A phylogeny of frugivorous hornbills linked to the evolution of Indian plants within Asian rainforests.

Understanding the origin and radiation of modern Asian hornbills and the influential ecological roles they play as seed dispersal agents within Asian rainforests should help reveal the evolution of these roles. We constructed a dated phylogeny of hornbills using mitochondrial DNA sequences of the cytochrome b gene and discovered that all clades leading to frugivorous hornbills originated in the mid-Eocene ∼48 Ma. This 'explosive' radiation coincided with a remarkable floral invasion of Asian rainforests from the Indian microcontinent. Analysis of phylogenetic data, in conjunction with palaeontological events, suggests that the invasion of distinctive flora comprised two waves, one during the mid-Eocene, when India was offshore of the Sunda Shelf, and the other late Eocene, when India collided with the Asian mainland. We propose that frugivorous vertebrates, such as hornbills, were present during the first wave and assisted rapid colonization of the Asian flora.

Natural parasitic infection of the golden apple snail, Pomacea canaliculata.

Golden apple snails, Pomacea canaliculata, were collected once a month during a year to search for their natural parasites. The collections were made at two localities having different ecological environments. Of 576 collected snails from a canal, 176 individuals (30.6%) were infected by three groups of metacercariae. These parasites were amphistome, distome and echinostome metacercariae, which had prevalences of 23.5, 19.5 and 0.5%, respectively. The incidence of infection was highest (68.4% in October) when the snail population was composed of the old, juvenile and young Pomacea. Amphistome metacercariae were found most frequently and echinostome metacercariae the least frequently; both parasites were localized in the foot muscle of the snails and had a Shannon index of zero. The range of amphistomes was 1 to 115 with the mean +/- SD of 1 +/- 2 and 95% CL of 1, 2. Distome metacercariae were found primarily in the heart (range: 1-13), and also in the foot muscle (range: 1-5) and kidney (range: 1-14), with a Shannon index of 0.4. The means +/- SD (with 95% CL) were 3 +/- 4 (95% CL = 1, 5), 3 +/- 4 (95% CL = 2, 4) and 2 +/- 1 (95% CL = 1, 2) for the foot muscle, heart and kidney, respectively. The snails from a pond, another locality, had a low proportion of infected individuals. Of 605 snails, only 24 individuals (4.0%) were infected, with the prevalence of amphistomes, distomes and echinostomes being 0.8, 1.8 and 2.1%, respectively. The incidence of infection for each month was zero or less than 10%, except in May when it was 30.2%.

Chaunocephalosis in a wild population of Asian open-billed storks in Thailand.

The most common trematode collected from Asian open-billed storks (Anastomus oscitans) was Chaunocephalus ferox (80% prevalence). The trematode was paired in granulomas in the intestinal wall. Based on histological examination of these capsules, there was degeneration and necrosis of muscle cells in the tunica muscularis. Granulation tissue with hetrophil and lymphocyte infiltration appeared in the granulomas. Intestinal villi were shorter and wider in infected areas than in non-infected areas. Some intestinal glands were dilated. Storks with high intensity of C. ferox appeared ill. The death of storks infected with C. ferox may result from malnutrition due to the loss of absorptive function of the intestine and from the effect of granuloma formation which might interfere with the intestinal peristalsis.