A review of the use of prebiotic in aquaculture for fish and shrimp

It has been documented in a number of food animals that gastrointestinal bacteria play important roles in affecting the nutrition and health of the host organism. Thus, various means of altering the intestinal bacteria to achieve favorable effects such as better resistance to pathogens, enhancing growth and immune stimulation of the host organism have been investigated in various fish and shrimp. In this respect, probiotics and prebiotics are used in farm animal and for aquaculture, although the probiotic approach has been extensively used and advocated, viability after ingestion is difficult to guarantee and almost impossible to prove. The prebiotic concept dictates that non viable dietary components fortifycertain components of the intestinal flora. This concept has the advantage that survival of the ingested ingredient through the upper gastrointestinal tract is not a prerequisite because it is indigenous bacterial genera that are targeted. Despite some positive effects prebiotic supplements on fish andcrustaceans have been published however it seems such information for aquatic organism is inadequate. This paper will give short review of recent studies in which the effects of various prebiotics have been evaluated for potential application in the aquacultural production of fish and shrimp

Generating gynogenetic common carp (Cyprinus carpio L.) by gama ray

We investigated the generation of gynogenetic common carp (Cyprinus carpio L.) during 1989-1990. After selection of suitable breeders containing special transferrin marker in breeding season, we applied ionizing radiation (60 Co gamma ray) for genetic inactivation of spermatozoa of the fish. We found that in the exposure of the sperm to a range 80-120 Krad irradiation, 100 Krad gave the best results. Application of various cold and heat shocks to the eggs at different time intervals after addition of water to the mixture of milk and eggs generated diploid gynogenetic fish. Cold and hot shock treatments generated significantly different gynogenetic fish (7% and 2.5% respectively). The optimum shock treatment was found to be 5 minutes after fertilization in 0 ֯C lasting 50 minutes. For each treatment, 100 fish fingerlings were subjected to electrophoresis which showed the mitotic diploid progenies were all-maternal inherited with BB genotype

Genetic parameters of growth in rainbow trout, Oncorhynchus mykiss, at early rearing stage

The heritability response for growth of rainbow trout during early developmental stages was detected on the basis of full-sib and half-sib cross between the selected lines. The experiment was done in Shahid Bahonar Salmon Propagation Center, Kelardasht, Iran. Breeders were taken from the stocks maintained in this station. A bifactorial cross was done between two line using four randomly sire and four randomly chosen dams form each line. Analysis of variance revealed a significant difference at 300 days of age between half and full-sib (p0.817) and 225 days (p>0.081). No significant difference between mean body weight of male and female half-sib group was found (p>0.05); neither were there significant differences between sireline (p<0.324) and dam line (p<0.230) at age of 300 days. The heritability ranged from 0.093 to 0.223 in sire and 0.11 to 0.329 in dam groups. The average heritability in sire regardless of age was 0.16 and in dams 0.21. The heritability in total regardless of age and sex was estimated about 0.185. Genetic parameters (h2) were different between dams (0.15-0.27) and sires (0.13-0.19) for all ages of samplings and for age of 150 day old, was significant (p<0.035)

Heritability estimation for growth-related traits in juvenile wild common carp (Cyprinus carpio L.) in the south of Caspian Sea

Wild common carp of the Caspian Sea is one of the important fish in the north of Iran, which has been introduced to inland aquaculture. Its genetic characteristics are investigated to set up for breeding programs that are still unknown. Using wild common carp in aquaculture is limited for uncontrolled variation in performance of fish derived from undomesticated breeders. A 7×7 factorial mating design was employed to examine genetic effects of dam and sire on growth and heritability of growth-related traits based on dam half-sib and sire half-sib families. Breeders were obtained originally from the Caspian Sea. A total of 1470 offspring were raised in 49 separate fiberglass tanks with common conditions. Body weight and length were recorded at three different ages of rearing. Estimation of heritability of weights ranged from 0.23±0.05 to 0.30±0.07 for dams and ranged from 0.15±0.03 to 0.26±0.04 for sire. Similar results were obtained with length but with less variation (0.24±0.02 to 0.26±0.01 for dams and 0.20±0.02 to 0.22±0.03 for sire). The broad-sense of weight and length are 0.23±0.04 and 0.23±0.01 respectively. The dam and sire effect on growth were significant, indicating the presence of variations among the native fish of the Caspian Sea. Therefore, it is suggested to use a length for selection that is more reliable and less affected by environment than weight at any time of growth and in respect of high phenotypic correlation (0.87-0.95) observed between weight and length. In the present study we even used wild common carp and the heritability was not higher than the domesticated common carp. It means the genetic variation for quantitative traits, for common carp of the Caspian Sea are low or it may be under pressure of inbreeding which should be studied further

