Influence of diets on growth and biochemical parameters of Babylonia spirata

Abstract A feeding experiment of three dietary protein levels (30, 35 and 40%) with three replicates was conducted to determine the proper protein level for the growth and survival of the Babylonia spirata under laboratory conditions. Snail with initial body weight ranged from 50.95 ± 0.33 g to 51.05 ± 0.21 g and initial length ranged from 5.96 ± 0.62 cm to 6.91 ± 0.70 cm were fed as the experimental diet for 3 months. Mean weight gain, survival rate and biochemical parameters of snail fed the 40% protein diets was significantly (p < 0.05) different from that snail fed the 30 and 35% protein diets. The results of the study indicate that a diet containing 40% dietary protein was recommended for snail growth under our laboratory conditions.


Introduction
Since ancient times, the finfish and shellfish have been noted as the rich protein source for mankind, all over the world. Besides, proteins source they also delivers various minerals and vitamins, with its own characteristic taste. Moreover, fish meat seems to contain significantly low lipids and higher water content than beef or chicken, it has been favoured over other white or red meats (Nestel, 2000). Malnutrition is considered as a serious problem and is being faced by many developing countries. In India, 20-30% of the population does not get adequate nutrition. This problem could be easily solved by effective utilization of nutrient-rich molluscs. This means that the proper exploitation of capture fishery and culture fishery would surely supply the balanced nutritious food and thereby, it controls the malnutrition problem.
Generally, meats of molluscs, especially gastropods were highly nutritious, owing to its contents of proteins, rich vitamins and minerals (Thanonkaew, Benjakul, & Visessanguan, 2006). Therefore, the biochemical composition of marine gastropod persists as an excellent nutritional assurance for millions of malnourished peoples. The gastropod meat has been considered to be free of cholesterol but contains high nutritive substances (Abdullah, Nurjanah, Hidayat, & Gifari, 2016).
The use of prepared feed formulation would helps to manipulate in a proper way and obtain an optimum nutritional value. Further, it could be properly prepared and stored for a longer duration according, to their demands (Nyameasem & Borketey-La, 2014). The usages of, such as formulated feeds in spotted Babylon farming have made a significant contribution to their production in Thailand (Chaitanawisuti, Rodruang, & Piyatiratitivorakul, 2010). By adaptation, this strategy in Babylonia areolata may have been observed to increase within growth high protein content of 27 and 45%.
The artificial feed formulation and preparation can be done with optimal nutrition for Babylonia spirata at the lowest possible cost. The diet development is involved in certain factors, such as the cost of ingredients, pellet ability and diet acceptability, water stability of the feed and handling requirements . In recent days, the increasing demand of the meat, operculum and shells of the gastropod have led to the development of active fishery in different parts of India (Periyasamy, Srinivasan, Devanathan, & Balakrishnan, 2011). The heavy fishing may result in the depletion of natural stocks to a large extent. Several bivalves are produced through aquaculture, but gastropods are not produced through aquaculture and they can also be cultured for commercial production. Only a few studies were done in India on breeding, larval rearing and sea ranching of gastropods (Mohanraj et al., 2010). A few studies have only been conducted in the commercially important gastropods. However, information on the gastropod species of commercial (ornamental) interest from the Indian coast remains scarce. In recent days, the increasing export value of the meat, operculum and shells of the gastropods have led to the development of active fishery in different parts of India. Several bivalves have been produced through aquaculture. The present study deals with the work, influence of formulated diets on growth and biochemical parameters of B. spirata.

Materials and methods
The samples of B. spirata with their initial weight ranged from 50.68 to 52.52 g and initial length ranged from 5.53 to 5.82 cm were collected at the Therespuram coastal area (80° 48′N; 78° 94′E), Tuticorin, south-east coast of India. Collected samples were made to acclimatize in 7 days using aerated plastic holding tanks (1.5 m × 2 m × 0.5 mL: W:H) in the Marine Gastropod Hatchery Research Laboratory, Kamaraj College, Tuticorin, Tamil Nadu, India. During this study period, the snails were fed with natural live clam meat. Then they were randomly distributed into triplicate FRP tank containing 200 L at 40 snail/tank and three experimental groups were maintained. The tanks were regularly cleaned, disinfected and allowed to dry for 24 h after which they were filled with dechlorinated ambient seawater to 2/3 sizes of the tanks. The bottom of the rearing tanks was covered with 3 cm layer of coarse sand (500-1000 micron mean grain size) as substrate. After removing the snails from culture tanks, sand was cleaned using a water jet flushing and sun-dried at 30 days intervals in order to remove the accumulated waste materials. During this period, the snails were fed with formulated (30, 35 and 40% crude protein) at once day. The total experiment was conducted for 90 days.

Experimental diet
The procedures for feed preparation were modified by Hardy (1980). The feed ingredients were homogenized thoroughly in a food mixer. After adding distilled water to the mixed ingredients, a paste was made using a hand mixer. The paste was shaped into 0.5 mm thick sheets and they were cut into 2 cm 2 flakes, sealed in a plastic bag and stored at −20 °C. The experimental diets were formulated with the composition protein of 30, 35 and 40%. The fish meal and groundnut oil cake serves as the protein source, fish oil serves as the lipid source, tapioca powder serves as the carbohydrate source, wheat flour serves as a binder and vitamin and mineral mixtures were also added (Table 1).

