Fungal diversity of mangrove-associated sponges from New Washington, Aklan, Philippines.

Sponge-associated fungi are the least explored marine fungal groups. It is only in recent years that fungal symbionts of marine sponges have received attention mainly due to the isolation of bioactive metabolites while not much attention was given to their specificity, biogeography and exact roles in marine sponges. The diversity of fungi associated with mangrove sponges (Axinella sp., Halichondria cf. panicea, Haliclona sp., Tedania sp.) collected from New Washington, Aklan, Philippines were investigated using morphological observation. A total of 110 species of sponge-associated fungi belonging to 22 genera of ascomycetes with 18 genera of asexual morphs whose sexual stage is unknown, 2 genera of basidiomycetes, 21 morphospecies of Mycelia sterilia, 1 unidentified yeast species and 11 unidentified hyphomycetes were isolated from four species of mangrove sponges. This is the first study that explored the diversity and ecology of sponge-associated fungi in mangrove habitats from the Philippines. The results of the study suggest host-preference by various fungal taxa and the development of fungi on these hosts appeared to be strongly influenced by the characteristics or nature of the immediate environment.

The Kuroshio current influences genetic diversity and population genetic structure of a tropical seagrass, Enhalus acoroides.

Information on genetic diversity and differentiation of seagrass populations is essential for the conservation of coastal ecosystems. However, little is known about the seagrasses in the Indo-West Pacific Ocean, where the world's highest diversity of seagrasses occurs. The influence of sea currents on these populations is also unknown. We estimated the genetic diversity and population genetic structure and identified reproductive features in Enhalus acoroides populations from the Yaeyama Islands, Hainan Island and the Philippines. The Philippines are situated at the centre of the E. acoroides range, Yaeyama and Hainan are peripheral populations, and the Yaeyama population is at the northern limit of the species range. The powerful Kuroshio Current flows from the Philippines to Yaeyama. Genetic analyses using nine microsatellite markers indicated that reproduction of E. acoroides is mostly sexual. Clonal diversity does not decrease in northern populations, although genetic diversity does. However, the genetic diversity of the Yaeyama populations is greater than that of the Hainan populations. Significant genetic differentiation among most populations was evident; however, the Yaeyama and north-east Philippines populations were genetically similar, despite being separated by ~1100 km. An assignment test suggested that recruitment occurs from the north-east Philippines to Yaeyama. The strong current in this region is probably responsible for the extant genetic diversity and recruitment patterns.

Development of 10 novel polymorphic microsatellite markers for the Indo-Pacific horned starfish, Protoreaster nodosus.

Ten novel polymorphic nuclear microsatellite simple sequence repeat (SSR) markers were isolated from an Indo-Pacific horned starfish, Protoreaster nodosus. The isolated SSR markers provided polymorphisms of 2-9 alleles per locus in three populations obtained from Indonesia and the Philippines. The expected and observed heterozygosities ranged from 0.049 to 0.691 and from 0.050 to 0.800, respectively. Pairwise FST values among three populations ranged from 0.018 to 0.050 (global FST=0.031). All P. nodosus individuals collected from three populations exhibited different genotypes for the ten identified SSR markers, indicating that P. nodosus reproduces sexually. Then the developed SSR markers will be useful for studying the population and conservation genetics of P. nodosus.