Characterization of intake and effluent waters from intensive and semi-intensive shrimp farms in Texas

Two commercial shrimp farms in south Texas were evaluated for influent and effluent water quality from June to October 1994. The intensive farm, Taiwan Shrimp Village Association (TSV) had an average annual yield of 4630 kg ha^?1 while the semi‐intensive farm, Harlingen Shrimp Farm (HSF), had a yield of 1777 kg ha^?1. The study had three objectives: (1) to compare influent and effluent water from the intensive and semi‐intensive shrimp farms, (2) to show which effluent water‐quality indicators exceeded allowable limits, (3) to indicate inherent problems in farms operated with water exchange and summarize how findings from this study led to changes in farms' management that limited potential negative impact on receiving streams. Water samples were collected and analysed twice a week for the TSV farm and once a week for the HSF farm. Samples were analysed for dissolved oxygen (DO), salinity, pH, ammonia‐nitrogen (NH₃‐N), nitrite‐nitrogen (NO₂‐N), nitrate‐nitrogen (NO₃‐N), total phosphorus (TP), total reactive phosphorus (TRP), five‐day carbonaceous biochemical oxygen demand (cBOD₅), total suspended solids (TSS) and settleable solids (SettSols). Most of the effluent constituents showed fluctuations throughout the sampling period often related to harvest activity. Effluent pH at TSV was lower than influent values but within the regulatory requirements set by Texas Commission of Environmental Quality (TCEQ), formerly known as Texas Natural Resource Conservation Commission (TNRCC). HSF effluent pH values were higher than its influent, but still within TCEQ limits. Effluent DO mean levels were generally below the regulatory daily mean requirement, with values at TSV often below those for influent. Effluent nutrient concentrations and net loads were generally higher at the intensive shrimp farm, with NH₃‐N mean concentrations above the daily mean set by the TCEQ on several occasions. Effluent TSS concentrations were higher than influent for both farms, with daily mean values above the TCEQ limit. The two farms presented similar TSS concentrations despite their different stocking densities. However, TSS total net load and net load per hectare were higher at the intensive farm. The semi‐intensive farm presented higher cBOD₅ concentrations and net loads despite its lower stocking density, with daily mean values above the TCEQ limit. The cBOD₅ net load at TSV presented negative values indicating higher load at the influent than at the effluent. Analyses showed no evidence of self‐pollution between influent and effluent at the two farms. The high feed conversion ratio (FCR) values (2.3 and 2.7 for the intensive and the semi‐intensive farm respectively) suggest that better feed management is needed to reduce nutrient and solid net loads release from the two farms. The data obtained from this study resulted in several modifications in design and management of the two farms that reduced the potential negative impact on receiving streams. A brief summary of the improvement in selected effluent water‐quality indicators at the intensive shrimp farm is provided.     

Anal leiomyoma in a Holstein heifer.

A 2-year-old heifer was presented with masses on her anus that were interfering with cervical manipulation during embryo flushing. The masses had broad stalks attached within the anal sphinchter. Recovery was without incident after surgical resection. No recurrence of the masses had occurred 3 months later. Histologic diagnosis was benign leiomyoma.     

Evaluation of microbial culture techniques for the isolation of Pythium insidiosum from equine tissues.

