Effect of carp PG doses on induced breeding of Shing, Heteropneustes fossilis (Bloch)

Five hormone doses viz. 25, 50, 75, 100, and 125 mg of carp PG/kg of body weight of the recipient fish were tested and they were designated as T1 T2, T3, T4, and T5 respectively. Significantly higher fertilization (98%) and hatching rates (38%) were obtained from T3 (75 mg of carp PG extract/kg body weight). While T4 (100 mg of carp PG extract/kg body weight) and T5 (125 mg of carp PG extract/kg body weight) gave the highest (90%) ovulation rate. In June and July the highest fertilization rate of 96 and 96.4% respectively and hatching rate 42.5 and 48.7% respectively were obtained. In over all consideration carp PG extract at a dose of 75 mg/kg body weight appears to be the suitable dose for induced breeding of H. fossilis and June and July are the suitable time for its induced breeding.

The hydrography of Elkhorn Slough: a shallow California coastal Eebayment: Annual Report, Part 2, 1973

From October 1970 through February 1972, temperature, salinity, dissolved oxygen, secchi depth and five major nutrients were observed at approximately monthly intervals in Elkhorn Slough and Moss Landing Harbor. In addition, similar hourly observations were made during two tidal studies during the wet and dry seasons. From the salinity measurements during the summer, a salt balance for Elkhorn Slough is formulated and rnean eddy diffusion coefficients are determined. The diffusion nlodel applied to longitudinal phosphate distributions yielded a mean diffusive flux of 12 kg P04/day (140 pg-at/m^2/day) for the area above the mean tidal prism. Consistent differences, apparently due to differing regenerati on ra tes, were observed in the phosphate and nitrogen distributions. Bottom sediments are proposed as a possible source for phosphate and as a sink for fixed nitrogen. Dairy farms located along central Elkhorn Slough are apparently a source for reduced nitrogen. During summer, nitrogen was found to be the limiting nutrient for primary production in the upper slough. Tidal observations indicated fresh water of high nutrient concentration consistently entered the harbor from fresh water sources to the south. This source water had a probable phosphate concentration of 40 to 60 ug-at/l and seasonally varying P:N ratio of 1:16 and 1:5 during the winter and summer respectively. Net production and respiration rates are calculated from diurnal variations in dissolved oxygen levels observed in upper Elkhorn Slough. Changes in phosphate associated with the variations in oxygen was close to the accepted ratio of 1:276 by atoms. Document is 88 pages.

A Baseline Study of the Moss Landing/Elkhorn Slough Environment

In July, 1974 we began a baseline study of the Moss Landing-Elkhorn Slough marine environment for PG&E as mandated by the Coastal Commission. This report constitutes results of the first year's program. It is divided into three sections, oceanography, benthic invertebrate ecology, and fish and zooplankton ecology. (PDF contains 226 pages)

The effects of dieldrin on various life stages of the African catfish Clarias gariepinus (Burchell)

Early life stages (ELS) of Clarias gariepinus were found to be less sensitive to acute dieldrin toxicity than ELS of Nile tilapia, Oreochromis niloticus; 96 h LC50 for 37 day old fry were 11.7 and 4.95pg/l, respectively. Growth of O. niloticus fry was significantly reduced in 22.4 pg/l dieldrin whereas growth of C. gariepinus fry was unaffected. Adult C. gariepinus rapidly absorbed dieldrin from aquaeous solution and accumulated it in their tissues, especially in the liver where after 30 days in 4.0 pg/l bioconcentration was close to 1000 fold. Chronic exposure of C. gariepinus to dieldrin had no effect on blood haematocrit and haemoglobin, but appeared to slow the growth of catfish, and had a clear negative effect on the reproductive potential of mature females

Modulation of the effectiveness of 17-alpha-hydroxy-20-beta-dihydroprogesterone or of a gonadotrophic extract on the in vitro intrafollicular maturation of oocytes of the rainbow trout Salmo gairdnerii by various non-maturing steroids [Translation from: Compte Rendu Hebdomadaire des Seances de l'Academie des Sciences, Paris, Series D 281, 811-814, 1975]

