Figure 15. 2-d MDS based on a Bray – Curtis similarity matrix. Symbols represent the different islands of Fuerteventura (1), Lanzarote (2), Gran Canaria (3), La
There are differences in the larval community between the different islands (Figure 15). Especially Fuerteventura and Gran Canaria seem to have different communities. The two oceanic stations from La Bocaina east from Fuerteventura are similar to the Fuerteventura community. The oceanic stations northern from the Islands are similar to the community of GC. The two stations western of Tenerife and close to La Gomera are not similar at all. The global ANOSIM test showed there were significant differences (Global R: 0.162, significance: 0.1 %) in assemblage composition among the Islands. The highest difference (Pairwise test: r: 0.679; significance level: 6.7) shows ANOSIM between the Islands of Fuerteventura and Tenerife/La Gomera and Fuerteventura and the oceanic station north of Tenerife. Even the communities between Tenerife/ La Gomera and oceanic north of Tenerife are significantly different (Pairwise test: r: 0.5; significance level: 33.3) though with a low significant level. In general the Tenerife community is different from all other, but still most similar to the community of Gran Canaria (Pairwise test: r: 0.182, significance level: 7). Not overlapping at all are the communities between the La Bocaina assemblage and the community north of Tenerife (Pairwise test: r: 1.0; significance level: 33.3). Most similar are the communities of La Bocaina and the assemblage around Lanzarote (Pairwise test: r: -0.008; significance level: 50.8).
3.4. Diversity of fish larvae For investigating the influence of the different spatial and seasonal factors of seasons (Months), daytime, type of habitat, and regions (single islands) on indices of diversity (Total Species S, Shannon Index H’ and Simpson’s D) and Evenness (Pielou’s Evenness Index J’) ANOVA analyses were performed. The indices of H’, J’, D and S for each station are listed in Table 8. A scatter plot in Figure 16 shows eventual trends among the indices in dependence on the habitat type. Stations with only one single specimen have a Simpson Index of 1 and a Shannon Index H’ of 0 and consequently no Evenness Index can be calculated. A low Evenness J’ indicates a dominance phenomenon. Especially within neritic stations, dominance of species occurs (Figure 16), while in the epi- and mesopelagic realms the species are distributed more evenly.
Inf. Téc. Inst. Canario Cienc. Mar. n°13
Published on Mar 26, 2013
Published on Mar 26, 2013
Technical report consisting on a comprehensive annotated larvae taxa list with the most important taxonomic characters of this region