Innovative pond-based seed production technique of giant freshwater prawn Macrobrachium rosenbergii (De Man, 1879) in Odisha, India: A case study

Abstract

An innovative method of seed production of giant freshwater prawn Macrobrachium rosenbergii (De Man, 1879) in brackishwater ponds, in place of sophisticated indoor hatcheries is in practice in the Balasore District of Odisha, India. A survey was conducted in
the Balasore District to collect data on various aspects of pond-based seed production of M. rosenbergii (scampi) using a structured interview schedule during September to November 2021. The present paper provides a detailed account of this farmer-led innovative and low-cost technology of pond-based scampi seed production. The study revealed that, younger farmers, with lower educational attainment but extensive experience in scampi and shrimp farming are primarily involved in pond-based seed production as a secondary activity. The seed production season begins in December and continues until July of the following year. The duration of each seed production (crop) cycle ranges from 45-60 days. The ponds used for scampi seed production are connected to a canal that supplies brackishwater with a salinity of 12-20 ppt from the nearby sea. Berried prawns are collected locally and stocked in well-prepared plankton-rich ponds @ 1952 ± 831 nos. ha-1. The hatched scampi larvae in the ponds are fed on a variety of feed items until they reach the post-larvae (PL) stage, which takes approximately 18-25 days. About a week after the appearance of post-larvae, the PLs are harvested and sold. In 2021, the selling price per piece of scampi PL ranged from ₹0.30 to 0.65. Although the survival from zoeaI to PL10 ranges from 0.4 to 8%, with an average of only 1.50%, the cost of seed production using this technique (₹0.21 seed-1) is much lower than that of standard hatchery-based seed production. On an average, each farmer produces 10.5 lakh seeds per hectare per crop, with an investment of ₹2.24 lakh seeds per hectare per crop, contributing a net income of ₹2.7 lakhs over a span of 2 months. This innovative and low-cost pond-based seed production technology offers a viable alternative to wild collection or hatchery production of scampi seeds, helping to meet the growing demand for scampi seed in the country. Despite these advantages, the seed growers are face several challenges. The major constraints include the lack of seed acclimation facilities to freshwater, the unavailability of good quality berried prawns and the absence of an effective seed marketing strategy. Addressing these challenges through policy intervention, is urgently needed for sustainable development in the long run.

Keywords: Macrobrachium rosenbergii, Pond-based seed production, Post-larvae, Prawn farming, Scampi