We used acoustic telemetry and environmental monitoring to elucidate preferred microhabitats of juvenile steelhead trout (Oncorhynchus mykiss) in a Central California intermittent estuary (IE) during historic drought. We collected over half a million fish locations in the Pescadero IE (San Mateo County, CA) across 15 weeks during an extended sandbar-closed period which permitted quantification of fine

Acoustic telemetry allows collection of data on the movement and survival of fish and other aquatic organisms. The passive form of this technology uses transmitters (tags) and fixed receivers to record when an organism is present at a given location. Understanding and interpretation of these data depends on knowledge of the detection range and detection probability of the receivers. This study examines

We examined the distribution and genetic variability of the greater amberjack Seriola dumerili in the East China Sea (ECS) from the mitochondrial DNA (mtDNA) control region of young-of-the-year (YOY) individuals, which may reflect the genetic characteristics of the spawning population. In the years 2016 and 2017, a total of 165 YOY S. dumerili were collected from two different locations in the ECS:

Carbon and nitrogen stable isotope analyses were used to infer relative trophic structure and examine regional variation in trophic dynamics of fishes in the Florida Big Bend, an approximately 300 km stretch of relatively pristine coastline in the eastern Gulf Of Mexico that contains over 250,000 ha of seagrass. The Florida Big Bend is home to a diverse assemblage of fauna; and the ecosystem is regionally

Green Sturgeon (Acipenser medirostris) and White Sturgeon (A. transmontanus) are closely related species inhabiting the San Francisco Estuary (SFE) and Sacramento River. Both spawn in the Sacramento River. White Sturgeon typically remain within SFE throughout their lives while subadult and adult Green Sturgeon make marine migrations. These broad-scale patterns are known. However, the reach-specific

In the remote high-elevation streams and rivers in the northwest of Mexico, there is an endemic and highly diverse group of native trout related to the rainbow trout lineage (Oncorhynchus mykiss). Currently, only two species have been formally described from this trout complex, the Mexican golden trout, O. chrysogaster, and the San Pedro Mártir rainbow trout, O. m. nelsoni, but only the former occurs

Fishes in the genus Nocomis function as keystone engineers via their mound-building spawning behavior. Furthermore, mound construction grants some Nocomis spp. resistance to excess sedimentation, as it concentrates gravel in an otherwise silty substrate. However, it is unclear whether silt-resistance is a general trait of Nocomis spp. or is instead more species-specific. The objectives of our research

In the early 1990s, the Atlantic cod (Gadusmorhua) population on the Newfoundland and Labrador shelf declined dramatically, leading to a fishing moratorium in 1992. The Northern cod population has not fully recovered, possibly due to the simultaneous population collapse of an important prey type, capelin (Mallotus villosus), which migrates from the continental shelf into coastal Newfoundland to spawn

California horn sharks (Heterodontus francisci) are relatively small (122 cm maximum total length; TL), nocturnally active sharks that have been observed refuging in shelters during the day; however, little is known about how they select their daytime resting shelters, and what factors may drive their degree of shelter fidelity. Depending on body size, thermal tolerance, and ability to avoid predators

The native fishes of the Neotropical region have been heavily impacted by the construction of reservoirs that block the rivers in different degrees. Small Hydroelectric Power Plants (SHPP) have been an alternative way to take advantage of small electricity production potential, with low cost. However, there is no basis in the belief that SHPP have less deleterious effects on river habitat than large

While navigating through the same migratory corridor, different species may experience differing reproductive success due the interaction of species-specific movement behavior with habitat configuration. We contrasted the migratory behavior of White Sturgeon Acipenser transmontanus and fall-run Chinook Salmon Oncorhynchus tshawytscha, two native fishes in Central Valley of California. These species

We conducted a bibliometric analysis in order to quantify and characterize the scientific knowledge about threatened freshwater fish species in Brazil based in studies published in peer-reviewed journals from Web of Science database from Clarivate Analytics. We verified an increase in the number of papers for threatened freshwater fish species in Brazil, especially in the last eleven years of studied