The effectiveness of 17 α-hydroxy-20 β-dihydroprogesterone (17 α-20 β Pg) or of a trout hypophyseal gonadotrophic extract on the in vitro intrafollicular maturation of trout oocytes can be modulated by steroids which do not have a direct maturing effect; the effectiveness of the gonadotrophic extract is lowered by oestradiol and oestrone and increased by testosterone. As these steroids have no significant effect on maturation induced by 17 α-20 β Pg, the site of their activity is probably in the follicular envelopes. Corticosteroids, and Cortisol and cortisone in particular increase the effectiveness of the gonadotrophic extract, but increase the effectiveness of 17 α-20 β Pg even more strongly, suggesting that this 'progestagen' has a direct effect on oocyte sensitivity.

Lista de los peces de la provincia de La Rioja

Esta serie tiene como finalidad dar a conocer las especies presentes en los diferentes estados provinciales. Tomando como base los trabajos de López et al., (2003); Reis et al., (2003); Liotta (2006) y Ferraris (2007) actualizamos el elenco ictiofaunístico de cada territorio provincial. No se realizan, con excepción del nombre vulgar y localidad tipo, comentarios y/o observaciones de las especies señaladas ya que estos se encuentran en la bibliografía adjunta. Se incluyen dos tablas que contienen información sobre especies introducidas y de aquellas de presencia dudosa o que requieran confirmación en el territorio provincial. Para éstas últimas se cita el trabajo que las menciona por vez primera. Consideramos que este modesto aporte contribuirá a precisar el conocimiento ictiofaunístico regional ya que además de la lista de especies, presentamos el marco biogeográfico e hídrico correspondiente. Por otra parte entendemos que la participación de autores involucrados en la región considerada, le da un verdadero sentido federal a esta contribución, además de reforzar vínculos en los protagonistas de nuestra especialidad. En este nuevo número presentamos la provincia de La Rioja que se encuentra enclavada en el centro-oeste de nuestro territorio, limitada por Catamarca, Córdoba, San Luis y San Juan. La familia Trichomycteridae es uno de los grupos más representativos del sistema hidrográfico de La Rioja adaptados a vivir en elevada altura y arroyos que ocasionalmente permanecen alimentados por el deshielo (López, et al., 2002). Esta familia es un ejemplo de gran adaptabilidad siendo capaz de vivir en ambientes de llanura como los de la Provincia de los Grandes Ríos (López et al., 2008) así como también en arroyos cordilleranos a más de 4000 m de elevación. A las 6 especies citadas por Liotta (2006: pág. 668) para la provincia de La Rioja debemos agregar 10, de las cuales 3 son endémicas y 4 son introducidas (Tabla I).

1983 Biscayne Bay hydrocarbon study: final report

A two year, comprehensive, quantitative investigation was conducted to analyze and identify the spatial distribution of petrogenic and biogenic hydrocarbons in sediments, surface waters, fish and shellfish of Biscayne Bay, Florida. The goal for the first year of the project was to establish baseline information to support oil spill impact assessment and clean-up. One hundred fifty-five sediment and eleven biota samples were collected. The areas sampled included the Miami River, Intracoastal Waterway, tidal flats, access canals and environmentally sensitive shorelines. The second year of the study centered on areas exhibiting petroleum contamination. These areas included the Miami River, Little River, Goulds Canal, Black Creek and Military Canal. Surface and subsurface sediment, biota and surface water were collected. Sample collection, analyses, and data handling for the two year project were conducted so that all information was court-competent and scientifically accurate. Chain of custody was maintained for all samples. Total hydrocarbon content of surface sediments ranged from below detection limits to a high of 2663.44 pg/g. Several sample stations contained petroleum contamination. The majority of biota samples exhibited hydrocarbon concentrations and characteristics that indicated little, if any, petroleum contamination. Surface water samples ranged from 0.78 to 64.47 μg/L and several samples contained petroleum hydrocarbons. Our results indicate several areas of petroleum contamination. These areas are characterized by industrial complexes, port facilities, marinas, major boating routes and many of the major tributaries emptying into Biscayne Bay.

