The growth, survival and influence of environmental factors were analysed in two cohorts of cultured Pteria sterna in Ayangue Bay, Province of Santa Elena, Ecuador (tropical Eastern Pacific). Juveniles representing cohorts I and II (8.4 AE 0.54 and 5.0 AE 0.17 mm in dorso-ventral axis) were deployed in November 2015 and Februwileyonlinelibrary.com/journal/are Aquaculture Research. 2018;49:832-838.

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Monoalgal and bialgal diet were tried in 2 stages of larval development of Striostrea prismatica: phase I from mixotrofic to early umbonated veliger larva and phase II until eyespot larvae. The monoalgal diets in phase I were Tisochrysis lutea, Pavlova lutheri and Nannochloropsis sp. In phase II, Tetraselmis suecica, T. chuii, Chaetoceros gracilis and Ch. muelleri were incorporated. The bialgal diets (combination of P. lutheri + Ch. gracilis in proportions 1:3, 1:1 and 3:1) were chosen according to the results of the monoalgal trials and were evaluated against the classic diet = control (T. lutea + Ch. gracilis). The microalgae size and their fatty acid composition were determined. We recommend the combination T. lutea + Ch. gracilis, initially using T. lutea for mixotrophic larvae (6 days Post Fertilization‐PF), then incorporating Ch. gracilis in a ratio of 1:1 until completing phase I (8–10 PF). In phase II, the ratio should change to 1:3 until larvae with eyespot are obtained (18–20 PF). Suggestions were based on the higher demand for DHA in initial larvae and the need for EPA from the early umbonated phase. Finally, as a third experiment, microsubstrates (pieces of shells, sandpaper, polycarbonate and ground rubber) were evaluated to promote the settlement of pediveliger larvae. A settlement of 20% was obtained in pieces of shells of the same species. We consider that the settlement technology has not been optimized; therefore, evaluations directed at the behaviour of the species are recommended.

The growth and survival of Crassostrea gigas were evaluated in hanging culture in the Chone River estuary (Bahía de Caráquez), Manabí province, Ecuador. Oyster seeds (~10 mm) were confined in lantern nets at a density equal to the occupation of half the surface of the basket base, until reaching commercial size (80 mm). A sample for oyster biometric, parasitic and bacterial analysis was obtained monthly. Temperature, salinity, oxygen concentration, seston and phytoplankton biomass were determined. At the end of the study, the oysters were analysed for heavy metal concentration. The commercial oyster production was extrapolated to estimate the possible economic performance of a family production module (a 7 × 7 m bamboo raft). The results show a great biological feasibility of culture of C. gigas with harvests of commercial size oysters in only 5 months and acceptable survivals (accumulated >70%, after 3 weeks of crop seed selection). The heavy metal concentrations and the parasitological and bacteriological analyses did not indicate levels of contamination. The economic projections suggest that, even with a profitability of 57%, the initially invested capital could be recovered within the first harvest.