S. Ananth

Effect of different dosages of zinc on the growth and biomass in five marine microalgae

Marine environment often restrain toxic heavy metals that may enter into the food web via uptake by microalgae and eventually cause severe poisoning problems at higher tropic levels. The effects of Zinc cations upon growth of five native microalgal species, Chlorella marina, Isochrysis galbana, Tetraselmis sp., Nannochloropsis sp., and Dunaliella salina were evaluated. Growth inhibition of the microalgal cells were determined by exposing them to different concentrations of aqueous solutions of zinc metal for 15 days. A major reduction in cell density was observed in all the five cultures in the concentration of 50 ppm. Among the five micro algal species tested, Tetraselmis sp. alone showed growth up to 250 ppm concentration of zinc metal till the final day (15th day) of experiment. Key words: Zinc, microalgae, heavy metal, Chlorella marina, Tetraselmis sp.

Bioremediation of shrimp (Litopenaeus vannamei) cultured effluent using copepod (Oithona rigida) and microalgae (Picochlorum maculatam & Amphora sp.)—An integrated approach

AbstractNitrogenous compounds are major contaminants in aquaculture effluent and thereby needs a potential candidate for removing these nutrients. The present study tested the efficacy of immobilized microalga, diatom Amphora sp. and copepod Oithona rigida to remove excessive nutrients from the shrimp (Litopenaeus vannamei) cultured effluents. Nutrient removal was evaluated with five different combinations: (1) copepod, O. rigida; (2) immobilized Picochlorum maculatum and copepod O. rigida; (3) immobilized P. maculatum; (4) immobilized Amphora sp. and copepod O. rigida; and only (5) immobilized diatom, Amphora sp. Preliminary studies showed maximum reduction of about nitrate 86% and nitrite 88% in treatment 2–4, respectively. The maximum phosphate (69%) and ammonia (91%) removal was recorded in the treatment 3. In disparity, the phosphate concentration recorded was significantly higher (6%) at the end of the experiment in the treatment 1 than other experiments. While in the treatments 1, 2, and 4 the cope...

Intensive Indoor and Outdoor Pilot-Scale Culture of Marine Copepods

Copepods are more abundant than any other group of multicellular animals, including the hyper-abundant insects and nematodes. They consume phytoplankton and microorganisms, and they are in preyed upon by higher trophic levels, animals including fish and whales. In particular, they serve as primary prey for the larval stages of many fish species of economic importance. In aquaculture, copepods have been proven to be the much preferred and most adequate food for many marine fish larvae (Houde 1973; May et al. 1974; Kraul 1983, 1989, 1993) and are also used for the shrimp larvae (Shamsudin and Saad 1993). Good fish productivity of an aquatic ecosystem is related to the presence of copepods and their role as the main food component (May 1970; Bent 1993). The larvae of many marine fish require prey with size of about 50–100 μm wide at their first feeding stage (Detwyler and Houde 1970; Yufera and Pascual 1984). Even the rotifer of type “S” is too large in many cases (Houde 1973; May et al. 1974; Doi and Singhagraiwan 1993). The results concerning first feeding of commercially important fish on dry food organisms are encouraging (Fernandez-Diaz and Yufera 1997; Cahu and Zambonino Infante 2001). However, live feeds cannot always be substituted because of biochemical and behavioural constraints of the fish larvae (Drillet et al. 2006).

