Fish that inhabit shallow water are exposed to periodic changes in tidal cues including hydrostatic pressure (HP). The present study aimed to verify differentially expressed genes (DEGs) in the brain of the threespot wrasse Halichoeres trimaculatus (tropical species) and the honbera wrasse H. tenuispinis (temperate species), both of which were exposed to HP at 30 kPa (possible high tide stimuli in

The presence of the opal chimaera, Chimaera opalescens , is reported for the first time in the deep waters of the Azores, with the capture of four specimens by fishermen and the video recording of an additional five individuals. Species identification was supported by the 646 bp sequenced fragment of the mitochondrial gene cytochrome oxidase subunit I. Because C. opalescens is a recently recognised

The majority of batoids are listed as Threatened (20.4%) or Data Deficient (41%) by the IUCN Red List. A key challenge to assessing Data‐Deficient species is obtaining estimates of key life‐history characteristics. Here, a Bayesian approach was used to estimate derived life‐history characteristics from a growth model applied to the Data‐Deficient Brazilian electric ray Narcine brasiliensis . The age

Fish are both consumers and prey, and as such part of a dynamic trophic network. Measuring how they are trophically linked, both directly and indirectly, to other species is vital to comprehend the mechanisms driving alterations in fish communities in space and time. Moreover, this knowledge also helps to understand how fish communities respond to environmental change and delivers important information

The Baraka's whipray (Maculabatis ambigua ) is a major constituent of small‐scale fisheries catch in the south‐western Indian Ocean. Despite this, little is known of its life‐history or exploitation status. We provide the first estimates of crucial life‐history parameters and the maximum intrinsic population growth rate r max, using specimens collected from small‐scale fisheries landings in Kenya,

Potamodromous fishes require safe migration routes between spawning, feeding and wintering habitats to complete their life cycle. As knowledge on asp migrations is restricted, we studied the movements of adult asp tagged with acoustic transmitters for three years in the large Peipsi‐Emajõgi‐Võrtsjärv lake‐river system, Estonia, which is free of migration barriers. Asp showed complex migration patterns

Elasmobranchs are particularly vulnerable to overexploitation and population depletion, especially due to their life‐history traits, such as low reproductive output and slow growth. Given that capture‐induced parturition (abortion or premature birth) is a common consequence of fisheries in elasmobranchs, but still little studied, we investigated how the abortion/premature birth process varies in response

Sexual patterns of teleosts are extremely diverse and include both gonochorism and hermaphroditism. As a protogynous hermaphroditic fish, all orange‐spotted groupers (Epinephelus coioides ) develop directly into females, and some individuals change sex to become functional males later in life. This study investigated gonadal restructuring, shifts in sex hormone levels and gene profiles of cultured

Four specimens corresponding to three rare deep‐water fish species were caught on the Porcupine Bank (Northeast Atlantic) in September 2019. These catches include the new northernmost records of Azores rockling Gaidropsarus granti and deep‐water dab Poecilopsetta beanii in the Atlantic Ocean and the second record of the latter species in its eastern zone. Three of the specimens were retained and their

Species specific life history information is critical for successful conservation, particularly in establishing an accurate baseline status. Obtaining such information is challenging for most species, but in particular for rare and threatened marine species. To facilitate future conservation of the Endangered Knysna seahorse (Hippocampus capensis) this study aimed to determine important life history

The broadnose sevengill shark (Notorynchus cepedianus ) is a common high trophic level predator around coastal New Zealand. Data on the ecology of the species in New Zealand are severely lacking and anthropogenic impacts are unquantified. To partially address this, we undertook a study of the demographics of a population at Stewart Island. Sampling trips were carried out seasonally from winter 2016

The atrioventricular junction of the fish heart, namely the segment interposed between the single atrium and the single ventricle, has been studied anatomically and histologically in several chondrichthyan and teleost species. Nonetheless, knowledge about myosin heavy chain (MyHC) in the atrioventricular myocardium remains scarce. The present report is the first one to provide data on the MyHC isoform

