International Journal of Aquatic Biology
Volume:6 Issue: 5, Oct 2018

Wetlands are of the unique and productive ecosystems in the world. The present study was conducted to determine primary production statues of the international Gavkhooni Wetland, based on chlorophyll-a. Sampling was performed seasonally from March 2017 to February 2018. Four sampling stations were assigned based on latitude and longitude. Water salinity, temperature, pH, nitrate, phosphate, BOD5, TDS, EC, TSS and dissolved oxygen were determined in triplicate in each station. Trophy level was determined using index TSI. The results showed that there was no significant difference in mean chlorophyll-a content between the seasons. The highest and lowest chlorophyll-a contents were observed in spring and winter, respectively; and the significantly highest content was measured in the station A (Shakh Kenar). There was no significant difference in the water physicochemical parameters between the seasons (P>0.05). The mean water nitrate level of the sampling stations was 4.255 mg/l; the highest (5.07 mg/l) and lowest (3.35 mg/l) levels were recorded in the summer and autumn, respectively. The mean water phosphate level of the sampling stations was 1.082 mg/l; the highest (1.75 mg/l) and lowest (0.57 mg/l) levels were recorded to the winter and summer, respectively. The mean dissolved oxygen level during the study was 5.64 mg/l. According to the results, nitrate is the limiting factor for production in the Gavkhooni Wetland. Based on index TSI, the wetland is oligotrophic in the spring, autumn and winter, but mesotrophic in the summer.

Fish exposure to agrochemicals can suppress their immune system and survival. Therefore, this study investigates adverse effects of sublethal concentrations of Dimethoate alone or combined with Bacilar (an organophosphorus pesticide and bio-fertilizer) on the innate immune parameters of common carp, Cyprinus carpio, within 14 days. No significant changes were found in levels of total protein, immunoglobulin, the activity of lysozyme and complement C3 in fish exposed to Bacilar alone; however, globulin and complement C4 level indicated a significant reduction. Fish exposure to Dimethoate alone or combined with Bacilar resulted in a decrease in the activity of ACH50, lysozyme, complement C3, C4 and levels of total protein, globulin, and immunoglobulin in compared with the control group. In conclusion, the results of this study showed that innate immune parameters decreased in fish exposed to dimethoate and/or Bacilar. As consequences: Dimethoate or/and Bacilar have the immunosuppressive effect on fish.

Zooplankton is a biological compartment widely used in the bio-monitoring of aquatic ecosystems. It allows early detection of environmental disturbances even before reaching the upper compartments of interest to humans. The present study evaluated the ability of two rotifer species Brachionus falcatus and Platyias patulus to indicate organic pollution in the Ouémé River basin. Sampling was done between October 2014 and September 2015. Plankton net of 20 μm mesh size was used. Parameters such as NH4+, NO2- and PO43- were measured in water and used for the calculation of the Organic Pollution Index (IPO). The results showed that the occurrence of B. falcatus and P. patulus was 96.66% and 81.11%, respectively. Both species were particularly abundant in sites such as Kaboua and Vossa as well as downstream of the basin (Agonlin-lowé and Bonou). These strong abundances are linked to a very strong organic pollution in Kaboua and Vossa then to a high organic pollution at downstream. The least organically polluted station (Kpassa) had the lowest abundance of both species. B. falcatus and P. patulus are therefore two indicator species of organic pollution in the Ouémé River’s basin in Benin.

Al Wathba Wetland Reserve (AWWR) lake, in the United Arab Emirates (UAE), is an artificially created water body in a natural wetland region that experienced seasonal flooding before the establishment of the lake. The lake is mostly fed by treated waste water, and became a protected wetland reserve after the Greater Flamingo started to successfully breed in the area in 1998. Detailed monitoring of several hydrochemical parameters and water depth at nine stations and two inlets of treated water in the lake was conducted over a period of seven years starting in January 2010. As a result, the seed-shrimps (Ostracoda: Podocopida) Heterocypris salina, previously reported from a late Miocene location in the UAE, and Cyprinotus cingalensis were recorded for the modern fauna of the UAE for the first time. The presence of the ostracods only at the station with the lowest salinity in the AWWR Lake shows that their distribution is predominantly controlled by the salinity of the water which covered an extremely large range of more than two orders of magnitude (1.45-457%) at the different sampling sites and inlets during the monitoring period. Thus, the lake represents an interesting and important ecological research laboratory under semi-natural conditions.