Genetic parameters estimation of growth in Salmo trutta caspius as a function of body weight and length

There is no available adequate information on the biology and genetics of the Caspian salmon (salmo truta Caspiu) living in the Caspian Sea with other species such as common carp families, sturgeons and etc., therefore we are interested in knowing whether selection for rapid growth rate in salmo trutta Caspius will potentially lead to correlated genetic response in body weight and length. The potential for correlated responses was evaluated by the heritability estimation, estimating heritabilities of body weight and length. The genetic parameter estimations were obtained for different stages of growth from 5400 fish consisting 27 unrelated families that reached maturity at 36 months of age. The parent which used to produce separate family groups had been caught from the Caspian Sea and spawned during the autumn season. The estimated heritability of body weight and length was 0.42±0.13 and 0.49±0.01, respectively based on differential and selection response between parent pairs and their offsprings. Several factors may have affected the creation of this high level of estimation, dominant effect, inherited from different breeders to offspring

Two-microphone spatial filtering provides speech reception benefits for cochlear implant users in difficult acoustic environments

This article introduces and provides an assessment of a spatial-filtering algorithm based on two closely-spaced (∼1 cm) microphones in a behind-the-ear shell. The evaluated spatial-filtering algorithm used fast (∼10 ms) temporal-spectral analysis to determine the location of incoming sounds and to enhance sounds arriving from straight ahead of the listener. Speech reception thresholds (SRTs) were measured for eight cochlear implant (CI) users using consonant and vowel materials under three processing conditions: An omni-directional response, a dipole-directional response, and the spatial-filtering algorithm. The background noise condition used three simultaneous time-reversed speech signals as interferers located at 90°, 180°, and 270°. Results indicated that the spatial-filtering algorithm can provide speech reception benefits of 5.8 to 10.7 dB SRT compared to an omni-directional response in a reverberant room with multiple noise sources. Given the observed SRT benefits, coupled with an efficient design, the proposed algorithm is promising as a CI noise-reduction solution.National Institutes of Health (U.S.) (Grant R01 DC 000117)National Institutes of Health (U.S.) (Grant R01 DC DC7152)National Institutes of Health (U.S.) (Grant 2R44DC010524-02

Mental Health Services in Rural Jails [Policy Brief]

Based on interviews with state and local corrections and mental health informants in four rural states (Minnesota, Montana, Texas, and Vermont), the researchers sought to learn more about hte challenges that rural jails face along with promising practices being used to meet the needs of inmates with mental health concerns

A study on oogenesis of Liza saliens

In this study, gametogenesis of sharp-nose mullet (Liza saliens) was investigated bassed on morphological and histological characteristics. For this purpose, about 150 specimen of this species were collected from beach-seine nets in the southern Caspian Sea and were transferred to the laboratory for futher examinations on gonads. The gonad development was classified to 6 different stages consist of: stage I: The oocytes small, colourless with a big nucleus. stage II: The low increase in size of oocytes; globular yolk of nucleus appearing. stage III: Blood vessels are appearing on the ovary; the oocytes are in the primary vitellogenesis stages; vacules and zona radiata are seen around them. stage IV: The ovules can be easily observed with naked-eyes, vitellogenesis are complete and oocytes are mature. stage V: Oocytes are in maximum growth, nucleus migrating towards animal pole; spawning occures in this stage. stage VI: This stage is after spawning, ovary contains empty follicles. Based on this study, the stage of I to III were observed in August to April; stage of IV in May and June; stage of V in June and July and stage VI in August

The investigation and morphological study of two type of Crass carp: Ctenopharyngodon idella and survival rate of their larvae

The two groups of grass carp, have been propagated in North and South fish farms and then the larvae were transferring to Abziroshd and culture fish farm of Mazandaran. The fingerling at eight weight classes of 2 to 500 gram were investigated morphologically and some morphometric and meristic were compared. The South grass carp was significant difference (P<0.05) with the North, in case of weight with the same length, number of vertebral and gill raker. The coefficient of variance (CV) of meristic characters of South Grass carp was in the range of 1.2 to 9.8 while in Mazandaran grass carp 2.8 to 8.6. This CV illustrate the low variance in both population. This research study showed that the two stocks can be regard as difference races from one ancestor