To gain a better understanding on the trophic ecology of New Granada sea catfish, Ariopsis canteri , and their linkage to mangroves, nitrogen and stable carbon isotopes (δ15N and δ13C), as well as Bayesian mixing models, were used to explore trophic dynamics and potential ontogenic feeding shifts across different size classes: class I (8–20 cm), class II (21–32 cm) and class III (>32 cm). The study

Predator‐prey size (PPS) relationships are determined by predator behaviour, with the likelihood of prey being eaten dependent on their size relative to that of the consumer. Published PPS relationships for 30 pelagic or benthic marine fish species were analysed using quantile regression to determine how median, lower, and upper prey sizes varied with predator size and habitat. Habitat effects on predator

Tessellated calcified cartilage (TCC) is a distinctive kind of biomineralized perichondral tissue found in many modern and extinct chondrichthyans (sharks, rays, chimaeroids and their extinct allies). Customarily, this feature has been treated somewhat superficially in phylogenetic analyses, often as a single “defining” character of a chondrichthyan clade. TCC is actually a complex hard tissue with

Among the thermophilic fishes that have become established in the north‐western Mediterranean as a consequence of sea warming, the yellowmouth barracuda (Sphyraena viridensis Cuvier, 1829) appears to be one of the most successful and abundant in the coastal rocky environment, having increasingly become the object of recreational and commercial exploitation in the study area. Lure‐fishing sessions were

Here we report the first cases of intersex (abnormal development of both male and female reproductive tissues in a gonad) Paddlefish Polyodon spathula , an Acipenseriform species of large rivers in the central United States and in aquaculture worldwide. Despite a large, multi‐decadal dataset in Oklahoma, Montana, and North Dakota, intersex development was not observed until 2019, when two individuals

The effect of dietary supplementation with Saccharomyces cerevisiae on gilthead seabream (Sparus aurata L.) was studied. Four replicates of fish (n=6) were fed with a commercial diet containing 0 (control, no yeast added) or 10 mg per kg of heat killed (30 min, 60°C) S. cerevisiae . After four weeks, half of the fish (two replicates) were injured and continuing being fed the same diet. At three and

The almaco jack Seriola rivoliana is a circumtropical pelagic fish of importance both in commercial fisheries and aquaculture. To understand levels of genetic diversity within and among populations in the wild, population genetic structure and the relative magnitude of migration were assessed with mtDNA sequence data and SNPs from individuals sampled from locations in the Pacific and Atlantic Oceans

The tench Tinca tinca is a freshwater species, with human‐mediated translocations, aquaculture interest and limited information on its genetic structure. Mitochondrial DNA sequencing analysis of three genes in 50 individuals from five European populations identified two phylogroups, with greater variability than reported until now, and a hybridization zone in the Danube river region. Restriction analyses

Prolactin‐releasing peptide2 (PrRP2) was administered intraperitoneally to male intertidal blenny Rhabdoblennius nitidus , a species with male uniparental care of eggs, to investigate the effect on their feeding activity. A significant inhibitory effect on appetite was observed in the breeding season, but not in the nonbreeding season. These results suggest that PrRP2 and PrRP2 receptors are more active

At Palmyra Atoll, the environmental DNA (eDNA) signal on tidal sand flats was associated with fish biomass density and captured 98%–100% of the expected species diversity there. Although eDNA spilled over across habitats, species associated with reef habitat contributed more eDNA to reef sites than to sand‐flat sites, and species associated with sand‐flat habitat contributed more eDNA to sand‐flat

Male olfactory cues may guide aggregation on spawning reefs, mate evaluation, and synchronized gamete release in lake trout Salvelinus namaycush , but a lack of information on the source and identity of the cues precludes direct tests of their function. Using a two‐channel flume, we found ovulated female lake trout increased time spent in the channel treated with spermiated male‐conditioned water,

This study reports the first records of cowsharks (Hexanchidae) in the Galápagos Islands, in particular Notorynchus cepedianus and Hexanchus griseus, observed between depths of 210 and 418 m on footage from free‐falling autonomous deep ocean cameras. These sightings provide new information on the habitat preferences and range distribution for N. cepedianus, and the first records of H. griseus in Ecuadorian

