Mrigal Research Articles

Accelerating full thickness wound healing using collagen sponge of mrigal fish (Cirrhinus cirrhosus) scale origin

The potentiality of collagen sponge as a skin substitute, derived from mrigal (Cirrhinus cirrhosus) scale has been explored in this study. Acid soluble collagen (ASC) and pepsin soluble collagen (PSC) from the scale of mrigal were isolated and characterized. The yields of ASC and PSC were ∼3% and ∼7% based on the dry weight of scale while the hydroxyproline content was ∼90mg/g. Scanning electron microscope revealed progressive demineralization with EDTA on time dependent scale. Further, the D-Spacing in fibril bundles were calculated to be ∼67nm. Fourier transform infrared and circular dichroism spectra confirmed extracted protein to be collagen I, where both ASC and PSC comprised of two different α-chains (α1 and α2). The denaturation temperature (Td) of the collagen solution was 35°C closer to Td of mammalian collagen. In vitro cell culture studies on the extracted collagen sponge showed efficient cell growth and proliferation. Additionally, co-culture with fibroblast and keratinocyte cells showed development of stratified epidermal layer in vitro. Faster wound healing potential of the extracted collagen in a rat model proved its applicability as a dermal substitute.

Nutritional evaluation of groundnut oil cake in formulated diets for rohu, Labeo rohita (Hamilton) fingerlings after solid state fermentation with a tannase producing yeast, Pichia kudriavzevii (GU939629) isolated from fish gut

De-oiled groundnut oil cake (GOC) was bio-processed through solid state fermentation (SSF) for 15 days at 34±1°C by a tannase producing yeast, Pichia kudriavzevii (GU939629) isolated from the gut of a freshwater carp, Cirrhinus cirrhosus. SSF of GOC was effective in significantly (P<0.05) reducing crude fibre content and antinutritional factors (e.g., tannin, phytic acid and trypsin inhibitor), whereas enhancing crude protein, lipid, ash, total free amino acids and fatty acids. Bio-processing revealed significant increase in the levels of argenine, histidine, isoleusine, lysine, methyonine and threonine in the GOC. Eight isonitrogenous (37.5%) and isocaloric (18.8kJg−1) experimental diets were prepared incorporating raw (R1–R4) and fermented (F1–F4) GOC at 20%, 30%, 40% and 50% levels by weight replacing fishmeal and other feed ingredients into a fishmeal-based reference diet (RD) and fed to rohu, Labeo rohita, fingerlings (initial weight 3.24±0.11g) for 80 days. In general, diets with SSF-processed GOC produced significantly better performance than the raw GOC in terms of growth, feed utilization, nutrient digestibility, carcass composition and digestive enzyme activity. Rohu fingerlings fed the diet F3 containing 40% fermented GOC resulted in best performance in terms of weight gain (final weight 7.08±0.06g), specific growth rate (% day−1), protein efficiency ratio and apparent net protein utilization. Highest protein (14.93±0.51%) and lipid deposition in the carcass were also recorded in the group of fish reared on diet F3. In comparison to the FM based reference diet, the present study explored the possibility of replacing 45–55% of FM through incorporation of 40–50% (w/w) SSF-processed GOC in the diets for rohu fingerlings.

The phylogenetic position of Myxoboluscarnaticus (Myxozoa, Myxosporea, Bivalvulida) infecting gill lamellae of Cirrhinus mrigala (Hamilton, 1822) based on 18S rRNA sequence analysis.

Myxozoans are an economically important group of microscopic parasites best known for the diseases they cause in commercially important fish hosts. The classification of myxosporeans is generally based on the morphology of their myxospores. Without molecular data, it is very difficult to identify new or existing species. DNA sequence information is therefore, a prerequisite to taxonomic and phylogenic studies of myxosporeans. In the present study, a myxozoan parasite, Myxobolus carnaticus, infecting the gill lamellae of mrigal carp, Cirrhinus mrigala, was characterized by the 18S rRNA gene sequence. The DNA sequence of M. carnaticus clustered phylogenetically with other gill infecting Myxobolus spp. of freshwater clades, forming a dichotomy with closely related M. pavlovskii (HM991164) that infects the gill lamellae epithelium of silver carp, Hypophthalmichthys molitrix with 95% similarity. Evolutionary pair-wise distances among M. carnaticus and other species of myxosporeans indicated high genetic diversity among myxosporeans. The present study demonstrated that tissue tropism, host specificity and habitat play important roles in phylogenetic relationships among myxozoan species.

