Marine fish larvae are an integral part of the marine environment because their abundance can become an ecological indicator. The abundance is dependent on the environmental variations that include but are not limited to lunar phases and diel changes, both of which predictably influence them to drift between inshore and outshore of the nearshore system. This study determined the effects of those environmental variations at the spatio-temporal level on the larval fish abundance along the Negeri Sembilan coastline of the Straits of Malacca, Malaysia. Samples were collected using a Bongo net of 300 μm in mesh size during the inter-monsoon season of March through April 2021 (n = 32). Larval fish density for the 32 samples ranged between 1 and 31 larvae/m³. There were 18 larval fish families identified from the study, with the most sampled larvae of Engraulidae, contributing to 24.20% of 892 total fish larvae identified. Other families with notable abundance were Gobiidae (16.30%), Blennidae (13.15%), Ambassidae (10.40%), Apogonidae (9.95%), and Leiognathidae (3.73%). The larval fish abundance was significantly higher during the new lunar phase than the full lunar phase (P < 0.01). Although there were marginal differences between the night and day as well as between outshore and inshore in some of the samples, there was no significant difference within both diel changes and shore distances. The study indicated that the dynamics in the larval fish assemblages in the study area were markedly attributed to lunar phases.

• Ara, R., Amin, S. M. N., Yusoff, F. M., Arshad, A., & Romano, N. (2020). Larval fish assemblage, diversity and habitat ecology in the Matang Mangrove Ecosystem, Perak, Malaysia. Journal of Environmental Biology, 41, 1316–1325. https://doi.org/10.22438/jeb/41/5(SI)/MS_25

• Arévalo-Frías, W., & Mendoza-Carranza, M. (2015). Influence of temporal and spatial factors on abundance and richness of fish early stages in shallow tropical estuaries. Environmental Biology of Fishes, 98, 891–904. https://doi.org/10.1007/s10641-014-0324-x

• Catalán, I. A., Reglero, P., & Álvarez, I. (2020). Research on early life stages of fish: A lively field. Marine Ecology Progress Series, 650, 1–5. https://doi.org/10.3354/meps13491

• Chen, G., & Li, Y. (2003). Distribution of the Carangidae fishes in the continental shelf waters of northern South China Sea. Journal of Shanghai Ocean University, 12(2), 146–151.

• Chu, C., Loh, K. H., Ng, C. C., Ooi, A. L., Konishi, Y., Huang, S. P., & Chong, V. C. (2019). Using DNA barcodes to aid the identification of larval fishes in tropical estuarine waters (Malacca Straits, Malaysia). Zoological Studies, 58, 30. https://doi.org/10.6620/ZS.2019.58-30

• Colombano, D. D., Litvin, S. Y., Ziegler, S. L., Alford, S. B., Baker, R., Barbeau, M. A., Cebrián, J., Connolly, R. M., Currin, C. A., Deegan, L. A., Lesser, J. S., Martin, C. W., McDonald, A. E., McLuckie, C., Morrison, B. H., Pahl, J. W., Risse, L. M., Smith, J. A. M., Staver, L. W., ... Waltham, N. J. (2021). Climate change implications for tidal marshes and food web linkages to estuarine and coastal nekton.Estuaries and Coasts, 44, 1637-1648. https://doi.org/10.1007/s12237-020-00891-1

• Díaz-Astudillo, M., Castillo, M. I., Cáceres, M. A., Plaza, G., & Landaeta, M. F. (2017). Oceanographic and lunar forcing affects nearshore larval fish assemblages from temperate rocky reefs. Marine Biology Research, 13(10), 1015–1026. https://doi.org/10.1080/17451000.2017.1335872

• Dove, S., Tiedemann, M., & Fock, H. O. (2021). Latitudinal transition of mesopelagic larval fish assemblages in the eastern central Atlantic. Deep-Sea Research Part I: Oceanographic Research Papers, 168, 103446. https://doi.org/10.1016/j.dsr.2020.103446

• Feng, Y., Yao, L., Zhao, H., Yu, J., & Lin, Z. (2021). Environmental effects on the spatiotemporal variability of fish larvae in the western Guangdong waters, China. Journal of Marine Science and Engineering, 9(3), 316. https://doi.org/10.3390/jmse9030316

• Ferreira, A. S. A., Stige, L. C., Neuheimer, A. B., Bogstad, B., Yaragina, N., Prokopchuk, I., & Durant, J. M. (2020). Match−mismatch dynamics in the Norwegian−Barents Sea system. Marine Ecology Progress Series, 650, 81–94. https://doi.org/10.3354/MEPS13276

• Guobao, C., Yongzhen, L., & Pimao, C. (2002). Spawning ground of Nemipterus bathybius in northern continental shelf waters of South China Sea. Journal of Zhanjiang Ocean University, 22(6), 20–25.

