Sea Cage culture of spiny lobsters and natural collection of lobster post larvae (Puerulii)in India: An alternate employment / additional source of income for coastal fishers. Technology on fattening of Indian juvenile spiny lobsters Panulirus homarus Background: From India under sized juvenile lobsters were exported ed to South East Asian countries for further fattening to marketable size. Technology was developed to fatten the juvenile lobsters under captive c conditions using live feeds. Maximum growth of 25 27 g /month was achieved with almost 95% survival. Species tried: P. homarus, P. ornatus,, P. versicolor and P. penicillatus Suitable species: P. homarus
Transfer of technology The technology was transferred to coastal fishers through a pilot scale demonstrative cage culture. Size of stocking: 100 125 g Maximum growth of 35 37 g/month was achieved with almost 90% survival.
As a part of its societal programme to enhance the earning capacity of coastal people in and around the islands, the NIOT decided to introduce sea cage culture of lobsters. The NIOT has developed a floating cage for fattening of lobster in open sea. The cage has been successfully tested at Tharuvaikulam in Thoothukudi.
NIOT s design (MS CAGE)
First demonstrational MS cage
NIOT s Modified FRP Cage
Lobsters within the cage
NIOT s demonstrational cage culture site at Tharuvaikulam, Tamil Nadu Lo bster cage M ussel culture poles
The beneficiaries were able to collect approximately 34 lobster juveniles through auto stocking over a period of 6 months in the demonstrational cage culture activity.
Live Feed Back up facility
Monthly growth rate of lobsters 45 40 35 30 25 20 15 10 5 0 reared in sea cages June-July July-Aug Aug-Sep Sep-Oct Oct-Nov Nov-Dec Rearing period 6 5 4 3 2 1 0 Mean increment in weight (g) Mean increment in carapace length (mm) Wt (g) CL
Some important observations made during the cage culture One of the notable features of the cage culture was that it acted as a lobster aggregating device and many baby lobsters entered the cage and grew with the stocked ones. More Numbers (rough estimate of 1250/site/year) of post larvae settled around the cages and returned with 95% survival.
Number of lobster post larvae entered during the demonstrational cage programme (6months) Date 02.07.2003 14.07.2003 16.08.2003 16.10.2003 19.11.2003 21.12.2003 Number of post larvae (Puerulii/post Puerulii) 5 23 5 1 23 35
The arrival of new juveniles may be due to the suitable substratum for settlement, conspecific attraction and acoustic signals emitted by the lobsters.
Growth of puerulii in sea cages The first measurement of post puerulii was taken in August and its growth was monitored for 10 months till the end of April 2004. From an average weight of 12g in August 2003 the lobsters grew to 140g in 8 months time. This is a very fast growth rate and theoretically makes it possible to grow spiny lobster post larvae to marketable size of over 200g in a year.
Involvement of Self Help Group women under Rural Development Programme