عصر حاضر میں قرض بیچنے کی اقسام اور اس کی شرعی حیثیت

In this article, the definition of current loans and its kinds, debt issued by the banks and financial institutions in the light of Qurʾān and Sunnah, Ijmāʿ-e-Ummah and Islamic jurists and legal scholars has been extensively studied and analyzed to reach their Islamic legal status. This will help understand transactions of these financial matters. 

Study of Biology and Population Dynamics of Exotic Fishes Oreochromis Mossambicus and O. Niloticus from Keenjhar Lake Sindh Pakistan.

Keenjhar Lake is one of the largest freshwater lakes in Pakistan. It was declared Wildlife Sanctuary in 1977 under Sindh Wildlife Protection Ordinance, 1972. It is a Ramsar site and also known as Kalri Lake. In Pakistan two exotic species Oreochromis mossambicus and O. niloticus show wide range of expansion and prolific colonization in most freshwater and saline inland waters of Pakistan. The specimens and data were collected from the landing site Khambo at Keenjhar Lake twice in a month for three years (January 2014- December 2016). A total of 43200 specimens were examined during three year period. The total length (TL) and weighed (TW) were measured. For the study of Length-weight relationship (LWR) the collected length-weight data was transformed logarithmically.The Length-weight relationship (LWR) and condition factor of fish was determined. For the biological study 2880 mature specimens of O. mosambicus and O. niloticus were examined for the determination oflength, weight, sex, maturity stage, fecundity, GSI and DSIaccording to prescribed methods.Only ovaries of maturity stage (IV,V and VI) were preserved in Gilson’s fluid. The eggs were counted and weighed. For the calculation of gonadosomaticindex (GSI) and digestosomatic index(DSI), the fishes were dissected and the weight of gonads and the weight of digestive tract was noted in grams. Asymptotic length (L ), growth constant, (K),growth performance index(GI), total mortality(Z), natural mortality(M), Fishing motality (F), exploitation rate( E) andmaximum exploitation rate (E max) were calculated. For the determination of fishery status, the data from landing site Khambo was collected monthly.Species diversity and their catch in kilograms were recorded from each boat. The natural mortality, total mortality and fishing mortalities were determined. Regression analysis and Oneway ANOVA was performed to test the length-weight relationship. The TL and weight in both sexes ranged between 11-28 cm and 17 to 430 gin O. mossambicus and from 11- 29.5 cm and 27 – 430 g in O. niloticus. The value of regression coefficient b ofO. mossambicus and O. niloticus was 2.7 and 2.975 respectively. The comparison of length-weight data indicated that the range of length remains same between the studied years in contrast to weight which showsincreasing trend. The GSI values of both sexes of both species were low in contrast to DSI values which was high in both species. The data indicates that O. mossambicus and O. niloticus spawn throughout the year. O. niloticus show two recruitments per year. Sex ratio is almost similar (1:1) in both species which do not appears to affect the fish population. The peak spawning months in male and female were different which might cause negative influence on the fish population. Overall the data collected during 2014 and 2016 shows similarity in results whereas the data collected during 2015 shows variation in all results. The Low weight and length or stunted growth is mainly because it breeds throughout the year which utilized great amount of energy for the development of gonadal products which in turn lowers the rate of feed conversion towards its growth. Another reason for the low weight of females is that they are maternal mouth brooder and during incubation of the eggs they can’t eat for several days. The diversity of fish catches from landing site Khambo at Keenjhar Lake comprised of both indigenous and introduced species representing a total of 21 fish species namelyMystus oar, Botia birdi, Wallago attu, Channa marulius, Mastacembalus armatus, Cirhinna spp, Chitala chitala, Cirhinna mirigala, Labeo rohita, Notopterus spp, Ciprinus carpio, Xenenthodon, Heteropneusteus spp, Catla catla, Mystus tengra, Mystus carasius, Heteropneusteus fossilus, Rita rita, Mastacembalus punctatus, Oreochromis mossambicu, and Oreochromis niloticus. During this study a total of 454680 fishes were landed with a total weight of 298231Kg. In the present study the asymptotic length (L ) ofO. mossambicus was 28.43 cm and growth rate (K) was 0.42 yr 1whereas, the asymptotic length (L ) of O. niloticus was 29.23 cm and growth rate (K) was 0.57 yr1. The growth performance index in O. mossambicus ranged from 2.259 - 2.587 and in O. niloticus ranged from 2.398 - 2.67 in studied years. The natural mortality, fishing mortality washigher in in both species and shows increasing trend with a passage of time. The overall exploitation rate (E) was 0.7 in both species which is higher that E max. Smaller sized individuals of O. mossambicus and O. niloticus were rare in total catch. The absence of small size fishes in catch indicates the use of larger mesh size nets for fishing which facilitate the escape of small size fishes. The presence of higher number of carnivorous fishes in total catch indicates that fingerlings of both cichlids fishes might serve as a food for these abundant carnivorous and predatory fishes. In this lake heavy fishing is reflected by the minimum number of large size specimens of both cichlid species. Factors such as availability of food, stress, pollution, seasons and environmental conditions might be a possible cause to affect the condition of fishes. In Keenjhar Lake the main sources of pollution are municipal and industrial effluents during flood seasons. The increase in catch as indicated through catch statistics and higher fishing mortality, appears to exert pressure in population of tilapia and other fishes in the lake. Control and management of fishing activities is strongly recommended.