Judul: Filogeografi Caridina sulawesi Spesies Grup (Crustacea: Decapoda: Atyidae)
Abstrak: Phylogeography study using mitochondrial DNA becomes popular to reveal spatial structuring among close related taxa of animals including the members of atyid shrimp. Caridina H. Milne-Edwards, 1837, the most diverse genus of the family Atyidae, faced a high extinction level especially for those endemic species with a limited range of distribution. Sulawesi Island holds the highest number of endemic species of the genus Caridina, both lacustrine and riverine species are inhabitants with unique distribution because many are restricted to certain areas. Based on several studies, in contrast, C. sulawesi has a wide distribution range from South to Central Sulawesi. However, their systematic status remains unclear due to lack of comprehensive analysis among the populations through genetic approach. This study provides the first molecular approach to reveal (i) the phylogenetic relationships, and (ii) genetic differentiation both intra- and inter populations of C. sulawesi and (iii) the relationship between spatial distribution and the geological processes of Sulawesi Island in the past. The samples were originated from seven localities covering the Central and South Sulawesi. A fragment of cytochrome oxidase subunit I (COI) with a final length of 781 bp was obtained from 36 individuals. A phylogenetic tree shows C. sulawesi to be monophyletic and contains of six different subclades with samples from South Sulawesi as a sister clade of the Central Sulawesi population. These two populations were separated by 10.2 to 11.3% genetic distance (K2P), and mostly correlated to the geographical region where the specimens were found. Caridina sulawesi specimens are potentially contained of two different species (cryptic), although they display sharing morphological characters. From the whole populations, a total of 21 haplotypes were found with moderate to high genetic diversity. The genetic variation was observed higher among the populations than within the populations, with high and significant FST indicated strong genetic structuring in C. sulawesi species group. The current distribution of the lineages of C. sulawesi can be explained by both large and small scales phylogeography. Long-distance dispersal as the result of ancestor life traits thus can expand their distribution. Furthermore, the geographical (mountain range) and ecological barriers (climate change) become barriers to the isolation of the C. sulawesi populations. The hidden diversity that might produce from the cryptic species emphasizes that the conservation efforts should place freshwater management strategies to prevent the population from decreasing through human activities., Studi tentang filogeografi menggunakan penanda DNA mitokondria menjadi populer untuk mempelajari penataan spasial pada kelompok taksa yang berkerabat dekat termasuk anggota udang air tawar famili Atyidae. Caridina H. Milne Edwards, 1837, genus dengan anggota spesies terbanyak, menghadapi tingkat kepunahan yang tinggi terutama untuk spesies endemik yang memiliki cakupan distribusi terbatas. Pulau Sulawesi memiliki jumlah spesies endemik udang Caridina paling banyak, baik spesies yang menghuni perairan danau maupun sungai dengan sebaran unik karena banyak yang terbatas pada daerah tertentu. Sebaliknya, C. sulawesi berdasarkan beberapa penelitian memiliki sebaran yang luas mulai dari Sulawesi Selatan hingga Sulawesi Tengah. Namun demikian, status C. sulawesi masih belum jelas karena belum pernah dilakukannya analisis komprehensif antar populasi dengan menggunakan pendekatan genetik. Penelitian ini menyajikan analisa molekuler pertama untuk mengungkap (i)
Keyword: Conservation genetics, freshwater shrimps, gene flow, landlock species, population genetics