Increased toxicity of Karenia brevis during phosphate limited growth: ecological and evolutionary implications

Karenia brevis is the dominant toxic red tide algal species in the Gulf of Mexico. It produces potent neurotoxins (brevetoxins [PbTxs]), which negatively impact human and animal health, local economies, and ecosystem function. Field measurements have shown that cellular brevetoxin contents vary from 1–68 pg/cell but the source of this variability is uncertain. Increases in cellular toxicity caused by nutrient-limitation and inter-strain differences have been observed in many algal species. This study examined the effect of P-limitation of growth rate on cellular toxin concentrations in five Karenia brevis strains from different geographic locations. Phosphorous was selected because of evidence for regional P-limitation of algal growth in the Gulf of Mexico. Depending on the isolate, P-limited cells had 2.3- to 7.3-fold higher PbTx per cell than P-replete cells. The percent of cellular carbon associated with brevetoxins (%C-PbTx) was ~ 0.7 to 2.1% in P-replete cells, but increased to 1.6–5% under P-limitation. Because PbTxs are potent anti-grazing compounds, this increased investment in PbTxs should enhance cellular survival during periods of nutrient-limited growth. The %C-PbTx was inversely related to the specific growth rate in both the nutrient-replete and P-limited cultures of all strains. This inverse relationship is consistent with an evolutionary tradeoff between carbon investment in PbTxs and other grazing defenses, and C investment in growth and reproduction. In aquatic environments where nutrient supply and grazing pressure often vary on different temporal and spatial scales, this tradeoff would be selectively advantageous as it would result in increased net population growth rates. The variation in PbTx/cell values observed in this study can account for the range of values observed in the field, including the highest values, which are not observed under N-limitation. These results suggest P-limitation is an important factor regulating cellular toxicity and adverse impacts during at least some K. brevis blooms.

Human chorionic gonadotrophin: a substitute for pituitary gland for induced breeding

Pituitary extract is in use for fish breeding since a long. Due to the difficulties in procuring pituitary glands and its preservation, scientists were looking for its substitute. Results on the use of human chorionic gonadotrophin in combination with pituitary for breeding of Cirrhina mrigala and Labeo rohita were encouraging. It has been possible to breed C. mrigala and L. rohita by use of HCG also. An increase in hatching percentage was observed with HCG & PG mixture in modern carp hatchery CIFE D-81.

Comparison of two hormone preparations on the reproductive performance of air breathing catfish Clarias batrachus (Lin.)

Two hormone preparations viz. Human Chorionic Gonadotropin (HCG) and pituitary gland (PG) suspension were compared for their comparative efficacy on the breeding performance of a air breathing catfish Clarias batrachus. It was found that HCG induced fish gave better ovulation response than PG. Both fertilization and hatching of eggs were significantly (p

Early developmental stages of Nandus nandus (Ham.)

In order to study the early developmental stages of Nandus nandus an experiment was conducted, where eggs and milt were obtained from the laboratory reared N nandus by stripping after 15 hours of 150 mg/kg body weight of carp PG extract injection. Then the eggs were fertilized in the laboratory and subsequent developmental stages were studied. First cleavage (two cell), four cell, eight cell, sixteen cell and multi cell stages were found 30, 50, 70, 105 and 160 minutes after fertilization respectively. Morula, early gastrula, middle gastrula, late gastrula and yolk plug stages were found 5, 8, 9, 11 and 13 hours after fertilization respectively. Hatching occurred within 20±2 hours after fertilization, and larvae were measured 1.60 mm in diameter. After one hour of hatching two melanophore bands were found at the caudal region of the body of the larvae. Eyes were first observed in l 0 hours, pectoral and pelvic fin buds appeared in 22 hours and well developed in 38 hours old larvae. Mouth cleft and brain lobes were visible when the larvae were 34 and 38 hours old respectively. Myomeres partially appeared in 16 hours, which were clearly visible in 74 hours old larvae. Larvae started wandering and searching for food after 56 hours of hatching. The yolk sac was completely absorbed when larvae became 62 hours old.