Strain crossing in mrigal (Cirrhinus cirrhosus): An avenue to persuade heterosis in F1 generation of wild×hatchery hybrid

While the increase of the yield of commercially trendy farmed fishes are of special priority in aquaculture, a number of handy technologies are indispensable to realize the surplus production aiming to feed the growing population. As a genetic means of doing this, hybridization technology has been being used for years, because it can produce hybrid vigor through inducing heterosis. Similar attempt was made in mrigal, Cirrhinus cirrhosus, by crossing the hatchery strain with the riverine strain to investigate the heterotic effect in the progeny the species could generate through such intra-specific hybridization. Mean fertilization and hatching rates in hybrids were found to be lower by 7% and 4% respectively than that in purebreds, which envisioned to be trivial to impact the purpose of crossing. Comparative growth test between purebreds and hybrids showed significant differences (p&lt; 0.05) in weight and length, and resulted 30.51% heterosis in hybrid mrigal. This experiment can be considered as a preliminary investigation to motivate the application of strain crossing in mrigal farming and the result found thereof can be used as a clue to optimize this growth boosting technique for the species through further research.

Strain crossing in mrigal (Cirrhinus cirrhosus): An avenue to persuade heterosis in F1 generation of wild×hatchery hybrid

While the increase of the yield of commercially trendy farmed fishes are of special priority in aquaculture, a number of handy technologies are indispensable to realize the surplus production aiming to feed the growing population. As a genetic means of doing this, hybridization technology has been being used for years, because it can produce hybrid vigor through inducing heterosis. Similar attempt was made in mrigal, Cirrhinus cirrhosus, by crossing the hatchery strain with the riverine strain to investigate the heterotic effect in the progeny the species could generate through such intra-specific hybridization. Mean fertilization and hatching rates in hybrids were found to be lower by 7% and 4% respectively than that in purebreds, which envisioned to be trivial to impact the purpose of crossing. Comparative growth test between purebreds and hybrids showed significant differences (p&lt; 0.05) in weight and length, and resulted 30.51% heterosis in hybrid mrigal. This experiment can be considered as a preliminary investigation to motivate the application of strain crossing in mrigal farming and the result found thereof can be used as a clue to optimize this growth boosting technique for the species through further research.

A preliminary checklist of the fishes of Yercaud, Shevroy Hills, Eastern Ghats, Tamil Nadu, southern India

Twenty-one species of fishes were recorded in Yercaud Lake and the surrounding hill streams during five surveys conducted from May 2011 to August 2012. Of the 21 species, 19 were recorded in Yercaud Lake, 10 in the stream leading to Kiliyur Falls and six and eight respectively in the Manjakuttai and Puthur hill streams. One translocated species (Gibelion catla) and two exotics (Poecilia reticulata and Oreochromis mossambicus) were recorded. Only one species Cirrhinus cirrhosus is listed as threatened in the IUCN Red List of Threatened Species.

