Character Size
Home > Our Projects > Preliminary survey to establish collaborative research on freshwater and estuarine fish fauna of the Philippines: Toward elucidation of the larval dispersal mechanism of diadromous fish along the Kuroshio Current
Preliminary survey to establish collaborative research on freshwater and estuarine fish fauna of the Philippines: Toward elucidation of the larval dispersal mechanism of diadromous fish along the Kuroshio Current
Prior to World War II, American researcher Dr. A. W. C. T. Herre conducted extensive research on the classification and ichthyofauna of Philippine-river fishes. However, all type specimens kept in Manila were lost during the war, and since then, only a few taxonomic studies have been conducted on Philippine-river fishes. In order to understand the Philippine-river fishes, a taxonomic review based on the latest knowledge is essential. The ichthyofauna varies from region to region, and there are thought to be endemic species and populations in small areas, but knowledge about them is currently very limited. In the Philippines, development has progressed and invasive species such as tilapias and guppies have become widespread, and it is thought that the biodiversity of rivers is being lost, so elucidation of the ichthyofauna and population structure is urgently needed to conserve it.
Many of the fish species living in Philippine rivers are presumed to be diadromous fish that spend their pelagic larval stage in the sea. Some of them have an opportunity to disperse their larvae to other rivers or islands far away during the pelagic stage. However, knowledge about the mechanism of dispersal is poor. For example, rare fishes that are assumed to have been brought from Southeast Asia are occasionally found in rivers along the Kuroshio Current in Japan, but due to lack of taxonomic research, they are often unable to be identified as species, and in many cases, due to lack of accurate distribution information, it is not even possible to identify potential sources. In addition, it is assumed that there are common species that receive a large number of larvae from Southeast Asia every year, but the actual state of dispersion is unknown. The Philippines is expected to be an important region as a source of larvae for neighbouring countries, especially Taiwan and Japan in the Kuroshio Current basin, but the connectivity between regions is unknown. Elucidation of the classification and fish fauna in the Philippines will contribute to the conservation of biodiversity not only in the Philippines but also in neighbouring countries and is expected to provide important knowledge that will lead to the elucidation of the dispersal mechanism of larvae and understanding of the interesting ecology of freshwater fish migration across the sea.
In this project, we will conduct a feasibility study to establish a system for elucidating the fish fauna in multiple regions of the Philippines.
Implementation Organisations (as of December 2024)
Principal investigator
Dr. Ken Maeda
Staff Scientist, Okinawa Institute of Science and Technology (OIST)
Collaborators
| Japan | Midori Iida (Hokkaido University) Hirozumi Kobayashi (Natural History Museum and Institute, Chiba) Shotaro Hirase (The University of Tokyo) |
|---|---|
| Philippines | Herminie P. Palla (Western Philippines University) Emma L. Ballad (Bureau of Fisheries and Aquatic Resources) Jemimah Ziegler (Bureau of Fisheries and Aquatic Resources) Glycinea M. de Peralta (Cagayan State University) Ernesto S. Del Rosario, Jr. (Mariano Marcos State University) |
Project Updates
The 2024 field survey has started in the Philippines.
- Duration of the field survey: November 22 to 30
- Location: Palawan Island and Luzon Island in the Philippines
- Report: PDF 3MB
Project Reports & Deliverables
Nagao Natural Environment Foundation
4-20-9 Midori, Sumida-ku
Tokyo 130-0021 Japan
Phone : +81-3-6659-2070
Fax : +81-3-6659-2272