The taxonomy and systematics of corals genus Favia in Thai waters
Our understanding of the composition of coral communities is based on species identification, which is the baseline for all biological disciplines where it provides the building blocks for biological research. Traditional taxonomy and more recently systematics is also central to our understanding of the biodiversity of ecosystems such as coral reefs. This role has become more important as coral reefs worldwide have begun to be influenced by the activities of humans such that, despite their persistence in geological time, coral reefs have begun an unprecedented decline in abundance and community composition over the last three decades (Hughes et al., 2003). Given potential losses to coral reefs due to disturbance and climate change, the need for knowing what is being lost (i.e. via effective taxonomies) cannot be underestimated.
This project focuses on exploring some of the taxonomic issues associated with Favia, particularly in regard to the largely unexplored coral fauna of Thailand. Favia is one of the most widely and uniformly distributed coral species throughout the Indo-Pacific and the Atlantic, and is represented by approximately 30 species worldwide (Veron, 2000). Besides being widely distributed, most species have wide depth ranges on reefs, and are tolerant of a wide range of environmental conditions (Veron, 2000). As a result, a colony on an intertidal reef flat may appear very different from another colony of the same species on the same reef but from deeper water, and both may be different from other colonies of the same species in similar conditions but from a different locality. In many cases Favia are also difficult to recognize underwater due to color variation and that the soft tissue of living polyps obscures underlying skeleton structures. Whilst Carlon & Budd (2002) conclusively showed the distributions of morphotypes with depth in Favia fragum in the Atlantic, no information currently exists on the taxonomy and morphological variation of Favia in the Indo-Pacific despite having more species.
Thailand’s coastal waters provide an ideal study location in the Indo-Pacific to address questions on biogeography, taxonomy, and systematics of the genus Favia. The Thai coastline is divided into two main regions: the Gulf of Thailand on the Pacific side and the Andaman Sea in the Indian Ocean. Both of these regions contain favorable conditions for coral reef development. The coral reefs in Thailand are well developed and extensive with an estimated 153 km2 of coral dominated ecosystems along a total coastline of 2614 km. These reefs are categorized into four distinct areas with different physical conditions: the north (inner gulf), the eastern shore, the western shore of the Gulf of Thailand and the coastline on the Andaman Sea (Chou et al., 2002; Spalding et al., 2001).
The main aims of this project are to:
1) Assess species boundaries within Favia in Thai waters and whether this can be done purely on morphological characters, or is genetic assessments necessary.
2) Explore whether there are any ecological and morphological patterns evident in terms of species compositions, distribution, and abundance in Favia species in Thai waters.
3) Investigate the hybridization potential among closely related species of Favia in Thai waters.
4) Describe the genetics of Symbiodinium that are associated with Favia species in Thai waters.
5) Understand whether the land barrier between the Gulf of Thailand and the Andaman Sea influences the ecological and evolutionary relationships of Favia species in Thai waters.
6) Re-describe the genus Favia for Thailand.
