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Low-density environment ideal for juvenile scallop growth, study finds

A study in Brazil on the “occurrence of compensatory growth, in view of enabling the storage of juveniles at densities in the intermediate culture phase” showed that juvenile scallops (Nodipecten nodosus) have ideal growth rates in a low-density environment.


February 14, 2019
By Ruby Gonzalez

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Dr. Helcio Luis Almeida Marques and his team, in the study, Compensatory growth in scallops Nodipecten nodosus farmed in tropical region, looked into this aspect of production while looking for procedures to reduce production costs.

The culture in Brazil of the species is still “beginning” and “studies on the aspects of culture management are necessary,” the study abstract cited.

The experiment was conducted at the Cocanha farm of mussels and scallops in Caraguatatuba, Brazil.

Smaller scallops and lower survival rates were observed from growing juvenile scallops, commonly known as lion’s paw scallops, in a high-density environment during the intermediate phase before transferring them to low-density at grow-out phase.

The control group, which was consistently exposed to a low-density stocking, had the highest growth rate in the intermediate phase. In the growing phase, however, it posted the lowest increase
in height.

While there was a high compensatory increase in height for the high-density groups in the grow-out stage, this was not enough to make up for the low height gained in the high-density stocking of the intermediate phase, the study said.

 “The results showed the occurrence of a partial compensatory growth in scallops reared at high densities in the intermediate phase when transferred to an optimum density in the growing phase.

“However, the compensatory growth was insufficient to allow scallops to reach the same height of mollusks reared at an optimum density from the beginning of the experiment,” the abstract stated.

Survival rates in both phases were consistently the highest in the control group.

The 148-day experiment started with stocking juvenile scallops in Japanese lanterns at 50 (control), 800, 1,600 and 3,200 per density control of 50 m-2 for the intermediate phase.

At the grow-out stage, the juvenile scallop groups were put in a low-density of 50 per 50 m-2.

The lion’s paw scallop has been identified as having the highest culture potential among the kinds of scallops in Brazil.