Water temperature is an important abiotic factor that impacts physiological processes in fish. Attempts to quantify thermal tolerance of fishes exposed to various temperatures have been performed since the 1800s. A common approach to test the thermal tolerance of fishes is the critical thermal method. Traditionally this method has required access to large and expensive lab equipment. However, many

Protein kinase RNA‐activated (PKR) is an important component of the innate immune system induced by interferon. This antiviral protein senses a variety of stresses and pathogen‐driven double‐stranded RNAs (dsRNAs). In the present study, we cloned and characterized the PKR gene from Dabry's sturgeon (Acipenser dabryanus). Bioinformatics analysis revealed that the AdPKR gene comprises a coding sequence

The aim of the present study was to demonstrate the usefulness of fish scales as a bioindicator reflecting the concentrations of heavy metals in the environment as compared to typical recognized bioindicators such as the liver or kidney. Heavy metal (Zn, Mn, Cu, Cd, Fe, Ni, Pb) concentration analysis (with the atomic absorption technique) was performed in different annuli on the fish scale to characterize

The unknown status of inland fish stocks hinders their sustainable management. Therefore, increasing stock status information is important for sustainable inland fisheries. Fisheries reference points were estimated for five exploited fish species (11 stocks) in the Lake Edward system, East Africa, which is one of the most productive inland water systems. The aim was to ascertain the status of the fisheries

The length–weight relationships (LWR) were estimated for five selected demersal marine fishes from the relatively undisturbed shelves and slopes of the Cabo Verde Islands. Most of them were of ecological and/or commercial interest. Occasional sampling was carried out during different fisheries research projects. LWRs were taken for the following bycatch species for which no such estimates exists in

Main purpose of this work is the identification of females of artificial sturgeon hybrids capable to produce unreduced oocytes. The importance of this task is due to the ability to receive clonal all‐female lines. Experiments were performed on the previously obtained reciprocal hybrids of sterlet, Acipenser ruthenus (S) with ~120 chromosomes and kaluga, Acipenser dauricus (K) with ~260 chromosomes

Predation on early life stages of Atlantic Sturgeon Acipenser oxyrinchus oxyrinchus (ATS) may be a constraint to species recovery. Due to the difficulty in assessing consumption of early life stages with traditional diet analysis methods, we pursued an alternative DNA‐based approach. We extracted total gut content from gastrointestinal tracts of 23 fish species (593 samples) within the tidal‐fresh

The length‐weight relationships (LWRs) of six Nemacheilid species (Schistura chindwinica, S. fasciata, S. khugae, S. minuta, S. reticulata and S. rubrimaculata) have been analyzed. Fish samples were collected on quarterly basis from March 2018 to February 2019. Sampling was performed using cast nets (mesh size 5–10 mm; about 50 sq m area covered each time and water depth was 4 ft approx.), and electrofishing

The morphological variation of the endangered catfish Rita rita was studied based on meristic, length–weight relationship (LWR), traditional (TRA) and truss (TRU) distance based morphometric analysis of 200 juveniles collected from the Old Brahmaputra, Jamuna, Meghna and Kangsa rivers. Data were subjected to Kruskal–Wallis test for meristic counts, t test for LWR, univariate ANOVA, multivariate discriminant

Carinotetraodon travancoricus or Malabar puffer fish is an endemic species described from rivers originating from the Western Ghats in South India. This species is captured extensively as an aquarium fish and is having substantial demand in global markets. However, being prone to overfishing and impacts of anthropogenic alterations in its habitats, IUCN has categorized it as a threatened/vulnerable

The Channel catfish is one of the most important freshwater fish species in North America. Conventionally their selection for genetic improvement is focused in growth related traits but not on quality traits as flavor and fatty acid deposition. The aim of this study was the sequencing of Stearoyl‐CoA Desaturase (SCD) and Fatty Acid Desaturase 2 (FADS2) genes, two of main genes in the biosynthesis of

The purpose of this study was to develop a novel method for the external attachment of ultrasonic transmitters on hard fin‐spines fish (Sparidae). Acanthopagrus latus, one of the main stocking Sparidae fishes in the northern South China Sea, was employed to conduct the 40‐day tank experiment by using dummy ultrasonic transmitters. The experiment consisted of 3 treatment groups, i.e., drilling on dorsal