Aquaculture practices in two seasonal floodplains of Bangladesh

A comparative technical and economic analysis of two communitybased seasonal floodplains (Khirai and Angrail) of Daudkandi Upazila, Comilla during 2008 to 2010, are represented in this paper. The two floodplains differed mainly in management and fish production which were related to capital investment, variable cost, share of profits and proportional reimbursement to the fishers. Local management committees have been developed in each floodplain with significant differences. Average 142 kg/ha of fish fingerlings (carps such as Catla catla, Labeo rohita, Cirrhinus cirrhosus, Labeo calbasu, Labeo bata and exotic species such as Hypopthalmicthys molitrix, Aristichthys nobilis, Cyprinus carpio, Ctenopharyngodon idella, Pungasius hypophthalmus, Barbonymus gonionotus, Oreochromis niloticus) were stocked at the varying proportions. Fish production obtained were 2.8 to 4.4 mt/ha and 1.1 to 1.3 mt/ha in Khirai and Angrail floodplain, respectively. The average cost of fish production, total income and the net income have been estimated as Tk. 209650 ± 54167.12/ha, Tk. 281306 ± 88263.42/ha and Tk. 71656 ± 35152.51/ha in Khirai floodplain and Tk. 62349 ± 5768.90/ha, Tk. 111930 ± 12711.02/ha and Tk. 49580 ± 6948.26/ha in Angrail floodplain, respectively. The benefit cost ratio (BCR) has been recorded as 1.33 and 1.79 in Khirai and Angrail floodplain, respectively. The results reveal that the fish production and economic benefit was higher in Khirai floodplain.Bangladesh J. Zool. 41(2): 217-228, 2013

Integrated floating cage aquageoponics system (IFCAS): An innovation in fish and vegetable production for shaded ponds in Bangladesh

Farmer participatory action research was carried out from July to December 2013 to design and construct a technology known as IFCAS (integrated floating cage aquageoponics system) for growing fish and vegetables in shaded ponds in the Barisal region of Bangladesh under the EU funded ANEP (Agriculture and Nutrition Extension Project). Here the terms aqua, geo and ponics means pond water, pond mud/soil and cultivation, respectively. Producing and regularly harvesting fish in shaded ponds and growing vegetables on surrounding dykes for household consumption was constrained. To overcome the difficulties, an IFCAS (3.66m×2.44m=9m2) was set in each of 9 shaded ponds – 5 highly shaded ponds (HSP) and 4 moderately shaded ponds (MSP) – in which GIFT tilapia strain (Orechromis niloticus) was stocked at the rate of 100m−3 cage. In the ponds, carp species (Catla catla, Labeo rohita, Cirrhinus cirrhosus and Cyprinus carpio) were stocked at the ratio of 1:2:2:1, and at the rate of 14,820ha−1. Tilapia were fed floating feed and the carp were fed with supplementary feed. Vegetables were grown on the IFCAS scaffold, and tilapia were grown in the net-cage constructed underneath. Women members of HSP households participated fully in the action research in the production of vegetables and fish in IFCAS. Participating households started consuming vegetables and tilapia from IFCAS within 1.5 and 1 month of the start of the experiment, respectively. Average fish consumption of 20kghousehold−1 was recorded within four months, of which more than 50% was tilapia from IFCAS. Overall fish and vegetable production was higher in MSP as compared to HSP. A financial analysis showed the benefit-cost ratio of IFCAS was >1, indicating the investment efficiency of IFCAS for farmers.

Effect of Use of Duckweed Powder as a Fish Feed on Polyculture of Carps

An experiment on the use of duckweed (Lemna minor) powder as an ingredient of feed on production of rui (Labeo rohita), mrigal (Cirrhinus cirrhosus) and silver carp (Hypophthalmicthys molitrix) in polyculture, was conducted in six ponds for a period of three months. The experiment was carried out under two treatments, each with three replications. Mean survival rates under treatment-I and treatment-II were 95.55% and 88.88% respectively. The specific growth rate (SGR, % per day) of the fish found under treatment-I and treatment-II were 0.28% and 0.25% respectively. The calculated net fish production of the ponds under treatment-I was 1.416 ton/ha/yr and that of the ponds under treatment-II (control) was 0.846 ton/ha/yr. The net fish production of T-I was significantly (p&lt;5%) higher than that of T-II.DOI: http://dx.doi.org/10.3329/jesnr.v6i2.22121 J. Environ. Sci. &amp; Natural Resources, 6(2): 213-216 2013

Myxozoan infections of the three Indian major carps in fish ponds around Meerut, UP, India, with descriptions of three new species, Myxobolus basuhaldari sp. n., M. kalavatiae sp. n. and M. meerutensis sp. n., and the redescription of M. catlae and M. bhadrensis.