Isolation and Culture of Microalgae

Marine microalgae or phytoplankton are the floating microscopic unicellular plants of the seawater which are generally free living, pelagic with the size range of 2–20 μm. The important components of microalgae are the diatoms, dinoflagellates, green algae, blue-green algae, and coccolithophores. Most microalgae have got immense value as they are rich sources of essential fatty acids, pigments, amino acids, and vitamins. They play a critical role in the coastal aquaculture of fish, molluscs, shrimps, and oysters, especially to meet the nutritional requirement of the larvae as well as for bioencapsulation. It is an established fact that the success of any hatchery operation mainly depends on the availability of the basic food, the phytoplankton. The maintenance and supply of the required species at appropriate time form a major problem being encountered by the algal culturists. The procedure for the phytoplankton culture involves aspects such as the isolation of the required species, preparation of the suitable culture media, and maintenance of the culture in the laboratory scale, as well as large scale under controlled conditions of light, temperature, and aeration, and their constant supply to the aqua farmers in different phases of growth. A culture may be defined as an artificial environment in which the microalgae grow. The culture of phytoplankton is an important aspect of planktonology, and the mass culture of phytoplankton is achieved under laboratory-controlled conditions and under field/outdoor conditions. Under laboratory conditions, sterilized or thoroughly cleaned containers are filled with filtered/sterilized seawater (28–34‰) and enriched with the addition of fertilizers, i.e., Guillard and Ryther’s F medium, Walne’s medium, or TMRL medium. The culture containers are inoculated with pure strains of the desired phytoplankton previously cultured in the laboratory. They are provided with heavy aeration and light using aerators and fluorescent bulbs respectively in a controlled laboratory with temperature of 25 ± 2 °C. The exponential growth phase is generally observed in 36 h to 3 days after inoculation. Cell density of 1.5–4.5 million cells per ml could be recorded. As a sufficient quantity of phytoplankton inoculums usually is present in the coarsely filtered seawater when the nutrients are added, a phytoplankton bloom develops in a course of few days under substantial sunlight. However, it happens sometimes that diatom bloom is inhibited by lack of sunlight or due to the nature of seawater in the tank. In such cases, the addition of new seawater and/or addition of ferric chloride in small amounts may stimulate instant resumption of the diatom in culture.

Seasonal Composition and Diversity of Zooplankton from Muthupet Mangrove Wetland Ecosystem, Southeast Coast of India

The mangrove environment has been considered as a plankton abundant area (Robertson and Blaber 1992), and it acts as feeding and nursery platform for a variety of secondary consumers like fish and invertebrates (Chong 2007). The carbon source of mangrove wetland is the main factor for their high productivity which has always been linked to detritus-based food web (Odum and Heald 1975). Zooplankters are tiny organism which was abundantly available in all depth of the ocean. The Indian Ocean plankton bibliography was composed by Prasad (2003). Subramanian (1987) has introduced the ecological survey of primary consumers in Indian Ocean. While going in to the mangrove-associated fishes, their main primary food is zooplankton, and also there is a need to study their community structure and abundance in relation with the environment (Chong 2007). Some of the researchers has made attempt on zooplankton ecology previously in the mangrove ecosystem worldwide (Robertson et al, 1988; McKinnon and Klumpp 1998; Krumme and Liang 2004). Studying about zooplankton ecology is an important feature of biological oceanography because of their major role in the marine food chain of the aquatic environment. Zooplankton dominantly occupied the intermediate level between the primary and tertiary producers. Zooplankton distribution and their life cycle have been determined by the physical and chemical characteristics of the marine environment. The present study dealt with the assessment of diversity and abundance of zooplankton from Muthupet mangrove wetland ecosystem, Southeast coast of India, in relation to the environmental factors.

Distribution of Phytoplankton in Selected Salt Pans of Tamil Nadu, Southeast Coast of India

Salt is one of the world’s best-known minerals and the chemical substances most related with the history of human civilization (Korovessis and Lekkas 2009). Solar evaporation is a process that has been profitably used for salt production for millennia. However still, the biology of a saline ecosystem in relation with the salt production process has not been well studied. Recently many countries have shown interest in maintaining and manipulating the hypersaline ecosystem for aquaculture and other related activities. Salt pan ecosystem is highly dynamic where the organisms are subjected to vulnerable physico-chemical disturbances. Salt pans are unique enclosed ecosystem that is characteristically exposed to a wide range of environmental stress and perturbations manifest mainly through salinity changes. In the extreme astatic physico-chemical conditions of these hypersaline habitats, only a few plant and animal species can live. Salt pan ecosystem offers a number of unique ecological niches having a strange combination of environmental factors. The nutrient-rich seawater in saltworks favours algal blooms in reservoirs and evaporators.