The present study provides the length‐weight relationships (LWRs) for 10 marine fish species collected from the coastal waters of the East China Sea by bottom trawl surveys. The open width of the sampling net was 40 m and the mesh size of the codend was 20 mm. Specimens were collected from November 2015 to November 2019 at seasonal intervals. The measurement accuracy of weight and length were 0.1 grams

The present study provides the first detailed early embryonic development of the Shalyni barb, Pethia shalynius (Yazdani & Talukdar, 1975), a vulnerable cyprinid fish occurring in streams and lentic waters of Meghalaya, northeast India. Induced spawning by synthetic hormone injection in May 2019 was conducted to a pair of mature female and male P. shalynius under controlled conditions in a well‐aerated

Seamount fish communities are susceptible to variations due to the oceanographic conditions and level of historical fishing effort. In the NE Atlantic, the Azores is considered an “oceanic seamount ecosystem area” because seamount concentration is high relative to other regions. Scientific information on seamounts in the Azores remains scarce and demersal fishery occurs mostly without any knowledge

This study evaluated the length‐weight relationships (LWRs) for three teleost fish species sampled from the Stung Russei Chrum River basin, Kingdom of Cambodia. The fish were collected during two dry seasons (April 2019 and November 2019) and one rainy season (October 2018) using monofilament trammel nets (2–12 cm mesh size), cast net (mesh size 2 cm) and scoop‐nets (mesh size with 0.3 cm). Results

Trachurus japonicus is an economically important fish in the northwestern Pacific Ocean. However, its resources have declined seriously and there is an urgent need for a wide‐range of investigations of the existing genetic resources. This requires a large number of diverse molecular markers with high discriminating power. In this study, we identified 43,264 perfect SSRs in T. japonicus genome using

Genus Chirostoma belongs to Atherinopsidae family and it is an endemic species from the Mesa Central in Mexico. Abundance of its species have decreased and some ones have been placed on the threatened species list, because of overfishing, urbanization, industrialization, destruction, habitat fragmentation, pollution and exotic species introduction. Chirostoma jordani (Woolman, 1894) is a freshwater

This study aimed to determine the age and some growth characteristics of Atlantic stargazer (Uranoscopus scaber) from Iskenderun Bay (Northeastern Mediterranean). For this purpose, a total of 150 Atlantic stargazer ranging in size from 9.1 to 28.0 cm in total length (weight: 11.7–345.7 g) were collected as by‐catch from a commercial trawl fishing boat at a depth of 80–100 m between May 2015 and January

Between September 2010 and June 2012, a total 291 (166 females and 125 males) blackchin guitarfish Glaucostegus cemiculus were captured by a commercial bottom trawler (F/V Coşkun Reis) in Iskenderun Bay, Turkey (northeastern Mediterranean Sea). The total length (L) and total weight (W) of the female and male guitarfish ranged between 32.0–165.0 cm and 88 g–16.68 kg, and 34.3–128.3 cm and 112 g–6.00 kg

Fish specimens were captured by a commercial bottom trawler at a depth of 50–80 m from Iskenderun Bay (Hatay, Turkey) between December 2017 and May 2018. The bottom trawl gear used was equipped with a 44 mm stretched mesh size net at the cod‐end. Blind side and eyed side otolith lengths (OL), otolith breadths (OB) and otolith weights (OW) were measured from each specimen to the nearest 0.001 mm and

In this study, the efficiency of two fishing methods (a) traditional handline commonly used in the Strait of Istanbul and (b) light rock fishing (LRF), which is beginning to spread in recent years, were investigated by monthly sampling between September 2014 and September 2015. One classic handline fishing tackle and one LRF fishing tackle were used in the test fishing exercise. In addition, the effects

The objective of this study was to investigate the differences in proximate lipid composition, heavy metals, and mineral contents between bogue (Boops boops, Linnaeus, 1758) captured directly around and near a cage fish farm and those captured far away from it (“wild”). Wild fish were obtained from the fishery of the Aegean Sea and Northeastern Mediterranean. Fish were also caught at a distance of

This study attempts to delineate the nutritional value and potential problem of toxic metal contamination in Sardinella maderensis (Lowe,1838) originating from Mauritanian fishery destined for regional common human consumption. Samples caught in Mauritania were delivered to Turkey by ship in 22 days in cold storage. Amino acids, fatty acids and toxic metal analyses of the samples were carried out by

