Info,MALANG — A research team led by Prof. Hagus Tarno, a lecturer from the Faculty of Agriculture (FP)Brawijaya University(UB), has discovered 5 new species of wormsNematodafrom the genus Caenorhabditis originating from various regions of Indonesia.
Professor Hagus Tarno said that this finding was published in July 2025 in the internationally reputable scientific journal G3: Genes|Genomes|Genetics, published by Oxford University Press, and has become one of the important contributions of Indonesia in nematode biodiversity research at the global level.
“This research is the result of international collaboration involving UB and the French Centre National de la Recherche Scientifique (CNRS), and is supported by researchers from Academia Sinica, Taiwan, and New York University, United States,” said Hagus Tarno on Wednesday (8/6/2025).
This research utilizes interdisciplinary expertise, ranging from taxonomy, molecular genetics, and nematode ecology.
From the research results, five new species that were successfully identified are Caenorhabditis indonesiana, Caenorhabditis malinoi, Caenorhabditis ceno, Caenorhabditis brawijaya, and Caenorhabditis ubi.
According to him, the two last species specifically immortalize the name of Brawijaya University as a tribute to the university’s contribution in this research.
The naming of C. brawijaya is taken from the name of a Javanese prince who inspired the university’s name, while C. ubi is a direct abbreviation of Universitas Brawijaya Indonesia.
According to Prof. Hagus, the naming of this is not only a symbol of honor, but also a strategy to strengthenBrandingUB in the international scientific world.
“This is how we honor UB. We want the university’s name to remain alive and well known in the scientific world through research like this,” he said.
She added that using the name UB for a new species will keep the university’s name appearing in international scientific publications and databases every time the species is studied by other researchers.
This research was conducted through a series of field expeditions from April to May 2024 on four major Indonesian islands, namely Java, Bali, Lombok, and South Sulawesi.
Out of a total of 204 samples collected, 58 were positive for the nematode Caenorhabditis. These samples were collected from various habitat types, including forests, agroforestry areas, agricultural land, urban parks, and mountainous regions with varying altitudes.
In East Java, sampling was carried out at UB Forest in Malang, the Batu forest area, and the slopes of Mount Bromo.
In South Sulawesi, nematode species were found in the areas of Malino and Lanna, while samples from Lombok were obtained in the regions of Lingsar and Setiling, as well as from Bali in Sayan, Ubud, Marga, Ababi, and Besakih.
The sampling process focuses on decaying plant materials such as flowers, fruits, stems, leaves, wood, and fungi, which are known to be natural habitats of the nematode Caenorhabditis.
For example, C. indonesiana was found on rotten banana flowers in Batu forest, while C. brawijaya was found on rotten banana stems (Musa) on the slopes of Bromo.
These samples were then taken to the Faculty of Agriculture Laboratory UB and also analyzed at the Institut de Biologie de l’École Normale Supérieure (IBENS), Paris, for further identification and characterization processes.
The identification method combines morphological analysis with DNA-based molecular tests. Morphological analysis was performed using a Nomarski microscope to observe the structural details of nematodes.
Meanwhile, molecular analysis was carried out by DNA sequencing of the ITS2 region of ribosomal DNA to distinguish species that are morphologically similar.
In addition, RNA analysis was also conducted on 1,861 single ortholog genes to build a phylogenetic tree showing the evolutionary relationships among species in the Elegans group.
She emphasized that the research team also conducted a series of hybridization or interspecies crossbreeding tests to determine reproductive compatibility.
Interestingly, the research results show an exception to Haldane’s rule, a genetic principle stating that in interspecies hybridization, the heterogametic sex (usually male) tends to be infertile or non-viable.
In this study, some crosses actually produced viable male hybrids, and in some cases, some of them remained fertile.
One of the most notable findings is in the species C. ubi from East Java. This species has been proven to partially crossbreed with Caenorhabditis sp. 41 from the Solomon Islands, producing fertile hybrid males.
This phenomenon is very rare in the nematode world and has become an attractive research model for studying the processes of speciation and genetic incompatibility between species.
Prof. Hagus emphasized that this finding proves the high level of nematode biodiversity in Indonesia, especially in tropical areas.
“Only by exploring four islands, we have already discovered five new species. Imagine if the exploration was done more extensively, the potential for discoveries would be much greater,” he said.
He also emphasized that this research serves as an entry point for further studies on the ecology, evolution, and genetics of nematodes, and opens up opportunities for applied research in agriculture and the environment.
For UB, this success is not only an academic achievement but also strengthens the university’s position on the international research stage. Collaboration with foreign researchers enables UB to access advanced technology, research resources, and opens up opportunities for researcher and student exchanges.
“International collaboration is very important for building research networks and expanding publication opportunities in reputable journals,” said Prof. Hagus.
The article titled “Five new Caenorhabditis species from Indonesia provide exceptions to Haldane’s rule and partial fertility of interspecific hybrids” is openly accessible because it was published under a Creative Commons Attribution license.
This allows researchers around the world to utilize the research results for further studies. This publication not only introduces five new species to the world, but also strengthens Indonesia’s and UB’s reputation as one of the centers for nematoda biodiversity research in Southeast Asia.
“Naming two species with the name UB is a symbol that the academic and scientific contributions of the university are not only recognized at the national level, but also preserved in the history of world science,” he said.