this study was designed to determine the effects of dietary replacement of fish oil with canola oil ongrowth performance, feed efficiency of body and economic indices of experimental diets of juvenilecommon carp (cyprinus carpio). during the experiment 270 juvenile fish with an average initialweight of 16.24 ± 0.10g were randomly distributed in 18 well aerated cylindrical polyethylene tanks(15 ...

mass mortality of stinging catfish, heteropneustes fossilis, was observed in a fish farm of kulgaria, burdwan in west bengal, india. the cumulative mortality rates reached up to 5% of the total fish in the farm per day. the clinical signs of the affected fish showed ulcers on the skin which gradually grew in size and progressed to form ulcerous dermatitis. clinical signs of catfish experimental...

there are 61 species in 14 families of fish-eating birds in iran. the fish-eating birds of the north of iran belong to 41 species in 10 families which include 67.2 percent of total fish eating bird species and 71% of fish-eating bird’s family of iran. resident birds constitute 13% of the fisheating birds of the caspian sea coasts and the rest are migratory in autumn and winter. there exist 3 ...

the present study was carried out to determine the effects of fish oil long-chain fatty acids and thyme essence supplementation on performance and carcass traits in mahabadi goat kids. twenty-eight mahabadi goat kids (average initial bw of 17/8 ± 2/8 kg, 4-5mo) were randomly assigned to four treatments of: 1. control (basal diet), 2. 0.2% thyme essence, 3. 2% fish oil, and 4. 2% fish oil +0.2% ...

The effect of different sublethal concentrations of diazinon at 1, 2 and 4 mg/L on some hematological and biochemical parameters of grass carp (Ctenopharyngodon idella) weighing 850±155g was studied after 1, 7, 15, 30 and 45 days post exposure to the toxicant as a bath for 12 hours at 18-22 C. In one day exposure fish to the toxicant, the values of neutrophiles exposed to 2 and 4mg/L were signi...

Fishes with internalized and endothermic red muscles (i.e. tunas and lamnid sharks) are known for a stiff-bodied form of undulatory swimming, based on unique muscle-tendon architecture that limits lateral undulation to the tail region even though the red muscle is shifted anteriorly. A strong convergence between lamnid sharks and tunas in these features suggests that thunniform swimming might b...

Sharks, rays, and chimaeras (Class Chondrichthyes; herein 'sharks') are the earliest extant jawed vertebrates and exhibit some of the greatest functional diversity of all vertebrates. Ecologically, they influence energy transfer vertically through trophic levels and sometimes trophic cascades via direct consumption and predation risk. Through movements and migrations, they connect horizontally ...

We compared life-history traits and extinction risk of chondrichthyans (sharks, rays and chimaeras), a group of high conservation concern, from the three major marine habitats (continental shelves, open ocean and deep sea), controlling for phylogenetic correlation. Deep-water chondrichthyans had a higher age at maturity and longevity, and a lower growth completion rate than shallow-water specie...

The adult morphology of the tail varies greatly among extant fishes despite sharing both ontogenetic similarities and the functional need to propel the body through a fluid medium. Both sharks (Chondrichthyes) and ray-finned fishes (Actinopterygii) control caudal fin musculature independently of axial body myomere activity to modify the stiffness and shape of their tails. For example, sharks an...

Predator avoidance is fundamental for survival and it can be particularly challenging for prey animals if physical movement away from a predatory threat is restricted. Many sharks and rays begin life within an egg capsule that is attached to the sea bed. The vulnerability of this sedentary life stage is exacerbated in skates (Rajidae) as the compulsory ventilatory activity of embryos makes them...