The muscle tissues of a total 154 sampled eels from the Asi (Orontes) River were analyzed between January and December 2018 to determine the content of heavy metals (Hg, Pb, Cd and As). Determination of heavy metals in muscle tissue was carried out with an Inductively Coupled Plasma Mass Spectrometer (ICP‐MS). To express the risk level for human consumption of heavy metal contaminated eels we used

The biological characteristics of eels from the Asi River, Turkey, were assessed between December 2017 and November 2018. Eels were sampled monthly using fyke nets (operated by professional fishermen), yielding a total of 509 specimens. Total length and weight were measured, sex, age and maturity stages (silver or yellow eel) were determined. Catch Per Unit Effort (CPUE) was calculated for both biomass

Thirteen river basins draining into the Marmara, Aegean and Mediterranean Seas were selected for evaluation of European eel (Anguilla Anguilla L., 1758) catch in Turkey. These basins were grouped into three so‐called “eel monitoring area” (EMA). The official province‐based annual landing data between 1996 and 2018 were assessed for each of the monitoring areas. Statistically significant decreases over

A tentative survey on selected marine fish farms was undertaken to delineate the extent to which infections with Staphylococcus species occur in Turkish aquaculture systems. To determine the presence and the distribution of fish pathogenic staphylococci, representative farm types such as marine cages as well as inland pond farms working with saline‐ground water and a large hatchery were selected. Field

The aim of the present study was to determine the morphologic and histopathologic characteristics of tumors observed in samples from moribund Capoeta capoeta. For this purpose, ten fish, captured from the Fırat River located in southeastern Anatolia of Turkey, were examined for gross malformations and histopathological morphology. Externally, two different morphological types of tumours were detected

Deformities/anomalies in fish body shapes have important implications on the marketability of the fish and thus can affect particularly the consumer perception of aquaculture‐produced fish, raising concerns on animal welfare. The aim of this study was to detect the distribution of deformities in cultivated Sparus aurata that were raised to market size and sold in Istanbul Gürpınar Wholesale Fish Market

The marbled spinefoot, Siganus rivulatus (Forsskål&Niebuhr, 1775) was recorded for the first time in Izmit Bay, Sea of Marmara. One specimen was caught on 30 September 2019 by a small scale fisherman at depth of 25 m. The fish measured 151 mm in total length and weighted of 43.45 g. S. rivulatus is one of the Lessepsian immigrants who entered the Mediterranean more than half a century ago, and has

Taxonomic position of the Balkan spined loach, Sabanejewia balcanica (Karaman, 1922) is still uncertain. There are pronounced differences in morphological characters among individuals from different populations, which led to description of various populations as species, subspecies and clinal variation. In this investigation we aimed to describe morphological and genetic diversity of S. balcanica in

The present study reports the length‐weight relationships (LWRs) for eight fish species sampled in Hailang River, a left‐bank tributary of the Mudan River in Northeast China. The fishes were collected from April to October bimonthly 2017 by electrofishing (fishing 2 kilometers along the river and within 5 meters from the bank) and netting (drift gillnet: mesh size 2 cm × 3 cm; 200 m net length). The

The genetic diversity of 289 spotted scat (Scatophagus argus) from seven populations along the northern coast of the South China Sea was studied by analyzing the full‐length sequences of the mitochondrial control region (D‐LOOP). The S. argus D‐LOOP sequence was 1,004–1,010 bp long and contained 156 variant sites. The seven studied S. argus populations had a high degree of genetic diversity (haplotype

In genetic fish breeding research, clear pedigree information is of great significance for breeding and parental management. In order to establish a stable, highly accurate, and widely applicable parentage identification method for tilapia, 13 highly polymorphic microsatellite loci within populations of Oreochromis niloticus, O. aureus, O. niloticus × O. aureus, and their mixed population were screened

Early development of the endemic dace Telestes karsticus is described in a Dinaric karst stream in Croatia. Larvae were acquired from successful rearing in an aquarium. Basic morphometric and meristic measures of larvae were taken during 55 days of observation. The mean total length of larvae at the time of hatching was 6.45 mm. The yolk sac was completely absorbed in all larvae by day 9 post‐hatching