• Gutiérrez-Martínez, M., Muñoz-Lechuga, R., Rodríguez-García, C., Sanz-Fernández, V., & Cabrera-Castro, R. (2021). Spatial-temporal patterns of fish and macroinvertebrate communities in sandy beach surf zones: Short and medium-term variations. Journal of Sea Research, 168, 101993. https://doi.org/10.1016/j.seares.2020.101993

• Ikegami, T., Takeuchi, Y., & Takemura, A. (2014). Lunar clock in fish reproduction. In H. Numata & B. Helm (Eds.), Annual, lunar, and tidal clocks: Patterns and mechanisms of nature’s enigmatic rhythms (pp. 163–178). Springer. https://doi.org/10.1007/978-4-431-55261-1_9

• Ikegami, T., Takeuchi, Y., Hur, S. P., & Takemura, A. (2014). Impacts of moonlight on fish reproduction. Marine Genomics, 14, 59–66. https://doi.org/10.1016/j.margen.2013.11.007

• Irigoien, X., Klevjer, T. A., Røstad, S., Martinez, U., Boyra, G., Acuña, J. L., Bode, A., Echevarria, F., Gonzalez-Gordillo, J. I., Hernandez-Leon, S., Agusti, S., Aksnes, D. L., Duarte, C. M., & Kaartvedt, S. (2014). Large mesopelagic fish’s biomass and trophic efficiency in the open ocean. Nature Communications, 5, 3271. https://doi.org/10.1038/ncomms4271

• Islam, M. S., Hibino, M., & Tanaka, M. (2007). Tidal and diurnal variations in larval fish abundance in an estuarine inlet in Ariake Bay, Japan: Implication for selective tidal stream transport. Ecological Research, 22(1), 165–171. https://doi.org/10.1007/s11284-006-0001-4

• Jaxion-Harm, J., & Speight, M. R. (2016). Distribution of fish larvae within a weakly tidal mangrove lagoon. Marine and Freshwater Research, 68(2), 396–400. https://doi.org/10.1071/MF15292

• Jeyaseelan, M. J. P., & Ramamathan, N. (1998). Manual of fish eggs and larvae from Asian mangrove waters. Unesco Publishing.

• Joshi, K. K., & Sreekumar, K. M. (2015). Basics of sample collection, preservation and species identification of finfish. In K. K. Joshi, M. S. Varsha, V. L. Sruthy, V. Susan, & P. V. Prathyusha (Eds.), Summer school on recent advances in marine biodiversity conservation and management (pp. 134-137). Central Marine Fisheries Research Institute.

• Kawaguchi, K. (2003). Guide for sampling and identification of fish larvae in the straits of Malacca. Unri Press.

• Konishi, Y., Chayakul, R., Chamchang, C., & Duangdee, T. (2012). Early stages of marine fishes in Southeast Asian Region. http://repository.seafdec.or.th/handle/20.500.12067/566

• Krumme, U., Grinvalds, K., Zagars, M., Elferts, D., Ikejima, K., & Tongnunui, P. (2015). Tidal, diel, and lunar patterns in intertidal and subtidal mangrove creek fish assemblages from southwest Thailand. Environmental Biology of Fishes, 98, 1671-1693. https://doi.org/10.1007/s10641-015-0393-5

• Lelièvre, S., Vaz, S., Martin, C. S., & Loots, C. (2014). Delineating recurrent fish spawning habitats in the North Sea. Journal of Sea Research, 91, 1–14. https://doi.org/10.1016/j.seares.2014.03.008

• Li, J. S., Lin, N., & Ling, J. Z. (2018). Temporal variation in the composition and abundance of fish larvae and juveniles off the Yangtze River Estuary in spring and summer. Journal of Fisheries Science China, 25(3), 586-594. https://doi.org/10.3724/SP.J.1118.2018.17265

• Lies, J. M., & Carson-Ewart, B. M. (Eds.). (2004). The larvae of Indo-Pacific coastal fishes: An identification guide to marine fish larvae. Brill.

• Makrakis, M. C., Nakatani, K., Bialetzki, A., Sanches, P. V., Baumgartner, G., & Gomes, L. C. (2005). Ontogenetic shifts in digestive tract morphology and diet of fish larvae of the Itaipu Reservoir, Brazil. Environmental Biology of Fishes, 72, 99–107. https://doi.org/10.1007/s10641-004-6596-9

• McGeady, R., Lordan, C., & Power, A. M. (2021). Shift in the larval phenology of a marine ectotherm due to ocean warming with consequences for larval transport. Limnology and Oceanography, 66(2),543–557. https://doi.org/10.1002/lno.11622

• Mehner, T. (2014). Partial diel vertical migration of sympatric vendace (Coregonus albula) and fontane cisco (Coregonus fontanae) is driven by density dependence. Canadian Journal of Fisheries and Aquatic Sciences, 72(1), 116–124. https://doi.org/10.1139/cjfas-2014-0009

• Mwaluma, J. M., Kaunda-Arara, B., & Rasowo, J. (2014). Diel and lunar variations in larval supply to Malindi Marine Park, Kenya. Western Indian Ocean Journal of Marine Science, 13(1), 57–67.

