Sandipan Gupta

Food And Feeding Habit Of Amblypharyngodon mola (Hamilton- Buchanan, 1822) In West Bengal, India

To get success in culture of any fish species, detail knowledge on food and feeding habit of that particular fish species is really essential. Except the work of Piska et al. (1991) no such detail work till date has been performed on food and feeding habit of Amblypharyngodon mola in agro-climatic context of India. So the present study has been performed to get the information on the food and feeding habit of this fish species. Gastro-Somatic-Index, Relative Length of Gut, Gut Fullness & Feeding Intensity and Gut Content Analysis have been studied. Results have revealed Amblypharyngodon mola as herbivorous fish and phytoplankton as the basic food group for this fish species; chlorophyceae has been observed as the most preferable food class. Feeding activity has been observed to vary according to the breeding season; lowest and highest feeding activity has been observed during intense breeding season and pre-spawning months respectively. Food And Feeding Habit Of Amblypharyngodon mola (HamiltonBuchanan, 1822) In West Bengal, India Samir Banerjee Aquaculture Research Unit, Department of Zoology, University of Calcutta, 35, Ballygunge Circular Road, Kolkata700019, West Bengal, India Introduction Amblypharyngodon mola, commonly known as Mola Carplet or Pale Carplet is a freshwater species; a natural inhabitant of ponds, streams, ditches, beels, baors, reservoirs and inundated fields. The species is distributed in India, Bangladesh, Pakistan and Myanmar (Talwar and Jhingran, 1991). In West Bengal it is locally known as mourala, mowa or mowka. It is a popular food fish here in West Bengal due to its good taste as well as high nutrient value with presence of good amount of vitamin A, protein and mineral contents (Zafri and Ahmed, 1981; Saha et al., 2009). In recent times, it has also got its entry in ornamental fish trade and has been reported to be available in ornamental fish markets with moderate demand and availability (Gupta and Banerjee, 2012). Feeding is the dominant activity of the entire life cycle of fish (Royce, 1972) and food is the main source of energy which plays an important role in determining the population levels, rate of growth and condition of fishes (Begum et al., 2008). The success on good scientific planning and management of fish species largely depends on the knowledge of their biological aspects, in which food and feeding habits include a valuable portion (Sarkar and Deepak, 2009). Study of food and feeding habits of fishes have manifold importance in fishery biology and in fisheries management programme (Khan and Fatima, 1994; Sarkar and Deepak, 2009). Like all organisms, fishes require energy to fuel their body machinery and processes, including growth, metabolism and reproduction. For successful fish farming a thorough knowledge about the food and feeding habit is necessary (Bhuiyan et al., 2006; Begum et al., 2008). As the nature of food depends to a great extent upon the nature of environment, the problem is interesting from specific, as well as ecological point of view. The food and feeding habit of fishes vary from season to season; seasonal change in temperature not only influence food consumption and rate of digestion but also quality and quantity of available food organisms. Earlier detail work on food and feeding habit of Amblypharyngodon mola have been carried out in Bangladesh (Mustafa, 1991; Miah and Siddique, 1992; Mamun et al., 2004) but the same is lacking here in India except the work of Piska et al. (1991). So, the present work has been conducted to study the food and feeding habit of Amblypharyngodon mola. Materials and Methods Monthly samples of Amblypharyngodon mola have been collected from September, 2009 to August, 2010 from an undisturbed wetland near Baruipur, South-24-Paraganas, West Bengal, India (Latitude N 22°34’, Longitude E 88°43’). In total, 240 specimens have been collected during the entire study period for studying the feeding biology. After collection, fish specimens have been transferred to ice box and morphometric study has then been performed after reaching laboratory. Total Length (TL) in cm has been measured for each of the individual fish from tip of the mouth to tip of the caudal fin using a measuring scale to the nearest of 0.1 cm and the Total Body Weight (TBW) in grams has been measured for each individual fish species to the nearest of 0.01 gm using an electronic balance (Sartorius, Model No. BT 223S). Before weighing, each of the specimens has been washed with water and left exposed to air and the excess of moisture has been dried off with the help of a blotting paper for taking accurate weight. After that fish specimens have been dissected and then gut has been removed carefully. Then Total Weight of Gut (TWG) and Total Length of Gut (TLG) have been measured to the nearest of 0.01 gm and 0.1 cm respectively. Gastro Somatic Index (GaSI), Relative Length of Gut (RLG), Gut Fullness & Feeding Intensity and Gut Content Analysis have been done to study the food and feeding habit of Amblypharyngodon mola. Gastro Somatic Index (GaSI) has been measured using the following equation: Total Weight of Gut (gm) x 100 GaSI = ----------------------------------------Total Body Weight (gm) Relative Length of Gut (RLG) value has been measured following the formula (Al-Hussaini, 1949): Total Length of Gut (cm) RLG = ---------------------------------------Total Body Length (cm) The RLG values calculated have then been grouped in response to different size classes (length interval of 1.0 cm) to know any change of RLG value in respect to size. After that gut fullness has been assessed according to the subjective scale described by Lebedev (1946) as empty, 1⁄4 full, 1⁄2 full, 3⁄4 full and full. The data have then been used to calculate the monthly Fullness Index (FI) to determine the percentage of feeding intensity: Number of gut with same degree of fullness x 100 FI = ---------------------------------------------Total number of gut examined Gut Content Analysis has been performed following two methods; namely Percentage of Occurrence (Hynes, 1950) and Points

