Ecotax Announcement
PhD Defense Seminar cum Oral Exam
Department of Biological Sciences, National University of Singapore

All are welcome!

"The Systematics of the Torrent Loaches (Balitoridae: Gastromyzon, Hypergastromyzon and Neogastromyzon) of Borneo"

Tan Heok Hui
Department of Biological Sciences,
National University of Singapore.

Tuesday, 5th August 2003: 3.00pm

DBS Conference Room
Blk S3 Level 5, Department of Biological Sciences
National University of Singapore
Science Drive 4

Visitors may park at Carpark 10
See map

About the Talk

The systematics of the genera Gastromyzon, Hypergastromyzon and Neogastromyzon of the family Balitoridae (Teleostei: Cypriniformes) are revised. All three genera are endemic to Borneo, although there are superficially similar taxa in Indochina and southern China. The Bornean genera possess a high count and enlarged size in the pectoral and pelvic fins, fused pelvic fins and dorso-ventrally flattened bodies. They occur in the headwater and hillstreams, in fast-flowing water over a rocky substratum. All type material of the 13 known species of Gastromyzon are re-described and split into 11 species groups based on morphological characters, with another 23 new taxa discovered. The identities of the two known species of Neogastromyzon are clarified and four new species described. The genus Hypergastromyzon is also examined. The biogeography of the dorso-ventrally flattened balitorid fishes is discussed, and the ecology and biology of these balitorids is also reviewed.

Phylogenetic analyses using morphology and the 12S rRNA region of mtDNA were conducted to investigate the phylogenetic relationships between 18 genera of balitorids - Barbatula, Balitora, Crossostoma, Gastromyzon, Glaniopsis, Hemimyzon, Homaloptera, Homalosoma, Liniparhomaloptera, Nemacheilus, Neogastromyzon, Neohomaloptera, Protomyzon, Pseudogastromyzon, Schistura, Sewellia, Sinogastromyzon and Vaillantella, using Psilorhynchus (Cyprinidae: Psilorhynchinae) as the outgroup. The analyses show that Gastromyzon and Neogastromyzon belong to the same clade and most of the species groups presently recognised within Gastromyzon are natural. A new classification for the Balitoridae is proposed and the dorso-ventrally flattened body form is believed to have evolved independently in Balitoridae at least twice.


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Locations of venues, Dept. Biological Sciences, NUS

Please refer to this map
Parking at Carpark 10

Seminar Room 3 (SR3)
Seminar Room 4 (SR4
Block S3, Level 2
Science Drive 4

Life Sciences Lab 7A-D
Block S2, Level 3
Science Drive 4

Lecture Theatre 32
(LT32, next to Block S1A)
Science Drive 4

Raffles Museum
Block S6, Level 3
Science Drive 2

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Meetings of the Biodiversity & Ecology Journal Club, 2003

Tan Sen Min - "Heritage of the Seas - Ancient mariners' tales to sea-worthy vessels...tradewinds to rare fish of Siam". 2nd August 2003

DBS Seminar
Paul Clark - "Natural History Museum, London - Business or Pleasure, Sir?". 1st August 2003

Tony Wu - "Silent Symphony Under the Waves". 17th July 2003

Archived meetings, Jul 2000 -Dec 2002