T. T. Ajith Kumar

Isolation of antibacterials from the mangrove, Avicennia marina and their activity against multi drug resistant Staphylococcus aureus

Abstract Objective leaf extract of A. marina was tested on the growth of clinically isolated multi-drug resistant Staphylococcus aureus and its bioactive compounds were attempted. Method Clinical strain of Staphylococcus aureus, were isolated from sputum, pus and blood of different patients and 22 strains were screened for antibiotic susceptibility. Avicennia marina was extracted in different solvents and antibacterial assay was carried out using Kirby-Bauers disk diffusion method. Crude methanol extract of the mangrove was loaded on a silica gel column and eluted with chloroform and methanol (9:1 to 1:9) followed by ethyl acetate and methanol (9:1 to 1:9). Based on in vitro assay, the 12th fraction was subjected for minimum inhibitory concentration (MIC). The active fraction was analysed by using a Clarus 500 Perkin Elmer gas chromatography. Result Based on the antibiotic susceptibility test, six strains (RMSA 6, RMSA12, RMSA16, RMSA18, RMSA19 and RMSA21) were resistance against methicillin, vancomycin and ciprofloxacin. The results indicated that the methanolic leaf extract showed the highest antibacterial activity against all the tested strains RMSA 6 (16mm), RMSA12 (15 mm), RMSA16 (13 mm), RMSA18 (10 mm), RMSA19 (17 mm) and RMSA21 (16 mm). The MIC of the partially purified extract showed potential results against all the multidrug resistant strains however, the lowest concentration was recorded against RMSA 6, RMSA19 and RMSA21 strain. In the GC-MS results, 5 bioactive compounds were identified from the partially purified extract of A. marina. Conclusion The methanolic extract of A. marina has the more potential candidate to inhibit against multidrug resistant S. aureus.

Reef fish Breeding and Hatchery Production Using Brackishwater, A Sustainable Technology with Special Reference to Clark's Clownfish, Amphiprion Clarkii (Bennett, 1830)

The present study on spawning and larval rearing of reef associated clownfish, Amphiprion clarkii was investigated under captive condition. Fishes and sea anemones were obtained from the traders and maintained in a conditioning tank. After pair formation, they laid eggs in the spawning tank, which were sticky, capsule shaped and yellow orange in colour. The eggs were allowed to remain in the same tank till hatching up to eight days for incubation. Spawning, embryonic development, hatching success, larval survival and juvenile production were studied in detail. Optimum water quality parameters were also standardized for the hatchery operations. The size range of newly hatched larvae measured 3.5 to 3.8 mm in length and they were transferred to separate larval rearing tanks. The first white band was prominent on the body between 15 to 17 th day, an indication of metamorphosis. The complete metamorphosis was occurred on 25 th day after hatching. The larvae were initially fed with micro-algae, rotifers, Artemia nauplii and later they accepted frozen Artemia and squashed boiled meat of oysters and clams. The present findings have shown the prospective sign for captive breeding of a highly demanded aquarium fish using brackishwater, by removing the existing foremost technological snag of rearing them in running seawater.

Influence of host anemone (Stichodactyla haddoni, saville-kent, 1893) locomotion on its resident anemonefish reproduction

Anemonefish are found commonly in reef habitats and they select only limited anemone species to exist their life. This study describes the movement of anemone, Stichodactyla haddoni and its impact on the reproduction of anemonefishes in captivity. The anemone movement was found to be creeping and in straight-line between successive positions (based on overlay mapping). The distance traveled by the host with (60%) and without substrate (20%) varied significantly (P<0.05) at a random direction. Spawning interval of the resident fish (3-4 days) increased significantly to 8-12 days (P<0.001) because of anemone mobility. Furthermore, host locomotion affected the embryonic development of harbored fish clutches. Percentage of egg maturity (3.5-35.3%) showed an exponential decrease with increase in the distance of substrate from the clutches, from 98 to 100% in the absence of host mobility to 3.5-35% with movement of >60cm. This study concludes that the sedentary habitat would enhance the reproduction value of the harbored fish. Further, in captivity providing with a substrate, supplying regular feed and good light intensity could prevent anemone migration and its implications on the reproductive success of the anemonefish.

