International Journal of Aquatic Biology
Volume:4 Issue: 4, Aug 2016

Size at sexual maturity and patterns of somatic growth are important aspects of reproductive history of crab. The main purpose of this study is to provide an estimate for the onset of morphological sexual maturity in mangrove crab, Opusia indica from a population located in Korangi creek intertidal mud flat (Karachi, Pakistan) based on relative growth. The crabs were monthly collected through quadrat method from March 2001 to February 2002. A total of 1702 crabs was obtained, of which 764 were males, 939 were female. The morphometric measurement of carapace, abdomen, cheliped and male gonopod was related to carapace width. Based on carapace width males were significantly larger than female, indicating sexual dimorphism. The size at onset of sexual maturity in males was estimated as 5.51 mm carapace width and 5.3 mm carapace width in females. The positive allometric growth of female abdominal width were likely related to the incubation process.

Activity of fresh neem leaf juice to immobilize, anaesthetize and fatal effect were studied against two live fish species, Anabas testudineus and Channa punctatus. The concentrations, 5, 10, 15 and 20% of neem leaf juice affected both the species, but A. testudineus was found to be comparatively more susceptible to the treatment than C. punctatus. The time required to immobilize were 4 to > 6 hours for A. testudineus and 7 to 9 hours for C. punctatus; to anaesthetize were 6 to > 12 hours and 8 to 10.15 hours for A. testudineus and C. punctatus respectively; and death occurred 7 to > 13 hours in A. testudineus and 9 to 10.45 hours in C. punctatus after treatment depending on the concentrations. The toxic effects were positively co-related with the concentrations and negatively co-related with the total weight of the fish, though the values of the coefficient of the correlations (r) were low. At the anaesthetic stage, the colour of skin, gills and eye were changed, the fishes showed irritated movement first (A. testudineus) and then became sluggish (both species), and instead of the normal fishy smell the fishes gave neem leaf like smell.

Epidemiological data suggest that arsenic ultimately results in cancer in different parts of the body. Several synthetic therapeutic agents manifest inadequate potency with severe side effects against arsenic toxicity. The flesh of B. bengalensis, has long been used as an ethno-medicine in case of arthritis, blood-impurities, impaired immune system, conjunctivitis and liver anomalies. This potent organism might be a natural choice against arsenic and several other toxicities. Our earlier studies on arsenic-exposed human can correlate carcinogenesis with DNA-damage. In an attempt to investigate the possible protective and therapeutic effect against arsenic induced hepatotoxicity, the extract of B. bengalensis was tested in arsenic intoxicated rat model. The time- and dose-dependent effect of arsenic toxicity was also tested in B. bengalensis. Sodium-meta-arsenite NaAsO2 (0.6 ppm/100g bw/day for 28 days, as earlier reported) was treated alone or in combination with the B. bengalensis water extract (BBE, 100 mg/100g bw) to rat and compared with vehicle treated control. In a separate experiment, the B. bengalensis was exposed to high concentration of NaAsO2 contaminated water (5 to 20 ppm for 1 to 9 days) in laboratory condition and their DNA quality was evaluated in relation to its possible oxidative threat. Any concentration of arsenic was incapable to initiate a significant DNA damage in B. bengalensis. Lipid peroxidation was increased in arsenic exposed B. bengalensis after longer duration of its exposure. Increase in reduced antioxidant like non-protein-soluble thiol (NPSH) is concordant with the decrease in lipid peroxidation and DNA stability in this organism. In rat experiment, the BBE supplementation strongly prevented arsenic-induced oxidative, necrotic and apoptotic damages to liver tissue/DNA by strengthening antioxidant systems, which has been shown in hepatic DNA-fragmentation, comet-assay, histo-architecture (hematoxylin/eosin), alkaline-phosphatase, serum-glutamate-pyruvate-transaminase and lactate-dehydrogenase (tissue-degeneration-marker) results. Only arsenic exposure decreased hepatic superoxide-dismutase (SOD) in-vivo and in-vitro (H2O2/arsenite redox-stress to dialyzed and concentrated, 6-8kd cutoff-Millipore liver cytosolic SOD), catalase, xanthine-oxidase, lactoperoxidase activities and the level of NPSH with a concomitant increase in malondialdehyde resulting in mutagenic DNA-breakage and apoptotic liver damage which has been decisively restrained in B. bengalensis extract. The present investigation offers strong evidence on the hepato-protective and medicinal efficiencies of BBE against oxidative stress induced by arsenic.