• Okiyama, M. (1989). An atlas of the early-stage fishes in Japan. Tokai University Press.

• Olivar, M. P., & Beckley, L. E. (2022). Latitudinal variation in diversity and abundance of mesopelagic fishes associated with change in oceanographic variables along 110°E, south-east Indian Ocean. Deep-Sea Research Part II: Topical Studies in Oceanography, 198, 105053. https://doi.org/10.1016/j.dsr2.2022.105053

• Olivar, M. P., Contreras, T., Hulley, P. A., Emelianov, M., López-Pérez, C., Tuset, V., & Castellón, A. (2018). Variation in the diel vertical distributions of larvae and transforming stages of oceanic fishes across the tropical and equatorial Atlantic. Progress in Oceanography, 160, 83–100. https://doi.org/10.1016/j.pocean.2017.12.005

• Pattrick, P., & Strydom, N. (2014a). Recruitment of fish larvae and juveniles into two estuarine nursery areas with evidence of ebb tide use. Estuarine, Coastal and Shelf Science, 149, 120–132. https://doi.org/10.1016/j.ecss.2014.08.003

• Pattrick, P., & Strydom, N. A. (2014b). Larval fish variability in response to oceanographic features in a nearshore nursery area. Journal of Fish Biology, 85(3), 857–881. https://doi.org/10.1111/jfb.12477

• Pattrick, P., Minguzzi, M., Weidberg, N., & Porri, F. (2022). Ecological value of the earliest human manipulated coastal habitats: Preliminary insights into the nursery function of a pre-colonial stonewalled fish trap in South Africa. Regional Studies in Marine Science, 52, 102266. https://doi.org/10.1016/j.rsma.2022.102266

• Pattrick, P., Weidberg, N., Goschen, W. S., Jackson, J. M., McQuaid, C. D., & Porri, F. (2021). Larval fish assemblage structure at coastal fronts and the influence of environmental variability. Frontiers in Ecology and Evolution, 9, 684502. https://doi.org/10.3389/fevo.2021.684502

• Picapedra, P. H. S., Lansac-Tôha, F. A., & Bialetzki, A. (2015). Diel vertical migration and spatial overlap between fish larvae and zooplankton in two tropical lakes, Brazil. Brazilian Journal of Biology, 75(2), 352–361. https://doi.org/10.1590/1519-6984.13213

• Picapedra, P. H. S., Sanches, P. V., & Lansac-Tôha, F. A. (2018). Effects of light-dark cycle on the spatial distribution and feeding activity of fish larvae of two co-occurring species (Pisces: Hypophthalmidae and Sciaenidae) in a Neotropical floodplain lake. Brazilian Journal of Biology, 78(4), 763–772. https://doi.org/10.1590/1519-6984.179070

• Pielou, E.C. (1966). The measurement of diversity in different types of biological collections. Journal of Theoretical Biology, 13, 131-144.

• Polte, P., Kotterba, P., Moll, D., & von Nordheim, L. (2017). Ontogenetic loops in habitat use highlight the importance of littoral habitats for early life-stages of oceanic fishes in temperate waters. Scientific Reports, 7, 42709. https://doi.org/10.1038/srep42709

• Ridho, M. R., Patriono, E., Sarno, S., & Wirda, S. (2020). Diversity of fish larvae around the estuary of the Banyuasin river, South Sumatera province. BIOVALENTIA: Biological Research Journal, 6(2), 45-51. https://doi.org/10.24233/biov.6.2.2020.181

• Shannon, C. E. (1948). A mathematical theory of communication. The Bell System Technical Journal, 27, 379–423. https://doi.org/10.1145/584091.584093

• Simpson, E. H. (1949). Measurement of diversity. Nature, 163, 688. https://doi.org/10.1038/163688a0

• Team, R. (2020). RStudio: Integrated development for R. http://www.rstudio.com/

• Tiedemann, M., & Brehmer, P. (2017). Larval fish assemblages across an upwelling front: Indication for active and passive retention. Estuarine, Coastal and Shelf Science, 187, 118–133. https://doi.org/10.1016/j.ecss.2016.12.015

• Vorsatz, L. D., Pattrick, P., & Porri, F. (2021). Ecological scaling in mangroves: The role of microhabitats for the distribution of larval assemblages. Estuarine, Coastal and Shelf Science, 253, 107318. https://doi.org/10.1016/j.ecss.2021.107318

• Wang, Y.-C., Tsai, S.-C., & Chen, W.-Y. (2022). Diel vertical distribution patterns of pelagic fish larvae in Yilan Bay, Taiwan. Journal of Marine Science and Technology, 29(6), 6. https://doi.org/10.51400/2709-6998.2557