Riverine ecosystems around the world have undergone extensive anthropogenic alterations, often to the detriment of native aquatic biodiversity. Migratory fishes are particularly vulnerable to habitat fragmentation and degradation. For example, Chinook Salmon populations in the Sacramento River, CA have been declining for nearly a century. Its Mediterranean climate, position in a landscape dominated

Little is known about the ecological importance of low-order tidal marsh channels to fishes in the San Francisco Estuary, California. We conducted a passive mark-recapture study to compare residency, site fidelity, and movement patterns of fishes in a small intertidal channel (0.1 km2) in a large tidal marsh reserve (4.25 km2). We coupled continuous, high-frequency data on movements of fish tagged

Hatchery production of Pacific salmon for release into the environment is a common tool for conservation and supplementation of depleted stocks. Hatchery conditions are controlled to support high survival rates; however, once released into the environment, managers have little control over conditions experienced by juveniles. Thus, release timing is a critical decision in hatchery operations. This

As fish move, they incur an energetic cost of transport (COT) from the use of aerobic muscles. Water currents are an integral component of the physical world of fishes, and if water currents are present, fish may pay higher costs fighting the currents, or may use the currents to facilitate movement and reduce COT. Some fish use “selective tidal stream transport” (STST) to move efficiently through tidal

Arctic and sub-Arctic ecosystems are rapidly changing, but morphological diversity can increase a species’ resilience to these environmental fluctuations. Capelin Mallotus villosus is a cold-water forage fish distributed throughout the northern hemisphere, but is not thoroughly studied outside the Atlantic Ocean, which impedes our ability to infer the functional significance of morphometric variation

There is a great need to understand how resource interactions alter the functioning of ecosystems, where the selective elimination of pelagic fishes can lead to changes in food web structure. This work analyzes the trophic niches of three species of commercial importance in the Galapagos Marine Reserve, yellowfin tuna, Thunnus albacares (TA), skipjack tuna, Katsuwonus pelamis (KP), and wahoo, Acanthocybium

The feeding ecology of Raiamas moorei, Enteromius kerstenii, and Enteromius pellegrini was studied as a contribution to the comprehension of the ecological functioning of Lake Kivu, especially its littoral zone. Fish specimens were collected during 68 fishing campaigns from 2007 to 2017 among which are 25 campaigns 24-h full daily cycles and 43 overnights campaigns. Morphometric parameters and gut

Cichlidae have a magnificent ecological versatility that provides the species to explore many trophic niches, and behavioural biology. This versatility was achieved by modifications in the cranial and pharyngeal apparatus of cichlids. Accordingly, we aim to examine the relationships between pharyngeal morphology and diet of three species of the genus Crenicichla. We analysed the stomach contents and

The effects of sex and training on mitochondrial function and its sensitivity to in vitro reactive oxygen species (ROS) exposure were investigated in male and female silver European eels. The critical swimming speed (Ucrit) was used as an index of training intensity and of overall swimming performance. After four days of training (10 h at 70% and 14 h at 50% of their Ucrit before training), Ucrit increased

The use of sound in social interactions has been documented in several species of sculpin and may be used to convey information concerning species identity, intent, or fitness. Sound production may be a particularly important mode of communication in sculpin due to their nocturnal behavior and construction of nests in rock cavities where the efficacy of visual cues may be diminished. In this study

Characterizing the potential for, and mechanisms of, organismal response to environmental stress, particularly in the context of temperature, remains important for predicting effects of global change on natural populations. A number of studies have looked at changes in behavioral variation, focusing primarily on activity, boldness and aggression, while many behavioral traits have gone unexplored. In

The morphology and morphometry of otoliths have emerged as powerful indicators of ecological characteristics of fishes. However, shape descriptors that can accurately predict well-documented functions played by species in tropical ecosystems are either restricted to a few groups or poorly known. Therefore, we evaluated the power of two otolith shape descriptors (ecomorphological indexes and Fourier

We used fishery-independent gillnet and longline surveys to document the elasmobranch and large teleost assemblages in the Florida Big Bend seagrass system and examine how ichthyofaunal assemblages were related to environmental factors across the region. A total of 159 paired gillnet sets were conducted in June through August from 2009 to 2012. The Big Bend, an expansive system nearly 300 km in length

