International Journal of Aquatic Biology
Volume:4 Issue: 3, Jun 2016

The systematics, morphology, distribution, biology, economic importance and conservation of the perches of Iran are described, the species are illustrated, and a bibliography on these fishes in Iran is provided. There are three species, Perca fluviatilis, Sander lucioperca and S. marinus, found naturally in the Caspian Sea basin, with S. lucioperca translocated.

Heavy metal pollution plays an important role in global biodiversity decline. However, there is paucity of information concerning the effects of metals on amphibians. In the present study, investigations were made on the accumulation of heavy metals, copper (Cu) and lead (Pb) in water, sediment and tadpoles inhabiting the water bodies of Barak Valley, Assam. Tadpoles of six different anuran species, Hoplobatrachus tigerinus, Leptobrachium smithi, Clinotarsus alticola, Fejarvarya sp., Sylvirana leptoglossa and Euphlyctis cyanophlyctis were selected for this purpose. Heavy metal concentrations were determined in intestine, liver and tail of tadpole samples of these species. The results revealed that the copper concentration in water samples was within the maximum permissible limit of WHO (2 mg L-1), but the concentration of lead in water samples increased beyond the permissible limit of WHO (0.01 mg L-1) resulting in possibilities of higher accumulation of the metal in tadpoles and decline of amphibians’ population. Total concentration of Cu in the tadpoles of different species of amphibians followed the order: H. tigerinus > S. leptoglossa > E. cyanophlyctis > C. alticola > Fejarvarya sp. > L. smithi, while concentration of lead followed the order: E. cyanophlyctis > C. alticola > S. leptoglossa > Fejarvarya sp.> H. tigerinus > L. smithi.

A total of 90 species, belonging to 29 genera and 15 families, observed from an urban wetland of Meghalaya is the species-rich Rotifera assemblage known till date from any sub-tropical ecosystem of the Indian sub-region. Total richness (S) merits biodiversity value as ~56.0, ~ 38.0 and ~23.0 % of the species recorded from Meghalaya, northeast India (NEI) and India, respectively while several rotifers of global and regional importance impart biogeographic interest. One species is new to NEI and 19 species (including two unidentified) are new to Meghalaya; this study resulted in an earlier report of five and two new records from India and NEI, respectively. The diverse Lecanidae > Lepadellidae together comprising ~ 57.0 % of S; largely littoral periphytonic nature of taxa; and distinct paucity of the Brachionidae and lack of Brachionus are notable features. The speciose Lecane, high richness of cosmopolitans and occurrence of several tropicopolitan and pantropical species impart broadly ‘tropical’ character to the fauna. With low monthly richness and low community similarities, our results affirm heterogeneity of rotifer species composition; the richness is positively influenced only by water temperature.

Aquatic plants have a major influence upon other aquatic organisms, by altering both water chemistry and spatial structure of the habitat in shallow water bodies. Some of them, such as Stratiotes aloides L., may suppress algal growth. But how aquatic plants would ultimately influence the heterotrophic community and the aquatic ecosystem as a whole is far from clear. Our microcosm-based study demonstrated that even a modest density of S. aloides caused a decline in phytoplankton chlorophyll concentration and periphytic algae abundance, including cyanobacteria, whereas diatoms appeared to be immune to the plant influence. Photosynthetic rate remained unaltered despite decreased chlorophyll concentration. While bacterial counts remained largely unchanged, more bacteria were observed forming microcolonies as well as associating with particulate organic matter. Numbers of periphytic heterotrophic organisms did not differ significantly between the planted and plant-free control microcosms. Zooplankton diversity increased and cladocerans assumed a more prominent position within the microcosms with macrophytes. We assume that the presence of plant’s leads to increased importance of bacteria and protists in the functioning of the food webs. Therefore, decreasing of algal abundance does not involve reducing the number of heterotrophic planktonic and periphytic organisms.

The present study reports range extansion of Moenkhausia oligolepis to the Pindaré river drainage, of the Mearim river basin, and Itapecuru river basin, Maranhão state, northeastern Brazil. This species was previously known only from Venezuela, Guianas, and the Amazon River basins. In addition, we present some meristic and morphometric data of the specimens herein examined and discuss on its diagnostic characters.

The pollutants due to effect on the immune system of fish increase fish sensitivity to pathogens. Diazinon is one of the most used organophosphates pesticide in many agricultural areas. This study aimed to evaluate the effect of diazinon on the immune system of rainbow trout (Oncorhynchus mykiss) and application of Milk thistle plant, Vitis vinifera extract to reduce the adverse effects of this pesticide on its immune system. The reduction in the level of plasma peroxides, IgM, total complement and lysozyme were observed in fish exposed to diazinon showing its effect on the fish’s immune system. No significant difference between control group and fish fed by Milk thistle plant extract and exposed to diazinon can reflect protective impact of Milk thistle plant extract on the immune system of rainbow trout by eliminating the free radicals and boosting the immune system.

Osteological features are important to study the taxonomy and phylogenetic relationship of fishes. Since there is no information is available about osteological features of Squalius orientalis, therefore this study was aimed to provide a detailed description of the osteological features of this species from the Urmia lake basin of Iran and comparing it with population of S. orientalis from the Caspian Sea basin. For this purpose, the specimens were collected from Zarineh River of the Urmia lake basin and cleared and stained with alizarin red S and alcian blue for osteological examinations. Finally, a detailed osteological features of this species was provided and compared with those of the Caspian Sea basin. Based on the results, having a longer pre-vomer, dorsally oriented parasphenoid alar, longer ventral blade-shaped process of the orbitosphenoid, concaved masticatory plate, pointed ascending process of the palatine, concaved posterior margin of the opercle, and a small posterior process of the cleithrum can differentiate S. orientalis of the Urmia Lake basin from those of the Caspian Sea basin. In addition, the observed osteological difference suggest that both studied populations belong to same taxon.