The global production of marine bivalves for human consumption is more than 15 million tonnes per year (average period 2010-2015), which is about 14% of the total marine production in the world. Most of the marine bivalve production (89%) comes from aquaculture and only 11% comes from the wild fishery. Asia, especially China, is by far the largest producer of marine bivalves, accounting for 85% of the world production and responsible for the production growth. In other continents, the production is stabilizing or decreasing (Europe) the last decades. In order to stimulate growth, sustainability (Planet, Profit, People) of the aquaculture activities is a key issue. Environmental (Planet) aspects for sustainable aquaculture include the fishery on seed resources, carrying capacity, invasive species and organic loading. Food safety issues due to environmental contaminants and biotoxines should be minimized to increase the reliability of marine bivalves as a healthy food source and to stimulate market demands. Properly designed monitoring programs are important tools to accomplish sustainable growth of marine bivalve production.

This paper reviews current knowledge on two feedstuffs, that is, insect meal and fish by-products, as alternatives to conventional animal protein sources. After an introductory part that highlights the need for sustainable development of animal production, the alternative protein sources are discussed. In particular, after providing some indications on their production and supply focussing on EU, a SWOT (Strengths, Weaknesses, Opportunities, and Threats) analysis was performed to identify the key factors that could help or impair the development of both protein sources production sectors. Finally, future perspectives are presented. The use of processed animal proteins derived from insects in farmed fish feeding is recognised by the EU legislation that authorises the use of proteins from seven insect species and the allowed substrates to rear insects. Insects have several advantages in nutritional value and the amino acid composition of their proteins generally meet animal requirements for good growth and health. The SWOT analysis indicated that insect meals can be considered as feed functional ingredients with beneficial properties that depend on the insect species, rearing system adopted, and the substrate used for their growth. Insects are expected to be increasingly used as a replacement for conventional animal-derived proteins, especially in aquafeeds. In the section regarding fishery and aquaculture by-products, the potential use of raw materials obtained during seafood processing is discussed. Peptides and amino acids recovered from as hydrolysed proteins can be used in animal feeds to partially substitute conventional protein feedstuffs thus providing nutrients, bioactive compounds and feed additives for animals. The SWOT analysis identified opportunities and weaknesses. Both the alternative protein sources are promising alternative feed ingredients for livestock production. HIGHLIGHTSThe sustainable development of animal production sector needs alternative protein sources for feeds formulation. Insects and fishery-and aquaculture by-products represent optimal alternative protein sources. A SWOT analysis has identified the key factors for the development of both protein sources production sectors. ARTICLE HISTORY

Currently available data show that shell-fish and finfish production in Italy, derived both from fisheries and aquaculture activities, is on the order of 474,000 tons, each activity representing 50 % of the total amount. In this context, the finfish aquaculture industry contributes on average 31 % to the national aquaculture production and on average 59 % of its value, giving a total amount of 72,000 tons and a value of around 351 million € (2010). According to FEAP statistics, Italy is the fourth largest finfish producer in EU27, after the UK, Greece, and Spain, while it is also one of the six largest finfish producers among the nonEU and EU member countries, together with Norway, UK, Greece, Turkey, and Spain. Presently, fish culture\ud activities are mainly focused on rainbow trout (Oncorhynchus mykiss, 55.5 %), followed by European sea bass (Dicentrarchus labrax, 13.6 %), gilthead sea bream (Sparus aurata, 12.2 %), gray mullet (Mugil cephalus, 5.3 %), sturgeon (Acipenser spp., 2 %), and European eel (Anguilla anguilla, 1.7 %). Over the last 20 years, freshwater fish production and aquaculture (trout, carp, and eel) have decreased in Italy, with the exception of sturgeon. In contrast, marine fish production has significantly increased during the same period, and the two leading species, European sea bass and gilthead sea bream, presently contribute 25.8 % of the finfish production. From 1,900 tons in 1990, production reached 19,000 tons in 2010, with a 900 % increase, at an average percentage of 4.5 %. In addition, new marine fish species were successfully cultured over the same period. This\ud review outlines the past and present situation of finfish culture in Italy and discusses future developments and priorities, with particular emphasis on new, emerging aquaculture species

A pre-fattening trial was performed to evaluate the effect of replacement of fishmeal (FM) with insect meal (IM, Tenebrio molitor) on growth performance and survival rate of common catfish (Ameiurus melas). Fingerlings of A. melas (mean body weight, 0.248±0.07g) were randomly distributed over 4 indoor tanks of 2 m3 at a density of 2,000 fish/tank, and kept at a temperature of 23-25°C in two separated recirculating aquaculture systems (RAS). Fish were divided into two groups (two tanks per group): FM and IM. Fish of the FM group were fed with a control diet (51.6% protein and 18.1% lipid), whereas those of the IM group received a diet (50.8% protein and 22.1% lipid) in which 50% of FM was substituted with IM. Chemical parameters (moisture, crude protein, total lipids, ether extract, and ash) and fatty acid profile of the two feeds is reported. The feeding trial lasted 90 days and fish were weighed at the beginning of the trial and then on monthly basis. Growth performance was good in both groups. However, fish of the IM group reached a final mean body weight (4.2±0.6 g) significantly lower (p < 0.01 than that of the FM group (5.13±0.7 g). The survival rate of FM group (79%) was higher than that of IM (70%), too. In conclusion, the results of this study demonstrated that the diet with insect meal was able to sustain growth in catfish fingerlings but fish fed with FM performed better than those fed with IM

The effects of partial substitution of soybean (SB) with faba bean (FB) and of genotypes [fast-growing Cobb 700 (FG), medium-growing naked-neck Kabir (MG), slow-growing Brown Classic Lohman (SG)] on the lipid composition as well as the meat quality attributes of chickens reared under organic conditions were evaluated. A total of 720 1-day-old male chicks were equally divided into three groups according to genotype and raised for 81 (MG and FG) or 96 days (SG): half birds of each genotype received either SB grower diet or FB grower diet. Meat from SG and MG birds exhibited a lower lipid content than that from FG birds. Both in breast and thigh meat, MUFA were significantly increased from SG to MG and FG. SG meat contained the highest amounts of either arachidonic acid, eicosapentaenoic acid, docosahexaenoic acid, or docosapentaenoic acid, but the lowest amounts of a-linolenic acid. Total PUFA gradually decreased from SG to MG and FG birds (413, 358, and 324 g/kg of fat), as well as total n À 6 and total n À 3. The D 5-plus D 6 -desaturase index was 54.0, 34.4, and 23.6 for SG, MG, and FG birds, respectively. The n À 6/n À 3 ratio was lower in SG and MG than in FG birds. The partial replacement of SB with FB had a lesser effect than the genotype on the meat quality characteristics.