Steelhead (Oncorhynchus mykiss) are a species of conservation concern in California’s Sacramento River, and their poor status is hypothesized to be due in significant part to poor survival in freshwater. We used acoustic telemetry to examine the migratory survival of hatchery reared steelhead smolts through five contiguous regions of the Sacramento River and its estuary (upper river, lower river, delta

Char samples distributed in rivers originating from the Chugoku Mountain Chain, Japan, were collected, identified to two subspecies; Gogi and Nikkoiwana. They were categorized into 8 head-spot types by morphology, and into genetic haplotypes based on DNA sequences of the Cyt.b region of mtDNA. A genetic tree was constructed based on the sequences. In addition, head-spot types were categorized by haplotype

Diel and tidal studies are critical to understanding many aspects of fish behavior and habitat use. In this study, diel and tidal abundance, size composition and food habits of four common juvenile fish (Anchoa mitchilli, Cynoscion regalis, Leiostomus xanthurus, Micropogonias undulatus) present in Delaware Bay (USA) marsh creeks was assessed. Fish were collected with otter trawls near daytime and nighttime

The population structure and demographic history of a pelagic lumpsucker, Aptocyclus ventricosus, were investigated on the basis of sequence variation in the mitochondrial cytochrome b gene (1038 bp). The haplotype network clearly recovered two haplotype groups, consisting of western and eastern North Pacific individuals, except for some specimens collected from offshore of Tohoku, northern Japan.

Japanese eel (Anguilla japonica) is a commercially important species; however, its population has declined in recent years. Appropriate conservation management, including habitat protection, is required to reverse this decline. However, their habitat use pattern during the riverine life stage is poorly understood. In this study, we investigated the longitudinal distribution and microhabitat of small-sized

Pacific Lamprey Entosphenus tridentatus is an anadromous fish native to the west coast of North America and the Pacific coast of Asia. In the 1950s, construction of dams on the Middle Fork Willamette River blocked upstream migration of adult Pacific Lamprey which resulted in their extirpation from otherwise suitable habitats. We report evidence of landlocked Pacific Lamprey surviving for >40 years

We quantified patterns of circannual reproductive breeding periodicity in a multi-species assemblage of the gymnotiform knifefish genus Brachyhypopomus from Amazonian floodplain and terra firme stream habitats. We applied linear mixed-effect models and model selection to a dataset of 3205 fish from the five most abundant species to identify environmental variables predictive of gonadosomatic index

Phenotypic responses to the environment may be controlled via cytosine methylation (5mC) and its effects on gene expression. We test whether hypoxia influences plastic or heritable changes in the quantity of 5mC in the genomes of a widespread African cichlid, the Egyptian mouth-brooder, Pseudocrenilabrus multicolor (Schöller, 1903). Fish were collected from three sites in southwestern Uganda: one hypoxic

The original version of this article unfortunately contained mistakes introduced during the production process. Tables 1 and 2 were presented incorrectly. The original article has been corrected.

The scientific name Cottus kazika has been used for over a century as valid for the catadromous fourspine sculpin endemic to Japan. However, recent DNA sequence analyses have indicated a sister relationship between two catadromous species, so-called C. kazika and Trachidermus fasciatus with a great phylogenetic divergence, separated from a monophyletic freshwater spawning clade including the other

Introduced non-native fishes have the potential to substantially alter aquatic ecology in the introduced range through competition and predation. The Alaska blackfish (Dallia pectoralis) is a freshwater fish endemic to Chukotka and Alaska north of the Alaska Range (Beringia); the species was introduced outside of its native range to the Cook Inlet Basin of Alaska in the 1950s, where it has since become

Closely related species of fishes often have different sex chromosome systems. Such rapid turnover of sex chromosomes can occur by several mechanisms, including fusions between an existing sex chromosome and an autosome. These fusions can result in a multiple sex chromosome system, where a species has both an ancestral and a neo-sex chromosome. Although this type of multiple sex chromosome system has