Bryconops cyrtogaster , a poorly‐known species endemic from the Oyapock River at the border between French Guyana and Brazil, is redescribed herein based on examination of available type material, as well as newly collected material. Additionally, a new rheophilic species from the rio Jari rapids, lower Amazon basin, Brazil, is described. The two species belong to the subgenus Creatochanes, and are

When describing the architecture and ultrastructure of animal skeletons, introductory biology, anatomy and histology textbooks typically focus on the few bone and cartilage types prevalent in humans. In reality, cartilage and bone are far more diverse in the animal kingdom, particularly within fishes (Chondrichthyes and Actinopterygii), where cartilage and bone types exist that are characterized by

An oceanic whitetip shark (Carcharhinus longimanus ) was observed off the coast of Kona, Hawaii, with scars caused by the tentacles of a large cephalopod. While the exact species could not be confirmed, candidate species include the giant squid (Architeuthis dux ) or species from the genera Thysanoteuthis (flying squids) and Megalocranchia (glass squids). Telemetry shows C. longimanus will dive within

Environmental signals act primarily on physiological systems, which then influence higher‐level functions such as movement patterns and population dynamics. Increases in average temperature and temperature variability associated with global climate change are likely to have strong effects on fish physiology and thereby on populations and fisheries. Here we review the principal mechanisms that transduce

A new species of Hypostomus with spoon‐shaped teeth is described from the Rio Cupari basin, a right margin affluent of the lower Rio Tapajós, Pará State, Brazil. The new species inhabits rocky bottom areas in the main channel of Rio Cupari and its tributaries. The new species can be distinguished from all its congeners, except from the Hypostomus cochliodon group, by having six to eight spoon‐shaped

In Lulijwa et al . (2020), the following errors were published on pages 733, 736, and 737. On page 733, reactive oxygen species (ROS) was defined at its second mention (instead on the first mention on page 732). Therefore, on page 732, the sentence with the mention of ROS should read as “At the cellular level, repeated poly (I:C) stimulation enhanced reactive oxygen species (ROS) production of HK macrophages

The introduction of nonnative species is one of the most critical problems facing freshwater systems today. The rivers of the Great Basin (USA) have been particularly imperilled by nonnative species introductions and represent a valuable location to study the dietary trends of native and nonnative fishes in isolated, endorheic systems. We collected fish from 23 sites, spanning three Great Basin watersheds

To investigate whether wild fish populations are food limited, this study explored whether the provision of supplementary food had a positive effect on the abundance, condition and growth characteristics of estuarine fish assemblages in New Zealand. Feed (7690 kg) was delivered from an anthropogenic feeding station over a 60‐week period to a naturally occurring assemblage of wild fish. Yellow‐eyed

The cuckoo catfish Synodontis multipunctatus and S. grandiops are endemic to Lake Tanganyika and the only known nonavian vertebrates that exhibit obligate interspecific brood parasitism. Seven maternal mouth‐brooding cichlid fish species are reported to be natural hosts of the parasitic catfish and share a common reproductive behaviour that the catfish exploits: cichlid females spawn eggs on the bottom

Uehara, M, Tachihara, K. (2020). Early development and occurrence patterns of the Pagrinae seabream Argyrops bleekeri (Perciformes: Sparidae): Does early life history have implications for sparid relationships? Journal of Fish Biology, 96, 631–641. https://doi.org/10.1111/jfb.14249 On page 636, in Figure 6, the vertical axis title has been changed from “Measured proportions (%)” to “Total number of

Marine fish species check‐lists from six Chinese coastal waters were combined for the analysis of taxonomic diversity. The Genus‐Family index (G‐F index) ranged between 0.39 and 0.84, which generally indicated a decreasing trend with increasing latitude, with the exception of the southernmost area. Average taxonomic distinctness showed a slight increasing trend from northern to central study areas;

