Molecular ecology and evolution of anemonefishes (Amphiprion spp) in the Indo-Malay Archipelago

In this thesis, genetic differentiation processes on different levels were studied in the anemonefish genus Amphiprion. The studied species inhabit the Indo-Malay Archipelago, located between the Pacific and Indian Ocean comprising the world's richest marine shallow water biodiversity. Differentiation processes on species and intra-specific levels were revealed by phylogenetic and population genetic analyses, based on mitochondrial DNA sequences and microsatellites. Phylogenetic analysis uncovered cryptic diversity within the genus Amphiprion that should be considered when assessing biodiversity of the region and the classification of conservation units. Population genetic analyses showed strong population structuring within the species A. ocellaris, influenced by the oceanographic complexity and dynamic geological history of the area. Information about connectivity patterns among populations of commercially caught coral reef organisms like A. ocellaris can be useful for effective conservation efforts and the sustainable use of marine resources

Molekulare Ökologie und Evolution von Anemonenfischen (Amphiprion spp) im Indo-Malayischen Archipel

In this thesis, genetic differentiation processes on different levels were studied in the anemonefish genus Amphiprion. The studied species inhabit the Indo-Malay Archipelago, located between the Pacific and Indian Ocean comprising the world's richest marine shallow water biodiversity. Differentiation processes on species and intra-specific levels were revealed by phylogenetic and population genetic analyses, based on mitochondrial DNA sequences and microsatellites. Phylogenetic analysis uncovered cryptic diversity within the genus Amphiprion that should be considered when assessing biodiversity of the region and the classification of conservation units. Population genetic analyses showed strong population structuring within the species A. ocellaris, influenced by the oceanographic complexity and dynamic geological history of the area. Information about connectivity patterns among populations of commercially caught coral reef organisms like A. ocellaris can be useful for effective conservation efforts and the sustainable use of marine resources

Interspecific, spatial and temporal variability of self-recruitment in anemonefishes.

Polymorphic microsatellite DNA parentage analysis was used to investigate the spatio-temporal variability of self-recruitment in populations of two anemonefishes: Amphiprion ocellaris and A. perideraion. Tissue samples of A. ocellaris (n = 364) and A. perideraion (n = 105) were collected from fringing reefs around two small islands (Barrang Lompo and Samalona) in Spermonde Archipelago, Indonesia. Specimens were genotyped based on seven microsatellite loci for A. ocellaris and five microsatellite loci for A. perideraion, and parentage assignment as well as site fidelity were calculated. Both species showed high levels of self-recruitment: 65.2% of juvenile A. ocellaris in Samalona were the progeny of parents from the same island, while on Barrang Lompo 47.4% of A. ocellaris and 46.9% of A. perideraion juveniles had parents from that island. Self-recruitment of A. ocellaris in Barrang Lompo varied from 44% to 52% between the two sampling periods. The site fidelity of A. ocellaris juveniles that returned to their reef site in Barang Lompo was up to 44%, while for A. perideraion up to 19%. In Samalona, the percentage of juveniles that returned to their natal reef site ranged from 8% to 11%. Exchange of progeny between the two study islands, located 7.5 km apart, was also detected via parentage assignments. The larger Samalona adult population of A. ocellaris was identified as the parents of 21% of Barrang Lompo juveniles, while the smaller adult population on Barrang Lompo were the parents of only 4% of Samalona juveniles. High self-recruitment and recruitment to nearby island reefs have important implications for management and conservation of anemonefishes. Small MPAs, preferably on every island/reef, should ensure that a part of the population is protected to enable replenishment by the highly localised recruitment behaviour observed in these species

Reduced Genetic Diversity in the Clown Anemonefish Amphiprion ocellaris in Exploited Reefs of Spermonde Archipelago, Indonesia

Populations of the clown anemonefish in Spermonde Archipelago, one of the main collection sites for ornamental fish in Indonesia, are potentially overfished, which might lead to a reduction in population size and genetic diversity. Loss of genetic diversity can reduce the adaptability, population persistence and productivity of the targeted species. Therefore, a study investigating the genetic diversity and its potential correlation to population densities of A. ocellaris was conducted. Two islands were chosen as study sites that differed in the degree of exploitation. Barrang Lompo has a high fishing pressure, whereas Samalona has less. Underwater visual censuses showed that population densities in Samalona were threefold higher than in Barrang Lompo (p = 0.005). Analysis of eight microsatellite loci in 364 tissue samples of A. ocellaris revealed that genetic diversity (numbers of alleles, private alleles, and allelic richness) was significantly reduced at the island with high fishing pressure. Allelic richness was also positively correlated with fish density (p < 0.05). These results indicate that ornamental fishery might be a factor contributing to the loss of genetic diversity in A. ocellaris. Therefore, the marine ornamental trade in Spermonde Archipelago needs to be managed (e.g., management of the fishing strategy, implementation of marine protected areas, regular monitoring, and quota determination). Otherwise the populations of A. ocellaris might collapse

Sample collection in Spermonde Archipelago, Indonesia.

<p>*Parentheses: the number of anemones with a single resident anemonefish and thus excluded from the relatedness analysis.</p><p>**juveniles collected in the 2009 at Barrang Lompo for <i>A. ocellaris</i> were limited to size a maximum of 2 cm total length.</p

Figure 1

<p>Map of study sites (A): Barrang Lompo and Samalona in Spermonde Archipelago, Indonesia. Barrang Lompo, divided into 5 sample sites. Samalona, divided into 4 sample sites. N: North, E: East, W: West, SW: Southwest, and S: South. Black areas on maps depict land and grey areas shallow coral reefs. (B) A group of <i>A. ocellaris</i> (photograph: H. Madduppa); and (C) a pair of <i>A. perideraion</i> (photograph: M. Kochzius) in their respective host anemones.</p

The coefficient of relatedness (<i>r</i>) within reef-sites and within island at Barrang Lompo and Samalona for <i>Amphiprion ocellaris</i> and <i>A. perideraion</i>.

<p>The coefficient of relatedness (<i>r</i>) within reef-sites and within island at Barrang Lompo and Samalona for <i>Amphiprion ocellaris</i> and <i>A. perideraion</i>.</p

Summary statistics for <i>Amphiprion ocellaris</i> (two populations) over seven polymorphic microsatellite loci, and <i>A. perideraion</i> over five polymorphic microsatellite loci.

<p>For each locus, the data given are allele size range (bp = base pairs), number of alleles (<i>k</i>), polymorphic information content (<i>PIC</i>), the coefficient of inbreeding (<i>F_IS</i>), the observed (<i>Ho</i>) and expected (<i>He</i>) heterozygosity, and <i>P</i> values for Hardy-Weinberg exact test (Prob. = Probability test; H₁ = Heterozygote deficiency).</p

Distribution of the average relatedness (<i>r</i>) within group anemones and comparison with the mean relatedness within the island (Table 5).

<p>(A) <i>Amphiprion ocellaris</i> in Barrang Lompo (53 individuals, 17 groups; <i>P</i> = <.0001), (B) <i>A. ocellaris</i> in Samalona (276 individuals, 83 groups; <i>P</i> = 0.515), and (C) <i>A. perideraion</i> in Barrang Lompo (100 individuals, 35 groups; <i>P</i> = <.0001).</p