Culture Techniques of Marine Copepods

In recent years, marine finfish resources have been stagnating or showing a declining trend. It is generally accepted that mariculture of suitable marine finfishes is the only option to meet the increasing demand for fish in the years to come. In this context, the availability of seed is the major issue and the ICAR-Central Marine Fisheries Research Institute has been intensifying its research in the recent past on the seed production of high value finfishes which are suitable for mariculture. Already technologies for commercial seed production of cobia (Rachycentron canadum) and silver pompano (Trachinotus blochii) have been standardised. One of the major hurdles for the seed production of many lucrative high value finfishes is the lack of proper technologies for mass production of suitable live feeds to initiate the first feeding of the larvae. The larvae of many species of high value food fishes are very small and the conventional live feeds employed in the hatchery such as rotifer and Artemia nauplii are not suitable to initiate the larval feeding during the critical stage mainly because of their larger size compared to the mouth size of the concerned fish larvae and also their poor nutritional value especially the fatty acid profile. Copepods are the best live feed due to their small sized nauplii and better fatty acid composition especially the DHA, EPA and ARA combination. But the major bottleneck for employing copepods as live feed is the lack of technologies for their mass culture in hatcheries. Even at a global level, this is a vital issue and even though some technologies were developed, research efforts are now being intensified in this area. In India, not much effort was taken to solve this problem till very recently. In the last few years, the ICAR-Central Marine Fisheries Research Institute has been focusing on this aspect and has come out with technologies for mass production of nine species of copepods. These technologies were successfully applied to seed production of the orange spotted grouper (Epinephelus coioides), the Indian pompano (Trachinotus mookalee) and the pink ear emperor (Lethrinus lentjan). I congratulate Dr. B. Santhosh and his team for developing this unique technology for mass production of nine species of marine copepods for the first time in India. This publication titled ‘Culture techniques of Marine Copepods’ details this technology. I hope that the same will be a landmark in the near future which will pave the way for successful seed production of many more species of finfishes in mariculture

Breeding, early development and larval rearing of cloudy damsel, Dascyllus carneus Fischer, 1885

As the demand for marine ornamental fish is ever increasing, the industry largely relies on collections from natural habitat due to insufficient breeding and seed production technologies. Fishes of the family Pomacentridae are popular in marine aquaria throughout the world. Among these, damsel fishes of the genus Dascyllus has high demand and are mostly collected from the wild. The present study forms the first-ever report on successful breeding and larval development of Cloudy Damsel (Dascyllus carneus Fischer, 1885). Though there are a few reports on breeding of other species of Dascyllus, there has been no report on the complete larval development of any of the species in this genus. This forms the first description of early larval development of a Dascyllus species. Using the copepod Parvocalanus crassirostris as first feed the larval rearing was done. Successful breeding and larval development were achieved from the wild-caught broodstock of D. carneus at Vizhinjam Research Centre of ICAR-CMFRI, India. Brood stock from the wild took 4 months to spawn, laid 6500–10,500 eggs per spawning and hatching rate ranged from 90.6 to 98.81%. Newly hatched larvae were the smallest among all the reported larvae of pomacentrid fishes and measured 1.95 ± 0.14 mm in total length. Yolk reserve was completely absorbed within 72 h of hatching. Preflexion stage is from 4 to 10 dph, flexion stage is from 11 to 12 dph and postflexion period is 13–15 dph. Larvae accepted only copepod naupliar stages as first feed and calanoid copepod P. crassirostris alone was fed until 25 dph. Larvae settled from planktonic stage in 22–23 days and all the larvae metamorphosed into juveniles by 50 dph. The egg development, larval development and larval pigmentation up to 50 dph has been described. The feeding protocols and feed size preference in relation to their age or mouth gape, the gut contents and mouth gape of the larvae caught from a feed trial with surplus copepods of all stages were analysed at regular intervals. Larvae preferred larger stages of copepods in later stages of their development. Finally larval feeding protocols were modified accordingly and better survival was observed. A final feeding regime has been developed and a strategy for the consistent hatchery production of this species was achieved. Different stages of copepod P. crassirostris were used till the settlement of planktonic stage of larvae and Artemia nauplii were used from 25 dph. The larvae were completely weaned to artificial diet from 50 dph

Thyroid disorders in India: An epidemiological perspective

Thyroid diseases are common worldwide. In India too, there is a significant burden of thyroid diseases. According to a projection from various studies on thyroid disease, it has been estimated that about 42 million people in India suffer from thyroid diseases. This review will focus on the epidemiology of five common thyroid diseases in India: (1) hypothyroidism, (2) hyperthyroidism, (3) goiter and iodine deficiency disorders, (4) Hashimoto's thyroiditis, and (5) thyroid cancer. This review will also briefly cover the exciting work that is in progress to ascertain the normal reference range of thyroid hormones in India, especially in pregnancy and children