Comparative water quality and channel catfish production in earthen ponds and a biofloc technology production system

This 210-day study compared variation in water quality and fish growth for channel catfish (Ictalurus punctatus; 47 g/fish) stocked in earthen ponds (1.5 fish/m², 14,820/ha) and in a biofloc technology (BFT) production system with high-density polyethylene-lined rectangular tanks (12.6 fish/m², 126,000/ha). Feed input and culture environment affected water-quality dynamics. In ponds, phytoplankton uptake predominated and little nitrification occurred, whereas in the BFT system phytoplankton uptake and nitrification maintained low ammonia-nitrogen concentrations. Size classes of fish were skewed toward the larger market sizes in ponds and toward smaller market sizes in the BFT system. Mean final fish weight was 630 g/fish in ponds and 542 g/fish in the BFT system. Despite these differences, fish yield was higher in the BFT system (7.7 kg/m³ v. 1.5 kg/m³) because of the greater initial stocking rate.     

Collection of equine cord blood and placental tissues in 40 Thoroughbred mares

Reasons for performing study: Stem cells derived from umbilical cord tissue (UCT) and umbilical cord blood (UCB) in human subjects and horses can be obtained in a minimally invasive fashion with successful propagation of mesenchymal stem cells (MSCs). Currently there are no detailed protocols documenting a procedure to harvest UCB and UCT safely for equine stem cell propagation. Hypothesis: UCB and UCT could be collected without harm to mare or foal. Objectives: To develop a standard and safe method for UCB and UCT collection, and prospectively to compare foal and mare health between groups of animals where tissue was and was not collected. Methods: This study was conducted at a Thoroughbred breeding facility in central California in 2008. UCB and UCT were collected from 40 mare and foal pairs. Clinical parameters including time for foal to stand and nurse, time for mare to pass the placenta, and foal haematology data at age 24 h were documented and compared to a control group, consisting of the succeeding 40 mare and foal pairs. Results: UCB was obtained successfully from 36 of 40 (90%) mares and UCT from 38 of 40 (95%) mares. Bacterial contamination was documented in 6 out of 36 (16.6%) UCB samples. There were no significant differences in time to stand or nurse for foals or time to pass the placenta for mares, between the experimental and control groups. There were no clinically relevant differences identified in haematological data obtained from foals with and without UCB collection. Conclusions: UCB and UCT can be harvested safely without harm to mares or foals. Potential relevance: UCB and UCT samples collected in an inherently contaminated environment can be successfully disinfected and transported with minimal bacterial overgrowth for use in cell culture to isolate MSCs.     

Renal myxozoanosis in crowned river turtles Hardella thurjii: description of the putative agent Myxidium hardella n. sp. by histopathology, electron microscopy, and DNA sequencing

Chelonian myxozoanosis is rarely reported and has previously not been documented to cause disease. This report describes myxozoanosis associated with significant renal disease in two Crowned River turtles (Hardella thurjii). One turtle presented with emaciation and died. The cage mate presented with emaciation and was euthanized. Histologically, renal intratubular myxozoan spores were associated with renal tubular necrosis, tubular mineralization, and chronic interstitial nephritis, with membranoproliferative and mes-angioproliferative glomerulopathy. Both turtles also had disseminated metastatic mineralization. On the basis of these findings, chronic renal insufficiency from myxozoanosis and subsequent metastatic mineralization were considered the primary problems. By light and electron microscopy, the myxozoan spores had features of the genus Myxidium. Maximum parsimony analysis of small-subunit rDNA sequences placed the turtle myxozoan basal to a clade containing Myxidium truttae and a Myxidium sp. with strong bootstrap support. This myxozoan agent appears to be a significant pathogen in H. thurjii on the basis of morphologic changes in the kidneys of in the infected turtles.     

Probabilities of Low Nighttime Temperatures during Stocking and Harvest Seasons for Inland Shrimp Culture

Litopenaeus vannamei is cultured in earthen ponds at southern US inland sites when water temperatures permit shrimp survival and growth. The probability of a minimum air temperature ≤14 C for one, three, or five consecutive days at one coastal and eight inland sites where L. vannamei is or could be grown in ponds is high (50%) from late March through late April at all sites except Arcadia, Florida, and Harlingen, Texas. Probabilities are 10% by early May to early June. In the autumn, the 10 and 50% probability levels are reached in early‐ to mid‐September and by late September to mid‐October, respectively. Arcadia, Florida, and Harlingen, Texas, have the longest periods with low probabilities and Pecos, Texas, has the shortest periods. The maximum pond water temperature from the previous afternoon and the minimum air temperature from that night predicted the minimum pond water temperature the following morning for Pine Bluff, Arkansas: (R² = 0.886): T_min = 1.464 + 0.169A_min + 0.727T_max, where T_min = minimum daily pond water temperature (C), A_min = minimum air temperature (C) for the same day, and T_max = maximum pond water temperature (C) from the previous day. Pond stock out and harvest decisions can be guided by minimum air temperature probabilities and predicted water temperature.     

Constituents of Cassia laevigata.

Calendin (1), cinnamic acid (2), 3-hydroxy-1-(4-hydroxy-3-methoxyphenyl)-propan-1-one (3), 2,3-dihydroxy-1-(4-hydroxy-3-methoxyphenyl)-propan-1-one (4), 3-hydroxy-1-(4-hydroxy-3,5-dimethoxyphenyl)-propan-1-one (5), syringic acid (6) and vanillic acid (7) have been isolated from a dichloromethane extract of the leaves and branches of Cassia laevigata.     

Bare Zone between California Shrub and Grassland Communities: The Role of Animals

Between shrub and grass communities in coastal California there is a zone that is normally bare of vegetation. Previous studies have emphasized the role of volatile inhibitors of plant growth in producing this bare zone. However, there is a concentration of feeding activity by rodents, rabbits, and birds in this zone; if this activity is prevented by means of wire-mesh exclosures, annuals grow in the bare zone. Thus, animal activity is sufficient to produce the bare zone.