New myxosporean species are described from Indian fishes cultured in pond farms of Meerut, Uttar Pradesh (UP) state. Based upon plasmodia found in the Indian major carps (Catla catla, Cirrhinus cirrhosus, Labeo rohita and their hybrids), three new Myxobolus spp., Myxobolus basuhaldari sp. n., Myxobolus kalavatiae sp. n. and Myxobolus meerutensis sp. n., are described, and two species, Myxobolus catlae and Myxobolus bhadrensis, are redescribed. Plasmodia of M. basuhaldari sp. n., M. kalavatiae sp. n., M. meerutensis sp. n. and M. catlae developed in small cysts in the gill lamellae, while plasmodia and scattered spores of M. bhadrensis were found in the muscles and kidney, respectively. Plasmodia and spores found in these fishes differed from each other with respect to their morphology, tissue tropism and 18S ribosomal DNA (18S rDNA) sequence. No major pathological changes were found, but severe infections were observed.

A Comparative Study of Present Status of Marketing of Formalin Treated Fishes in Six Districts of Bangladesh

The fish is an important food stuff and source of protein all over the world. In Bangladesh, fisheries sector contributes a lot, in the case of the earning foreign currency and meeting domestic need of the animal proteins. To fulfill the domestic need of protein and fish, Bangladesh imports fish and fish products from the neighboring county. In many studies, it was proved that most of the imported fishes are contaminated with formalin, which is the highly hazardous and carcinogenic chemical. Information was collected from the fish retailers and consumers on the marketing of the formalin treated fishes through survey using prescribed questionnaire at 18 different fish markets in 6 different districts of Bangladesh. It was found that most of the commercially imported fishes are highly contaminated with formalin. On the other hand, local big fishes, such as rui (Lobeo Rohita), catla (Catla catla) and mrigal (Cirrhinus cirrhosus) etc., are also formalin contaminated partially, but not all the fishes. All the local small fishes are free from the formalin contamination. In this study, it was found that, among the 939 fish samples collected from the different fish markets of the six districts, 213 fishes (22.68%) were directly contaminated with formalin. The contamination rate is so much higher in the big city like Dhaka (36.78%) and lower in the small town like Jamalpur districts (13.33%). This study also indicated that, all the village markets were totally free from the formalin contamination. As the fish traders used formalin to increase the shelf life of the fishes, it was also observed that, the shelf life of the local fishes or formalin free fishes was much higher and the organoleptic characteristics were much more excellent than the formalin contaminated local or imported fishes. The price of the imported fishes was also lower than the local fishes. It was also clear that, the organoleptic characteristics of the imported fishes and formalin contaminated fishes were greatly different than the local fishes, which were not satisfactory to the consumers. The study also indicated that, the overall hygienic practice and sanitary conditions of the markets and the fish traders/retailers were very poor, not satisfactory. This survey also revealed that, all the traders or retailers who were mixed formalin with the fishes, knew about the bad effects of the formalin.

Molecular phylogeny of Myxobolus orissae (Myxosporea: Myxobolidae) infecting the gill lamellae of mrigal carp Cirrhinus mrigala (Actinopterygii: Cyprinidae).

Myxosporeans are best known for the diseases they cause in commercially important fish species. Identification of myxosporeans at the species-level is mainly based on conventional methods. The 18S rRNA gene sequence of morphologically identified Myxobolus orissae infecting the gill lamellae of mrigal carp Cirrhinus mrigala was characterized in the present study. The plasmodia of M.orissae were small, elongated and white to pale in colour. Phylogenetically, the 18S rDNA nucleotide sequence of M.orissae was clustered with other gill-infecting Myxobolus spp. of cyprinids. The species closely related to M. orissae was M. koi (FJ841887) infecting the gill lamellae of Cyprinus carpio with 96% similarity. The carp fin-infecting Thelohanelluscaudatus (KC865607) from India exhibited only 78% DNA sequence similarity with M. orissae. Low level of M. orissae infection on gill caused thickening of epithelial cells surrounding the plasmodium. Under stressful conditions, it is likely that such infection can easily spread in confined fish and may cause serious disease outbreaks and economical losses.

