Posted on 10th Oct 2024 08:12:38 PM Fisheries
INTRODUCTION
Bangladesh is well known as an agricultural land with an area of 1,47,570 km2 within 20°34¢ to 26°38¢ North latitude and 88°01¢ to 92°40¢ East latitude. Fisheries and aquaculture plays a major role in this sector. Bangladesh has vast inland water body in the form of rivers, estuaries, beels, haors, lakes, canals, flood plains, reservoirs etc. Beside these many culturable seasonal water bodies are also included. In addition, marine water fisheries cover an extensive area of territorial water, coastlines, continental shelves and a vast area of Exclusive Economic Zone (41,040 sq n miles). Inland fishery cover an area of 44.36 lakh ha which comprise about 40.47 lakh ha inland open water body (88%) and about 5.28 lakh ha inland closed water body (12%) (DoF, 2010).
The production statistics of fish during 2008-09 showed that the total fish production is about 27.01 lakh metric ton where the contribution of inland closed water body is about 49% and the contribution of inland open water body is about 35%. Among different sources of inland closed water bodies the area of pond and ditches is about 3.05 lakh ha, i.e., 7% of total inland water body and fish production is about 9.12 lakh mt (DoF, 2010). Production from inland closed water body is increasing very sharply due to dissemination of adaptive technologies and effective extension services rendered by department of Fisheries.
Fisheries sector also made a significant contribution to the process of improving food security through the opportunities the sector provides for employment and income of people either directly on indirectly. This sector provides income for about 1.5 million full time professional fishermen, i.e., 5% of national lobour force. In addition there are about 12 million peoples whose livelihood depends indirectly on fisheries (DoF, 2010). The income from employment and/or the financial revenues from the sale of fish, provide cash which can then be used for further income. According to the statistics of 2008-09, fisheries sector contributes about 3.74% to the total GDP and 3% to the country total export earning. This sector accounts about 22.23% of country total agricultural income (DoF, 2010).
Poor people in developing countries like Bangladesh tend to depend essentially on carbohydrate based diets for their nutritional intake. These are however, relatively low in protein and micronutrients. In this context, fish can play a particularly important role in combating micronutrient deficiencies, as they contain high quality protein, essential fatty acids and also key micronutrients such as vitamin A, calcium, zinc and iodine. According to nutritionist 45 g protein is needed per capita per day. One third of this or 15 g should be animal protein. About 58% animal proteins are met by fish as an available and cheap source of protein and for this we need to eat about 56 g fish daily.
Bangladesh is blessed with an abundance of inland water bodies filled with a diversity of indigenous fish species and the majority of these fish species are small indigenous species (SIS) of fish. Small indigenous species (SIS) of fish have been defined as species which grow to a maximum length of about 25 cm (Felts et al., 1996). However many SIS are less than 10 cm long and they are typically eaten whole with organ and bones. There are 265 fresh water species at present in our country in which about 143 species are SIS (Felts et al., 1996). But about 50 species of small indigenous species are available in closed water bodies of Bangladesh. Among these about 20 species are carp fish and about 10 species are cat fish type (Hoq, 2006). These are important target species for small scale fisher in Bangladesh, who uses a variety of traditional fishing gears (Kibria and Ahmed, 2005).
Among the smaller fishes, Amblypharyngodon mola is locally known as ‘Mola’. ‘Molla’ is a commercially important naturally occurring auto stocked cyprinid fish in pond. Earlier the fish was considered as weed fish in the fish cultured ponds but in advent of time the fish is now highly demanded, economically valuable and costly fish in the market. Considering nutritional value, taste, income source, availability, preference and contribution in poverty alleviation recently emphasis is given to culture ten small indigenous fish in Bangladesh, out of which ‘Mola’ is one of them. However, this fish is captured only from different open water bodies, but can be cultured in the ponds and beels easily. But in Bangladesh the culture method for this species is not developed in scientific way. However, very recently some attention has also been given to increasing the production of nutrient-dense, commonly consumed, indigenous small fish- in particular mola. Based on a successfully developed technology of producing mola in small, seasonal ponds together with carps, the Ministry of Fisheries and Livestock in Bangladesh has issued a directive to project directors in the fisheries extension services to implement carp and mola pond polyculture throughout rural Bangladesh. At the same time, this production technology is being implemented by non-governmental organizations working with poor, rural households in Bangladesh and recently also in west Bengal, India.
