Dietary influence on the egg production and larval viability in True Sebae Clownfish Amphiprion sebae Bleeker 1853

Broodstock nutrition is one of the most important research areas in aquaculture. In this study, sebae clownfish was used to find out the influence of diet on reproductive performance parameters like egg production, fertilization rate, hatchability, and larval quality. The feeds used were of marine origin such as squid, cuttlefish, deep sea prawn, immature and mature mussel. The diets were analyzed for their proximate composition, amino acids profile, fatty acids profile and astaxanthin. The sub-adult fishes were collected from wild and conditioned prior to experiment. Data were collected after initial three spawning to achieve stability in egg production and quality. The egg production was found to be significantly influenced by diet and those fed cuttlefish meat gave the highest number of eggs per clutch (1520±260 eggs). The fertilization rate and hatchability were found to be unaffected by the tested diets. The highest larval survival (62.3±7%) after 12 days post hatching was obtained for fish groups fed deep sea prawn. The dietary carotenoid content was also found to influence the egg and larval pigmentation. The result also indicates the importance of dispensable amino acids in egg production. The role of protein, lipids, and essential fatty acids in the broodstock diets for sebae clownfish are also discussed

Adaptive evolution after duplication of penaeidin antimicrobial peptides

Penaeidin antimicrobial peptides in penaeid shrimps are an important component of their innate immune system that provides immunity against infection caused by several gram-positive bacteria and filamentous fungal species. Despite the knowledge on the identification and characterization of these peptides in penaeid shrimps, little is known about the evolutionary pattern of these peptides and the underlying genetic mechanisms that maintain high sequence diversities in the penaeidin gene family. Based on the phylogenetic analyses and maximum likelihood-based codon substitution analyses, here we present the convincing evidence that multiple copies of penaeidins have evolved by gene duplication, and positive Darwinian selection (adaptive evolution) is the likely cause of accelerated rate of amino acid substitutions among these duplicated genes.fisheries of the country has led to a remarkable increase in fish landings, the problem of by-catch and targeted juvenile fishing is ever increasing. The present analysis shows that the contribution in the form of annual average profit by various craft–gear combinations is often not sufficient to compensate the overall loss generated by the same to the fishery through the harvest of juvenile fishes. Even though the fishermen gain some transient economic incentives from the juveniles landed, the estimated economic loss calculated was at about US$ 19,445 million year−1 from the mechanised as well as motorised sector. Both intergenerational and conventional discounting was applied to show the net present value (NPV) of future loss due to juvenile fishing. Some of the less capital intensive gears also substantially contribute towards the economic deficit caused by juvenile fishing. We suggest that, while considering the ecosystem impacts of accidental by-catch and intentional juvenile fishing, the economic impacts also should be taken into account prior to formulating any management measures. The study provides an insight to the cost of juvenile fishing in a multi-species multi-gear fishery, where a homogeneous management system is ineffective. The possible causes of increased growth overfishing in the country and subsequent economic loss to the industry are also discussed

Nutritional studies on sebae Anemonefish, Amphiprion sebae Bleeker 1853, with special reference To protein and lipid requirements

Anemonefishes or clownfishes command higher price than most other pomacentrids in the marine aquarium fish trade. Commercial production of these reef fishes can generate valuable foreign exchange for the country. The sebae anemonefisi1, Amphiprion sebae Bleeker 1853, is one of the popular marine aquarium fish . At present rearing of the fish relies heavily on live and fresh diets, and formulated diets are seldom used due to inadequate knowledge of the nutritional needs of the different life-history stages. The present study focuses on the nutrition of broodstock, larvae and juvenile stages of the fish in captivity. In order to identify suitable diets for brood fishes the efficacy of six natural and five formulated diets was determined. The natural diets tested were deep sea shrimp, cuttlefish, squid, mature mussel, mussel meat, and a mixed diet of polychaete worm and mussel meat (1 :1). Among the natural diets cuttlefish meat gave significantly higher number of eggs per spawning (1521±264 eggs; mean ± SO, n=9) followed by the deep sea shrimp (1300±445 eggs). Among Ihe five formulated semi-moist diets used, diet CBOs with about 50% protein and 10% lipid, gave significantly higher number (2137±110) of eggs pHr spawning followed by diet CB02 (1683±436 eggs) which had 40% protein and 20% lipid. The number of eggs per spawning was found to decrease significantly when broodfish were fed ad libitum once a day (416128 eggs) compared to those fed ad libitum twice daily (885±55 eggs). Hatchery reared larvae weaned to a dry diet from 3rd week onwards matured and the broodfish spawned successfully in aquaria from 15th month (age of fish) onwards. Feeding experiments using exclusive or combinations of rotifers, Artemia, and Moina showed better survival when the larvae were reared with micro algae and fed rotifers and Artemia. Weaning studies revealed that weaning from livefeed to a dry microbound particulate diet after 3 weeks (21dph) did not Significantly affect survival, though the best age of weaning was found to be 30 days post hatching. Experiments with a purified and semi-purified diet having 50% protein and 6% lipid showed semi-purified diets to be better than purified diets. Analysis of data from protein requirement experiments using semi-purified isocaloric diets showed 46.2% as protein requirement for maximum weight gain in juveniles and 44.9% in terms of SGR. Lipid requirement experiment on juveniles using five isoproteic semi-purified diets showed 10.96% as lipid requirement for maximum weight gain and 11 .05% in terms of SGR. The present study proved the effectiveness of formulated diets in rearing larvae, juveniles and brood stock of the clownfish. The results are significant with enormous application in commercial production of these high value fishes and in promoting indigenous aquarium feed manufacture

Effect of salinity on the survival, Growth and biochemical composition of Penaeus monodon Fabricius Postlarvae.