Fry production, induced breeding practices and cost-profit analysis of the hatcheries of Rajshahi district in Bangladesh

This study was conducted on the 13 hatcheries of Rajshahi district from March to December 2013 to know about the fry production status, induced breeding practices and cost-profit status. Average fry production of Labeo rohita, 93.38±83.32 kg, Catla catla, 62.00±60.84 kg, Cirrhinus cirrhosus, 77.46±58.61 kg, L. calbasu, 14.20±14.60 kg, L. bata, 53.73±50.56 kg, L. gonia, 10.00±0 kg, Heteropneustes fossilis, 5.00±0 kg, Clarias batrachus, 20.00±0 kg, Hypophthalmichthys molitrix, 149.77±138.45 kg, Aristichthys nobilis, 104.54±148.11 kg, Ctenopharyngodon idella, 19.20±15.35 kg, Cyprinus carpio 108.08±77.39 kg and Barbonymus gonionotus, 23.10±14.04 kg were recorded in the surveyed hatcheries. Two types of hormone injections PG (pituitary gland) and HCG (Human chorionic gonadotropin) were used for induced breeding. The rate of 1st dose of injection of PG varied from 1 to 2 mg/kg and HCG from 100-150 IU/kg and the rate of 2nd dose of injection of PG varied between 5 and 8 mg/kg. The incubation period and hatching rate in different fish species varied from 10 to 72 hours and 55% to 80%, respectively. The average total cost, gross return and net profit of the hatcheries were 0.667±0.798, 1.152±1.636 and 0.485±0.846 million BDT respectively.

Fry production, induced breeding practices and cost-profit analysis of the hatcheries of Rajshahi district in Bangladesh

This study was conducted on the 13 hatcheries of Rajshahi district from March to December 2013 to know about the fry production status, induced breeding practices and cost-profit status. Average fry production of Labeo rohita, 93.38±83.32 kg, Catla catla, 62.00±60.84 kg, Cirrhinus cirrhosus, 77.46±58.61 kg, L. calbasu, 14.20±14.60 kg, L. bata, 53.73±50.56 kg, L. gonia, 10.00±0 kg, Heteropneustes fossilis, 5.00±0 kg, Clarias batrachus, 20.00±0 kg, Hypophthalmichthys molitrix, 149.77±138.45 kg, Aristichthys nobilis, 104.54±148.11 kg, Ctenopharyngodon idella, 19.20±15.35 kg, Cyprinus carpio 108.08±77.39 kg and Barbonymus gonionotus, 23.10±14.04 kg were recorded in the surveyed hatcheries. Two types of hormone injections PG (pituitary gland) and HCG (Human chorionic gonadotropin) were used for induced breeding. The rate of 1st dose of injection of PG varied from 1 to 2 mg/kg and HCG from 100-150 IU/kg and the rate of 2nd dose of injection of PG varied between 5 and 8 mg/kg. The incubation period and hatching rate in different fish species varied from 10 to 72 hours and 55% to 80%, respectively. The average total cost, gross return and net profit of the hatcheries were 0.667±0.798, 1.152±1.636 and 0.485±0.846 million BDT respectively.

Investigation on culture and health status of Mrigal Cirrhinus cirrhosus from the farming system of Mymensingh region

