Structure des assemblages des Post-larves de poissons récifaux du Sud-ouest de Madagascar : Cas de Nosy Ve (Anakao) et le Grand récif de Toliara.

Abstract

As little is known about the structure of reef fish larvae assemblages of the SW Madagascar,
survey has been carried out for comparing reef fish larvae distribution between two reefs
within the region, and evaluating for the first time the general patterns of the reef fish
community structure. Thus, spatial and temporal structure of reef fish larvae assemblages in
the southwest coast of Madagascar were examined nearby the reef of Anakao (ANA), and
Toliara Great Barrier Reef (GRT). Fish larvae were collected during five nights of the new
moon periods from August 2013 through February 2014, using light trap (CAREs). A total of
34 and 36 families (95 and 101 species) were collected from the two sites respectively. Fish
assemblages in abundance differed among reefs: Siganidae and Pomacentridae with high
interest of economic activities were more abundant in ANA and Apogonidae in GRT.
Differences in reef fish assemblage structures between the two reefs through some periods
were mainly due to Pomacentridae (Pomachromis richardsoni and Parma spp1) and Mullidae
(Parupeneus spp), Siganidae (Siganus sutor) and Blenniidae (Istiblennius edentulus). This
difference may be affected by the heavy degradation of the Great reef of Toliara when
compared with Anakao reef. Significant difference on the assemblages of larval reef fish
structure in taxonomic composition and abundance was also detected between seasons. Fish
larvae were more abundant and more diverse for the period of December and January. TheIII
relationship between the structure of reef fish larvae assemblages and abiotic factors differed
between the two reefs. The species composition and the abundance of the larval reef fish
communities in Anakao reef were more influenced by the sea surface temperature, salinity
and water transparency than in GRT.
Keywords: CAREs, capture, post-larvae, structure, reefs, Madagascar