Controlled Breeding and Larval Rearing Techniques of Marine Ornamental Fishes

International trade of marine ornamental fishes has been expanding rapidly in recent years, and the fact that nearly 98% of the species traded are collected from reef habitats is of vital concern for the conservation of the fragile coral reef ecosystem. Hence, it is widely accepted that the ultimate answer to a long-term sustainable trade of marine ornamental fishes is only through the development of hatchery production technologies. The techniques for broodstock development, breeding and seed production of three species of damsel fishes viz. the three spot damsel, Dascyllus trimaculatus, the humbug damsel, Dascyllus aruanus and the blue damsel, Pomacentrus caeruleus, were developed and standardised, which can be scaled up for commercial level production. Broodstock development was done in one-tonne Fiber Reinforced Plastic (FRP) tanks with biological filter and by feeding with natural feeds. The size range of broodstock fish of D. trimaculatus, D. aruanus and P. caeruleus were 9-10, 7-8 and 7-9 cm, respectively. The number of eggs per spawning ranged from 5000 to 15000. The interval between two successive spawnings ranged from 3 to 14 days. The eggs were attached either on the sides of the broodstock tank or on the substratum provided in the broodstock tank. Parental care by the male was noted. Hatching occurred on the evening of the fourth day of incubation. The larvae were altricial type with no mouth opening at the time of hatching for D. trimaculatus and D. aruanus. The larvae of P. caeruleus were with mouth opening at the time of hatching. The length range of newly hatched larvae was 1.5-2.5 mm and the range of mouth opening was 150-200 μ

Breeding and larviculture of the sapphire devil damselfish Chrysiptera cyanea

The sapphire devil damselfish, Chrysiptera cyanea is one among the top ten species of marine ornamental fishes in the international trade. For the first time, broodstock development, breeding and larviculture techniques of C. cyanea were developed and standardised and the details are presented. Broodstock (length of fish:5 to 6.5 cm) was developed in two tonne capacity FRP tanks with biological filter and by feeding with natural feeds ad libitum. The number of eggs per spawning ranged from 2000 - 2500. The interval between successive spawnings ranged from 5 to 20 days. The eggs were oval - shaped and measured around 1.3mm in length and 0.6mm in width. Parental care by the male was noticed. Hatching occurred on the night of the third day of incubation. The larvae were altritial type but with mouth opening at the time of hatching. The length of newly hatched larvae averaged to 2.5mm and the mouth gape around 150μ. Larviculture was done in five tonne capacity FRP tanks by employing greenwater produced by the microalga Nannochloropsis sp. Different larviculture systems were experimented by varying the cell counts of greenwater and live feeds. The cell counts of greenwater employed for the experiments were in three ranges - 1 x 104 to 9 x 104 ml-1, 1 x 105 to 9 x 105 ml-1 and 1 x 106 to 9 x 106 ml-1. Four sets of experiments were conducted by feeding with different live feeds – one set with enriched rotifer (Brachionus rotundiformis) alone, the second set by employing mixed culture of two copepods species viz. Euterpina acutifrons and Pseudodiaptomus serricaudatus, the third set by employing copepods and rotifers together as live feed and the fourth set with copepods as starter feed for the first six days followed by enriched rotifers from 7 to 15 days post-hatch (dph). The larval survival was recorded on 15th dph . Feeding experiments with B. rotundiformis alone and those with B.rotundiformis and copepods together as live feeds were not successful. Coculturing of the two selected species of copepods in optimum range of cell count of greenwater gave the best survival. In this set, survival rate of larvae on 15 dph ranged from 5 to 8%. The maximum survival rate was 5-6% in the group fed with copepods as starter feed upto 6 dph followed by enriched rotifers from 7 to15 dph. It was noted that a cell count range of 1 x 105 cells ml-1 was the optimum, which yielded the maximum larval survival in both these sets of experiments. After 15 dph, the larvae were fed with freshly hatched Artemia nauplii and no further mortality was noted. Metamorphosis of larvae started from 24th day and all the larvae metamorphosed by 30th day. The technique developed has the potential to scale up to commercial level production