Water quality
The seawater quality parameter was analysed weekly for its purity. It includes parameters, like temperature (°C), salinity (ppt), pH and dissolved oxygen (mg/L) were examined using SYSTRONICS water analyser 371.

Growth parameters
The growth performance and biochemical profile were expressed in terms of weight measurements, like weight gain (g) and survival (%) were monitored according following formula of Chaitanawisuti, Choeychom, and Piyatiratitivorakul (2011).
Weight gain (g) = Final weight -Initial weight F 1 -Number of snail at the being of experiment. F 2 -Number of snail at the end of the experiment.

Estimation of biochemical profile
The Folin-Ciocallteu phenol method of Lowry, Rosebrough, Farr, and Randall (1951) was adopted for the estimation of total protein in the tissue. Total carbohydrate content method was followed by DuBois, Gilles, Hamilton, Rebers, and Smith (1956). The lipid content was estimated gravimetrically by following the method of Floch, Lees, and Sloane-Stanley (1956). The moisture and ash content was followed by AOAC (1990).

Statistical analysis
All experimental data obtained were analysed using oneway analysis of variance (ANOVA) followed by Duncan's multiple range test p < 0.05 was considered for describing the significant level (SPSS Version 20).

Results and discussion
The aquaculture of molluscs seems to be seriously affected worldwide by bacterial pathogens and predators' that cause high losses in hatcheries as well as in natural beds. The main responsible for the mortality outbreaks is a number of Vibriosp and Aeromonas species that are considered as important pathogens in aquaculture (Chen, Ke, Zhou, & Li, 2005). The pathologies caused by Vibrio in bivalves and gastropods have been described since the 1960s; however, over recent years successive episodes of high mortality have been recorded due to these microorganisms. The average shell length and weight and survival rate of B. spirata  Table 2. The growth expressed as body weight, shell length and survival rate were significantly not different p < 0.05 among the experiment diets. Among the average body weight gain, the highest was observed at 40% level of protein diet (2.14 ± 0.84 g) and the lowest was observed at 30% level of protein diet (1.01 ± 0.36 g). In average final shell length, the highest was observed at 40% diet (6.91 ± 0.70 cm) and the lowest was observed at 30% diet (5.96 ± 0.62 cm). The average survival rate, the highest was observed at 40% of protein diet (91 ± 1.04%) and the lowest was observed at 30% diet (89 ± 1.06%). The maximum growth and survival rate were observed in 40% protein diet. According to Chaitanawisuti, Kritsanapuntu, and Santaweesuk (2010), have reported B. areolata is one of the most important cultivable species with significant commercial value. Currently, the most common practice is spotted in Babylon culture in Thailand. Similarly, Chaitanawisuti and Kritsanapuntu (2000) have reported that average growth rate of juvenile spotted Babylon of B. areolata was 3.86 mm mo −1 in length and 1.47 mo −1 in weight after 8 months when cultured at a density of 300 snails/m 2 in flow through system and 3.21 mm mo −1 and 1.10 g mo −1 when held in a recirculation system. Sirusa Kritsanapuntu et al., (2013) reported the partial replacement of tuna oil by corn oil in formulated diets of B. areolata under hatchery conditions have no effects on growth performance but fat content of the whole body reduced to half than those contained in formulated diets. Recently, Jayalakshmi (2016) have reported that the edible body tissue of Babylonia sp. an excellent source of high protein, low lipid content but enriched with essential vitamins and minerals. It is can be taken regularly as animal protein supplement or nutritive seafood which supplies all vital nutrients for the growing children, pregnant women and people suffering from malnutrition. Temperature and salinity are considered to be the most important physical factors influencing marine organisms and the biological effects of these factors are complex and wide ranging. Secondly, temperature affects the hatch rate, incubation period, the size of the newly hatched larvae, larval yolk absorption and utilization, larval feeding behaviour, larval survival and larval growth (Shi, Zhang, Zhu, Liu, & Zang, 2010). The temperature, salinity, diet and rearing density are exogenous factors affecting larval growth, settlement and metamorphosis Crisp (1974). The average water quality parameters observed during the experimental period for 12 weeks are shown in Tables 3a-3c. These parameters were significantly p < 0.05 different, including the temperature which ranged between 26.66 ± 0.57 °C and 27.68 ± 0.30 °C, the salinity between 32.12 ± 0.37 ppt and 33.92 ± 0.77 ppt, the pH from 7.60 ± 0.46 to 7.83 ± 0.49 and the dissolved oxygen from 5.41 ± 0.36 to 6.21 ± 0.47 mg/L. These values are suitable for rearing of B. spirata. Similarly, Kritsanapuntu, Chaitanawisuti, Santhaweesuk, and Natsukari (2006) observed the higher body weight gain and shell length increments were observed in B. areolata held in recalculating seawater system at water exchange of 15 day intervals. The proximate compositions of B. spirata tissues fed with different formulated diet are shown in the

Conclusion
In conclusion, this study showed that the formulated diet can be readily used for B. spirata growout for maximizing growth, survival and biochemical parameters. However, further research is needed to improve the immunomodualtion activity of snail fed with herbal based supplement diets under intensive culture.