Aquaculture has immense potential to augment finfish and shellfish production to partially meet the growing demand for animal protein, It has emerged as the only growth sector of fisheries industries. Aquaculture clearly has the potential to continue to grow rapidly and to make a further substantial contribution to employment and food security, particularly in the rural areas. Penaeid shrimp culture has emerged as a highly profitable investment alternative. In past few decades researchers have gathered considerable information on the biology, production and culture of many of the commercially important shrimps but unfortunately not much attention has been paid to the ecophysiological aspects. In-depth studies on all biotic and abiotic factors are necessary in formulating ecofriendly aquaculture practices. This is particularly important in view of the sudden collapse of shrimp farming in 1994-95 after its rapid expansion in the early 1990'

Ornamental Chasmophytes of Urumbikkara Hills, Western Ghats Region of Idukki District, Kerala, India

The present study on the ornamental chasmophytes in the rocky habitats of Urumbikkara hills of Idukki district, Kerala reveals that, there are about 52 species of ornamental chasmophytic plants belonging to 46 genera and 29 families were collected because of their aesthetic value in both domestic and rock garden practices. These chasmophytes also possess certain biological peculiarities with different interesting adaptations and flower colour which can attract many people for making domestic or rock garden for ornamental purposes and psychological beneficial

Influence of salinity on the growth and body composition of juvenile Tiger Shrimp, Penaeus monodon

Giant tiger prawn dominated the global shrimp aquaculture industry before giving way to Pacific white shrimp in the early 21st century. This study evaluated the influence of salinity on the survival, growth and body composition of early juveniles. They were exposed to salinities ranging from freshwater (0‰) to marine (35‰) under ambient rearing conditions. Response parameters like survival, growth and body compositions were tested over the salinity range of 0, 10, 20, 30, and 35 ‰. The survival obtained was above 95% except in freshwater, wherein total mortality was observed by the third week of rearing. Growth was found to vary with salinity significantly and was found to be higher at 20‰ with an SGR of 7.31. Apart from its role in survival and growth, salinity was found to influence body composition. It was observed that body protein and carbohydrate content showed significant variations with the salinity. The body protein content was high at 20 ‰ with 14.45 mg/100mg wet weight, and carbohydrate of 1.01mg/ 100mg at 30 ‰. However, variations in lipid, ash, and moisture content did not have any significant difference. Though found insignificant, the lipid content was higher (2.15 mg/100mg) at lower salinity of10‰. The present study provides insights into the possible impact of rearing environment on the physiological and biochemical changes in this species

Annotation on adult male crab Ranina ranina landed at Sakthikulangara Fisheries Harbour

The adult male specimen of Ranina ranina (Linnaeus, 1758) landed at Sakthikulangara Fisheries Harbour, Kollam, India, representing an important observation of this species in the region. R. ranina, commonly known as the Frog Crab or Spanner Crab, is a species of crab found in tropical and subtropical regions of the Indian and Pacific Oceans, belonging to family Raninae

Intravenous doxycycline, azithromycin, or both for severe scrub typhus

BACKGROUND: The appropriate antibiotic treatment for severe scrub typhus, a neglected but widespread reemerging zoonotic infection, is unclear. METHODS: In this multicenter, double-blind, randomized, controlled trial, we compared the efficacy of intravenous doxycycline, azithromycin, or a combination of both in treating severe scrub typhus. Patients who were 15 years of age or older with severe scrub typhus with at least one organ involvement were enrolled. The patients were assigned to receive a 7-day course of intravenous doxycycline, azithromycin, or both (combination therapy). The primary outcome was a composite of death from any cause at day 28, persistent complications at day 7, and persistent fever at day 5. RESULTS: Among 794 patients (median age, 48 years) who were included in the modified intention-to-treat analysis, complications included those that were respiratory (in 62%), hepatic (in 54%), cardiovascular (in 42%), renal (in 30%), and neurologic (in 20%). The use of combination therapy resulted in a lower incidence of the composite primary outcome than the use of doxycycline (33% and 47%, respectively), for a risk difference of −13.3 percentage points (95% confidence interval [CI], (21.6 to −5.1; P=0.002). The incidence with combination therapy was also lower than that with azithromycin (48%), for a risk difference of −14.8 percentage points (95% CI, −23.1 to −6.5; P<0.001). No significant difference was seen between the azithromycin and doxycycline groups (risk difference, 1.5 percentage points; 95% CI, −7.0 to 10.0; P=0.73). The results in the per-protocol analysis were similar to those in the primary analysis. Adverse events and 28-day mortality were similar in the three groups. CONCLUSIONS: Combination therapy with intravenous doxycycline and azithromycin was a better therapeutic option for the treatment of severe scrub typhus than monotherapy with either drug alone. (Funded by the India Alliance and Wellcome Trust; INTREST Clinical Trials Registry–India number, CTRI/2018/08/015159.