Ha LM, Oka S, Iguchi K. 2021. Fluctuating asymmetry in the insular population of ayu, Plecoglossus altivelis ryukyuensis, estimating its genetic diversity at extinction. Ichthyological Research, in press.
Sasai T, Yamamoto T, Oka S, Toda M. 2021. Addition of the Sea Snake, Hydrophis stokesii (Reptilia: Squamata: Elapidae), to the Herpetofauna of Japan. Current Herpetology, 40:190-196.
Inoue T, Hara T, Nakazato K, Oka S. 2021. Superior mechanical resistance in the exoskeleton of the coconut crab, Birgus latro. Materials Today Bio, 100132.
Inoue T, Oka S, Hara T. 2021. Three-dimensional microstructure of robust claw of coconut crab, one of the largest terrestrial crustaceans. Materials & Design, 206, 109765.
Hanahara N, Miyamoto K, Oka S. 2021. Northernmost record of the surgeonfish Acanthurus nigros (Teleostei: Acanthuridae) from Minamidaitojima Island, southern Japan. Species Diversity. 26: 43–47. doi: 10.12782/specdiv.26.43
Hanahara N, Miyamoto K, Oka S. 2020. Morphological and genetic identification of formalin-fixed gobioid larvae and description of postflexion larvae of Paragunnellichthys sp. and Ctenogobiops feroculus. Ichthyological Research. 68: 182–190. doi: 10.1007/s10228-020-00769-z
Oka S, Doi H, Miyamoto K, Hanahara N, Sado T, Miya M. 2021. Environmental DNA metabarcoding for biodiversity monitoring of a highly diverse tropical fish community in a coral reef lagoon: Estimation of species richness and detection of habitat segregation. Environmental DNA. 3:55-69. doi: 10.1002/edn3.132
Oka S, Nakamura M, Nozu R, Miyamoto K. 2020. First observation of larval oarfish, Regalecus russelii, from fertilized eggs through hatching, following artificial insemination in captivity. Zoological letters. 6: 1-6. doi: 10.1186/s40851-020-00156-6
Oka S, Kobayashi N, Sato T, Ueda K, Yamagishi M. 2019. Sound production in the coconut crab, the largest terrestrial crustacean. Zoology. 137: 125710. doi: 10.1016/j.zool.2019.125710
Doi H, Fukaya K, Oka S, Sato K, Kondoh M, Miya M. 2019. Evaluation of detection probabilities at the water-filtering and initial PCR steps in environmental DNA metabarcoding using a multispecies site occupancy model. Scientific Reports. 9: 3581. doi: 10.1038/s41598-019-40233-1.
Tomita T, Toma H, Murakumo K, Yanagisawa M, Yano N, Oka S, Miyamoto K, Hanahara N, Sato K. 2018. Captive Birth of Tiger Shark (Galeocerdo cuvier) Revealed the Shift of Respiratory Mode Across Parturition. Copeia. 106: 296-296.
Oka S, Hanahara N, Shintani T. 2018. First Japanese record of the Mindoro snake eel Lamnostoma mindorum (Actinopterygii: Anguilliformes: Ophichthidae) from the Ryukyu Islands. Fauna Ryukyuana. 42: 5-8.
Tomita T, Toda M, Miyamoto K, Oka S & Sato K. 2018. Development of lunate-shape caudal fin in White shark embryo. The Anatomical Record. 301: 1068-1073. DOI: 10.1002/ar.23776
Tomita T, Miyamoto K, Kawaguchi A, Toda M, Oka S, Nozu R, Sato K. 2017. Dental ontogeny of white shark embryo. Journal of Morphology. 278 (2): 215-227. doi: 10.1002/jmor.20630
Oka S, Tomita T, Miyamoto K. 2016. A mighty claw: Pinching force of the coconut crab, the largest terrestrial crustacean. PLOS ONE. 11(11): e0166108. doi: 10.1371/journal.pone.0166108.
Miya M, Minamoto T, Yamanaka H, Oka S, Sato K, Yamamoto S, Sado T, Doi H. 2016. Use of a filter cartridge for filtration of water samples and extraction of environmental DNA. Journal of Visualized Experiments. e54741. doi:10.3791/54741.
Oka S, Miyamoto K, Matsuzaki S. 2016. Long-term sedentary behavior of coconut crab in their northernmost range. International Journal of Pure and Applied Zoology. 4: 174-178.
Tomita T, Murakumo K, Miyamoto K, Sato K, Oka S, Kamisako H & Toda M. 2015. Eye retraction in the giant guitarfish, Rhynchobatus djiddensis (Elasmobranchii: Batoidea): a novel mechanism for eye protection in batoid fishes. Zoology. 119(1): 30-35. DOI: 10.1016/j.zool.2015.09.004
Miyamoto K, Nonaka A, Oka S. 2015. Northernmost record of a poorly known tuskfish Choerodon margaritiferus (Perciformes: Labridae), from southern Japan, and first description of a female. Zootaxa. 4007(1): 82-90. DOIi: 10.11646/zootaxa.4007.1.5
Oka S, Miyamoto K. 2015. Reproductive biology and growth of bluestripe herring Herklotsichthys quadrimaculatus (Rüppell, 1837) in the northernmost waters. Journal of Applied Ichthyology. 31(4): 709-713. doi: 10.1111/jai.12811.
Oka S, Miyamoto K, Matsuzaki S, Sato T. 2015. Growth of the coconut crab, Birgus latro, at its northernmost range estimated from mark-recapture using individual identification based on carapace grooving patterns. Zoological Science. 32: 260-265.
Oka S. & Miyamoto K. 2015. Pelagic juvenile of Plectroglyphidodon johnstonianus Flower & Ball, 1924 (Perciformes, Pomacentridae, Stegastinae) identified from morphometric and genetic evidence. Fauna Ryukyuana. 20:1-6.
Oka S, Odoriba S. 2014. Morphological development of larval and juvenile Alectis indica (Perciformes: Carangidae) reared in captivity. Ichthyological Research. 61: 298-302. DOI 10.1007/s10228-014-0397-8
Oka S, Matsuzaki S, Toda M. 2013. Identification of individual coconut crabs, Birgus latro, on the basis of the pattern of grooves on the carapace. Crustacean Research. 42: 17-23.
Kawazu I, Maeda K, Kino M, Oka S. 2013. Structure of the Loggerhead Turtle Assemblage in Okinawan Waters Estimated from Variation in Body Size and Blood Profile. Current Herpetology. 32: 190-196. DOI: 10.5358/hsj.32.190
Oka S, T Higashiji. 2012. Early ontogeny of the big roughy Gephyroberyx japonicus (Beryciformes: Trachichthyidae) in captivity. Ichthyological Research, 59: 282-285. DOI: 10.1007/s10228-012-0282-2
Oka S, Tachihara K. 2008. Migratory history of the spotted flagtail, Kuhlia marginata. Environmental Biology of Fishes. 81(3):321-327. DOI: 10.1007/s10641-007-9203-z