Anti-dermatophytic activity of marine sponge, Sigmadocia carnosa (Dendy) on clinically isolated fungi

OBJECTIVE To screen the anti-fungal effects and find out the active metabolites from sponge, Sigmadocia carnosa (S. carnosa) against four dermatophytic fungi. METHODS The methanol, ethyl acetate and acetone extract of marine sponge, S. carnosa was examined against Trichophyton mentagrophytes (T. mentagrophytes), Trichophyton rubrum (T. rubrum), Epidermophyton floccosum (E. floccosum) and Microsporum gypseum (M. gypseum) and qualitative analysed to find out the active molecules. RESULTS The methanol extract of sponge was expressed significant activity than ethyl acetate and acetone. The minimum inhibitory concentration (MIC) of methanol extract of sponge that resulted in complete growth inhibition of T. mentagrophytes, T. rubrum, E. floccosum and M. gypseum were found to 125, 250, 250 and 250 µg/mL respectively. But, 100 % inhibition of fungal spore germination was observed in T. mentagrophytes at 500 µg/mL concentration followed by T. rubrum, E. floccosum and M. gypseum at 1 000 µg/mL concentration. Other two extracts showed weak anti spore germination activity against the tested dermatophytic fungi. Methanol extracts showed presence of terpenoids, steroids, alkaloids, saponins and glycosides. CONCLUSION Based on the literature, this is the first study which has conducted to inhibit the growth and spore germination of dermatophytic fungi with S. carnosa. Further research also needs to purify and characterize the secondary metabolites from the sponge, S. carnosa for the valuable source of novel substances for future drug discovery.

Breeding and Rearing of Marine Ornamentals

The marine aquarium trade is a billion dollar business that may sustain continued growth in the coming years. In the past decade, there has been a worldwide increase in the popularity of reef tanks, which has led to an increased demand for marine ornamental organisms (Wood 2001; Green 2003). In contrast to the freshwater ornamental species, most marine organisms being marketed in the aquarium trade are collected from the wild, particularly from coral reef areas. The prevalence of destructive low-cost harvesting techniques, such as the use of cyanide and explosives, has caused dramatic and drastic impacts on the health and biodiversity of the reef ecosystems. Developing hatchery technology for marine ornamental species is therefore urgently needed to guarantee the sustainable supply for the industry while minimising the negative impacts on the natural environment (Lin et al. 2002). In the recent years, researchers, traders, collectors and hobbyists have begun a worldwide effort to minimise the growing pressure on the natural populations of marine ornamental species and to promote the sustainable use of these high-valued resources (Corbin 2001).

Acclimation behaviour and bio-chemical changes during anemonefish (Amphiprion sebae) and sea anemone (Stichodactyla haddoni) symbiosis

Anemonefishes are known to exhibit an obligate symbiotic relationship with a limited number of sea anemone species. This has raised queries about the adaptive mechanisms of these fishes involved. The present study was carried out to understand the role of visual and chemical cues used for host recognition and the bio-chemical changes that occur during acclimation by the fishes. The experiments used the fishes Amphiprion sebae (a common anemone associate), Terapon jarbua (a control fish that does not associate with sea anemone) and Stichodactyla haddoni (an anemone commonly hosting anemonefishes). The results suggested that fish settlers use visual, tactile and chemical cues to select and distinguish their hosts. Furthermore, the acclimation times of A. sebae with the anemone host decreased exponentially during repeated trials. This fish apparently secreted a protective mucus. The epidermal mucus of A. sebae possessed unique glyco-proteins compared with T. jarbua. Chemical analyses showed that A. sebae and S. haddoni produced similar chemical substances, but T. jarbua produced a different kind of glycoprotein. This study helps to explain how anemonefishes are able to live with their host anemone, whereas other fishes are not.

Hatchery Production of Marine Ornamental Fishes: An Alternate Livelihood Option for the Island Community at Lakshadweep

The hobby of marine ornamental fish keeping is more valuable as aquarium keeping has become more popular and more hobbyists are interested in this lucrative trade. The export value of ornamental fishes has increased 10 times higher from 0.9 to 9 million US

Isolation of pigments from sea-anemones, Heteractis magnifica (Quoy and Gaimard, 1833) and Stichodactyla haddoni (Kent, 1893) and their effects against aquatic and human bacterial pathogens

and continues to reach almost 29 million US

Isolation of symbiotic bacteria and bioactive proteins from the marine sponge, Callyspongia diffusa

in 2007 (Tissera, 2010).

Breeding, embryonic development and salinity tolerance of Skunk clownfish Amphiprion akallopisos

Abstract Objective To screen inhibitory activity of pigments extracted from two sea-anemones, Heteractis magnifica (H. magnifica) and Stichodactyla haddoni (S. haddoni) against 10 aquatic and 10 human bacterial pathogens. Methods Crude pigment were extracted by using acetone solvent and the pigment extracts were fractionated into 7 for H. magnifica and 5 for S. haddoni by using silica gel column chromatography and also tested for the antibacterial activity using Agar welldiffusion method. Results The 3rd fraction of H. magnifica and 2nd fraction of S. haddoni displayed higher activity against eight aquatic bacterial pathogens and seven human bacterial pathogens. Conclusions The 3rd fraction of H. magnifica showed higher antibacterial activity than the crude pigment extracts and other fractions of H. magnifica and S. haddoni. Thus the sea-anemone Heteractis magnifica is promising for further exploration of antibacterial drugs.