Differential inheritance of pepper (Capsicum annuum) fruit pigments results in black to violet fruit colour

Colour is a critical determinant of fruit and vegetable quality. We characterized the inheritance of black and violet immature pepper fruit colour and chlorophyll, carotenoid and anthocyanin pigments responsible for fruit colour. Segregation for black vs. violet fruit colour deviated from expectations for simple inheritance. The primary determinant of fruit colour was the concentration of chlorophyll and carotenoid pigments relative to anthocyanin concentration. Whereas anthocyanin concentration was 34% greater in violet fruit, chlorophyll and carotenoid concentrations were 20‐fold and fourfold greater, respectively, in black fruit relative to concentrations found in violet fruit. Measurement of Commission Internationale d'Eclairage (CIE) colour space scores revealed larger a* values and smaller b* values for violet fruit relative to corresponding parameters for black fruit. An additive–dominance model was sufficient to explain the variation in individual fruit pigments as well as the CIE parameter a*. Addition of additive × additive effects to the additive–dominance model resulted in the best‐fit model m[d][h][i] for L* and b* colour space parameters. For all pigment classes, significant additive effects contributed to the genetic variance for fruit colour.     

Paramyxovirus infection in caiman lizards (Draecena guianensis).

Three separate epidemics occurred in caiman lizards (Dracaena guianensis) that were imported into the USA from Peru in late 1998 and early 1999. Histologic evaluation of tissues from necropsied lizards demonstrated a proliferative pneumonia. Electron microscopic examination of lung tissue revealed a virus that was consistent with members of the family Paramyxoviridae. Using a rabbit polyclonal antibody against an isolate of ophidian (snake) paramyxovirus, an immunoperoxidase staining technique demonstrated immunoreactivity within pulmonary epithelial cells of 1 lizard. Homogenates of lung, brain, liver, or kidney from affected lizards were placed in flasks containing monolayers of either terrapene heart cells or viper heart cells. Five to 10 days later, syncytial cells formed. When Vero cells were inoculated with supernatant of infected terrapene heart cells, similar syncytial cells developed. Electron microscopic evaluation of infected terrapene heart cells revealed intracytoplasmic inclusions consisting of nucleocapsid strands. Using negative-staining electron microscopy, abundant filamentous nucleocapsid material with a herringbone structure typical of the Paramyxoviridae was observed in culture medium of infected viper heart cells. Seven months following the initial epizootic, blood samples were collected from surviving group 1 lizards, and a hemagglutination inhibition assay was performed to determine presence of specific antibody against the caiman lizard isolate. Of the 17 lizards sampled, 7 had titers of < or =1:20 and 10 had titers of >1:20 and < or =1:80. This report is only the second of a paramyxovirus identified in a lizard and is the first to snow the relationship between histologic and ultrastructural findings and virus isolation.     

Multiple predator effects and native prey responses to two non‐native Everglades cichlids

Abstract – Non‐native predators may have negative impacts on native communities, and these effects may be dependent on interactions among multiple non‐native predators. Sequential invasions by predators can enhance risk for native prey. Prey have a limited ability to respond to multiple threats since appropriate responses may conflict, and interactions with recent invaders may be novel. We examined predator–prey interactions among two non‐native predators, a recent invader, the African jewelfish, and the longer‐established Mayan cichlid, and a native Florida Everglades prey assemblage. Using field enclosures and laboratory aquaria, we compared predatory effects and antipredator responses across five prey taxa. Total predation rates were higher for Mayan cichlids, which also targeted more prey types. The cichlid invaders had similar microhabitat use, but varied in foraging styles, with African jewelfish being more active. The three prey species that experienced predation were those that overlapped in habitat use with predators. Flagfish were consumed by both predators, while riverine grass shrimp and bluefin killifish were eaten only by Mayan cichlids. In mixed predator treatments, we saw no evidence of emergent effects, since interactions between the two cichlid predators were low. Prey responded to predator threats by altering activity but not vertical distribution. Results suggest that prey vulnerability is affected by activity and habitat domain overlap with predators and may be lower to newly invading predators, perhaps due to novelty in the interaction.     

Incidence of lameness in dairy cows

A survey of the number of treatments for lameness in 21,000 dairy cows from 185 herds in the University of Edinburgh/Dalgety Spillers dairy herd health and productivity service in England and Wales showed an average incidence of cases of 25 per cent. Veterinary surgeons treated 6.3 per cent and farmers 18.7 per cent and 1.4 per cent of cows were culled because of lameness. Monthly and regional variations were recorded. An assessment of the economic effects suggested that the average annual cost in a 100 cow herd was 1175 pounds with an overall cost to British farmers of more than 35 million pounds. The economic importance is such that research into specific factors affecting foot health should be carried out. Meanwhile, a broad approach to prevention and control of lameness on farms is recommended under the general headings of management/environment, nutrition and breeding.     

Tropical fish medicine. Copper treatments. Uses and precautions

Copper is an old but effective treatment for fish diseases. It is now primarily used to treat acute infestations of parasites such as Amyloodinium and Cryptocaryon. Many fish are sensitive to copper and may become intoxicated at concentrations required to control pathogens. Copper concentrations in treatment tanks must be measured frequently to ensure that levels are therapeutic but not toxic. A knowledge of the solution chemistry of copper is essential in understanding how to avoid unexpected changes in copper concentrations. Factors such as pH, salinity, decorative materials, nature of the filter bed, and the type of therapeutic agent used for treatment must be considered.     

Emergency and critical care of fish.

Most fish emergencies are the result of inappropriate environmental conditions and primary or secondary infectious disease or trauma. The immediate response should be to increase aeration, provide suitable water, and decrease stressors. A thorough history, evaluation of the fish and their environment, and some rapid diagnostic tests (particularly direct and stained cytology) often provide the information needed to make a diagnosis and render appropriate treatment. When cohorts are at risk and the patient is unlikely to recover, euthanasia and necropsy are recommended to reach a definitive diagnosis. Some common emergencies include ammonia and nitrite toxicity; low dissolved oxygen; copper and chlorine toxicity; gas supersaturation; and certain bacterial, protozoal, and viral diseases.