Analysis of the Potential Distribution of Eels (Anguilla spp.) Along the Luk Ulo River, Kebumen Regency, Central Jawa, Indonesia
Abstract
Eels are catadromous fish that utilize river systems, especially estuaries, as migration corridors from marine to upstream habitats. This study assessed the abundance potential and spatial distribution of eels in the Luk Ulo River, Kebumen Regency, to support conservation efforts. Sampling was conducted at 10 stations from upstream areas to the estuary. Analyses included morphometric identification, spatial distribution, length–weight relationships, growth modeling, Principal Component Analysis, and cross-correlation with environmental parameters. A total of 30 individuals were collected, consisting of two species: Anguilla bicolor bicolor (22 individuals) and A. marmorata (8 individuals). Most specimens (93.54%) were in the yellow eel phase, indicating a growth stage dominance, while 6.45% were elvers. The mean length was 49.90 cm (SD = 34.95 cm), with non-normal distribution (p < 0.05) and dominance in the 32–48 cm size class. Growth followed a negative allometric pattern (W = 0.00083L2.87), where length increases faster than weight, with a high determination coefficient (R² ≈ 0.93), indicating a strong relationship between length and weight. The population structure suggests that the Luk Ulo River primarily functions as a growth habitat with stable environmental conditions. Cross-correlation analysis showed strong positive relationships between eel abundance and salinity (r > 0.81), total dissolved solids (r > 0.79), and phosphate (r > 0.61), indicating that higher values of these parameters are associated with increased eel presence.
Full text article
References
Aoyama, J. (2009). Life history and evolution of migration in catadromous eels (genus Anguilla). Aqua-BioSci. Monogr (ABSM), 2(1),1-42. https://doi.org/10.5047/absm.2009.00201.0001
Aoyama, J., Nishida, M., & Tsukamoto, K. (2001). Molecular phylogeny and evolution of the freshwater eels, genus Anguilla. Mol, Phylogenet, Evol., 20, 450-459. https://doi.org/10.1006/mpev.2001.0987
Aoyama, J., Wouthuyzen, S., Miller, M. J., Inagaki, T., & Tsukamoto, K. (2003). Short-distance spawning migration of tropical freshwater eels. Biol, Bull., 204, 104-108. https://doi.org/10.2307/1543494
Arai, T., Kadir, S.R.A. (2017). Diversity, distribution and different habitat use among the tropical freshwater eels of genus Anguilla. Scientific Reports, 7(1), 1-12. https://doi.org/10.1038/s41598-017-07837-x
Arai, T. (2014a). Evidence of local short-distance spawning migration of tropical freshwater eels, and implications for the evolution of freshwater eel migration. Ecology and Evolution, 4(19), 3812-3819. https://doi.org/10.1002/ece3.1245
Arai, T. (2014b). Do we protect freshwater eels or do we drive them to extinction? SpringerPlus, 3, 534, http://www.springerplus.com/ content/3/1/534. https://doi.org/10.1186/2193-1801-3-534
Arai, T. (2016). Environmental Biology of Anguillid Eels. Springer. https://doi.org/10.1201/b19925
Arai, T., & Chino, N. (2019). Variations in the migratory history of the tropical catadromous eels Anguilla bicolor bicolor and A, bicolor pacifica in Southeast Asian waters. J. Fish Biol., 94(5), 1-7. https://doi.org/10.1111/jfb.13952
Arai, T., & Kadir, S.R.A. (2017). Opportunistic spawning of tropical anguillid eels Anguilla bicolor bicolor and A. bengalensis bengalensis. Scientific Reports, 7, 41649. https://doi.org/10.1038/srep41649
Arai, T. (2022). Early life history and recruitment processes of a tropical anguillid eel (Anguilla marmorata) revealed by otolith Sr:Ca ratios and microstructure. Biology, 11(6), 803. https://doi.org/10.3390/biology11060803
Astuti, R., & Rahul. (2023). Analisis Hubungan Panjang-Berat dan Faktor Kondisi Ikan Sidat (Anguilla marmorata) di Danau Laut Tawar, Simeulue Barat, Kabupaten Simeulue, Provinsi Aceh. Jurnal Perikanan Unram, 13(1), 98-105. https://doi.org/10.29303/jp.v13i1.439.
Badan Pusat Statistik Kabupaten Kebumen. (2024). Kabupaten Kebumen dalam Angka 2024. Kebumen.
Chang, Kang-tsung. (2018). Introduction to Geographic Information Systems (9th ed.). McGraw-Hill Education.
