Haemogregarina pseudemydis n. sp. (Apicomplexa: Haemogregarinidae) and Pirhemocyton chelonarum n. sp. in Turtles from Louisiana*

SYNOPSIS. The blood of each of 95 turtles (8 species) collected from southeastern Louisiana was infected with some or all of the merogonic stages and gametocyte stage of Haemogregarina pseudemydis n. sp. Five species of turtles harbored Pirhemocyton chelonarum n. sp. Turtle Haemogregarina and Pirhemocyton are locality records for Louisiana. Pirhemocyton is reported for the first time in turtles and in the continental U.S.A.     

Xylem, Phloem and Transpiration Flows in Developing Apple Fruits

Xylem, phloem and transpiration flows were measured in developingfruits of the apples Royal Gala and Cox's Orange Pippin at early,mid and late stages during their development. Fruit volume growthwas first computed from measurements of diameter made usinga system of sensitive displacement transducers. Xylem, phloemand transpiration flow components (of which fruit volume growthis the integral) were then separated using a scheme of treatmentswhich disabled one or other flow at a time. Changes observed during development in the patterns of the threeflows are in general agreement with expectations based on lessdirect observations (loc. cit. Ferguson and Watkins, 1989).Recognizing the distinctive mineral compositions of xylem andphloem streams, the changes also accommodate, and seem to explain,published observations of mineral accumulation in apple. Significant differences in the pattern of xylem and phloem flowwere observed between the varieties examined. These may explainvarietal differences in susceptibility to the mineral imbalancedisorder bitter-pit. Xylem flows were shown to reverse at times; that is they flowedfrom fruit to tree. This occurred particularly during periodsof high evaporative demand. Xylem reversal is of importanceto the overall water economy of a tree but may also have specialimportance to the mineral composition of the fruit. Key words: Mineral nutrition, bitter-pit, apple, xylem, phloem, transpiration, water balance     

Testing Predictions of the Prey of Lion Derived From Modeled Prey Preferences

Abstract: Apex predators are often threatened with extinction, and reintroduction is one method conservation managers are using to secure their persistence. Yet the ability to predict what these predators will eat upon reintroduction is lacking. Here we test predictions of the diet of the lion (Panthera leo), derived from dietary electivity index and optimality theory, using independent data collected from reintroduced and resident populations. We solved the Jacobs’ index preference equation for each prey species of the lion using values calculated by Hayward and Kerley (2005) and prey abundance data from 4 reintroduction sites and one resident lion population over several years. We then compared these estimates with actual kill data gathered from each site and time period, using the log-likelihood ratio and linear regression. The model precisely predicted the observed number of kills in 9 of the 13 tests. There was a highly significant linear relationship between the number of lion kills predicted to occur at a site and the number observed for all but one site (x̄r² = 0.612; β = 1.03). Predicting predator diet will allow conservation managers to stop responding and start planning in advance for reintroductions and environmental variation. Furthermore, ensuring that sufficient food resources are available is likely to increase the success of reintroduction projects. In addition, managers responsible for threatened prey species will be able to predict the vulnerability of these species to predation in the event of predator reintroductions or changes in abundance. These methods are applicable to virtually all large predators that have been sufficiently studied.