The purpose of this study was to evaluate the effects of sample handling, storage, and culture techniques on the isolation of Pythium insidiosum from infected equine tissues. Tissue and kunker samples obtained immediately posteuthanasia from a horse with subcutaneous pythiosis were used to assess the effects of sample type (kunkers vs. tissues), media type (selective vs. nonselective), storage technique, and storage time on P. insidiosum isolation rate. Overall, isolation rates were higher from fresh kunkers (94.6%) and stored kunkers (76.4%) than from fresh tissues (8.3%) or stored tissues (4.6%). Isolation of P. insidiosum also occurred more often on antibiotic-containing media than on nonselective media for both fresh and stored samples. For samples that were stored for 1-3 days prior to culture, P. insidiosum isolation rates were highest for the following techniques: kunkers stored at room temperature and plated on selective media (100%), kunkers stored at 4 C and then plated on either nonselective (91.7%) or selective (95.8%) media, kunkers stored on cold packs and then plated on either nonselective (93.8%) or selective (100%) media, kunkers stored in ampicillin solution and plated on selective media (100%), and kunkers stored in ampicillin/gentocin solution and plated on selective media (87.5%). For samples stored for 4-5 days, P. insidiosum isolation rates were highest for kunkers stored at 4 C and then plated on either nonselective (81.3%) or selective (87.5%) media, kunkers stored in ampicillin solution and then plated on selective media (87.5%), and kunkers stored in ampicillin/gentocin solution and plated on selective media (87.5%). Results of this study suggest that optimal isolation rates of P. insidiosum from infected equine tissues are achieved by culturing fresh kunkers on selective media. For samples that cannot be processed immediately, acceptable handling techniques include storage at room temperature for up to 3 days, refrigeration for up to 5 days, shipping on cold packs, and storage in antibiotic solution, each combined with subsequent inoculation on selective media.     

Plant–Water Relations of Kidney Bean Plants Treated with NaCl and Foliarly Applied Glycinebetaine

Salinity is at present one of the most serious environmental problems influencing crop growth. It has been extensively demonstrated that salinity affects several physiological processes in the plant, including the plant–water relations of most salt-sensitive crops species. In this study, the effects of salinity on the plant–water relations of kidney bean ( Phaseolus vulgaris L.) and the possibility that foliarly applied glycinebetaine improves these water relations are examined. Kidney bean plants were grown in a greenhouse and treated with 0, 30, 50 and 100 m M NaCl, combined with 0, 10 and 30 m M glycinebetaine in foliar applications. Increased salinity levels decreased stomatal conductance, photosynthetic rate, transpiration and leaf relative water content in the 30, 50 and 100 m M treatments relative to the control treatment. Glycinebetaine applications of 10 m M increased stomatal conductance at 50 m M NaCl, ameliorating significantly the effect of salinity on water relations through increases in the leaf relative water content. At 100 m M NaCl, 30 m M glycinebetaine applications in particular contributed to osmotic stress, and had an adverse effect on plants. Our experiment suggests that glycinebetaine can be used as an alternative treatment to reduce the effects of salt stress on the water relations of salt-sensitive plants, but only to limited salinity levels. Furthermore, the improvement in the water status of kidney beans was dose dependent, suggesting that the concentration of glycinebetaine essential for the survival of salt-sensitive plants is species specific and must be determined individually for each plant species.     

Topographie des Collecteurs Lymphatiques Mammaires de la Chienne

The topography of the lymph drainage was examined by in vivo injections of india ink into the mammary parenchyma of 73 female dogs. Only one gland was injected at a time on each side. Only the cranial abdominal mammary gland had direct drainage to the axillary as well as to the superficial inguinal nodes. The principal routes of drainage differ for each gland. The glands on each side are completely independent as regards their lymph drainage. The cranial thoracic mammary glands on each side had their own collecting duct which led to the sternal lymph nodes. The results of this study suggest to develop a new model for the surgical extirpation of mammary tumors in the bitch.     

Heterologous strain immunity in bovine babesiosis using a culture-derived soluble Babesia bovis immunogen

The cross-protective capacity of culture-derived soluble immunogens against heterologous Babesia bovis strains from different geographical locations of Latin America was examined. Susceptible yearling cattle were either immunized with immunogens derived from Venezuelan or Mexican strains, or were administered a multi-component immunogen containing antigens of the Australian, Mexican and Venezuelan strains. Cattle were challenged with virulent B. bovis organisms of the Argentinian, Colombian, Ecuadorean, Mexican and Venezuelan strains. The major parameters used to evaluate cross-protection were the following: presence, level and duration of parasitemia; maximal PCV reduction; level and duration of fever; determination of fibrinogen and cryofibrinogen; homologous and heterologous antibody levels; and net gains in body weight. Results showed good protection with a Venezuelan B. bovis immunogen after homologous and heterologous challenge exposures. A low degree of cross-immunity was observed when cattle vaccinated with the Mexican immunogen were challenged with each of the heterologous strains.     

