Effect of Confinement and Starvation on Stress Parameters in the American Lobster (Homarus Americanus)

Interactions of temperature and dietary composition on juvenile European lobster (Homarus gammarus, L.) energy metabolism and performance

Optimal rearing temperatures for European lobster Homarus gammarus in aquaculture differ from those prevalent in their aquatic ecosystems and acclimating juveniles to the prevailing temperatures before release may aid in the success of re-stocking programs. As the dietary nutritional composition is important for optimal performance of H. gammarus, in this study we aimed to investigate whether juvenile growth and energy metabolism responses to temperature variation could be modulated by the diet. Prior to the trial start, the juveniles were divided into two groups. One was maintained at 19 °C and the other gradually adapted to 13 °C. From this point and for a 24-day period, juveniles (~ 100 mg) within each temperature group were assigned one of two experimental diets: a carbohydrate-rich (HC) or a protein-rich (HP) extruded feed. Antarctic krill (AK) was used as a control diet within each temperature group. Feed intake, growth, glycogen, glucose, lactate, and protein concentrations of H. gammarus in each group were evaluated. Regardless the dietary treatment, feed intake, cephalothorax protein and glucose, and abdominal glycogen and glucose levels decreased at colder temperature. The effect of lower temperature on growth (SGR and moulting rate declines) and energy metabolism (reduction on cephalothorax glycogen and protein) was more severe in HC-fed lobsters. Results showed that the impact of lower temperature on juvenile H. gammarus can be modulated by diet highlighting the importance of designing optimized diets not only for growth and feed efficiency but also for resilience to environmental variation.

Evaluation of the marketing methods and handling of live shellfish (American lobsters) for the purpose of sale as food: First evaluations in Piedmont, Italy

Some species of crustaceans pose problems during marketing, being sold alive. Food Business Operators (FBO) have the need to adopt specific measures based on opinions and guidelines of national and international associations. This investigation was aimed at evaluating the practices in use in the marketing of live crustaceans in Piedmont. Twenty-three plants were analyzed using checklists and through physical and chemical measurements of the water in the holding tanks. The situation appears uneven in the application of Good Handling Practices (GHP), management of animals and knowledge of FBO. Only 48% of the Hazard Analysis and Critical Control Point plans had a dedicated section. Immobilization of the claws was the option identified to control aggressiveness. Dead animals are mainly identified as Category 3 instead of other hygienically safe options. Only 1/3 of interviewed can indicate the slaughtering methods recognized as most suitable for these animals. The aquariums show a good state of maintenance and most of evaluated parameters complaint to GHP except for nitrites (35%). In conclusion, the situation reflects the different levels of knowledge of the FBOs. Therefore the veterinarian of the public health service can propose itself as a reference point for specific training.

The effects of claw ligatures in American lobster (Homarus americanus) storage: a preliminary study of haemolymph parameters

American lobsters are crustaceans that are offered for sale live and are stored in controlled temperature recirculating aquaria. During marketing, they are subjected to stressors that can affect their welfare, such as air exposure, confinement, and handling. European legislation does not provide specific criteria or retention requirements, and so their management depends largely on the common sense of food business operators. Claw ligatures before and during storage are not legally required but are recommended because they prevent lobsters from damaging each other and ensure workers’ safety. The aim of the present study is to evaluate the effect of claw ligatures on the lobsters’ welfare by analysing eight different haemolymph stress indicators, vitality, and weight. The calcium level showed significant differences in the two experimental groups (P < 0.05). Our results suggested that the absence of rubber bands did not offer any significant contribution to the lobsters’ welfare.

Retail Stores Policies for Marketing of Lobsters in Sardinia (Italy) as Influenced by Different Practices Related to Animal Welfare and Product Quality

The aim of the present study was to evaluate the marketing policies of lobsters as influenced by different practices related to product quality in seven supermarkets located in Italy. Retailers were divided in two categories: large scale and medium scale. The two groups were compared to screen for differences and to assess differences in score distribution attributed to different practices related to product quality. Our results showed no statistical differences (p > 0.05) between the two categories. Lobsters were often marketed alive on ice and/or stocked for long periods in supermarket aquariums, highlighting the need to improve the specific European regulations on health, welfare, and quality at the market stage. Retail shop managers should be encouraged to develop better practices and policies in terms of marketing of lobsters. This will help in keeping the animals in good health and improve product quality at the marketing stages.