Manipulation of fatty acids in the estuarine clam Meretrix casta (Gmelin, 1791) by supplementation with the microalgal diet, Isochrysis galbana

The present study evaluated the changes in fatty acid profile of the estuarine clam Meretrix casta, an important food organism used in the larval rearing of scyllarid lobsters, after supplementation with the microalgal species Isochrysis galbana. The uptake and assimilation of lipids from the microalgal feed were verified by gas chromatographic analysis of fatty acids in the clam tissues after eight days of feeding with I. galbana. Increase in concentrations of polyunsaturated fatty acids (PUFA), in particular docosahexaenoic acid (DHA, C22:6n3) and C18:2n-6, was observed in clams supplemented with I. galbana. Changes in monounsaturated fatty acid (MUFA) composition were less marked and related to the increasing proportions of C18:1, after supplementation. Feeding with I. galbana also induced a decrease in the proportion of saturated fatty acids, which was related to decrease in proportions of both C16:0 and C18:0. Although the fatty acid composition showed significant differences, the gross lipid content of the clam tissues did not seem to be excessively influenced by the algal feeding. Tissues from clams supplemented with I. galbana are being evaluated as feed for sand lobster larval trials

खुले सागरों में स्थापित पिंजरों में कोबिया, पोम्पानो और ग्रूपर के अंडशावकों का पालन

कृपया पूरा लेखा पढ

பழங்குடியினர் துணைத் திட்டம் (TSP), தமிழ்நாட்டின் கடலோர நீர்நிலைகளில் மீன் வளர்ப்பு நடைமுறைகள் பற்றிய - பயிற்சி கையேடு (10-12 அக்டோபர் 2022).

பழங்குடியினர் துணைத் திட்டம் (TSP), தமிழ்நாட்டின் கடலோர நீர்நிலைகளில் மீன் வளர்ப்பு நடைமுறைகள் பற்றிய - பயிற்சி கையேடு (10-12 அக்டோபர் 2022). Hands on training manual for mariculture practices in coastal waters of Tamil Nadu (TSP

ஆதிதிராவிடர் துணைத் திட்டம் (SCSP), தமிழ்நாட்டின் கடலோர நீர்நிலைகளில் மீன் வளர்ப்பு நடைமுறைகள் பற்றிய - பயிற்சி கையேடு (13-15 டிசம்பர் 2022)

ஆதிதிராவிடர் துணைத் திட்டம் (SCSP), தமிழ்நாட்டின் கடலோர நீர்நிலைகளில் மீன் வளர்ப்பு நடைமுறைகள் பற்றிய - பயிற்சி கையேடு (13-15 டிசம்பர் 2022) Hands on training manual for mariculture practices in coastal waters of Tamil Nadu (SCSP