Ambient temperature modulates reproductive processes, especially in poikilotherms such as teleosts. Consequently, global warming is expected to impact the reproductive function of fish, which has implications for wild population dynamics, fisheries, and aquaculture. In this extensive review spanning tropical and cold‐water environments, we examine the impact of higher‐than‐optimal temperatures on teleost

Biogeographical transition zones are important areas to investigate evolutionary ecological questions but long‐term population monitoring is needed to obtain a better understanding of ecological processes that govern populations variations in such edge environments. The southernmost Brazilian rocky reefs are the southern limit of distribution for 96% of the tropical ichthyofauna of the western Atlantic

The genus Pareuchiloglanis , distributed in the Salween, Mekong, Red, Pearl, and Yangtze River basins in China, Laos, Myanmar, and Vietnam consists of 20 valid species and five uncertain species. Herein, we provided a taxonomic revision to Pareuchiloglanis occurring in the Yangtze River. According to the results of a morphological comparison, the type locality of Pareuchiloglanis sinensis was updated

Corals create complex reef structures that provide both habitat and food for many fish species. Due to numerous natural and anthropogenic threats, many coral reefs are currently being degraded, endangering the fish assemblages they support. Coral reef restoration, an active ecological management tool, may help reverse some of the current trends in reef degradation through the transplantation of stony

Sturgeon spermatozoa are unique for their sustained motility. We investigated the relative importance of bioenergetic pathways in the energy supply of Siberian sturgeon Acipenser baerii spermatozoa during motile and immotile states. Spermatozoon motility and oxygen consumption rate (OCR) were analysed following exposure to inhibitors of oxidative phosphorylation (sodium azide, NaN3), glycolysis (2‐deoxy‐D‐glucose

This study investigated the impact of the third dimension in geometric morphometrics (GM) using sailfin silversides (Telmatherinidae) from the Malili Lakes of Sulawesi (Indonesia). The three morphospecies of the monophyletic “roundfin” radiation are laterally compressed and vary in shape traits. The results of 2D and 3D GM were compared and quantified to discuss the advantages and disadvantages of

Knowledge of skate ecology must be improved to ensure their effective protection. This study represents the first description of diet composition for one of the largest European rajid, the blue skate Dipturus cf. flossada . A total of 346 specimens collected in the Celtic Sea from 2012 to 2015 were analysed for their gut content, with respect to individual total length, maturity stage and sex. Overall

Environmental DNA (eDNA) analysis is increasingly used for biomonitoring and research of fish populations and communities by environmental resource managers and academic researchers. Although managers are much interested in expanding the use of eDNA as a survey technique, they are sceptical about both its utility (given that information is often limited to presence/absence of a species) and feasibility

Resistin as an adipokine identified from rodents in 2001 is involved in many biological processes. However, little is known about this gene in fish. We cloned Siberian sturgeon (Acipenser baerii ) resistin cDNA of 795 base pairs, encoding 107 amino acids, which showed 38–40% identity to human and rodents. Real‐time quantitative PCR showed that the resistin gene was widely distributed in tissues of

This study documented the parasite faunas of the spiral valves of blue sharks Prionace glauca (L. 1758) and common thresher sharks Alopias vulpinus (Bonnaterre, 1788) caught in the California Current Large Marine Ecosystem (CCLME) north of the Mexican border. The spiral valves of 18 blue and 19 thresher sharks caught in the CCLME from 2009 to 2013 were examined for parasites. Seven parasite taxa were

We evaluated the use of measurements of length and mass to predict larval metamorphosis of Pacific lamprey Entosphenus tridentatus . During 2004–2008, larval E. tridentatus were collected from Cedar Creek (Washington, USA) in either the spring or autumn, measured for total length and total mass, reared in captivity and monitored for metamorphosis. The minimum total length, total mass and condition

The present study determined the effect of body mass and acclimation temperature (15–28°C) on oxygen consumption rate (ṀO2) and the size dependency of preferred temperature in European perch Perca fluviatilis . Standard metabolic rate (SMR) scaled allometrically with body mass by an exponent of 0.86. Temperature influenced SMR with a Q10 of 1.9 regardless of size. Maximum metabolic rate (MMR) and aerobic