Dekker, W. (2003). Québec Declaration of Concern: the worldwide decline of eel resources necessitates immediate action. Fisheries, 28, 28-30. https://doi.org/10.1577/1548-8446(2003)028
Edeline, E., Lambert, Rigaud, C., & Elie, P. (2006). Effects of body condition and water temperature on Anguilla anguilla glass eel migratory behavior. Journal of Experimental Marine Biology and Ecology, 331(2), 217-225. https://doi.org/10.1016/j.jembe.2005.10.010
Effendie, M. I. (2002). Biologi Perikanan. Yayasan Pustaka Nusatama, Yogyakarta
Ege, V. (1939). A revision of the genus Anguilla Shaw. Dana Rep., 16, 8256. https://doi.org/10.1163/9789004629585
Fahmi, M.R., Solihin, D.D., Soewardi, K., Pouyaud, L., Shao, Z., & Berrebi, P. (2013). A novel semi-multiplex PCR assay for identification of tropical eels of genus Anguilla in Indonesian waters. Fish Sci., 79, 185-191. http://doi.org/10.1007/s12562-012-0587-0.
Falah, I.N., Adharini, R.I., & Ratnawati, S.E. (2023). Molecular Identification of Elvers (Anguilla spp.) from River Estuaries in Central Java, Indonesia Using DNA Barcoding Based on mtDNA CO1 Sequences. Jurnal Ilmiah Perikanan dan Kelautan, 15(1), 121-130. http://doi.org/10.20473/jipk.v15i1.36416.
Hakim, A.A., Kamal, M.M., Butet, N.A., & Affandi, R. (2015). Komposisi spesies ikan sidat (Anguilla spp,) di delapan sungai yang bermuara ke Teluk Pelabuhan Ratu, Sukabumi, Indonesia. Jurnal Ilmu dan Teknologi Kelautan Tropis, 7(2), 573-585. https://doi.org/10.29244/jitkt.v7i2.11027
Jellyman, D.J., & Tsukamoto, K. (2010). Eels and Humans. Springer. https://doi.org/10.1007/978-90-481-9109-5
Kuroki, M., & Tsukamoto, K. (2012). Eels on the move: Mysterious creatures over millions of years. Tokyo, Japan: Tokai University Press.
Kuroki, M., Aoyama, J., Wouthuyzen, S., Sumadhiharga, O.K., Sumadhiharga, Miller, M.J., Minagawa, G., & Tsukamoto, K. (2006). Age and growth of Anguilla interioris leptochephali collected in Indonesian waters. Coastal Marine Science, 30(2), 464-468. https://doi.org/10.15083/00040739
Kuroki, M., Miller, M.J., Aoyama, J., Watanabe, S., Yoshinaga, T., & Tsukamoto, K. (2012). Offshore spawning for the newly discovered Anguillid spesies, Anguilla luzonensis (Teleostei: Anguillidae) in the western North Pacific. Pacific Science, 66(4), 497-507. https://doi.org/10.2984/66.4.7
Lokman, P.M., & Young, G. (2000). Tissue distribution and seasonal changes in the steroidogenic enzyme activities in the freshwater eel, Anguilla dieffenbachii. Fish Physiology and Biochemistry, 22(4), 267-278. https://doi.org/10.1023/A:1007779630225
McKinnon, L.J., & Gooley, G.J. (1998). Key environmental criteria associated with the invasion of Anguilla australis glass eels into estuaries of south-eastern Australia. Bulletin Francais de la Peche et de la Pisciculture (349), 117-128. https://doi.org/10.1051/kmae:1998037
Miller, M.J., Otake, T., Minagawa, G., Inagaki, T. & Tsukamoto, K. (2002). Distribution of leptocephali in the Kuroshio Current and East China Sea. Mar Ecol Prog Ser, 235, 279-288. https://doi.org/10.3354/meps235279
Miller, M.J., Wouthuyzen, S., Minagawa, G., Aoyama J., & Tsukamoto, K. (2006). Distribution and ecology of leptocephali of the congrid eel, Ariosoma Scheelei, around Sulawesi Island, Indonesia. Marine Biology, 148, 1101-1111. https://doi.org/10.1007/s00227-005-0144-9
Minegishi, Y., Aoyama, J., Inoue, J.G., Azanza, R.V., & Tsukamoto, K. (2009). Interspecific and subspecific genetic divergences of freshwater eels, genus Anguilla including a recently described spesies, A. luzonensis, based on whole mitochondrial genome sequences. Coastal Marine Science, 33, 1-14. https://doi.org/10.15083/00040705
Monticini, P. (2014). Eel (Anguilla spp.): Production and trade according to Washington Convention Legislation. GLOBEFISH Research Programme, 114, 78.
Rachmawati, F., & Sistina, Y. (2020). Reproduction Characteristics of Tropical Eel Anguilla bicolor McClelland in Different Developmental Stages. IOP Conf. Ser.: Earth Environ. Sci., 593, p.012019. https://doi.org/10.1088/1755-131 5/593/1/012019.