Genotypic effects of sorghum accessions on fecundity of sorghum head bug,Calocoris angustatus Lethiery

Summary Sorghum head bug (Calocoris angustatus Leth.) (Hemiptera: Miridae) is an important pest of grain sorghum in India. We studied the fecundity of head bug females reared for one to three generations on head bug-resistant and head bug-susceptible genotypes during the 1988 and 1989 rainy and 1988–89 post-rainy seasons. Head bug population increase was lower for the first, second and/or third generation when the bugs were reared on IS 2761, IS 19955, IS 14334, IS 23748, IS 16357, IS 17610, and IS 21444 compared with the susceptible controls CSH 1, CSH 5, and CSH 9. These genotypes also suffered a low grain damage (damage rating (DR) 5) (except IS 2761) compared with the susceptible controls (DR>6). A marginal decrease in fecundity was observed when the bugs were reared on IS 2761, IS 14334, IS 16357, IS 20740 and IS 17610 and then transferred to the susceptible control, CSH 1. Sorghum genotypes having lower increase in bug population across generations, suffering low grain damage, and showing adverse effects on fecundity can be used in breeding for resistance to head bugs.     

Biodiversity of mannose-specific lectins within Narcissus species

Mannose-specific lectins (MSLs) were isolated from the bulbs of 27 species of wild Spanish Narcissi and compared to the commercially available MSL from daffodil (Narcissus pseudonarcissus, NPA). Molecular weight analysis showed the monomers of all the MSLs were at, or around, 12.5 kD. Haemagglutination assays showed that the MSLs exhibited activities at up to four times greater than that displayed by NPA and other MSLs derived from other species such as Galanthus nivalus (snowdrop) and Allium ursinum (ramson). Elution profiles from ion exchange chromatography exhibited similarities for species within the same taxonomic section suggesting that this method could aid in species classification. Further analysis by isoelectric focusing showed many isolectins are present in vivo and that even within a single peak from ion exchange chromatography there are numerous isolectins present. The basis of the isolectin heterogeneity is suggested to reside in the tetraploidy (sometime triploidy) nature of Narcissus genes.     

Impacts of urbanization on Florida Key deer behavior and population dynamics

Rapid human population growth and urbanization have had a negative impact on species biodiversity. As competition for resources between man and wildlife continues, it is important to understand the effects of urbanization on species. Endangered Key deer (Odocoileus virginianus clavium) are endemic to the Florida Keys which have undergone rapid human population growth and development over the past 30 years. Our study objectives were to evaluate the impacts of urban development on Key deer habitat use, population dynamics, behavior, and body mass. We used data from two comprehensive studies on Key deer spanning 30 years to evaluate these changes. Our results suggest that Key deer have become more urbanized, using urban areas more today than they did 30 years ago. Contrary to our predictions, survival was higher for more urban deer than for less urban deer. Problems still exist with mortality factors heavily impacting some portions of the deer population including lower survival associated with less urban male deer. Analysis of Key deer body mass also was converse to our predictions as deer weights appear to have increased over time. Collectively, our results suggest that over the past 30 years Key deer have become more urbanized and that deer plasticity has allowed them to adapt and persist in an urbanizing environment. However, the future ability of Key deer to persist in an environment with continued urban development is unknown. At some threshold, urban development would become unsustainable and unlike other forms of habitat change or environmental disturbances, urban development is in most cases irreversible requiring careful planning in habitat conservation strategies.