Not Available

Not AvailableThe sapphire devil damselfish, Chrysiptera cyanea is one among the top ten species of marine ornamental fishes in the international trade. For the first time, broodstock development, breeding and larviculture techniques of C. cyanea were developed and standardised and the details are presented. Broodstock (length of fish:5 to 6.5 cm) was developed in two tonne capacity FRP tanks with biological filter and by feeding with natural feeds ad libitum. The number of eggs per spawning ranged from 2000 - 2500. The interval between successive spawnings ranged from 5 to 20 days. The eggs were oval - shaped and measured around 1.3mm in length and 0.6mm in width. Parental care by the male was noticed. Hatching occurred on the night of the third day of incubation. The larvae were altritial type but with mouth opening at the time of hatching. The length of newly hatched larvae averaged to 2.5mm and the mouth gape around 150μ. Larviculture was done in five tonne capacity FRP tanks by employing greenwater produced by the microalga Nannochloropsis sp. Different larviculture systems were experimented by varying the cell counts of greenwater and live feeds. The cell counts of greenwater employed for the experiments were in three ranges - 1 x 104 to 9 x 104 ml-1, 1 x 105 to 9 x 105 ml-1 and 1 x 106 to 9 x 106 ml-1. Four sets of experiments were conducted by feeding with different live feeds – one set with enriched rotifer (Brachionus rotundiformis) alone, the second set by employing mixed culture of two copepods species viz. Euterpina acutifrons and Pseudodiaptomus serricaudatus, the third set by employing copepods and rotifers together as live feed and the fourth set with copepods as starter feed for the first six days followed by enriched rotifers from 7 to 15 days post-hatch (dph). The larval survival was recorded on 15th dph . Feeding experiments with B. rotundiformis alone and those with B.rotundiformis and copepods together as live feeds were not successful. Coculturing of the two selected species of copepods in optimum range of cell count of greenwater gave the best survival. In this set, survival rate of larvae on 15 dph ranged from 5 to 8%. The maximum survival rate was 5-6% in the group fed with copepods as starter feed upto 6 dph followed by enriched rotifers from 7 to15 dph. It was noted that a cell count range of 1 x 105 cells ml-1 was the optimum, which yielded the maximum larval survival in both these sets of experiments. After 15 dph, the larvae were fed with freshly hatched Artemia nauplii and no further mortality was noted. Metamorphosis of larvae started from 24th day and all the larvae metamorphosed by 30th day. The technique developed has the potential to scale up to commercial level production.Not Availabl

Not Available

Not AvailableInternational trade of marine ornamental fishes has been expanding rapidly in recent years, and the fact that nearly 98% of the species traded are collected from reef habitats is of vital concern for the conservation of the fragile coral reef ecosystem. Hence, it is widely accepted that the ultimate answer to a long-term sustainable trade of marine ornamental fishes is only through the development of hatchery production technologies. The techniques for broodstock development, breeding and seed production of three species of damsel fishes viz. the three spot damsel, Dascyllus trimaculatus, the humbug damsel, Dascyllus aruanus and the blue damsel, Pomacentrus caeruleus, were developed and standardised, which can be scaled up for commercial level production. Broodstock development was done in one-tonne Fiber Reinforced Plastic (FRP) tanks with biological filter and by feeding with natural feeds. The size range of broodstock fish of D. trimaculatus, D. aruanus and P. caeruleus were 9-10, 7-8 and 7-9 cm, respectively. The number of eggs per spawning ranged from 5000 to 15000. The interval between two successive spawnings ranged from 3 to 14 days. The eggs were attached either on the sides of the broodstock tank or on the substratum provided in the broodstock tank. Parental care by the male was noted. Hatching occurred on the evening of the fourth day of incubation. The larvae were altricial type with no mouth opening at the time of hatching for D. trimaculatus and D. aruanus. The larvae of P. caeruleus were with mouth opening at the time of hatching. The length range of newly hatched larvae was 1.5-2.5 mm and the range of mouth opening was 150-200 μ.Not Availabl

Not Available

Not AvailableThe present study evaluated the changes in fatty acid profile of the estuarine clam Meretrix casta, an important food organism used in the larval rearing of scyllarid lobsters, after supplementation with the microalgal species Isochrysis galbana. The uptake and assimilation of lipids from the microalgal feed were verified by gas chromatographic analysis of fatty acids in the clam tissues after eight days of feeding with I. galbana. Increase in concentrations of polyunsaturated fatty acids (PUFA), in particular docosahexaenoic acid (DHA, C22:6n3) and C18:2n-6, was observed in clams supplemented with I. galbana. Changes in monounsaturated fatty acid (MUFA) composition were less marked and related to the increasing proportions of C18:1, after supplementation. Feeding with I. galbana also induced a decrease in the proportion of saturated fatty acids, which was related to decrease in proportions of both C16:0 and C18:0. Although the fatty acid composition showed significant differences, the gross lipid content of the clam tissues did not seem to be excessively influenced by the algal feeding. Tissues from clams supplemented with I. galbana are being evaluated as feed for sand lobster larval trials.Not Availabl