Efficacy of a starch-iodide swab technique to detect the illegal use of bleach in a Spiny Lobster (Panulirus argus) fishery

The destructive and illegal practice of using chemicals (bleach, dishwashing liquid, gasoline) to catch spiny lobster (Panulirus argus) is thought to be common throughout much of the Bahamian Archipelago. Injection of a chemical irritant into a lobster den will result in either a rapid escape response or a subduing effect, both of which make it easier to capture spiny lobster. We used both laboratory and field trials to determine the efficacy of a starch-iodide swab technique to identify lobsters that had been exposed to bleach solution (NaOCl). All lobsters exposed to bleach tested positive immediately following exposure and for varying periods thereafter. No false positives were detected on control lobsters. The average length of time that bleach remained detectable on the exoskeleton was 6.2 and 9.6 h in the laboratory and field, respectively, with some individuals testing positive 12 h after exposure. The swab technique will provide fishery officers with a powerful tool to reduce or eliminate the illegal use of bleach for harvesting spiny lobster.     

Generation of immunity against Fusobacterium necrophorum in mice inoculated with extracts containing leucocidin

The capacity of extracts from toxigenic and non-toxigenic ruminant strains of Fusobacterium necrophorum to protect against challenge with homologous and heterologous bacteria was examined in mice. The numbers of F. necrophorum which were infective or lethal for mice increased 5- to 8-fold in animals which had been previously inoculated with complete Freund's adjuvant (FCA). Although preparations containing lipopolysaccharide (LPS) and outer membrane proteins (OMP) from several strains gave protection against a non-toxigenic strain (FnB-3), they did not significantly immunize mice against a challenge infection with a toxigenic bovine strain, FnB-1. Only material which had been prepared by gel filtration of 18-h liquid culture supernates of toxigenic F. necrophorum elicited significant immunity against homologous challenge with FnB-1. This preparation contained LPS and the majority of the leucotoxic activity. However, passive protection was not afforded to mice inoculated with bovine or rabbit sera which possessed high neutralization titres against the leucocidin.     

Sperm Supply and Egg fertilization in the Ostrich (Struthio camelus)

We used egg break‐out and spermatozoa trapped in the perivitelline layer of eggs to test the hypothesis that sperm supply and egg fertilization rate are high in the ostrich. Egg fertilization status was determined at break‐out by the appearance of the germinal disc (GD) and then the perivitelline layer overlying the GD region was collected to count sperm (Sperm_OPVL) under fluorescence following staining with 4′,6′‐diamidino‐2‐phenyindole (DAPI). The study was carried out on commercial ostrich farms over two laying seasons. In the first year, 229 eggs from nine randomly chosen ostrich pens comprising pairs, trios (two females, one male) and larger groups were collected for 1 week of every month of laying. Eggs contained 253 ± 18 Sperm_OPVL/mm² of the GD (mean ± SEM; range 0–1330). Egg fertilization rate averaged 89.4 ± 3.4% and varied from 78.6 to 98.2% between pens. Month had no effect on sperm supply or egg fertilization status. Eggs from paired birds (sex ratio 1 : 1) had less sperm in the GD than the eggs from pens with a higher sex ratio. In the second year, 150 eggs from seven pens, each containing only one male and either one, two or three females, were studied for 2 weeks at the beginning (winter), middle (spring) and end (summer) of laying. Eggs contained 364 ± 45 Sperm_OPVL/mm² of the GD (range 0–2880). Season had no effect on sperm supply or egg fertilization. The number of Sperm_OPVL varied between pens, assumed to be due to variation between individual males. The number of Sperm_OPVL increased as the sex ratio increased only when very high‐ranking males were excluded from the analysis. Egg fertilization rate was 94.4 ± 3.1% but varied from 64.0 to 100% between pens. Egg fertilization was not affected by season or sex ratio. Low fertilization rates were observed in two pens and appeared related to the lack of synchrony between timing of laying and sperm production in the first, and lack of mating in the second pen. We conclude that ostrich flocks generally have high rates of egg fertilization and any infertility is associated with lack of sperm supply.     

LRH-A3对母猪繁殖性能的作用及效果观察

为了观察促排卵素3号（LRH-A3）对母猪繁殖性能的作用和效果，发情母猪配种前4—6h，用LRH-A3进行处理，并与不使用激素的发情母猪进行比较。结果地方品种母猪的受胎率、平均产仔数、仔猪成活率分别为93．3％、14．6头和89．5％。与对照组相比，母猪受胎率无显著差异（P〉0．05），平均产仔数显著高于对照组（P〈0．01），仔猪成活率比对照组低4．6％，差异显著（P〈0．01）。经产瘦肉型母猪的配种受胎率、平均产仔数、仔猪成活率分别为86．7％，12．3头和93．8％，与对照组相比，配种受胎率、仔猪成活率无显著性差异（P〉0．05），母猪平均产仔数显著高于对照组（P〈0．01）。青年瘦肉型母猪的配种受胎率、平均产仔数、仔猪成活率分别为83．3％、10．6头和94．5％，与对照组相比，母猪的配种受胎率、平均产仔数均显著高于对照组（P〈0．01），仔猪成活率与对照组无显著差异（P〉0．05）。试验结果表明，发情母猪配种前肌注LRH-A3后，青年瘦肉型母猪繁殖效果最理想，经产瘦肉型母猪次之，地方品种母猪不理想。     

Disturbance in the growth of the tibia and femur in dogs.

The clinical and radiographic features associated with premature cessation of the growth of the tibia (four) and femur (eight) in 12 dogs are described. Surgical correction of the resultant deformity was possible in only a few cases. Trauma was thought to be the cause of the local growth plate disorder.     

Metacontrast and evoked potentials: a reappraisal

Stimulation of the parafoveal retina may give rise to visual evoked responses generated in large part by stray light impinging upon the fovea. This effect appears to account for the absence of changes in the visual evoked response to parafoveal stimulation during metacontrast suppression. When the central retina is directly stimulated, the spatiotemporal interactions associated with brightness suppression during metacontrast may be readily demonstrated in a late component of the visual evoked response.