Development of artificial breeding techniques for long-whiskered catfish, Sperata aor and giant river catfish, Sperata seenghala of Bangladesh

Sperata aor and S. seenghala are the two important native catfishes of Bangladesh but commercial farming of these species is not possible due to lack of naturally collected or artificially produced seeds for stocking. Attempts were made to develop techniques for seed production by artificial breeding and nursery-rearing of fries of these catfishes. A total of 60 S. seenghala (750-1,500 g) and 10 S. aor (600-1,000 g) broods were collected from the Brahmaputra river-basin and floodplains in Mymensingh region four months prior to their breeding season. The collected brood fishes were reared in separate earthen ponds with supplementary feeds comprising of rice bran (40%), mustard oil cake (29%), fish meal (30%) and vitamin-premix (1 %). Three experiments were conducted to optimize the hormone dose. A total of nine S. seenghala females weighing from 750 to 1,500 g were given an initial and resolving dose of 12-20 and 16-24 mg PG/kg body weight, respectively. The males weighing from 650-950 g were administered a single dose of 18-26 mg PG/kg body weight at the time of the time of administering the resolving dose to the females. The females ovulated partially and the eggs were examined under a compound microscope, but most of them were found to be less ripe or damaged. Collection of milt by stripping the males was not successful. The testes were taken out and sperm were observed to be non-motile and less developed. In view of stimulating natural propagation of S. seenghala, artificial holes (nests) were constructed in the pond bottom. Each hole was 0.7 m in diameter and 0.3 m in depth. A total of 10 holes were made and then 10 pairs of S. seenghala breeders (800-1,200 g) were stocked in the pond. In mid February, 3,000 fry of S. seenghala with a mean length of 4.60 cm and weight of 0.36 g were collected by repeated netting followed by drying of the pond. The fry were then stocked in a nursery pond and fed with commercial feed (SABINCO starter-1). The average length and weight of the fingerlings were 9.01 cm and 3.95 g, respectively and the estimated survival was 60% after two months of rearing. S. aor did not respond to natural spawning. Further study is essential to develop techniques for their successful artificial and natural breeding.

Reproductive biology, artificial propagation and larval rearing of two freshwater eels, Monopterus cuchia and Mastacembelus armatus

Studies on reproductive biology and artificial propagation including larval rearing of freshwater mud eel, Monopterus cuchia and spiny eel, Mastacembelus armatus were attempted. The gonadosomatic index (GSI) of mud eel ranged from 0.41 (August) to 5.52 (June) in males and 0.53 (August) to 7.61 (June) in females. In both cases the GSI showed a peak in June. Fecundity ranged from 228 (TL - 396 mm; W - 78g) to 5510 (TL - 865 mm; W - 630 g). In case of spiny eel, the GSI varied from 0.65 (August) to 8.30 (July) in males and 0.70 (August) to 10.46 (July) in females. GSI showed single peak in July. Fecundity ranged from 570 (TL - 240 mm; W - 30 g) to 10870 (TL - 601; W - 350g). Histology of the testes and ovaries of the eels were carried out to investigate the gonadal development stages during the reproductive months (August to November 2003). In case of male M. cuchia, the secondary primordial germ cells, primary spermatogonium, some spermatogonia A and clone of spermatogonium B in testis were observed in September. In October-males different sized lobules having spermatogonia, spermatocytes and spermatids were observed. In the ovary of M. cuchia, polygonal shaped oocytes were seen during September. The oogonia were reduced with dense and irregular shaped during October. Numerous pycnotic cells were visible during November. In male M. armatus numerous broken lobule walls were found in testes during September. In October, abundant primary germ cells, pycnotic nests of degenerating cells, spermatogonia and spermatids were observed. In females, ovaries had distinct yolk vesicles stage and yolk granules stages in August. In September, the follicular cells of the oogonia were ruptured, shrunk forming irregular shaped in October. Oogonia were also shrunk with thin, irregular shaped structure but broken parts of the ruptured follicular cells were scattered in case of M. armatus. Experimental attempts on artificial propagation indicated that both freshwater eels were difficult to breed using inducing agents like pituitary glands (PG) of 10, 20, 50, 100 and 150 mg per kg of body weight. Same doses were used for both sexes with equal sex-ratio. In both cases, brood fish died at higher doses of injection given at 100 and 150 mg PG/kg bodyweight. However, M. cuchia breed naturally in cisterns when provided with water hyacinths and tunnel in muddy bottom. M. cuchia fed with chopped cooked fish attained a mean weight of 18.75 ± 2.3 g and cent percent survival. While in case of M. armatus best growth by weight (12.0 ± 2.48 g) and cent percent survival were achieved using chopped raw fish. Car tyre was observed as best shelter for attaining the mean weight gain 22.53 ± 2.24 g and cent percent survival of M. cuchia. While PVC pipe was found to be the best shelter for M. armatus, where it attained the mean weight of 12.73 ± 1.88 g and cent percent survival.

