia sp and the Copepoda.
The proposal for an application in active phase of the knowledge obtained at the time of the bioecologic study
and the experimental breeding is presented in the last part of this manuscript. A robust project of eclosery and
exposure of fish of aquarium was studied and presents a cost of 354 436 000 Ar.
Volume
1
Date of publication
May 26, 2009
Institution (University)
Institut Halieutiques et des Sciences Marines Université de Toliara
Page numbers (pp)
207