This study reports the length‐weight relationships (LWR) for seven endemic fish species from streams in the Ivaí (Characidium heirmostigmata, Corydoras lacrimostigmata, Curculionichthys oliveirai, Hisonotus pachysarkos, and Cambeva horacioi) and Ivaí and Piquiri (Apareiodon vladii and Planaltina kaingang) River basins, Paraná State, Brazil. Fish specimens measured and weighed were collected between

We analyzed ovarian dynamics of anadromous blueback herring, Alosa aestivalis, in Connecticut River with the principal aim of exploring oocyte recruitment and how it shapes the fecundity pattern. We examined the oocyte release strategy and analyzed spawning cyclicity by linking oocyte growth to the degeneration of postovulatory follicles. Females were accordingly classified as pre‐spawners, early and

The Yangtze sturgeon (Acipenser dabryanus) is a most important aquatic animal at the national level. Influenced by human activities such as dam constructions and overfishing, its natural population in the wild has almost disappeared. Since 2000, its natural reproduction has not been detected. In May 2018, in the Yibin reaches of the upper Yangtze River, 40 adult hatchery reared Yangtze sturgeons with

Hexanchus nakamurai is a deep‐water species, with very little scientific information. This study confirms the distribution of the species in the most eastern region of the Mediterranean Sea, Levantine Sea, in addition to providing some biological information from four pregnant individuals, which is being reported for the first time in the Mediterranean Sea. A total of four individuals were bycaught

The present study describes the length‐weight (LWR) and length‐length (LLR) relationships for three indigenous fish species from the Qingshui River, southwestern China. Fishes were collected by electrofishing in May 2015 in the middle Qingshui River. Total length (TL), standard length (SL) and fork length (FL) were measured to the nearest 0.1 cm with a digital calliper and weight (W) was determined

Fish morphometric relationships are key tools for fisheries science and studies of food web dynamics and predator foraging behaviour, but parameterisations are limited for Southern Ocean myctophids (Family Myctophidae). New standard length (LS) to total mass (MT) relationships are therefore described for the 12 biomass‐dominant myctophid fish species living in the Scotia Sea, Southern Ocean, using

National park Plitvice Lakes is the oldest, the largest and the most visited national park in Croatia, well known for its stunning karstic watersheds that supply Plitvice Lakes and exceptionally valuable biodiversity. Lack of knowledge on the taxonomic status, population structure and viability of trout in the Plitvice Lakes National park, as well as the possibility of existence of cryptic diversity

Yellowfin tuna are the mainstay of the traditional tuna fisheries in St Helena waters, but there is limited knowledge of their ecology and feeding behaviour in the area. In this study yellowfin tuna stomach contents were used to assess spatio‐temporal changes in feeding strategy and consider the role of tuna in the local ecosystem. Comparisons of the feeding spectra of yellowfin tuna between inshore

Spotted sand bass (Paralabrax maculatofasciatus) is one of the most common inshore reef fishes in the northern Gulf of California (GOC), Mexico, but has rarely been studied. Objectives of this study were to estimate age and growth parameters of this species from two areas in the northern GOC and use an age‐structured model to assess fishery yield and Spawning Potential Ratio (SPR) over a wide range

The length–weight relationships (LWRs) of four fish species were determined from Vembanad‐Kole Wetland, Kerala, India between June 2015 and May 2016. Fish samples were collected monthly from various fishing gears such as gill nets (50 m long and 1.5 m height, mesh sizes 30–100 mm, soaking time 8 hr) and seine nets (mesh sizes 8–16 mm). Values of the parameter b ranged from 2.896 to 3.165 and such values

The length–weight relationships (LWRs) for six species were estimated. Fish were captured in the mangroves of Qinzhou Harbour, China, but also some specimens were purchased from fishermen. The sampling was undertaken monthly between May 2011 and April 2012 using seines (mesh size 5–10 mm; height 4 m; length 400 m) and traps (mesh size 8.5 mm; 35 cm2 × 10 m for one unit) at seven sampling sites. Standard

Calcium is a prerequisite factor for triggering the sperm activation in salmonids. The aim of this study was to test different concentrations of Ca2+ on sperm motility activation and fertility of rainbow trout (Oncorhynchus mykiss). Semen samples activated with calcium free activator (0.0 mM) and increasing concentrations of CaCl2 (6.3, 7.9, 9.5 and 11 Mm) were evaluated by computer‐assisted sperm