Comparative study on the toxin production and profiles Raphidophytes at different salinities

PLEASE ALSO CHECK THE FULL TEXT ABSTRACT. Toxin production and toxin profiles of four Raphidophytes grown under different salinities were compared to investigate the influence of salinity on cellular content of neurotoxin. In Chatonella andqua CaTx-1, CaTx-11, and CaTx-111 peaked at 25 pplt with yields of 0.99, 0.42, and 2.90 pg/ceU, but the highest yields (2.35 pg/cell) of CaTx-IV was attained at 30 ppt. On the other hand, Chatonella marina yielded higher proportions of CmTx-1 (0.55 pg/ceH) and CmTx-111 (2.50 pg/cell) at 25 ppt. However, CmTx-IV was present in its highest amount (1.65 pg/cell) at 30 ppt, as seen in C anriqua. A smaH amount of CmTx-11 was also detected at 20-35 ppt. The toxin compositions indicate that H. akashiwo is more sensitive to higher salinities than the other three raphidophytes. Substantial compositional change was observed in case of H. akashiwo. HaTx-11 (corresponding to PbTx-9) was detected only as a trace at 20 and 25 ppt. Toxin HaTx-IV (corresponding to oxidized PbTx-2) was most dominant and peaked at 20 ppt with a yield of 0.3 pg/cell. Considerable amounts of HaTx-1 and III (corresponding to PbTx-2 and 3) were also detected. At higher salinities of above 25 ppt HaTx-11 was not detected. F. japonica gave highest yields of FjTx-11 (PbTx-2) and FjTx-IV (Oxidized PbTx-2) at 20 ppt with yields of 0.95, 1.54 pg/cell while the production of toxic profiles FjTx-1 (PbTx- 1) and FjTx-111 (PbTx-3) peaked at 25 ppt with yields of 0.99, 2.54 pg/ceU. A sharp decrease in all toxins profiles (CaTx, CmTx, HaTX and FjTx) was found at salinities of above 30 ppt.

Seed production and culture techniques of climbing perch, Anabas testudineus

Six treatments each with 12 replications designed to optimize the dose of inducing agent PG to achieve fertilization and hatching success of climbing perch, Anabas testudineus were tested. The females were given single injection of 7-12 mg PG/kg body weight and the males were given 4 mg PG/kg body weight. Fertilization and hatching rate varied from 67±4.55% to 66±3.0% and 59±4.88% to 57±6.21% for the doses of 10, 11 and 12 mg PG/kg of body weight, respectively. The hormone dose had significant (P<0.05) effect on fertilization and hatching. Six mini shallow cisterns (570 cm x 105 cm) were used to investigate the efficacy of zooplankton and Artemia nauplii as feed for spawn rearing. Three-day old spawns were stocked in six mini shallow cisterns at a stocking density of 100 individuals/L of water. Two treatments each with three replications were used to develop culture technique of the climbing perch. In case of treatment-1, the spawns were fed with Artemia nauplii three times daily, while in treatment-2, zooplankton were used as feed in the same manner as in treatment-1. After 14 days of rearing, mean final weight of the fry of treatments-1 and 2 were 95.55±6.71 and 57.69±5.40 mg, respectively. In treatment-1, spawn fed with Artemia nauplii showed significantly (P<0.05) higher mean weight than the spawn fed with zooplankton (treatment 2).