To identify the larvicidal activities of silver nanoparticles synthesised with Avicennia marina leaf extract against the larvae of Aedes aegypti and Anopheleus stephensi, in vitro larvicidal activities such as LC 50 and LC 90 were assessed. Further, characterisation such as UV and FTIR analysis were carried out for the synthesised silver nanoparticles. The LC 50 value of the synthesised silver nanoparticles was identified as 4.374 and 7.406 mg/L for An. stephensi and Ae. aegypti larvae respectively. Further, the LC 90 values are also identified as 4.928 and 9.865 mg/L for An. stephensi and Ae. aegypti species respectively. The synthesised silver nanoparticles have maximum absorption at 420 nm with the average size of 60-95 nm. The FTIR data showed prominent peaks in

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Insect-borne diseases remain to this day a major source of illness and death worldwide. The resistance to chemical insecticides among mosquito species has been considered as a setback in vector control. Mosquito control programs, botanical origin may have the potential to eliminate eggs and larvae. So, the larvicidal and ovicidal activities of crude benzene, hexane, ethyl acetate, chloroform and methanol extracts of were assayed for their toxicity against three important vector mosquitoes, viz.,, , and The larval mortality was observed after 24 h of exposure. All extracts showed moderate larvicidal effects; however, the highest larval mortality was found in the methanol extract of against the larvae of, , and with the LC values were 87.13, 93.24 and 111.98 ppm, respectively. Mean percent hatchability of the ovicidal activity was observed 48 h post treatment. The percent hatchability was inversely proportional to the concentration of extract and directly proportional to the eggs. All the five solvent extracts showed moderate ovicidal activity; however, the maximum egg mortality (zero hatchability) was observed in the methanol extract of at 200 and 250 ppm against, and showed 100% mortality at 300 ppm. No mortality was recorded in the control. The finding of the present investigation revealed that the leaf extract of possesses remarkable larvicidal and ovicidal activity against medically important vector mosquitoes and make this plant product promising as an alternative to synthetic insecticide in mosquito control programs.

Physico-chemical parameters were determined along the Vellapatti, Tharuvaikulam and Threspuram coastal waters, southeast coast of India. All the physicochemical parameters such as sea surface temperature, salinity, pH, total alkalinity, total suspended solids, dissolved oxygen and nutrients like nitrate, nitrite, inorganic phosphate and reactive silicate were studied for a period of

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Starfish are echinoderms that live among corals and occur from the supra-littoral to the hadal zone. Deviation from pentamerism is a rare phenomenon in starfish and was observed in the red-knobbed starfish (Protoreaster linckii) collected from the Tuticorin coast, India. Eighty-five specimens were collected and, among these, one was found to be abnormal and had only four arms. The reasons for this abnormality may be due to the changes that occur during larval metamorphosis or caused by an abnormal regeneration of the arm.

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The objective of the present study was to investigate the mosquito ovicidal, oviposition deterrent and larvicidal efficacy of hexane, benzene, chloroform, ethyl acetate and methanol extracts of, Lobophora variegata against malarial vector Anopheles stephensi. Among the five extract tested, the methanol extract was notable, which attained the 100 percent mortality at the concentration of 200.0 ppm and the hatchability rate ranged from 71.3 to 36.3 percent. In laboratory oviposition deterrent test, the extract of L. variegata greatly reduced the number of eggs deposited by gravid An. stephensi. The maximum and significant diminished fecundity in An. stephensi was observed with methanol extract which caused 76.15­–97.69% effective deterrence. Larvicidal response of An. stephensi was more susceptible in methanol extract. The LC50 ­value of methanol extract was 61.63 ppm and the Chi-square value were significant at p<0.05 level. It is concluded, that the extract of L. variegata could be used in control of malarial vector An. stephensi.