A Few words about Amblypharyngodon mola
Scales 65-75; 9-10 rows between lateral line and base of pelvics; lateral line extends up to 15 scales.
Taxonomic position
Kingdom: Animalia
Phyllum: Chordata
Super class: Pisces
Class: Osleichthyes
Sub-class: Actinopterygii
Super order: Teleostei
Order: Cypriniformes
Sub-order: Cyprinoidei
Family: Cyprinidae
Genus: Amblypharyngodon
Species: A. mola (Hamilton, 1822)
Local name: Mola, Molongi, Moya, Mowrala
Common name: Mola carplet, Pale carplet
Variety
The species has two recognized phenotypes according to the pattern of scaling.
Amblypharyngodon mola (Hamilton)
Amblypharyngodon microlepis (Bleeker)
Synonyms
Cyprinus mola (Hamilton, 1822).
Amblypharyngodon mola (Day, 1978; Shaw and Shebbeare, 1937; Bhuiyan, 1964; Qureshi, 1965).
Habitat
Available in the rivers, streams, beels and tanks and gets an invigorating effect in growth on change from one pond to another (Bhuiyan, 1964). According to Rahman (1989), extensively found in rivers, canals, beels, ponds and inundated fields of Bangladesh.
Food and Feeding
A. mola is generally a surface feeder. Its food may include unicellular and filamentous algae, protozoans and rotifers. According to Das and Moitra (1963) A. mola is a herbivorous fish. Mustafa (1991) reported that the main food of A. mola consisted of blue green algae and green algae with planktonic crustacea and rotifera.
Morphology
Body is moderately compressed. Dorsal profile more convex than ventral, mouth anterior, snout rounded, covered with thin skin. Upper lip is absent. Only a thin labial fold at angle of lower jaw. Lower jaw is longer with a symphyseal prominence. No barbels, Gill-membranes united to each other and to isthmus.
Head 3.0-3.5 in standard, 4.0-4.5 in total length. Height 3.2-3.6 in standard, 4.1-4.7 in total length. Eye 3.5-5.0 in head; snout 0.8-1.0, interorbital 1.3. Maximum length reported 8 cm (Bhuiyan, 1964), 20 cm (Talwar and Jhingran, 1991) and 9 cm (Rahman, 1989). Scales small, 65-75 lateral line scales, 9-10 rows between lateral line and base of pelvics (Rahman, 1989). Lateral line incomplete, extend to above posterior part of pectoral fin. Dorsal fin originates midway between anterior margin of eye and caudal base. Caudal deeply, forked, lobes pointed. Body golden yellow in colour. A silvery lateral band running from gill covers to base of caudal. Dorsal, anal and caudal with dark markings; pectoral and pelvic fins hyaline.
Breeding
Breeding season of this fish extends from May to October. A female lays about 500 egg (Bhuyian, 1964). Egg laying tendency increases at the commencement of the rains (Bhuiyan, 1964).
Geographical distribution
Pakistan; Indus Plain and the adjoining hills; India; throughout the country (except perhaps Kerala); Bangladesh; and Myanmer.
Economic importance and Utilization
Mola has high protein, vitamin and mineral contents. On account of its high nutritive value the fish is commonly eaten by people. A. mola is a good source of vitamin “A” and calcium (Hoq, 2006). In Bangladesh, where 30000 children become blind each year from vitamin A deficiency, A. mola can play a vital role as a rich source of vitamin A. Big fish which are promoted in aquaculture do not contribute significantly to calcium intake since the bones are not eaten where small fish like A. mola are eaten whole, “Bones and all” thereby providing a source of calcium and other micronutrients. This fish are especially important for poor consumers, as they can be purchased in small quantities at low cost. This fish are also more equally distributed among family members while males get a larger share of big fish. Besides, A. mola has special importance in Bangladesh where 70% of women and children suffer from iron deficiency. It is used to prepared common dish such as “Chorchori” and oil fry. The fish has a good market demand for its taste and nutritional value and marketed in fresh or dried condition.
