International Journal of Aquatic Biology
Volume:4 Issue: 2, Apr 2016

A total of 162 species (S) of Rotifera belonging to 40 genera and 20 families examined from Loktak Lake, an important floodplain lake of northeast India (NEI) that is one of the richest assemblages of the taxon known from the Indian sub-region. It merits biodiversity value as ~40.0% and ~62.0% of species recorded from India and NEI, respectively. One species is new to India, 23 species are new to Manipur and 14 species are new to Loktak basin. Biogeographically interesting elements included three Australasian, five Oriental, ten palaeotropical and one cosmo-subtropical species. Lecanidae > Lepadellidae > Brachionidae > Trichocercidae collectively comprised 65.4% of S; Lecane > Lepadella > Trichocerca are diverse genera; and paucity of Brachionus spp. is distinct. Loktak Rotifera indicated importance of cosmopolitan, the littoral-periphytonic and small-sized species, and ‘tropical character’. ANOVA recorded significant variations of the rotifer richness amongst three sampling sites of Loktak during June 2010–May 2012 survey. The richness followed osscillaring monthly variations and indicated lack of significant influence of any individual abioitic parameter at all three stations.

Heavy metal accumulation in the aquatic ecosystems is a main concern which threats human health. In this study two commercial fish species, Rutilus kutum and Chelon aurata were selected for assessing heavy metal (Cd, Pb, Zn) concentrations in gill and liver tissues at Babolsar’s coast, the southern Caspian Sea, Iran. Babolsar is one of the important fishery stations in the southern Caspian Sea. The results showed that liver tissue of C. aurata significantly accumulated higher concentration of Cd, Pb and Zn compared to that of R. kutum, but these results were not significant for gill tissue. Liver tissue accumulated higher concentration of Cd and Pb compared to gill tissue in C. aurata, but these results were not significant for R. kutum. It is concluded that the liver tissue of C. aurata has higher potential to accumulate heavy metal pollution compared to liver tissue of R. kutum.

Long term monitoring programme on Brine shrimp (Artemia sp.) is being carried out by the Environment Agency, Abu Dhabi, United Arab Emirates (EAD) with the prime purpose of understanding the population dynamics, ecology and habitat requirements of Artemia at Al Wathba Lake, situated within Al Wathba Wetland Reserve, which is an artificial wetland near Abu Dhabi City. The present study, being a component of this programme, intends to understand the influence of chemical parameters such as dissolved oxygen, nitrate, nitrite, phosphate, ammonia and total organic carbon on Artemia biomass and cyst production at different sites of the Al Wathba Lake. The study was carried out by sampling lake water quarterly for a period of 5 years from 2010 to 2014. The Artemia population was found to have direct impact of the above mentioned parameters on its abundance. The abundance was highest during the year 2010. Further, temperature, dissolved oxygen, nitrate and cadmium were found to be the most crucial parameters for production of Artemia. The study further aimed to determine the significant relationship between physico-chemical parameters and Artemia sp. population dynamics and cyst production.

The present study investigates the possibility of enriching adult Artemia franciscana with singular or combined administration of Pediococcus acidilactici and fructooligosaccharide (FOS). The experiment was conducted in a completely randomized design with four treatments, including synbiotic, P. acidilactici ᓤ (T1), probiotic, P. acidilactici (T2), prebiotic, FOS (T3) and control (T4). To evaluate the enrichment of adult Artemia with each treatment, sampling was performed at 2, 4 and 6 hrs post enrichment. The bacterial counts was measured using the microbial culture and expressed as log CFU per g Artemia. A pre-experiment has been designed and probiotic was used in three levels (107, 108 and 109 CFU per litter of suspension) and prebiotic was used in three levels of 1, 2 and 5 g per litter of suspension. Based on pre experiment results, 108 CFU per litter of probiotic and 5 g per litter of prebiotic was selected. The results of this experiment showed that over time, consumed bacteria increased by adult Artemia and there was a significant difference between sampling in terms of ingested bacteria. The highest bacterial count (6.78±0.03 log CFU g-1) was observed 6 hrs after the start of enrichment. Based on microbial culture, the number of bacteria P. acidilactici in T1 and T2 was significantly higher than those in T4 (control) and T3 (prebiotic). There was no significance difference between T2 (probiotic) and T1 (synbiotic). In conclusion, the results of this study showed that adult Artemia in a short time (about 4 hrs) can retain a large amount of probiotic bacteria.

The systematics, morphology, distribution, biology, economic importance and conservation of the freshwater eel (Anguilla anguilla) of Iran are described, the species is illustrated, and a bibliography on this fish in Iran is provided. The species is found in the Caspian Sea basin as an exotic.

The distribution, body size, and egg diameter and volume of ovigerous blue swimming crabs, Portunus pelagicus, were examined according to habitat type and egg color in Lasongko Bay, Central Buton, Indonesia between April 2013 and March 2014. Ovigerous female crabs were sampled using gillnets and traps at seven stations. Based on the results, the ovigerous female crabs with yellow to dark gray eggs were found over a range of depths from 0.35 to 31.0 m, on sandy to muddy substrate, and in sea bottom covered by seagrass and in bare areas. The carapace widths of the ovigerous female crabs varied significantly between the types of habitat, egg color, and season. Wet weight, diameter, and volume of eggs increased by 36.35%, 25.16%, and 91.76%, respectively, with embryonic development, while the dry weight of eggs decreased by 1.86%. Ovigerous blue swimming crabs with different levels of embryonic development showed a wide habitat distribution from shallow to deeper waters.