Indian major carp, Cirrhinus cirrhosus was considered to monitor culture and health status in farm condition from Bhaluka and Muktagacha of Mymensingh region of Bangladesh for a period of seven months starting from September, 2010 to March, 2011. Monthly sampling was carried out for growth and health condition. Samples of skin and muscle, gill, liver and kidney were observed by clinical and histological techniques. Water temperature was at unfavorable levels but, dissolved oxygen, pH, alkalinity, ammonia and nitrite of water were within the favorable range for fish culture during the months of December and January. Clinically weak body, rough skin, scale loss, thick gill filaments, ulcer and gray brownish color were observed. Among the affected fish organs like skin, muscle and gill were found to be more affected than those of the internal organs, liver and kidney. Major pathologies in the skin and muscle were loss of epidermis and dermis, presence of fungal granuloma, fungal hyphae, necrosis, hemorrhages, vacuums and melanocytes. Protozoan cysts, clubbing, hemorrhages, necrosis and hypertrophy were found in the gill. Necrosis, hemorrhage, pyknosis and vacuums were observed in liver. Common pathological signs like necrosis, hemorrhage, pyknosis, vacuums and degenerated kidney tubules were noticed in kidney. Overall, in the clinical and histopathological studies fishes were found to be more affected during the colder months i.e., December and January. Whereas, in the month of February the pathological condition of fish gradually started to heal up. In histopathological observation, fishes of Bhaluka farms were more affected than that of Muktagacha fish farms. Epizootic ulcerative syndrome (EUS) and protozoan diseases were noticed in Bhaluka fish farms. DOI: http://dx.doi.org/10.3329/jbau.v11i2.19947 J. Bangladesh Agril. Univ. 11(2): 391-397, 2013

Investigation on fish health and diseases in rural pond aquaculture in three districts of Bangladesh

The present study was conducted to know the culture strategies and fish health and disease problems in pond aquaculture in Mymensingh, Bogra and Pabna districts of Bangladesh. Questionnaire interview and participatory rural appraisal tools like focus group discussion (FGD) were conducted with selected fish farmers. In total 90 farmers were interviewed and 9 FGD sessions were conducted. Most of the respondents practiced carp and pangas polyculture and they had disease problems in their ponds. Prevalence of fish disease varied with cultured species and locations. The most prevalent diseases as reported by the farmers were pop eye (57.78%), ventral reddening (55.55%), tail and fin rot (48.89), hemorrhagic lesion over the body surface (45.56%), dropsy (40%), gill rot (40%), white spot (40%) and epizootic ulcerative syndrome or EUS (33.33%). According to farmers opinion most susceptible species to disease was silver carp, Hypophthalmichthys molitrix (57.78%); followed by mrigal, Cirrhinus cirrhosus (50%); catla, Catla catla (47.78%); sarputi, Barbodes gonionotus (47.78%); rui, Labio rohita (42.22%) and pangas, Pangasianodon hypophthalmus (42.22%). Higher mortality was found in pangas (53.56%). Clinically, pangas, koi and sarputi were found severely affected. Most of the farmers used some treatment measures against disease problems. This study also highlited some fish health management problems in pond aquaculture. Further studies should include identification and characterization of pathogens involved in different types of diseases in pond aquaculture. DOI: http://dx.doi.org/10.3329/jbau.v11i2.19944 J. Bangladesh Agril. Univ. 11(2): 377-384, 2013

Interaction between dopamine and neuropeptide Y in the telencephalon of the Indian major carp, Cirrhinus cirrhosus

In teleosts, while neuropeptide Y (NPY) has emerged as one of the potent regulators of GnRH-LH axis, entopeduncular nucleus (EN) in the ventral telencephalon serves as major site for NPY synthesis/storage. Neurons of the EN innervate preoptic area and pituitary, respond to gonadal steroids, undergo reproduction phase-related changes, and are believed to convey sex steroid-borne information to GnRH neurons. In spite of the importance of EN, the neural circuitry associated with the nucleus has not been defined. Aim of the present study is to examine the possibility of the dopaminergic regulation of EN. NPY-immunoreactive cells and fibers were extensively distributed in the forebrain and pituitary of Cirrhinus cirrhosus. NPY immunoreactivity was observed in the olfactory receptor neurons, ganglion cells of terminal nerve, and in neurons of area ventralis telencephali/pars lateralis, EN, nucleus preopticus periventricularis (NPP), and nucleus lateralis tuberis. NPY-fibers were observed in the dorsal telencephalon, tuberal area and pituitary. While the area ventralis telencephali/pars intermedialis (Vi) located just above the EN contained a distinct population of tyrosine hydroxylase neurons, their axons seem to innervate NPY neurons in EN. Superfused brain slices containing EN were treated with DA D1- and D2-like receptor agonists. NPY-immunoreactivity in the EN showed significant increase (P<0.001) following DA D1-like receptor agonist, SKF-38393 treatment, but DA D2-like receptor agonist, quinpirole was ineffective. DA may regulate NPY neurons in EN via D1-like receptors. DA-NPY interaction in the EN might be important in the central regulation of reproduction in teleosts.