A Method of Analysis of Pigments in Copepods

Pigmentation in the animals generally aids in the sexual attraction of partners or camouflage to reduce the risk of predation, but in some planktonic crustaceans, pigments are used as a guard against harmful ultraviolet (UV) radiation (Hansson 2000). Pigments occur almost in all phyla of marine organisms (Goodwin 1976) and are widely present in the zooplankton and micronekton (Cheeseman et al. 1967; Herring 1972). There are so many reports on zooplankton pigmentation, in which most of them focused on crustaceans (Herring 1968; Hairston 1979; Castillo et al. 1982). In marine pelagic food webs, copepods are the major producers of astaxanthin. Firstly, the most important function of astaxanthin in copepods is that it is an antioxidant for protecting lipids from peroxidation. Secondly, pigmentation and thereby photo protection against UV light have been suggested. Thirdly, it could be that astaxanthin esters, since they are lipids, serve as sources of metabolic energy, even if they contribute to only 2% of the total lipid content of a copepod body. In this chapter, some of the common techniques used for the extraction and analysis of pigments in copepods are elaborated.

A Method of Extraction, Purification, Characterization, and Application of Bioactive Compounds from Phytoplankton

Microalgae are an immense group of unicellular prokaryotic and eukaryotic organisms that are mainly autotrophic (Tartar et al. 2003; Ueno et al. 2003). Capability of microalgae as simple growth requirements and photoautotrophic and capacity to modulate their metabolism, make them attractive for demand by the pharmaceutical, food, cosmetic or biodiesel industries. Microalgae can be used as a feed for fish larvae in aquaculture and asanimal fodder, due to their rich content of fatty acids, protein, antioxidant pigments and polysaccharides (Yaakob et al. 2014). Microalgae produce a wide variety of bioactive products with potential commercial values such as antibacterial, antifungal, antiviral, antiplasmodial, enzyme-inhibiting, immunostimulant, and cytotoxic activities (Ghasemi et al. 2004). Even though the microalgae has high potential and comprise more and more bioactive substances, only β-carotene and astaxanthin have been produced at an industrial scale (Dominguez et al. 2005). This paper explains the methods involving extraction, purification, characterization, and application of bioactive compounds from phytoplankton.

Assessing the Efficacy of Marine Copepods as an Alternative First Feed for Larval Production of Tiger Shrimp Penaeus monodon

Intensive production of marine shrimp is mainly depending on live prey in rearing of the first feeding shrimp larval stages. Commonly rotifers and brine shrimps are the primary live feed for the shrimp, and commercial shrimp production has conventionally acclimatized with this. Because, commercial scale need fast growing and high reproductive rates live pray and they mainly depend on rotifers which fulfil all the requirements. At the same time, brine shrimp Artemia can be collected in nature and stored as cysts until needed. Regrettably, still marine larviculture faces an unbalanced live feed which contains low nutritional compositions, and it reflects in shrimp larval survival and their disease resistance capability. While there is a mass production of shrimp larvae, the high and fluctuating costs of Artemia push to find an alternative live prey such as copepods (Abate et al. 2015; Drillet et al. 2008).

Biofloc-Copefloc: A Novel Technology for Sustainable Shrimp Farming

For the last three decades, since the 1990s, aquaculture has become the fastest growing animal food-producing industry in the world (FAO 2014). It has experienced a tremendous growth in productivity during this period (Asche et al. 2008, 2013). Thus, aquaculture has been one of the most promising animal food-producing sectors, with the lowest feed conversion ratio (Smil 2001), while providing sufficient and highly nutritional food for a growing world population. Particularly, the industry will play a crucial role in meeting increasing demands for healthier animal proteins and lipids. Thus, the contribution of aquaculture in alleviating obesity and its resultant health and social benefits is clear and should not be underestimated.