Culture possibilities of the razor clam Ensis arcuatus (Pharidae: Bivalvia)

Abstract

This study investigated razor clam Ensis arcuatus culture from larval rearing to commercial size to assess it's aquaculture potential. Broodstock was spawned several times in hatchery facilities to demonstrate that larval availability is not a constraint for hatchery production. Larval culture lasted 20 days, showing an average survival of 14.35%. The razor clam seed reached a size of 28.5 mm at 4 months. Seed culture is feasible; however, it is constrained by the fact that razor clams need to be buried. Higher survival was observed when culturing razor clam seed with a substrate (82^83%), irrespective of the substrate grain size, while containers held without a substrate showed a signi¢cantly lower survival (56.5%). We showed that it is possible to rear E. arcuatus juveniles in bottles, with survival as high as 94^95% being achieved. The length increase of the hatchery-produced E. arcuatus over 600 days was described by the equation Ln L 5 4.51( À 141.17/t), where L is length in mm and t is time in days. On-growing showed adequate survival rates and it took 2^3 years to reach commercial size.

Larval and post-larval growth, spat production and off-bottom cultivation of the smooth venus clam Chionista fluctifraga

“…Supply of bivalve spat is one of the major constraints to restocking or initiating farming of clams and other bivalves (da Costa, Darriba, Martínez‐Patin & Guerra ). Our study provides useful information for producing spat of the smooth venus clam in hatcheries, especially using a down‐welling circulation system during the settlement stage.…”

Effects of stocking density on intermediate culture of the razor clamEnsis arcuatus(Pharidae: Bivalvia)

“…Razor clams have a slender and thin‐bladed shell shape. They are extremely fast burrowers and they require a substrate to allow burrowing, which influences culture conditions needed in hatchery, nursery and on‐growing culture (da Costa, Darriba, Martínez‐Patiño & Guerra ).…”

Molluscs and echinoderms aquaculture: biological aspects, current status, technical progress and future perspectives for the most promising species in Italy

“…Using seed 1.3 mm in length, da Costa and Martinez-Patiño (2009) achieved better survival when the rearing was done without substrate than when 2 types of sand were utilised. In E. arcuatus, recently da Costa et al (2011a) achieved the settlement of larvae on day 20, a survival from egg to newly settled postlarvae ranging between 4.8 and 24.8% (14.35% on average), and a very low (4.8%) survival from settlement (day 20) to 3-month-old spat (15.5 mm in length).…”

“…In experimental condition, E. arcuatus reached a length ranging from 90 to 100 mm (da Costa et al, 2011a) Froglia (1975) found that the size of 100 mm was reached in 2-year-old individuals. After 2 years, the growth is reduced as a consequence of the gametogenic activity both in E. arcuatus and in S. marginatus.…”

“…The effect of substrate (fine-grain sand or coarse sand, 150 to 600 or 300 to 1200 μm grain diameter, respectively) in comparison to the absence of substrate was tested by da Costa et al (2011a) in seed culture of E. arcuatus (3.76 mm in length) in nursery during a experiment lasting 30 days. No differences among treatments resulted for length, while the fine sand induced a lower weight and the absence of substrate a lower survival.…”