Tyrosine hydroxylase in the olfactory system, forebrain and pituitary of the Indian major carp, Cirrhinus cirrhosus: organisation and interaction with neuropeptide Y in the preoptic area.

Dopamine (DA) inhibits, whereas gonadotrophin-releasing hormone (GnRH) stimulates, luteinisiing (LH) cells in the pituitary of some but not all teleosts. A reduction in the hypophysiotropic dopaminergic tone is necessary for the stimulatory effect of GnRH on LH cells. Neuropeptide Y (NPY) has emerged as one of the potent, endogenous agent that modulates LH secretion directly or indirectly via GnRH. Involvement of NPY in the regulation of hypophysiotropic DA neurones, however, is not known, but there is good evidence suggesting an interaction in the mammalian hypothalamus. DA neurones, identified by tyrosine hydroxylase (TH)-immunoreactivity, were observed widely throughout the brain of the Indian major carp, Cirrhinus cirrhosus. The granule cells and ganglion cells of terminal nerve in the olfactory bulb, and cells in ventral telencephalon and preoptic area (POA) showed conspicuous TH immunoreactivity. In the POA, the nucleus preopticus periventricularis (NPP), divisible into anterior (NPPa) and posterior (NPPp) components, showed prominent TH-immunoreactivity. The majority of TH neurones in NPPa showed axonal extensions to the pituitary and were closely associated with LH cells. The NPPa also appeared to be the site for intense interaction between NPY and DA because it contains a rich network of NPY fibres and few immunoreactive cells. Approximately 89.7 ± 1.5% TH neurones in NPPa were contacted by NPY fibres. Superfused POA slices treated with a NPY Y2 -receptor agonist, NPY 13-36 resulted in a significant (P < 0.001) reduction in TH-immunoreactivity in NPPa. TH neurones in NPPa did not respond to NPY Y1 -receptor agonist, [Leu(31) , Pro(34) ] Neuropeptide Y treatment. We suggest that, by inhibiting DAergic neurones in NPPa via Y2 -receptors, NPY may contribute to the up-regulation of the GnRH-LH cells axis. The microcircuitry of DA and NPY and their interaction in NPPa might be a crucial component in the central regulation of LH secretion in the teleosts.

Study on the Growth Performance and Production of Juvenile Indian Major Carps (Catla catla, Labeo rohita and Cirrhinus cirrhosus) and Their Hybrids

Study on the Growth Performance and Production of Juvenile Indian Major Carps (Catla catla, Labeo rohita and Cirrhinus cirrhosus) and Their Hybrids

Comparison of Different Nutritional Parameters and Oil Properties of Two Fish Species ( Catla c atla and Cirrhinus c irrhosus ) from Wild and Farmed Sources Found in Bangladesh

Fishes are rich sources of different types on nutrients. Various types of fishes are available here, so Bangladeshies are called bangali of rice and fishes. Some species are only found in brine water; on the other hand some varieties are available in soft water. The soft water fishes are found almost everywhere in . Some soft water fishes are either found in natural sources such as ponds, rivers, lakes etc. or they may be farmed. Both wild and farmed fishes are rich sources of protein and also contain significant amount of moisture. The moisture content in wild Catla catla fish is higher than other species. The farmed species contain higher amount of ash than wild species. Protein content in farmed species is also higher than wild species. Calcium content in Catla catla wild species is significantly different from other species. Cirrhinus cirrhosus farmed species show higher potassium content than other species. All of the species are rich sources of iron. Iodine number is also higher in Catla catla wild species. The nutrients content are higher in farmed species than the wild species.