Fish populations are affected by dams in terms of morphology, reproduction, migration, growth rate and etc. To examine the hypothesis; how dams can affect the length-weight and length-length relationships in cyprinids, four Capoeta razii segregated populations (by dams) were studied. The length-weight (LWR) and length-length (LLRs) relationships were calculated for three populations from upstream, dam lakes and downstream of Manjil and Tarik dams in Sefid River, in the southern Caspian Sea basin. Also, one independent population from the damming impacts was considered as the control, to examine other possible annual effects on LWR. The b values in the LWR ranged from 2.893 to 3.586 in downstream and dam lakes populations, respectively. The r2 value ranged from 0.966 to 0.988. The averages of recorded length and weight in dam lake population were up to two and six times (respectively) more than the ranges in up and downstream populations. Monthly LWR is presented for the control population. The sex and maturity were found as effective factors on LWR in the control population. No significant differences were observed in LWR by seasons. All LLRs were highly significant (r2> 0.95). This study presents that the dams and the sex and maturity can be considered as effective non-biological and biological factors (respectively) affecting growth patterns as expressed by length and weight relationships in cyprinid (C. razii) populations. The results may be helpful in future fisheries studies and conservation programs.

Fishes have a good sense of smell and are able to ascertain odour with the help of a pair of olfactory organs connected to the olfactory lobes of the forebrain by means of olfactory tracts. The functional anatomy and structural characterization of olfactory organ in the freshwater Indian Catfish Clupisoma garua (Hamilton, 1822) was investigated by light microscopy. The paired well-developed olfactory organs were located in nasal cavity having two exterior apertures: incurrent and excurrent nares. The olfactory rosettes were elongated structure, possessed 40±02 lamellae on each side of the narrow median raphe. Histologically, each lamella consisted of two principal layers: an epithelium consisted of sensory and non-sensory cells and a central core, which was composed of connective tissues, nerve fibers and blood vessels. The sensory epithelium was composed of three types of receptor cells: two described as classical bearing cilia or microvilli and third bearing rod like dendritic terminal. Synapses between primary and secondary neurons were formed. The indifferent epithelium comprised the greater surface area of the olfactory lamella, was typified with ciliated non-sensory cells, secretory mucous cells, mast cells and supporting cells. Undifferentiated basal cells were scattered in the deeper part of the epithelium above the basement membrane. Organization of various cells on the olfactory epithelium was correlated with essential life process of the fish concerned.

This study aimed to investigate the concentration of some heavy metals in three fish species with high consumption in Shif Island, Bushehr Province, and calculation of the estimated daily intake (EDI), estimated weekly intake (EWI), Target Hazard Quotients (THQ) and hazarded index (HI). Three species viz. Euryglossaorientalis, Argyrops spinifer, and Sillago sihama were collected from the Bushehr coastal water using fishing boat. After the transfer of samples to the laboratory, the heavy metals were extracted and analyzed using Atomic Absorption Spectrophotometer (AAS). Based on the results, the average concentrations of Fe, Zn, Cu, Mn and Ni in E. orientalis were 10.02, 8.33, 1.18, 0.80, and 0.86 mg/kg, in A. spinifer 7.25, 5.75, 0.74, 0.43, and 0.37 mg/kg, and in S. sihama 6.20 , 8.27, 0.60, 0.47, and 1.28 mg/kg, respectively. Daily and weekly intake values in all three studied species in the group of children were higher than the adult group. The highest and lowest daily and weekly intake rates were observed for Fe in the E. orientalis and Cu in A. spinifer. The Target hazard quotient (THQ) and Hazard index (HI) for both adults and children showed less than 1. Also, the comparison of metal concentrations showed that the concentration of Mn in all three species and Ni in E. orientalis and S. sihama were higher than the WHO standard.

The present study reports length-weight relationship (LWR) of four fish species viz. Pennahia macrophtalmus, Epinephelus bleekeri, Acropoma joponicum and Trichiurus lepturus from the Oman Sea, Iran. A total of 880 specimens were collected from December 2016 to August 2017 by trawling. The LWR parameter b for the studied species was 2.68 to 3.07.