Thrissina mystica sp. nov. is described on the basis of 62 specimens collected from the northern Indian Ocean from Kuwait to Sri Lanka. The new species closely resembles Thrissina katana Hata, Lavoué and Motomura 2022 and Thrissina malabarica (Bloch 1795), all having a moderate maxilla (extending posteriorly beyond the posterior margin of the opercle, but not reaching the...
Fish assemblage structures in 1 × 1, 3 × 3 and 5 × 5 meter planted seagrass habitats, natural seagrass habitats and bare sand/mudflats in the intertidal bay at Trang Province, Thailand, were examined in detail by visual census, in order to clarify if the fish assemblage structures in the planted habitats had become similar to those in the natural seagrass habitats. Although the...
The new scorpionfish species Sebastapistes monospina, distributed in tropical/subtropical south Pacific waters from Lord Howe Island east to the Pitcairn Islands, closely resembles Sebastapistes perplexa Motomura, Aizawa and Endo 2014, which is restricted to the temperate waters of Japan. Both species share several morphological characteristics, including fusion of the first and...
In this study, we investigated mating system and mate choice of the triplefin blenny Enneapterygius etheostoma on a rocky reef at Banda, Tateyama Bay, Chiba, Japan, from 21 May to 19 July 2020. The larger males maintained a territory, while the smaller ones joined reproduction as a sneaker. The females visited the territorial males to spawn. The mating success of each territorial...
The behavioral activity of freshwater fishes is highly influenced by the hydrological regime. However, the relationship between the hydrological environment and the spawning behavior of landlocked amago salmon Oncorhynchus masou ishikawae in headwater streams remains unclear. We investigated the effects of rainfall-induced changes in the hydrological environment on the spawning...
Cryptobenthic reef fish (CRF), which are benthic reef fish with body lengths of less than 50 mm, generally exhibit life history characteristics, such as a short lifespan, early maturation, high mortality, and microhabitat specialization. In this study, we investigated breeding season and population fluctuation patterns of a gobiid CRF fish Lubricogobius exiguus. At our field...
The rich marine resources along the western coast of Spitsbergen (Svalbard) have given rise to colonies of breeding seabirds, which likely represent an important vector of nutrient transport from marine to terrestrial environments. These seabirds may also supply additional nutrients to lakes via their droppings, while bathing and/or when being attacked by other birds during...
A review of the validity of morphological traits defining the scorpionfish genus Parascorpaena Bleeker 1876 resulted in the re-identification of Parascorpaena bandanensis (Bleeker 1851) as Sebastapistes strongia (Cuvier 1829), reducing the number of valid species of Parascorpaena from nine to eight. A modified definition of Parascorpaena, based on morphological characters...
One of the greatest challenges for researchers today is understanding climate-change impacts on fish populations, particularly in vulnerable and understudied ecosystems such as the Canadian Arctic. Among other impacts, northern fishes will undergo thermal stress as atmospheric and sea surface temperatures are projected to rise globally. Models that consider how both environmental...
Indel (insertion–deletion) events observed in the genome represent irreversible mutational processes, making indel regions crucial characteristics for discussing phylogenetic relationships. The tribe Hippoglossoidini is a recently proposed taxonomic group based on the molecular phylogenetic analyses of both mitochondrial (mt) and nuclear DNA sequences. However, no synapomorphic...
In sympatry, juvenile brown trout (Salmo trutta) usually occupy the shallow and most productive areas (littoral zone) of lakes, while juveniles of Arctic charr (Salvelinus alpinus) are found in deeper, less productive parts. In contrast, when Arctic charr juveniles occur in allopatry, they often occupy shallow littoral areas as well. Habitat segregation has traditionally been...
Charrs (Salvelinus) reach their southernmost distribution in Japan, and are uniquely adapted to the short, steep streams of this island archipelago. Southern Asian Dolly Varden (Salvelinus curilus) occur only in Hokkaido Island, whereas white-spotted charr (Salvelinus leucomaenis) range to southern Honshu. Both species diverged from an ancestral lineage during the late Pliocene...
Anadromous migration of salmonid fish has been extensively studied, primarily focusing on the dichotomous framework of anadromy and residency. However, there remains a limited understanding of intermediate migratory behaviors within the anadromous framework. Our study aimed to classify the lifetime migration patterns of the anadromous white-spotted charr Salvelinus leucomaenis...
Extant ‘fishes’ belong to jawless, cartilaginous, actinopterygian, or sarcopterygian fish lineages. They comprise a non-monophyletic group of vertebrates from which tetrapods are excluded, and they are therefore paraphyletic. Recent advances in whole-genome sequencing have shed light on phylogenetic relationships, divergence times among major fish lineages, and the molecular...
Longitudinal distribution and niche partitioning phenomena have been extensively reported for streams containing two salmonid species but remain poorly understood for streams containing three or more salmonid species. Herein, we examined the abiotic environmental variables and population densities of fishes, including three salmonids, in 30 reaches of the Setose River, Hokkaido...
The striped eel catfish, Plotosus lineatus was first described by Thunberg in 1787 from the Indo-Pacific region in the East Indian Ocean. Since then, the species has been recorded in various marine and brackish habitats in Japan, southern Korea, the Ogasawara Islands, Australia, Lord Howe Island, Palau and Yap in Micronesia, East Africa to Samoa, Madagascar, Red Sea and the...
A large body of knowledge about life-history traits has arisen from research on viviparous fishes of the family Poeciliidae. Still, the wide variation among species in reproductive strategies provides an excellent opportunity to further explore how life-history traits covary and the causes of covariation patterns. In this study, we provide information on brood size, offspring...
We analyzed two morpho-species, Astyanax aeneus and Astyanax caballeroi, coexisting in Lake Catemaco, with ecological differences previously associated with different trophic niches. While A. aeneus is a widely distributed species, A. caballeroi is endemic to Lake Catemaco. Due to the contrasting morphology between these two sympatric species, they were originally assigned to...
Larvae and juveniles of three species in the family Gobiidae are described based on laboratory-reared material: Bathygobius fuscus to post-settlement, Bathygobius cyclopterus to 2 days old, and Bathygobius petrophilus to just after hatching. Newly hatched larvae of these species are distinguishable from each other by the melanophore arrangements on the dorsal region of the trunk...
Microichthys grandis n. sp. from off southwest Ireland, northeastern Atlantic Ocean, is described on the basis of a single specimen and compared with the other species of the genus. The new species is characterized by the following combination of characters: dorsal-fin rays VII–I, vii, 1; total pectoral-fin rays 18; total gill rakers 25; pyloric caeca 3; pored lateral-line scales...