For the assessment of probability of the culture of fish species in water bodies of the country, growth rate of this species is essential to know. Growth of an organism means a change in length or weight or both with the increasing age. Increment in size is due to conversion of the food matter into building matter of the body by the process of nutrition. In many fishes changes in the relative growth of the various body properties are known to occur at different stages of development and particularly at sexual maturity. The rate of growth of fish is easily influenced by many factors. Growth of fish may vary for the same fish at different localities or for the same fish at different seasons.
The length-weight relationship of fish is an important fishery management tool. Its importance is pronounced in estimating the average weight at a given length group (Beyer, 1887) and in assessing the relative well being of a fish population (Bolger and Connoly, 1989). The study of length-weight relationship has its applied value in fish biology. These studies are also widely used in stock assessment models and estimation of biomass from length observation (Weatherly and Gill, 1987; Wootton, 1990; Moutopoulos and Sleryion, 2002). Length-weight relationships also give information on the condition and growth patterns of fish (Bagenal and Tesch, 1978).
The length-weight relationship is also a useful tool for fish culturists. When large numbers of fishes must be individually sampled, it is faster and often more convenient to determine the fish length rather than weight (Steeby et al., 1991). This relationship is also used in commercial sales and population assessment (Steeby, 1995). According to Le Cren (1951) and Tandon (1961) the length-weight relationship is helpful in the determination of spawning season, onset of sexual maturity etc. The application of length-weight relationship in fishery biology solves various problems concerned with the life history of fishes. Besides providing a mathematical relationship between length and weight of fish as a means of introversion, such a relationship also yields information on the general well-being of the fish, variation in growth, size at first maturity, gonadal development and breeding season (Chatterji et al., 1977), and seasonal changes in their specific gravity (Tester, 1940).
The exact relationship between length and weight differs among species of fish according to their inherited body shape and within a species according to the condition (robustness) of individual fish.
Study of body measurements have been extensively used in the identification of the species of fishes. In recent years the significance of the statistical relationship has also been recognized in all taxonomic and systematic studies.
Condition factor is a quantitative parameter of the state of well-being of the fish that will determine present and future population success by its influence on growth, reproduction and survival (Hossain et al., 2006). The condition of a fish reflects recent physical and biological circumstances, and fluctuates by interaction among feeding conditions, parasitic infections and physiological factors (Le Cren, 1951). It is a numerical index by which weight and length in a particular sample are usually compared under standard conditions. Condition factors may be used to detect seasonal variations in the condition of fish, which may vary with food abundance and the average reproductive stage of the stock (King, 2007).
Condition factor decrease with increase in length (Bakare, 1970; Fagade 1979) and also influences the reproductive cycle in fish (Welcome, 1979). Condition factors of different species of cichlid fishes have been reported by Siddique (1977), Fagade (1983), Dadzie and Wangila (1980), Arawomo (1992) and Oni et al., (1983). Some condition factors reported for other fish species include; Alfred Ockiya (2000), Chana chana in fish water swamps of Niger Delta; Hart (1946), Mugil cephalus in Bonny estuary; Hart and Abowei (2007), ten fish species from the lower Nun River and Abowei and Davies (2009), Clarotes lateceps from the fresh water reaches of the lower Nun river.
Many workers have studied the length - weight relationship of fishes such as (Khan and Hussain (1941) on Labeo rohita, Narasimham (1970) on Trichiurus lepturus, Sinha (1973) on Clarias batrachus, Vinci and Kesavan (1974) on Nemipterus japonicus, Nautiyal (1985) on Tor tor, Kaliyamurthy et al.,, (1986) on Gerrus lacidus, Philip and Mathew (1996) on Priacanthus hamrur, Subba and Pandey (2000) on Botia lohachata, Mehata (2002) on Xenentodon cancila. Several studies on length-weight relationship have been carried out in other parts of the world on various fish species like Kowtal and Gupta (1985) on Cirrhinus mrigala, Naseem and Alikunhi (1971) on Cirrhinus reba, Talwar and Jhingran (1991). But there is little published information on the length-weight relationship of Amblypharyngodon mola in our country.
Length weight relationships, length-length relationships and condition factors are still scarce for most tropical and sub-tropical fish species (Martin-smith, 1996; Harrison, 2001; Ecoutin et al., 2005). Recently Hossain et al., (2006) studied the length-weight and length-length relationships of some small indigenous fish species from the Mathabhanga river, southwestern Bangladesh. Beside this, another study on condition factor, length-weight relationships and length-length relationships of Asian striped catfish (Mystus vittatus) has also recently been done by Hossain et al., (2006).