The length‐weight relationships (LWR) were estimated for five fish species from the Golfão Maranhense, Brazilian Amazon littoral region. Samplings were performed in August 2016, during the dry season, using trawl net with 6.0 m length by 3.0 m width (trawl mouth opening of 6.0 m2) and 1.0 cm mesh size between opposite knots. This study registers LWR for Anchoviella elongata and Gobioides broussonnetii

Monitoring trends in a long‐lived species such as lake sturgeon (Acipenser fulvescens) has it challenges. Targeting the correct life stage to monitor can provide different and contrasting results. Early life stages experience high variable mortality and are often not a good predictor of population trend. Juvenile lake sturgeon (i.e., 5–10 years) experience high survival and could be a good life stage

Environmental conditions during early life can have a profound impact on developmental trajectory and ultimately ecological fitness of individuals. Therefore, from a conservation perspective it is vital to understand the longer‐term implications of early phenotypic development on survival. In this study, we examined the effects of temperature (maintained at 16°C or ambient river temperature), prey

The ontogenetic structure and longitudinal variability of ichthyoplankton in a confluence zone of two river systems in the Eastern Amazon were evaluated between December 2018 and April 2019, at the time 137 eggs and 7,687 larvae of fish were captured. Ichthyoplankton proved to be heterogeneous between sections of rivers with differences in the number of taxa and abundance. The assemblages were distinguished

This study aimed to estimate the parameters of length‐weight relationship for 16 freshwater fish species that inhabit the Aracá and Demeni Rivers, which are two tributaries of the Negro River (Amazonas state, Brazil). The fishes were sampled using gillnets (15 × 2 m, mesh size 30–120 mm between opposite knots), during 6 days each year, in April 2016, November 2018 and April 2019. The gillnets were

The swimming performance of juvenile rock carp (Procypris rabaudi, Tchang) subjected to repeated fatigue exercise was studied using a flume‐type respirometer at 20°C. The critical swimming speed (Ucrit) and oxygen consumption rate (MO2) of juvenile rock carp were measured during two successive stepped velocity tests, following a 60 min rest interval. Ucrit of rock carp was giving a recovery ratio (Rr)

This work analysis the length‐weight relationships for fish species captured by artisanal fishery along the continental coast of Ecuador. Fishermen used the following fishing gear: beach seine nets (5.1–31.8 mm), shrimp trawl nets (21.8–31.8 mm) and bottom gill nets (54.1–203.2 mm). Sampling took place during the years 2012 and 2014. Frequency of sampling was monthly, and it was completed systematically

The present work provides length‐weight relationships (LWRs) for fish species captured around artificial offshore reef deployed 5 km from Guaxindiba Port, northern Rio de Janeiro, Brazil. The fish were captured during two sampling periods each year between 1996 and 2017 using bottom gill nets (25 mlength × 3 mdepth; 30 mm mesh). The fish were kept on ice and the biometric data, including total length

Length‐to‐weight and length‐to‐length ratios were estimated for six cavefishes including Yunnanilus longibarbatus, Yunnanilus bailianensis, Yunnanilus jinxiensis, Oreonectes polystigmus, Paranemachilus pingguoensis, and Paranemachilus genilepis from the upper reaches of the Pearl River, Guangxi Province, China (between 106.26E, 23.14N and 111.42E, 24.85N). The fish were captured between May and October

The length–weight relationships (LWRs) for six native fish species from the Chapala Lake, Mexico, are described in this paper. The fish were caught monthly with the support of local fishermen from different landing sites. The daily catch is obtained using the nasa charalera (pot) and the gill net. Each fisherman can operate 20 pots daily at each fishing site for approximately six or seven months; this

Aquarium and ornamental fish trade is currently recognized as a major source of invasive species in aquatic ecosystems around the world. The swordtail Xyphophorus hellerii is a popular ornamental freshwater fish that occurs as an introduced species in the aquatic habitats of at least thirty‐one countries. We report the first finding of an established population of the swordtail in Morocco. Twelve individuals

This study deals with the length‐weight relationships (LWRs) of three commercially important marine fishes belonging to the family Clupeidae from the major landing centers in Tuticorin, Mandapam, Thondi, Nagapattinam and Chennai in southeast coast of India. Monthly sampling were done at the respected landing centers from June, 2018 to April, 2019 from the commercial trawlers (with cod‐end mesh size