A new aspidorhynchid fish (Teleostei: Aspidorhynchiformes) from the Upper Jurassic of Ettling,Solnhofen, Bavaria,Germany

A new species of Aspidorhynchidae is described for the first time from the Late Jurassic of Ettling, some 50 km E-SE of Solnhofen, Bavaria, Germany. This new material is attributed to a new species, Aspidorhynchus sanzenbacheri, and is diagnosed by the abbreviated premaxillae, the form and disposition of teeth in the predentary, and the number of principal rays in the caudal fin.     

A Passiflora homolog of a D-type cyclin gene is differentially expressed in response to sucrose, auxin, and cytokinin

In higher plants, one of the major components of developmental processes is cell division. The cell division cycle in plants is controlled by cyclins and cyclin-dependend kinases. Nutrient and hormonal signals can influence the roles that D-type cyclins play in the G1-to-S phase transition. Auxins and cytokinins are long known to be important plant hormones controlling plant growth. Additionally, as sucrose is the major transported carbon source in higher plants, it is possible that it plays a major role in cell division. To access the molecular aspects of the effect of auxin, cytokinin and sucrose on the regulation of cell cycle machinery and plant development, we cloned a Passiflora morifolia putative homolog to a D-type cyclin, PmCYCD1, which showed high sequence similarity to other known plant D-type cyclins. We examined the expression patterns of PmCYCD1 during callus induction and growth in in vitro conditions. We observed incremented expression levels of PmCYCD1 correlated to increasing concentrations of sucrose, α-naphthalene acetic acid and 6-benzyladenine in the culture medium. Additionally, the results of in situ hybridization experiments indicated a dynamic spatial expression pattern for PmCYCD1 during callus growth.     

On the occurrence of the hydrocoral Millepora (Hydrozoa: Milleporidae) in the subtropical eastern Atlantic (Canary Islands): is the colonization related to climatic events?

The occurrence of a hydrocoral of the genus Millepora has been recorded for the first time in the eastern subtropical Atlantic (Tenerife, Canary Islands), at a latitude of 11o N of its previously known northernmost limit of distribution in the Cape Verde Islands. The moderate development of the colonies, their fast growth rate and very restricted location indicate a recent colonization process, possibly related to an extreme climatic event that took place in the summer of 2004, adding to the rising seawater temperatures in the region during recent years.     

Andromonoecy in Solanum lycocarpum A. St. -Hil. (Solanaceae): Floral attributes,visitors and variation in sexual expression over time

Sexual expression in andromonoecious species—those in which a single individual can bear both staminate and hermaphroditic flowers—may vary among reproductive events in the same plant, among individuals and across populations. This variation influences, in turn, the individual contribution of hermaphroditic plants via male and female fitness functions (i.e., Lloydʼs phenotypic gender). However, temporal variation in sexual expression in andromonoecious species and its relationship with seasonal changes in climatic conditions remain poorly understood. Here we analyze floral attributes, visitors and variation in sexual expression in three populations of Solanum lycocarpum A. St. -Hil. Seasonality in the production of floral types, the mating system and floral visitors were also investigated. Hermaphroditic flowers produced more pollen grains, but the pollen of staminate flowers had higher viability. Only hermaphroditic flowers produced fruits, and ovules in staminate flowers were sterile. Solanum lycocarpum is mainly pollinated by large bees with the ability to vibrate flowers. Phenotypic gender varied throughout the year, and the seasonal production of staminate flowers is associated with the local climate. We suggest that the higher and seasonally variable relative abundance of staminate flowers compared to the low and uniform production of hermaphroditic flowers may be explained by (a) the very high energetic costs incurred in producing large fruits, which in turn make hermaphroditic flower production very costly, and (b) the potentially lower energy expenditure of the smaller staminate flowers with reduced pistils and non-viable ovules that allow them to rapidly respond to climate variability.     

Embryogenesis and larval development of migratory matrinchã Brycon orthotaenia Günther 1864 (Characiformes: Bryconidae)

The present study aimed to characterize the embryogenesis and larval development of matrinchã (Brycon orthotaenia), through the analysis of egg and larval morphology. Fertilized eggs had a mean diameter of 1.17 mm, with yolk occupying most of the egg (1.06 mm). Embryogenesis lasted for 15 hr at an average temperature of 27°C. At hatching, yolk-sac larvae measured 3.67 mm in mean standard length (SL). Pre-flexion, flexion and post-flexion larva had 5.01, 8.24 and 11.88 mm mean SL, respectively, with significant increases observed particularly in head length, head height, and eye diameter. The yolk persisted in the yolk-sac and pre-flexion stages (5.96 mm SL). The mouth opening could first be observed 13 hr after hatching, and cannibalism was observed 29 hr after hatching in pre-flexion larvae after absorption of the yolk sac; in such cases, the larvae had already developed teeth and a complete digestive tract. For an endangered species such as matrinchã, early life history studies are important because they provide researchers with a better understanding of critical stages of development and thus enhance captive management by rearing and restocking of the species.     

Regionalized phosphorus fate factors for freshwater eutrophication in Bahia,Brazil: an analysis of spatial and temporal variability

The International Journal of Life Cycle Assessment - Fate factors, for freshwater eutrophication, represent the route of a limiting-nutrient, phosphorus or nitrogen, and their degradation in the...     

Fisheries and biotic homogenization of freshwater fish in the Brazilian semiarid region

Hydrobiologia - The construction of dams in Brazilian semiarid regions has been a common governmental practice since the early 1900s, initially with the aim of providing water to meet the needs of...     

Competitive interactions and partial displacement of Anastrepha obliqua by Ceratitis capitata in the occupation of host mangoes (Mangifera indica)

1. We examined the competitive interactions between a native fruit fly species (Anastrepha obliqua Macquart) and the invasive medfly (Ceratitis capitata Wiedemann) when these co-occur on a shared mango fruit host (Mangifera indica L.).
2. Using mango fruits of distinct levels of ripeness, we investigated both competition among larvae and among adult females for oviposition. We quantified competition by the numbers of eggs laid and the intensity of agonistic interactions between adult females.
3. Interactions between immature fruit flies led to reduced size and number of emerged adults of both species. These impacts were felt more acutely in the native species.
4. Interspecific competition between females led to fewer eggs laid on semi-ripe fruit by both species, which may be the result of niche overlap associated with oviposition.
5. Intraspecific interactions between A. obliqua individuals led to intense agonistic behaviour, with a concurrent decrease in number of landings on these host fruits.
6. These results suggest that the native species undergoes a partial niche displacement when facing the invasive species. A portion of the fundamental niche of A. obliqua remained unoccupied by the invading C. capitata, which may allow their coexistence under natural conditions.

     

Purification of adhesive proteins from mussels

The adhesive polyphenolic proteins from the mussels Mytilus chilensis and Choromytilus chorus have been purified based on their solubility in dilute perchloric acid and on differential precipitation with acetone containing about 0.3 N HCl. The specific activity of the proteins obtained was 0.16 mg of 3,4-dihydroxyphenylalanine per milligram of protein, or higher. The proteins have an apparent molecular weight of about 100,000 and they contain a high proportion of 3,4-dihydroxyphenylalanine, lysine, and proline.