Rachmawati, F.N., Affandi, R., & Sistina, Y. (2022). Anatomical and Histological Characteristics of Gonad of Tropical Eel Anguilla bicolor McClelland, 1844 in Different Length Body Size. J. Trop. Biodivers. Biotechnol., 7(2), 1-8. https://doi.org/10.2 2146/jtbb.68824
Réveillac, E., Gagnaire, P.A., Lecomte-Finiger, R., Berrebi, P., Robinet, T., Valade, P., & Feunteun, E. (2009). Development of a key using morphological characters to distinguish south-western Indian Ocean anguillid glass eels. Journal of Fish Biology, 74(9), 2171-2177. https://doi.org/10.1111/j.1095-8649.2009.02284.x
Shinoda, A., Yoshinaga, T., Aoyama J., Tsuchida, G., Nakazato, S., Ishikawa, M., Matsugamoto, Y., Watanabe, S., Azanza, R.V., & Tsukamoto, K. (2015). Early life history of the Luzon mottled eel Anguilla luzonensis recruited to the Cagayan River, Luzon Island, the Philippines. Coastal marine science, 38(1), 21-26. http://doi.org/10.15083/00040617
Sturges, H.A. (1926). The choice of a class interval. Journal of the American Statistical Association, 21(153), 65-66. https://doi.org/10.1080/01621459.1926.10502161
Sugeha, H.Y., & Genisa, M.U. (2015). External and internal morphological characteristics of glass eels Anguilla bicolor bicolor from the Cibaliung River estuary, Banten Indonesia. Oseanologi dan Limnologi di Indonesia, 41(1), 37-48.
Tesch, F.W. (2003). The Eel (5th ed.). Oxford, United Kingdom: Blackwell Science. https://doi.org/10.1002/9780470995389
Tsukamoto, K., & Aoyama, J. (1998). Evolution of freshwater eels of genus Anguilla: A probable scenario. Environmental Biology of Fishes, 52, 139-148. https://doi.org/10.1007/978-94-015-9016-7_8
Tsukamoto, K., Aoyama, J., & Miller, M.J. (2002). Migration, speciation, and the evolution of diadromy in anguillid eels. Can. J. Fish. Aquat. Sci., 59(12), 1989-1998. https://doi.org/10.1139/f02-165
Watanabe, S. (2003). Taxonomy of the freshwater eels, genus Anguilla Schrank, 1798. In Aida K., Tsukamoto K., Yamauchi K. (Eds.), Eel Biology, 318.
Watanabe, S., Aoyama, J., & Tsukamoto, K. (2004). Reexamination of Ege’s (1939) use of taxonomic characters of the genus Anguilla. Bulletin of Marine Science, 74(2), 337-351.
Watanabe, S., Aoyama, J., & Tsukamoto, K. (2008). The use of morphological and molecular genetic variations to evaluate subspecies issues in the genus Anguilla. Coastal Marine Science, 32(1), 19-29. https://doi.org/10.15083/00040709
Watanabe, S., Aoyama, J., & Tsukamoto, K. (2009). A new spesies of freshwater eel Anguilla Luzonensis (Teleostei: Anguillidae) from Luzon Island of the Philippines. Fisheries Science, 75, 387-392. https://doi.org/10.1007/s12562-009-0087-z
White, E.M., & Knights, B. (1997). Environmental factors affecting migration of the European eel in the Rivers Severn and Avon, England. Journal of Fish Biology, 50(5), 1104-1116. https://doi.org/10.1111/j.1095-8649.1997.tb01634.x
Wouthuyzen, S., Aoyama, J., Sugeha, H.Y., & Tsukamoto, K. (2020). Spawning areas and larval distribution of tropical anguillid eels in the Indonesian Seas. Scientific Reports, 10, 1-12. https://doi.org/10.1038/s41598-020-72788-9
Wyrtki, K. (1973). Physical Oceanography of the Indian Ocean. In: B. Zeitzschel, & Gerlach, S.A., Eds., Ecological Studies: Analysis and Synthesis, Vol. 3, Springer, Berlin, Heidelberg, 18-36. https://doi.org/10.1007/978-3-642-65468-8_3
Authors
Copyright (c) 2026 Waluyo, Hiskia Marceliko, Ellia Debby Leonny Putri Siswantoro

This work is licensed under a Creative Commons Attribution 4.0 International License.
This work is licensed under a Creative Commons Attribution 4.0 International License.
Jurnal Ilmu dan Teknologi Kelautan Tropis i is an open-access journal, meaning that all content is freely available without charge to the user or their institution. Users are allowed to read, download, copy, distribute, print, search, or link to the full texts of the articles in this journal without needing to request prior permission from the publisher or the author.
All articles published by Jurnal Ilmu dan Teknologi Kelautan Tropis are licensed under the Creative Commons Attribution 4.0 International License. This allows for unrestricted use, distribution, and reproduction in any medium, provided proper credit is given to the original authors.
Authors submitting manuscripts should understand and agree that the copyright of published manuscripts is retained by the authors. Copyright encompasses the exclusive rights of authors to reproduce, distribute, and sell any part of the journal articles in all forms and media. Reproduction of any part of this journal, its storage in databases, and its transmission by any form or media is allowed without written permission from Jurnal Ilmu dan Teknologi Kelautan Tropis.