An Overview on Morphology, Biology, and Culture of Spotted Scat Scatophagus argus (Linnaeus 1766)

ABSTRACT Spotted scat Scatophagus argus is a popular aquarium species around the world due to its colorful appearance, hardiness, slow growth, and calm behavior. It has also been admired as a food fish mainly in the South and South-East Asian countries due to its good nutrient quality with high protein content and taste. Considering its importance both as ornamental and food fish, several researchers have studied on different aspects of its morphology, food and feeding habit, reproductive biology, and culture; but to date no consolidated report is available on these aspects. This report seeks to consolidate all available information on its morphology, biology, and culture and explore the scope for future research that will be beneficial for its fishery and trade. Considering the information summed up in the present report, it is evident that ample information is available on morphological characters, food, and feeding habit of Scatophagus argus without adequate knowledge on different aspects of its reproductive biology and culture. Further study is needed on these comparatively less explored aspects to support its fishery and trade in the near future.

Fecundity Estimation of Mystus tengara (Ham.-Buch., 1822), A Freshwater Catfish from West Bengal, India

Fecundity is one of the most important aspects of reproductive biology study of any fish species. Though very little work so far has been done on fecundity study of different species of Mystus; but there exists a lacuna regarding the same for Mystus tengara specifically in the agro-climatic context of India. The study has revealed that the fecundity of Mystus tengara ranged from 6,770-21,708 with an average of 13,365.84±7,260.40; thus representing the highly fecund nature of this fish species. On the other hand, fecundity has shown highly significant (P<0.01) positive relationship with Total Body Weight, Total Length, Ovary Weight and Ovary Length; but comparison of correlation coefficients of fecundity with these above said parameters have indicated that variation in fecundity can be explained better in terms of Ovary Weight, Ovary Length and Total Body Weight than in terms of Total Length for this fish species. Introduction Mystus tengara is commonly known as tengra which is a freshwater species, inhabits both flowing and standing waters. This species is a preferred food fish in West Bengal due to its good taste, high nutrient profile; and in recent times it has also got its importance as ornamental fish too. Study of the reproductive biology of any fish species is essential for assessing commercial potentialities of its stock, life history, culture practice and actual management of its fishery (Doha and Hye, 1970) and fecundity is one of the most important aspects of fish biology that must be understood to explain the variations in the level of population, to understand the demography of fish populations as well as to make efforts to increase the amount of harvest (Alam and Pathak, 2010). Fecundity is defined as the total number of mature eggs present in ovary of a fish before spawning that should be laid in a single species not in a constant number but fluctuates within certain ranges which is species specific and is the indicator of auto recruitment of that species (Alam and Pathak, 2010). The knowledge of fecundity is of great value in fish culture (Bhatt et al., 1977) as it can be used to assess the abundance and reproductive