Successive developmental stages of both male and female gonad and estimation of gonado-somatic index (GSI) and fecundity of Puntius sarana were investigated. From the histological analysis, four developmental stages were distinguished in male gonad, such as, spermatogonia, spermatocytes, spermatids and spermatozoa. Six developmental stages of oocytes were identified in female gonad, such as, oogonia, previtellogenic oocytes (early and late perinucleolus stage), cortical alveoli, yolk granules and mature oocytes. Maximum mean gonad weight was recorded about 8.48±0.17 g in female and 4.02±0.11 g in male in May. The ovary, which contained oogonia, early, and perinucleolus stage and cortical alveoli were termed as 'immature', which were found in the month of April. Matured oocytes occupied the most areas of the ovaries, which were termed as ripe ovaries observed from May to mid September. The testes at early development stages up to September contained mostly spermatogonia, spermatocytes and spermatids, although a small amount of spermatozoa was also present. The mature testes began to develop from March to May. The testes were found to be lobular type containing lobule boundary.

(Page No: 1-9)

M. A. RAHMAN, M. M. HAQUE

The present study deals with the histological changes during different developmental stages of gonads, and fecundity of chapila, Gudusia chapra (Hamilton-Buchanan) in Rajdhala reservoir in Netrakona district of Bangladesh. The gonadosomatic index (GSI) and the histology of gonads revealed that chapila spawns during February to August in the reservoir but the peak period was during March, with a second peak in July. The fecundity of G. chapra was found to range from 32,798 - 1,80,329 with a mean of 1,13,465 ± 19,876 during the period of study. The regression equation between total length (X) and fecundity (Y) of the fish was estimated as Y = -197150 + 25906X, r = 0.698, and between body weight (X) and fecundity (Y) as Y = 34181 + 4281.239X, r = 0.653.

(Page No:10-15)

H. R. SINGH AND RAJSHREE SRIVASTAVA.

Age and growth of a minor carp Puntius sophore (Ham.) from the Ganga river system have been studied using its scales. The cycloid scales reveal the presence of a distinct larval mark under the SEM. The breaking and widening of circulii in the scales were considered as 'growth rings' or 'annulii'. A linear relationship between total fish length and lateral scale radius was observed. The larval mark, located very near the focus, appears during the first year of life. The life span of this fish was observed to be 4 years. The fish should be harvested only after the completion of second year of life when it has attained 62 mm total length.

(Page No:16-22 )

B. K. BISWAS AND V. V. SUGUNAN

Fishes from selected sites of the Brahmaputra river system in Assam were collected and identified during 1987 to 2000. A total of 151 species under 93 genera, 35 families and 10 orders were recorded. Important records were: Colisa labiosus (Day), Gagata sexualis Tilak, Hemibagrus microphthalmus (Day), Lepidocephalichthys annandalei Chaudhuri, Nangra assamensis Sen and Biswas, Nemacheilus pavonaceus (McClelland), Pangio pangia (Hamilton), Pillaia khajuriai Talwar, Yazdani and Kundu, Puntius fraseri (Hora and Misra) and Rama rama (Hamilton). Out of the 151 species recorded, 73 were considered as food fish as well as ornamentals, 26 with only food value, 21 as commercially important food fish as well as ornamentals, 10 as only commercially important food fish, 8 with only ornamental value, 7 commercially important exotic food fish, 3 commercially important food fish as well as sport fish, 1 food fish with sport value, 1 commercially important food fish with ornamental and sport values and one did not fall in any of this category. Conservation status of the species was assessed.

(Page No:23-31 )

A. K. ROY AND S. R. MARTHA

A total of 13 gene sequences of Cyprinus carpio available in the Genbank are made to undergo a detailed Correspondence Analysis (CoA). After the Relative Synonymous Codon Usage (RSCU) values are extracted using Codon Usage software, CoA using the statistical package SPSS (14.0) is carried out which reveals that all genes except two located far away from the origin in the plot generated, follow a common trend. These genes prefer TGT, AAG, CGT and gene 13 is associated with codons GGC, TTA, TAG while all other genes viz. 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 and 12 prefer GCG, CGG, TGC, TAC, ATA, TCG, GGA, GTC, CAG, CTC, CTG, CTT, ATC, CAC, TGA, ATG, AAT, ACC, GAA, TTC, AAC, GCA, GAC, ACT, GTA etc over other codons for synthesizing their respective proteins and hence they are associated with codons that are GC ending.

(Page No:32-38 )

Padmanabha Chakrabarti and Srimoyee Hazra Chowdhury

The histological architecture and functions of the different cells lining the olfactory epithelium in Cyprinus carpio (Linnaeus) have been studied. The olfactory organ consists of 25-26 lamellae arranged in rostrocaudal orientation. The olfactory epithelium encloses a central lumen called central core. The sensory epithelium is composed of olfactory receptor cells, secondary receptor cells, supporting cells, basal cells, mast cells, secretory and non-secretory mucous cells. The non-sensory epithelium is made up of ciliated supporting cells, stratified epithelial cells, basal cells and mucous cells. Different cells on the olfactory epithelium have been correlated with the functional significance of the fish concerned.

