Health & Welfare

As with other species, varied health problems – and treatments – related to parasites and bacteria have been encountered in pangasius catfish. 

Ultrasound may serve as an alternative to chemical treatments in channel catfish production. In studies, controlled application of ultrasound did not significantly affect catfish feed consumption and weight gain. 

Sodium bicarbonate is a useful chemical in recirculating aquaculture systems and fish transport tanks. However, two common uses of the compound in pond culture – to remove carbon dioxide and treat off-flavors – do not work. 

In studies, the authors found no significant difference in internal susceptibility to WSSV infection between shrimp in different molt stages. 

Since catfish fry survival lowers if subjected to an abrupt pH rise of 0.5, the authors recommend measuring pH in transport tanks and receiving ponds and the addition of buffering agents to transport tanks. 

Research with channel catfish found that the induction of puberty is a developmental pro­cess that requires temperature cycles and is independent of body size. It may be possible to achieve early maturation in channel catfish in less than two years. 

Experiments by the authors showed that the gene activity of the brain neurotransmitter CART changed in catfish in response to feed intake. 

By comparing the growth of shrimp fed different diets in big versus small net pens, trial results suggested that shrimp could compensate for lower diet quality by grazing on the algae growing on the surfaces of the net cages. 

A study of Nile tilapia provided feed with varying dietary lipid sources found that fish fed a diet with beef tallow exhibited poorer survival and growth performance than fish fed diets with plant oils, fish oil, or combinations of oils and tallow. 

Red-banded sea bream could be farmed in systems designed for other sparid species. The authors’ facilities have achieved spontaneous spawning. 

Using a series of equations, energy and protein requirements for every fish species can be cal­culated and adapted to changing conditions. 

The freshwater drum is a proposed snail-control vector in catfish ponds. In tank studies the drum showed high survival and reduced snail populations. 

The authors developed an efficacious combination vaccine against P. piscicida and L. garvieae for yellowtail and amberjack. Field trials showed posi­tive results, and the vaccine was approved for use in Japan. 

In a study, vaccination of juvenile tilapia by bath immersion followed by two booster vaccinations stimulated specific antibody responses and protection against S. iniae challenge. 

The foundation of a successful integrated aq­uaculture company is reliable production of healthy postlarvae. Methodical breeding selection of the offspring from carefully managed broodstock can lead to improved disease resistance and higher growth rates.