The Diversity of Freshwater Crab in Jambi

Nama : Vendi Eko Susilo G352110071
Pembimbing : Achmad Farajallah Daisy Wowor
Tanggal Lulus : 6 Nopember 2013
Judul Thesis : Keanekaragaman Kepiting Air Tawar (Crustacea: Decapoda: Brachyura) Di Propinsi Jambi
The Diversity of Freshwater Crab (Crustacea Decapoda: Brachyura) in the Regencies of Batanghari and Sorolangun, Jambi Province
Ringkasan :
Kepiting air tawar merupakan anggota kelompok Ordo Decapoda, Sub Ordo Brachyura. Kepiting air tawar dapat ditemukan di seluruh badan perairan sungai mulai dari dataran rendah sampai pegunungan. Keanekaragaman kepiting air tawar terus mengalami penurunan yang disebabkan oleh perubahan-perubahan kondisi habitat. Provinsi Jambi merupakan daerah dengan tingkat laju pembalakan hutan yang sangat tinggi dibandingkan dengan daerah Asia yang lain. Pembalakan hutan menyebabkan terjadinya fragmentasi habitat yang berdampak pada perubahan susunan dan komposisi biota, baik biota darat maupun perairan tawar. Penelitian ini dilakukan untuk mempelajari keanekaragaman kepiting air tawar di Kabupaten Batanghari dan Sorolangun Jambi pada beberapa tipe habitat.

Penelitian dilakukan di Kabupaten Batanghari dan Sorolangun pada sungai yang ada pada habitat kebun karet, kebun kelapa sawit, hutan rakyat dan hutan sekunder. Koleksi spesimen menggunakan hand net dan bubu. Sampel yang berhasil diperoleh kemudian diawetkan dalam alkohol 70%. Selain itu beberapa fakor lingkungan yang diamati adalah ketinggian (m), kecerahan (m), kecepatan arus (m/s), suhu (°C), kedalaman (m), lebar (m), pH dan tipe substrat sungai.

Di Kabupaten Batanghari dan Kabupaten Sorolangun didapatkan 5 spesies kepiting air tawar, yaitu Parathelphusa tridentata, P. batamensis, P. maindroni, P. maculata dan Geosesarma sp. Berdasarkan analisa gen COI mitokondria, P. batamensis dan P. maindroni memiliki perbedaan nukleotida sebesar 1.45% (8 nt).

Di Kabupaten Batanghari, faktor lingkungan yang mempengaruhi distribusi P. batamensis adalah pH, suhu dan lebar sungai, sedangkan untuk P. maculata, P. tridentata, dan Geosesarma sp adalah kedalaman; P. maindroni adalah ketinggian dari permukaan laut. Sedangkan, di Kabupaten Sorolangun, faktor lingkungan yang mempengaruhi distribusi Geosesarma sp dan P. maculata adalah kecepatan arus, P. batamensis dan P. tridentata adalah kedalaman dan kecerahan, dan untuk P. maindroni adalah ketinggian dari permukaan laut.

Keanekaragaman kepiting air tawar tertinggi terdapat pada habitat hutan rakyat baik yang terdapat di Kabupaten Batanghari maupun Kabupaten Sorolangun. Sedangkan keanekaragaman kepiting air tawar terendah terdapat pada habitat kebun kelapa sawit  di Kabupaten Sorolangun.

Struktur komunitas kepiting air tawar di Kabupaten Batanghari dan Sorolangun berbeda di setiap habitat. Parathelphusa batamensis ditemukan pada semua tipe habitat di Kabupaten Batanghari dan Sorolangun.

Hasil analisa uji statistik Multiple Comparisons menunjukkan bahwa di Kabupaten Batanghari jumlah individu yang ditemukan di hutan rakyat dan di kebun kelapa sawit sangat berbeda (P<0.01), begitu juga dengan yang ditemukan di hutan rakyat dan kebun karet. Di Kabupaten Sorolangun, jumlah individu kepiting antara yang ditemukan di kebun karet dan di hutan sekunder sangat berbeda (P<0.001).

Summary :
Freshwater crabs are members of the order Decapoda, sub order Brachyura. They can be found in all freshwater bodies. They can also adapt to semi-terrestrial and terrestrial environments. The diversity of freshwater crabs has declined due to habitat changes. Jambi province is an area with high deforestation rate compared to other Asian regions. The deforestation causes habitat fragmentation which alters the biota composition, both terrestrial and aquatic biota. The aims of this study were to study the diversity of freshwater crab in the Regencies of Batanghari and Sorolangun of Jambi in several habitats type.

The study was conducted in rubber plantations, oil palm plantations, community forests and secondary forests located at the Regencies of Batanghari and Sorolangun. The specimens were collected by using hand net and fish trap which were preserved in 70% alcohol. The environmental factors observed were altitude (m), brightness (m), velocity (m/second), temperature (°C), depth (m), width (m), pH and substrate type.

In Batanghari and Sorolangun Regency, was found 5 species of freshwater crabs that consisted of Parathelphusa tridentata, P. batamensis, P. maindroni, P. maculata and Geosesarma sp. through morphological identification. Based on mitochondrial COI gene analysis, P. batemensis and P. maindroni have nucleotide difference 1.45% (8 nt).

In Batanghari Regency, the environmental factors affecting the distribution of P. batamensis were pH, temperature and width of the river, while the distribution of P. maculata, P. tridentata, and Geosesarma sp was affected only by depth; and P. maindroni was altitude. In Sorolangun Regency, the environmental factors affecting the distribution of Geosesarma sp and P. maculata were velocity, the distribution of P. batamensis and P. tridentata was affected by depth and brightness, while the distribution of P. maindroni was influenced by altitude.

The highest freshwater crab diversity was found in community forest of both regencies. The lowest freshwater crab diversity was found in oil palm plantation  habitat in Sorolangun Regency.

The community structure of freshwater crab in Batanghari and Sorolangun Regencies was different in each habitat. Parathelphusa batamensis was found in all habitat types in both regencies.

The results of the Multiple Comparisons test showed that In Batanghari Regency there were differences in number of individual crab among community forest and oil palm plantation  (P<0.01), as well as at community forest and rubber plantation. In Sorolangun Regency, the number individual of crabs among rubber plantation and secondary forest (SF) were significantly different (P<0.001).

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