(Page No: 39-43)

T. S. ANNAPPASWAMY, H. R. V. REDDY AND T. S. NAGESH

Reproductive biology dealing with spawning, size at first maturity, sex ratio and fecundity of Sillago sihama from estuaries of Dakshina Kannada along southwest coast of India has been studied during April 1998 to March 1999. The fish spawns from August to March with peak during September-October and February. Males attain sexual maturity at 212 mm (TL) while females at 226 mm (TL). Studies on sex ratio revealed that females attain larger size than males. The fecundity ranged from 57,685 to 13, 47,340 with an average of 5,24,714 eggs. Linear relationships were found between fecundity and fish length, body weight and gonad weight.

(Page No:44-49 )

SUBHASIS PAL

Seasonal changes in water quality parameters including pesticide residues of a fish pond due to intentional misuse of endosulfan have been studied to assess the suitability of the pond for pisciculture. The mortality of aquatic organisms due to toxicity of endosulfan was recorded which in turn results into the increase of organic matter. Comparatively high level of nitrate and phosphate concentrations observed were due to the decomposition of these organic matters. High value of free carbondioxide (CO₂) in winter coincided with the persistence of endosulfan indicating aquatic pollution. Except total solids, parameters like temperature, dissolved oxygen (DO), biological oxygen demand (BOD) and pH were within desirable limits for fish culture for most part of the study period.

(Page No:50-53 )

D. JANA AND M. DASGUPTA

The length-weight relationship of the mud eel Monopterus cuchia from West Bengal was calculated using the methods of least squares, which can be expressed by the equation, Log W = 0.494 + 3.05 Log L, for sexes combined. A high degree of positive correlation (r = 0.9842) was noted between length and weight of M. cuchia. The exponential value of the length-weight relationship (b) in this fish followed the cube law (3.05), indicating an isometric pattern of growth. The 'b' value of length-weight relationship varied due to sex, size and season. Kn values at different length groups ranged from 0.798 to 1.179, with an average value of 1.046 and the Kn values varied from 0.8 to 1.99 during different months, with an average value of 1.35 which indicated that the general well-being of this fish was good in this region.

(Page No:54-58)

S. GIRI, P. PRADHAN AND S. K. CHAKRABORTY

Kansai and Dwarkeswar are two freshwater rivers in West Bengal, joining the Haldi and Rupnarayan rivers respectively. The present study was carried out to assess the physical and chemical characteristics, microbial load, diversity and distribution of macrophytes, phytoplankton, zooplankton and macrobenthos in the two rivers during July 2001 to June, 2003. A total of 84 macrophytes, 29 phytoplankton, 65 zooplankton, 50 macrobenthos (13 molluscs, 6 oligochaetes, 20 insects and 11 decapods) were recorded. The results of Sorensen Similarity Indices revealed differences in distribution of different biota due to different ecological conditions of the rivers. The present study also indicated that the water of these rivers might be good for outdoor bathing, industrial and agricultural use, wild life and fisheries but not safe as drinking water without treatment.

(Page No:59-64)

D. K. KAUSHAL

Investigation conducted on the macrobenthic fauna of Pong reservoir during 1991-92 to 1994-95 depicted a bimodal pattern of distribution with major peak during winter. Dipterans dominated the benthos in the reservoir constituting 48.2% (1994-95) to 78.5 % (1991-92). Molluscan fauna were abundant in intermediate sector compared to lentic and lotic sectors. Nutrient status of soil, morphometric and hydrographic features of the reservoir influence the distribution of benthic macrofauna. The reservoir level had an inverse relation with the density of benthos. It is suggested not to stock fishes like Cyprinus carpio and Puntius sp. in the reservoir as they may not get adequate food in the ecosystem. .

(Page No:65-68)

INDIRA BARUAH (BORA) AND BIBHA CHETIA BORAH

Gonadal development and fecundity of commercially important fish species Monopterus cuchia (Ham-Buch) was studied using live samples from natural resources. The gonado-somatic ratio (GSR) and maturity index indicate that the maturity cycle of the fish extends from February to August, while the breeding season is restricted from May to August, with peak during July. Presence of only one batch of maturing ova indicates that the species breeds only once in a year. The relative fecundity value ranges from 0.5 to 1.54 indicating very low fecundity. Low GSR value ranging from 0.30 to 18.08 in female also supports low fecundity of the species.

(Page No:69-74)

K.Karl Marx

(Page No:75-77)

K.D. Joshi and B.C. Tyagi

(Page No:78-81)

Nirmal Singh, and P.K.Gupta

(Page No:82-85)

Roopam Gandotra, Ravi Shanker, Shiraj Ahmed and Shakti Sagar

(Page No:86-87)