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- Effect of three diets on the growth and fatty acid profile of the common ragworm Hediste diversicolor (O.F. Müller, 1776)Publication . Santos, António; Granada, Luana; Baptista, Teresa; Anjos, Catarina; Simões, Tiago; Tecelão, Carla; Fidalgo E Costa, Pedro; Costa, José Lino; Pombo, AnaThe polychaete Hediste diversicolor has a high physiological tolerance to extreme environmental factors, being easily farmed and reproduced in different types of conditions. Both in the field and under laboratory conditions, this worm can feed on different types of food. In order to highlight the potential of H. diversicolor for aquaculture, specific growth rate (SGR), daily growth rate (DGR), survival rate and fatty acid profile of juvenile worms, fed with three different diets, were assessed. The experiments were conducted using juvenile polychaete from a controlled reproduction with wild adults. H. diversicolor individuals were fed with two commercial diets, seabream dry feed (Aquagold) and semi-wet pellets for reared sole (Moist Sole), and with a non-processed diet consisting on mackerel's fillets (Trachurus trachurus). Juveniles fed with Aquagold had the highest final individual weight (0.89 ± 0.10 g). The SGR was higher in H. diversicolor fed with Aquagold and Moist Sole, (6.49 ± 0.30% d−1 and 6.54 ± 0.06% d−1, respectively. The highest DGR was observed for juveniles fed with Aquagold (0.146 ± 0.02 g d−1). The survival rate of ragworms under different treatments ranged from 96 to 100%. Regarding the protein content, the Moist Sole diet provided the highest percentage of protein in the reared worms (8.87%). Results showed that the total fat content of the diets was reflected in the fat content of the reared worms. The Moist Sole diet treatment had the highest fat content (2.25%) and individuals fed with seabream dry feed showed similar results (2.18%), while the lowest percentage was observed for the mackerel diet (0.85%). According to the fatty acid profile, the major fatty acids found in the juveniles fed with the three different diets were palmitic (C 16:0), with a higher value in the individuals fed with mackerel's fillets. Oleic (C 18:1 n9), eicosapentaenoic (C 20:5 n3), docosahexaenoic (C 22:6 n3) and stearic (C 18:0) acids presented high values in H. diversicolor fed with all the experimental diets. Statement of Relevance: The common ragworm Hediste diversicolor is a potential high quality fatty acids source for reared fish and shrimp. Previous studies suggested that diet could be a relevant factor affecting the fatty acid composition of this polychaete (Luis and Passos, 1995). This study aimed to assess the effect of different diets on growth and survival of common ragworms juveniles (H. diversicolor), as well as the fatty acid profile and protein content in their tissues, aiming to find an appropriate diet to be used in commercial aquaculture.
- Trade of live bait in Portugal and risks of introduction of non-indigenous species associated to importationPublication . Sá, Erica; Fidalgo E Costa, Pedro; Cancela Da Fonseca, Luís; Alves, Ana; Castro, Nuno; Cabral, Sara; Chainho, Paula; Canning Clode, João; Melo, Pedro; Pombo, Ana; Costa, José LinoDifferent invertebrate groups are often exploited on sediment shores and mudflats, including polychaetes, sipunculids, bivalves and crustaceans. The commercial importance of polychaetes and sipunculids, that has increased in the early 2000's because of its use as a food source for the aquaculture sector and a growing demand of worms for use as sea angling bait, seems to be declining nowadays. In Portugal bait harvesting from natural populations became insufficient to meet market demands and as a result, polychaetes and sipunculids have been imported in recent years. Due to this it was important to know the ways of the live bait import to Portugal, and to assess the risk of introduction of non-indigenous species associated to that live bait trade. The origin and quantities of imported live bait were determined by examining the landing's records at Lisbon airport, from two periods: 2002-2003 and 2012-2015. Live worms imported to Portugal arrived almost exclusively from China, USA and Vietnam. Monthly import data and bait registers at fish auction landings were significantly correlated, showing that bait captures and imports are directly related to higher bait demand. In addition, the risk of live bait's importation as an introduction vector for non-indigenous species was evaluated by examining the bait boxes content. Five worm species were identified in bait boxes with foreign species: Glycera dibranchiata, Namalycastis rhodochorde, Perinereis cultrifera, Perinereis linea, and Sipunculus (Sipunculus) nudus. The examination of bait boxes in Portugal suggested that there is a low risk of associated hitchhiker species introduction and dissemination, mostly because of packaging procedures, which should be advised. The same is not true to the non-indigenous live bait species.
- Insight into aquaculture's potential of marine annelid worms and ecological concerns: a reviewPublication . Pombo, Ana; Baptista, Teresa; Granada, Luana; Ferreira, Susana; Gonçalves, Sílvia C.; Anjos, Catarina; Sá, Erica; Chainho, Paula; Cancela Da Fonseca, Luís; Fidalgo E Costa, Pedro; Costa, José LinoPolychaetes are marine annelid worms that can contribute to aquaculture diversification. Its culture has been viable, and commercially attempted, but intensive production has progressed only in few countries around the world. In the countries with no production, marine polychaetes are imported or harvested. A strong and sustained research investment provided to a better understanding of the nutritional requirements and reproduction of some species. Recent studies showed new technical improvements, which can lead to an important progress in productivity and give a new impetus to the polychaete production. Some marine worm species were identified as good candidates for integrated multitrophic aquaculture. The development of cost-effective aquaculture techniques for marine annelid worms is essential to ensure a balance between commercial interests and the preservation of ecosystems. The influence of polychaete aquaculture on the environment and vice versa raise important concerns related to ecological security and sustainability of this activity. This review focus on the main technical improvements and advances that have been made in areas as diverse as: aquaculture potential of polychaetes, reared species, main species used worldwide, and highlights biological and ecological concerns, important challenges and recommendations.