Objectives of the study
The objectives of the study were-
· To study the length-length relationship of A. mola from lentic water body over a study period of six months.
· To study the length-weight relationship of A. mola from lentic water body over a study period of six month.
· To establish a mathematical relationship between two variables i.e., length and weight so that if one is known, the other can be computed.
· To measure the variation from the expected weight for length of individual or group of fish.
· To study the condition factor to observe the growth of the specimen.
ABSTRACT
The present study was conducted to study the length-weight (L-W), length-length (L-L) relationships and condition factors, relative condition factor for Amblypharyngodon mola in the pond of Tanore thana under Rajshahi District. A total of 120 specimens used for this study caught by traditional fishing gear from November, 2010 to April, 2011. The sample studied were covered a reasonable size ranged from 49.26 mm to 76.50 mm in total length and weight ranged from 1.58 g to 5.07 g. A linear relationship was shown among Total length (TL), Standard length (SL), Fork length (FL), Head length (HL), Body depth (BD), Pre-dorsal length (PrDL), Post-dorsal length (PoDL), Pectoral length (PcL), Pelvic length (PvL), Anal length (AnL), Anus length (AL). Length weight relationship (TL-TW) showed curvilinear regression line. Most relationships were highly significant with ‘r’ values greater than 0.960. From the length-length relationship equations, it was observed that all length increases with increase of TL which was the expected linear relationship. The value of the exponent ‘n’ was less than 3 (2.9292) and the value of co-efficient of correlation ‘r’ was 0.955**. In the present study, the exponent ‘n’ indicated negative allometric growth for combined sexes of A. mola. The mean values of K0 and Kc were obtained as 1.15±0.112 and 1.27±0.15, respectively. The mean value of Kn were obtained as 0.91±0.05. The values of condition factor K0 (observed value), Kc (calculated value) and relative condition factor, Kn showed fluctuation.
CONTENTS
Acknowledgement
Abstract
Contents
List of Tables
List of Figures
Chapter One: Introduction
Chapter Two: Review of Literature
Chapter Three: Materials and Methods
Chapter Four: Results and Observations
Chapter Five: Discussion
Chapter Six: Summary and Conclusion
References
Appendices
LIST OF TABLES
Relation between total length and other body lengths of A. mola. The values of intercepts (a), regression co-efficient (b) and co-efficient of correlation (r) of A. mola.
Monthly describe statistics and estimated paramenters of different lengths for A. mola from November 2010 to April 2011
The values of constant a, n and r of length weight (TL-TW) relationship of A. mola.
LIST OF FIGURES
Map of Tanore Thana Under Rajshahi District
Schematic diagram showing the measurement of the different body lengths of A. mola.
Showing the weighting of A. mola
Showing the measurement of different body length of A. mola
Relationship between total length (TL) and standard length (SL) of A. mola.
Relationship between total length (TL) and fork length (FL) of A. mola.
Relationship between total length (TL) and head length (HL) of A. mola.
Relationship between total length (TL) and body depth (BD) of A. mola.
Relationship between total length (TL) and pre-dorsal length (PrDL) of A. mola.
Relationship between total length (TL) and post-dorsal length (PoDL) of A. mola.
Relationship between total length (TL) and pectoral length (PcL) of A. mola.
Relationship between total length (TL) and pelvic length (PvL) of A. mola.
Relationship between total length (TL) and anal length (AnL) of A. mola.
Relationship between total length (TL) and anus length (AL) of A. mola.
The relationship betwen total length (TL) and observed total weight (TW) of A. mola.
Relation between total length (TL) and observed condition factor (K0) of A. mola.
Relation between total length (TL) and calculated condition factor (Kc) of A. mola.
Relation between total length (TL) and relative condition factor (Kn) of A. mola.
Thesis, Study, Amblypharyngodon, Mola, Hamilton, Lentic, Water, Body, Agricultural, Land, Rivers, Estuaries, Beels, Haors, Lakes, Canals, Flood, Plains, Pond, Tanore, Thana, Rajshahi, District, Fishing, Gear, Animalia, Chordata, Pisces, Osleichthyes, Actinopterygii, Teleostei, Cypriniformes, Cyprinoidei, Cyprinidae, Molongi, Moya
Share on Facebook