The shrimp farming has been converted into a mature aquaculture industry dealing with over millions of metric tonnes of processed commodities. Nevertheless, the global shrimp productions are constantly threatened by disease outbreaks, mainly triggered by rapidly disseminating viruses. Infectious myonecrosis virus (IMNV) is one of these epizootic agents affecting shrimp production in Brazil, of which no treatment exists. Herein, the antiviral activity against IMNV of an eicosapeptide, named Ctn[15-34], derived from a member of the cathelicidin family of antimicrobial peptides, was demonstrated. Cultures of hemocytes from Litopenaeus vannamei were established that support IMNV replication and infectivity titration. The cytotoxic effect of IMNV in culture and the in vitro anti-IMNV activity of Ctn[15-34] were assessed using a high-sensitive fluorescent-based method in combination with quantitative PCR. The Ctn[15-34] (<12.5 µM) neutralized the toxic effects of IMNV at loads sufficient to kill 50% of shrimp hemocytes. This study reported for the first time the replication of IMNV in vitro and the employment of a straightforward methodology to assess cell viability and viral/antiviral activities. In addition, it provided the basis for the development of the anti-infective multi-effector Ctn[15-34] eicosapeptide and analogs as components of antiviral formulations against shrimp viral diseases.

In Brazil, Penaeus vannamei breeding is performed in specialized hatcheries. In the reproduction phase of larviculture, most of the time, it is used broodstock that undergo a maturation induction by eyestalk ablation. However, the use of this technique may present different disadvantages, as other physiological and metabolic processes are also affected by the removal of the eyestalk. This study aimed to perform a comparative analysis between ablation and non-ablation effects on the reproductive process of P. vannamei females. It was observed that the NAF showed higher values (p<0.05) for mating frequency (16.5 ± 4.7 days), spawning frequency (17.8 ± 4.8 days), number of eggs/female (297,208 ± 24,827), number of nauplii/female (210,625 ± 21,681). On the other hand, the AF group presented higher values for mortality rate (39.1 ± 0.3%) and daily mating rate (11.7 ± 2.8%). Spawning rate (92.7 ± 5.3%) and hatch rate (70.8 ± 2.7%) were not affected by non-ablation. This study has shown that the use of NAF results in a superior reproductive performance when compared to the AF performance, and that the use of NAF does not compromise the zootechnical performance in the larval stage.

Brazil was the third largest producer of white shrimp in Latin America, with 75,000 tons and R$ 600 million, in 2012. The present work focused on the impacts of the IMNV pathogen, the anti-dumping action imposed by USA and the exchange rate appreciation of Brazilian currency in marine shrimp culture in a semi-intensive system in Northeastern region and also on the identification of options for sustainable production. Data were collected on shrimp farms (Compescal and Aquafort) at Ceará state. During the period from 2003 to 2007, these factors affected directly the competitiveness of Brazilian farmed shrimp exportation. However, in 2007 the shrimp producers started to sell on domestic market, which made possible to increase their production, revenue, income and profit levels.