• percentage of females;
• gonadal length index (gonad length:body:length);
• gonadosomatic index (gonad length:body:length);
• diameter of ova;
• maximum egg bearing capacity;
• colouration of the gonads.
Artificial Breeding and Aquaculture:
Various attempts have been made to induce breeding in SIS, and to develop culture systems for them. Rajts et al (1996)
attempted continuous culture and controlled breeding in Mola (Amblypharyngodon mola) and several other small species.
They obtained a production of 386 kg/ha in 3 months, and mass breeding was successfully carried out between August and
November.
Mustapha (1997) achieved similar success in the same species (mola -A. mola). He measured various parameters including
intra-ovarian eggs, gonado-somatic index, relative condition factor and grading of spawn. He confirmed breeding three times
a year in April, July and October. In monoculture, he obtained an average yield of 2,472.48 kg/ha/yr, at different stocking
densities in "mini ponds".
In field trials in three districts in northwest and southwest Bangladesh, Akhtaruzzaman et al (1997) experimented with the
culture of Mola, Bata (Labeo bata), Bhanga (Cirrhinus reba), and Dhela (Rohtee cotio). Obtaining 1,327.80 kg/ha in 5
months, he concluded that small and shallow water bodies are suitable for such species using low cost inputs.
Kohinoor et al (1997) carried out trials with Mola (Amblypharyngodon. mola), Chapila (Gudusia chapra), and Punti (Puntius
sophore) in Mymensingh. Production rates of Chapila at 92.13 kg/ha were significantly higher than that of Mala at 57.88
kg/ha.
However, when grown in polyculture with carp, carps do less well than on their own.
Kabir (1997) experimenting with the polyculture of SIS (Mala, Punti and Chingri) and exotic carps (silver carp, grass carp and
mirror carp) in Mymensingh, achieved a per decimal growth rate over 5 months of 2.55 kg for the SIS and 5.96 kg for the
carps.
In a carp hatchery in Jessore, Hamilton and Tripathi et al (1997) successfully bred and produced large fingerlings of the
Bhagna or Raik (Cirrhinus reba).
In northwest Bangladesh (Bhuiyan, 1997) a few attempts have been made to cultivate Magur (Clarias batrachus), Pabda
(Ompak pabda) and Tilapia on a small scale. However, lack of availability of fish eggs, comparatively low price of fish in the
market, poaching and lack of appropriate research are cited as major constraints to expanding such cultivation in the region.
Harvest and Marketing:
Floodplain fishing for SIS is characterised by a wide variety of gears. Ahmed (1956) described 116 nets, 26 traps, hooks and
other devices. A study by Dutta (1983) in Rajshahi district listed 10 types of net, and 8 traps (types of dohar, anta, kholson,
jangla etc.). Nets include cast nets, drag nets, and mosquito nets, and fish are also caught using bare hands!
Dutta (1983) also found a number of different kinds of boats used to carry fishermen, nets and their catch. These include the
country boats called Kari-dingi, Kanai-dingi, Jailadingi etc.; crafts made of tree trunks (donga); and rafts made from various
fibrous plants, including parts of banana trees.
Fishing gears show a great deal of geographical specificity, and fishing methods vary with the hydrobiological and
physiographical conditions. Also in different regions the same device may be used, but of a different size and with a different
name, Fishing is also carried out with hook and line, and by draining water (Dutta 1983, FAP 6 1993).
There is a great deal of seasonal and regional variation in the quantity and type of fish available in local markets. Rural
markets are dominated by small fish such as puti, royna, and koi. The beel harvest peaks between January and April, whilst
14