Impacts of urban development on aquatic populations are often complex and difficult to ascertain, but population genetic analysis has allowed researchers to monitor and estimate gene flow in context of existing and future hydroelectric projects. The Lower Mekong Basin is undergoing rapid hydroelectric development with around 50 completed and under construction dams and 95 planned dams. We investigated

The present study was carried out in the marine area of Stratoni, Greece, where two seahorse species are present (Hippocampus hippocampus and Hippocampus guttulatus ). Two surveys were conducted (September 2016 and May 2019) to gather information regarding seahorse species' abundance, distribution and habitat characteristics. Four different seahorse natural and artificial habitat types were identified

Resource partitioning has an essential role in interspecific relations, especially in congener species, which share many morphological traits. In some places, small characids coexist through resource partitioning, which may reduce their interspecific competition. In this sense, Astyanax species (e.g. A. minor, A. gymnodontus and A. bifasciatus ) coexist in different water bodies from Iguaçu river basin

Variability in life history traits and structural diversity of commercially exploited fishes in response to stress can impact their population dynamics and sustainability. Using data from a fishery dependent sampling program from 1978 to 2011, we evaluated temporal variability of size and growth of adult Atlantic herring ( Clupea harengus ) in the Gulf of Maine. We then developed and tested the hypotheses

In fishes, sex is either determined by genetics, the environment, or an interaction of both. Temperature is among the most important environmental factors that can affect sex determination. As a consequence, changes in temperature at critical developmental stages can induce biases in primary sex ratios in some species. However, early sex ratios can also be biased by sex‐specific tolerances to environmental

Fish otoliths' chronometric properties make them useful for age and growth rate estimation in fisheries management. For the Eastern Baltic Sea cod stock (Gadus morhua ), unclear seasonal growth zones in otoliths have resulted in unreliable age and growth information. Here, a new age estimation method based on seasonal patterns in trace elemental otolith incorporation was tested for the first time and

Successful captive broodstock development of clupeid fish, hilsa is one of the major challenges for the artificial propagation of this economically valued fish. The present study provides novel insights in to the pond reared captive broodstock development of hilsa using artificial feed. In the present study, wild collected hilsa fry (weight: 1.35±0.13 g; length: 53.84±0.95 mm) were reared in grow out

Larval growth and survival of catfishes are largely influenced by the various biotic and abiotic factors. The present study investigated the effect of different light intensity and photoperiod on growth and survival of Ompok bimaculatus larvae. Three separate trials of 21 days each were carried out in an aquarium tank. In the first trial, we investigated the embryonic changes (based on hatching rate

Follicle cell processes (FCP) are actin‐based, tube‐like structures that connect the developing oocyte to the follicle cells throughout oogenesis. They were first described in Selachians (sharks) where their suggested roles were facilitating the transport of metabolites to the developing oocyte and providing structural support to the large egg cells of sharks, an early stage in the evolution of viviparity

Opsanus beta is endemic to the Gulf of Mexico and has recently been introduced to the Brazilian coast; probably the introduction is via ballast water and/or oil rigs. In this study, the presence of the species is recorded for the first time in Guaratuba Bay, southern coast of Brazil. In this region, there are no port terminals, which suggests that O. beta used a different mode of human facilitated

This study describes a new recreational fishing method focused on marine catfish, Genidens barbus (Endangered‐EN), through the adoption of its eggs as a natural bait during its reproductive period in southern Brazilian ecosystems. Male G. barbus perform parental care, collecting eggs released by females after the fertilization process. Owing to this male behavioural pattern during the reproductive

The present study aimed to assess the annual reproductive cycle of female brown banded bamboo shark, Chiloscyllium punctatum , from the Persian Gulf using macroscopic and microscopic evaluation of reproductive tract. The annual cycle of gonadal steroids (17b‐estradiol (E2), progesterone (P4) and testosterone (T)) was also assessed in this shark. Totally, 130 female C. punctatum were collected from