The systematics, morphology, distribution, biology, economic importance and conservation of the lamprey of Iran are described, the species is illustrated, and a bibliography on this fish in Iran is provided. There is one native and endemic species in the Caspian Sea basin, Caspiomyzon wagneri. The genus Caspiomyzon is characterised by having 2 dorsal fins, an oral disc narrower than the body, teeth are generally low and blunt, the supraoral lamina is small, oval and sometimes has 2 tubercles and rarely 2 teeth, the infraoral lamina has 4-6, usually 5, teeth which may be bicuspid at their tips; there are about 8 small teeth of equal size in the transverse lingual lamina, the exolaterals, anterials and posterials are strong and close together, anterior and endolateral circumorals 9-11, usually 11, and 3 long, papillose velar tentacles are present. Characters of the species are the same as the genus. Trunk myomeres number of C. wagneri are 53-68 in ammocoetes, and 68-69 in adults.

Benthic organisms have been studied in past to assess the health of an aquatic ecosystem. Moreover, being sedentary forms they have been used as indicator organisms. In the present study, an attempt has been made to study the distribution and assemblage of major macrobenthic forms occurring in Ponnani estuary. A total of 23 genera of benthic invertebrate fauna belonging to 6 groups viz., Polychaetes, Bivalve, Gastropod, Amphipod, Isopod and Tanaidacian were recorded during the study. Faunistic study revealed that in high saline regions of the estuary (Veliyancode), a very good macrobenthic biodiversity was present. Bivalves were the major group enumerated from Veliyancode and Ponnani (39% and 35%, respectively), while in Biyyam predominance of gastropods (37%) were observed. Among the bivalve groups, presence of Maculista senhousia and Pholas candida, both considered as invasive species was noteworthy. Another interesting observation was the presence of Amphipod Melita zeylanica, another alien species evenly represented in all the three stations, indicating that the species had well established in Ponnani estuary. The present study is the first description of benthic organism assemblages inhabiting in the region. Results indicate that salinity is a major parameter that governs the diversity, occurrence, abundance and distribution of macrobenthos in Ponnani estuary. It also elucidates that any perturbance in the physico-chemical nature of the estuary favours the invasiveness of alien macrobenthic species in Ponnani backwaters.

The present study investigated the effects of prebiotic (α-mune), a mixture of mannan oligosaccharide, β-1,3 and β-1,6 glucan, on the growth performance, haematology and innate immunity of beluga sturgeon (Huso huso) juvenile. Fish (46±3 g) were allocated into 12 tanks (15 fish per tank) and triplicate groups were fed a control diet or diets containing 1.5, 3.0 and 4.5 g kg-1 prebiotic for 46 days. Fish fed 1.5 g kg-1 prebiotic displayed significantly higher final weight, specific growth rate and feed conversion ratio. WBC, RBC, MCV, MCH, haemoglobin, haematocrit and lymphocyte levels were also significantly higher in the fish fed 1.5 g kg-1 prebiotic. Furthermore, the highest haematocrit content and lymphocyte level were found in the fish fed a diet containing 1.5 g kg-1 prebiotic. Alternative complement activity (ACH50), lysozyme activity and Ig concentration were significantly higher in the fed 1.5 g kg-1 prebiotic. These results indicate that α-mune can be considered as a beneficial dietary supplement for improving the growth performance, haematological and immunological parameters of beluga sturgeon juvenile.

This study evaluated the effects of probiotic, Lactobacillus plantarum on serum biochemical and some immune parameters of immunized rainbow trout weighting 29.6±1.84 g, with streptococcosis/lactococosis vaccine at 16±1.5°C, for 60 days. A commercial diet was used as the control. Fish in the first treatment were immunized with streptococcosis/lactococosis vaccine in bathing route for 1 min. In the second group, the vaccinated trout were also fed diet containing L. plantarum (108 CFU g-1). In the third treatment, fish were only fed the diet supplemented with L. plantarum (108 CFU g-1). The results showed that vaccinated trout with or without L. plantarum feeding diets significantly decreased heterophils. Meanwhile it enhances serum lysozyme, alternative complement activities, antibody titer, total leukocytes, lymphocytes, and serum biochemical parameters, including ALP, IgM, and total protein levels compared to control groups. Moreover, the highest levels of above mentioned parameters were found in vaccinated fish that fed L. plantarum. In addition, the vaccinated fish that fed L. plantarum showed significantly elevated cholesterol levels compared to the control group. The results showed that the dietary L. plantarum improved the immunity of immunized trout with streptococcosis/lactococosis vaccine.

Fish larvae have several sensory systems that are functional at or soon after hatching and then are developed further during larval and juvenile stages. This study was conducted to investigate development of the eye in Rutilus kutum, based on histological and allometric growth analysis during early developmental stages up to 35 day post hatching with emphasis on retinal morphology. For this purpose, the histological sections were prepared and allometric growth pattern of the eye was calculated. The results showed that the most eye’s structures along with the retina of the newly hatched larvae, as the inner sensory (photosensitive) tissue were completely differentiated. Allometric growth pattern of the eye diameter up to the inflexion point (7 dph) was somewhat positive and then it became negative. The results revealed that the Caspian kutum is dependence on visual capability as visual feeder during their larval period which itself explains completion of eye structures and the high growth rate of eye before 3 dph i.e. beginning of mixed feeding.