The roach, Rutilus rutilus, is normally a dioecius species. During an experimental study of reproduction in this species, a condition of apparently functional intersex was discovered. Anatomically the gonad was a testis, exhibiting various normal stages of spermatogenesis. A group of oocytes was found during the microscopical examination of the gonad, interspersed between lobules of normal testicular tissue. A few small oocytes were found to be in the chromatin-nucleolus stage, while the rest were in the perinucleolus stage. In addition, some large oocytes with an average diameter of 40 pm were randomly distributed among the lobules of the testis.

Reproduction and feeding habits of Eutropiichthys vacha were studied in Kotri hydrodam, a man-made and human impacted stretch of the Indus River, Pakistan during [2005][2006]. A total 303 specimens were sampled and analyzed for maturity stages and gonadal development and food and feeding habits assessed from gut contents. Results showed male dominance over females: sex ratio 1.16:1.0. Minimum size at sexual maturity was 13.9 cm total length (TL). Mean fecundity ranged 1.38x10 4 to 2.17 x 10 5 . Gonado-somatic index (GSI) was 0.1-2.5 and 0.3-6.5 for males and females, respectively. Highest GSIs were recorded in April. We observe an ontogenic dietary shift in E. vacha: young are omnivorous with insects dominating diet while adults are omni-piscivores with Puntius ticto accounting for 35.4% of species. Other species were Colisa spp., juveniles of Channa spp. and some cyprinids. Feeding intensities were lowest in April at peak of spawning. The intensities increase rapidly after spawning indicating voracious feeding in E. vacha. Feeding intensities in adults are low during the cold season. These results provide for assessment of spatial-temporal variations in feeding intensity in E. vacha while GaSI and diet composition reveal information on environmental shifts and ecosystem fluctuations in the impacted habitats of the River Indus for sound fisheries management.

A new combined stain is described for the study of cell types in the fish pituitary. Tissues are prepared by fixing in formol-sublimate and then embedded in paraffin wax. Tissue is sectioned at 5 micron and than stained sequentially with performic acid-alcian blue, periodic acid-Schiff, orange G, and acid fuchsin. As a result of this procedure acidophils stain as follows: lactotropes, red; corticotropes, light pink; melanotropes, bright pink; and somatotropes, orange. Cyanophils stain either magenta red (gonadotropes) or blue (thyrotropes). Neurosecretory material and the fibers of the pars nervosa which penetrate the pars intermedia stain light blue.

Abstract:The Tidal Link is constructed to dispose off the drainage water from Nawabshah, Sanghar, Mirpurkhas and Badin districts to Shah Samando Creek. It is connected with brackish water lakes belonging to Run of Kuch and Shah Samando Creek of Arbian Sea in District Badin. These lakes were examined in terms of biological life and water quality. The Sonahro and Mehro are saline lakes rich in primary productivity with 114 species of algae, 17 species of aquatic plants and five species of fresh water fish. Among the fishes Cirrhinus mirgala, Channa marulia, Notopterus notopterus, Oreochromis mossambicu's, Rita rita, Wallagoattu were identified and all are commercially important. Water quality revealed , value of pH as 7.7-8.0, conductivity, 2.74-9.97 mS/cm and salinity 1.5-5.9 ppt with a number of nutrients. Pateji and Cholari are brackish water lakes. Majority of algal flora belong to Bacillarophyta, Cyanophyta and Enteromorpha species of Chlorophyta. Beside, 28 species of fish and 8 species of shrimps were identified.

The pineal organ in the roach, Rutilus rutilus (L.), is covered by a semi-transparent area, the pineal window. Beneath this the pineal is attached to a long robust stalk, lyingjust under the parietal bone. The pineal is attached to the brain through the dorsal sac. Three cell types have been identified histologically. These are the sensory cells, supporting cells and the ganglia cells. The inner segment of the sensory cells respond to PAS and A F staining, while the remaining cells respond to Orange G, LG, or Acid Fuchsin. The evidence suggests that the roach pineal may have a dual photosensory and glandular function.