potential of the spawning stock (Sarker et al., 2002). Fecundity varies from one species to another, depending on the environmental conditions, length, age, location etc. (Musa and Bhuiyan, 2007; Alam and Pathak, 2010) and even among the individuals of the same species depending on various factors like size, age, condition, genetic potential etc. (Alam and Pathak, 2010) Very little works have been done on fecundity study of different species of Mystus (Bhatt et al., 1977; Rao and Sharma, 1984; Khan et al., 1992; Hoque and Hossain, 1993; Dasgupta, 2002; Sarker et al., 2002; Roy and Hossain, 2006; Musa and Bhuiyan, 2007; Islam et al., 2011) but there exists a lacuna on this aspect for Mystus tengara in Indian scenario. So, the present work has been performed to study the fecundity of Mystus tengara. Materials and methods Monthly samples of Mystus tengara have been collected from September, 2008 to August, 2009 from an undisturbed wetland near Baruipur, South-24-Paraganas, West Bengal (Latitude N 22°34’, Longitude E 88°43’). In total, 131 specimens have been collected during the entire study period for fecundity study. Total Length in cm has been measured for each of the individual fish from the tip of the mouth to the tip of the upper lobe of the caudal fin using a measuring scale to the nearest of 0.1 cm and the Total Body Weight in grams has been measured for each individual fish species to the nearest of 0.01 gm using an electronic balance. After that fish specimens have been dissected out carefully ventrally; then ovaries have been taken out cautiously and the surface moisture of the ovaries has been removed using the blotting paper. Ovary Weight and Ovary Length have been measured to the nearest of 0.01 gm and 0.1 cm respectively. Fecundity has been estimated using mature and ripe ovaries following the gravimetric method (Khan et al., 2002; Hussain et al., 2007). The relationship of fecundity with Total Body Weight (TBW), Total Length (TL), Ovary Weight (OW) and Ovary Length (OL) has been studied. To establish the relationship, the values of regression co-efficient (b), point of intercepts (a), co-efficient of correlations (r) and standard deviation have been calculated on those parameters by the least square method. “t” test has also been performed for testing the significance of co-efficient of correlation (r) between the above sited parameters. Results Fecundity has been observed to vary between 6,770 (for a fish of total length 8.21 cm, body weight 6.02 gm; ovary weight 1.04 gm and ovary length 1.13 cm) to 21,708 (for a fish of total length 11.2 cm, body weight 18.28 gm; ovary weight 2.68 gm and ovary length 3.06 cm) with an average of 13,365.84±7,260.40 (mean total length 9.96 cm; mean body weight 10.67 gm; mean ovary weight 1.55 gm and mean ovary length 2.55 cm). Fecundity (F) has shown significant (P<0.01) positive relationship with TBW, TL, OW and OL and the relationships are as follows: F = 4725.62 + 689 TBW (r = 0.73, P<0.01, SE = 1968.15) F = 4000.51 + 1613.70 TL (r = 0.53, P<0.01, SE = 2442.56) F = 5981.97 + 3930.74 OW (r = 0.85, P<0.01, SE = 1532.41) F = -3372.71 + 6069.77 OL (r = 0.84, P<0.01, SE = 1578.70) Discussion Khan et al. (1992) reported the fecundity of Mystus tengara to be ranged from 720-5,223. Rao & Sharma (1984), Hoque & Hossain (1993) and Islam et al. (2011) reported the fecundity of Mystus vittatus to be ranged from 3,500-18,800; 2,534-60,746 and 18,210-44,620 respectively. Sarker et al. (2002) and Dasgupta (2002) reported the fecundity of Mys-