Ticks (Acari: Ixodidae) Infesting Birds in an Atlantic Rain Forest Region of Brazil

Brazil has the third richest bird diversity of the world; however, there are few data concerning ticks (Acari: Ixodidae) parazitizing birds. The aim of the study was to report tick infestations on wild birds from an Atlantic rain forest region of Brazil. During 2 yr, ticks were collected from birds and from the environment in 12 forest sites. A total of 1,725 birds were captured representing 80 species from 24 families. In total, 223 (13%) birds were found infested by immature stages of Amblyomma ticks: 1,800 larvae and 539 nymphs. The prevalence of ticks was higher among-birds from the families Thamnophilidae, Conopophagidae, and Momotidae. The most common tick parasitizing birds was Amblyomma nodosum Koch. Other tick species, Amblyomma coelebs Neumann, Amblyomma cajennense (F.), Amblyomma ovale Koch, Amblyomma longirostre (Koch), Amblyomma calcaratum Neumann, and Amblyomma naponense (Packard), were found sporadically. Among free-living ticks collected in the environment, A. cajennense was the most common, followed by A. coelebs, A. naponense, Amblyomma brasilense Aragao, and Hemaphysalis juxtakochi Cooley.

Phosphorus kinetics in calves experimentally submitted to a trickle infection with Cooperia punctata

Ten male Holstein calves (74.3 +/- 3.2 kg LW) were used for a trial with trickle infection with Cooperia punctata to evaluate phosphorus (P) kinetics. Five calves were inoculated with 10,000 L(3) stage larvae per week during 35 days, while the other group of five calves was kept as a control. On the 29th day each calf was intravenously injected with 29.6 MBq of a (32)p solution. Blood samples were taken at 24 h periods for 7 days, after which all calves were slaughtered and worms burdens. Faeces, urine and tissue samples were taken for analysis using isotopic dilution and modeling techniques. The number of eggs per gram of faeces (EPG)was 1920 +/- 168 on 28th day and the total number of worms burdens was 11,131 +/- 1500. Infected calves showed lower feed intake and live weight gain, as well as lower P intake, absorption and retention than control calves. The P flows between body compartments were lower for blood to gastrointestinal tract (TGI), TGI to blood, blood to soft tissues, bone balance and soft tissue balance in infected calves when compared to the control. The trickle infection of C punctata affected P metabolism due to the decrease in P retained and live weight due to fall in feed intake. (C) 2009 Elsevier B.V. All rights reserved.

Biology and life cycle of Amblyomma incisum (Acari: Ixodidae)

Amblyomma incisum Neumann is a major tick species in the Atlantic Forest of Brazil. Tapir is the main host for adult ticks and a high aggressiveness of nymphs to humans has been reported. In this work data on the biology and life cycle of this tick species is presented for the first time. It was shown that horse is a suitable host for A. incisum adults and rabbit for larvae and nymphs. It was also shown that A. incisum is a big tick species (mean engorged female weight of 1.96 g) with a long life cycle which lasts 262.3 days when maintained at 27A degrees C and 85% RH. These laboratory conditions were, however, inappropriate and egg hatching rate (1.2%) was very low. Nevertheless egg hatching of ticks in a forest patch increased considerably (72.2%) indicating that this A. incisum population is highly dependent on a forest-like environment.

Transovarial passage of Leishmania infantum kDNA in artificially infected Rhipicephalus sanguineus

Phlebotomine sand flies are the only proven biological vectors of Leishmania parasites. However, Rhipicephalus sanguineus ticks have long been suspected to transmit Leishmania infantum in studies carried out in laboratory and natural conditions. In the present study, 5 mu l of L. infantum promastigotes (1 x 10(6) cells per ml) was injected into the hemocel through the coxa 1 of four engorged females (F1, F2, F3 and F4). Control ticks (F5 and F6) were injected with sterile phosphate-buffered saline (PBS) using the same procedure. Then, these females, their eggs, and the originated larvae were tested by real time polymerase chain reaction (real-time PCR) for the presence of L. infantum kinetoplast DNA (kDNA). Females and eggs were tested after the end of the oviposition period (about 5 weeks post-inoculation) whereas larvae were tested about 4 months after the inoculation of females. All artificially infected females were positive for L. infantum kDNA. In addition, two pools of eggs (one from F2 and other from F4) and four pools of larvae (one from each F1 and F4 and two from F2) were positive for L infantum kDNA. These results showed, for the first time, the transovarial passage of L. infantum kDNA in R. sanguineus ticks, thus suggesting that the transovarial transmission of L. infantum protozoa in ticks is worth to be investigated. (C) 2010 Elsevier Inc. All rights reserved.

The effect of resource aggregation at different scales: Optimal foraging behavior of Cotesia rubecula

Resources can be aggregated both within and between patches. In this article, we examine how aggregation at these different scales influences the behavior and performance of foragers. We developed an optimal foraging model of the foraging behavior of the parasitoid wasp Cotesia rubecula parasitizing the larvae of the cabbage butterfly Pieris rapae. The optimal behavior was found using stochastic dynamic programming. The most interesting and novel result is that the effect of resource aggregation within and between patches depends on the degree of aggregation both within and between patches as well as on the local host density in the occupied patch, but lifetime reproductive success depends only on aggregation within patches. Our findings have profound implications for the way in which we measure heterogeneity at different scales and model the response of organisms to spatial heterogeneity.

A comparison of anterior adhesive areas and secretions in Troglocephalus rhinobatidis and Neoheterocotyle rhinobatidis (Monogenea : Monocotylidae) from the gills of the shovelnose ray, Rhinobatos typus (Rhinobatidae)

This study continues the collection of data on the anterior adhesive areas and secretions of monopisthocotylean monogenean (flatworm) parasites and begins an investigation of their phylogenetic usefulness. Here, two species of parasitic worms from an elasmobranch, Troglocephalus rhinobatidis (Monocotylidae: Dasybatotreminae) and Neoheterocotyle rhinobatidis (Monocotylidae: Heterocotylinae), are compared and contrasted. It has been suggested in recent literature that these two taxa are more closely related than is currently recognised. Our data support this view. Both species have multiple apertures on the ventral anterior margin through which adhesive is secreted. Two types of secretion exit from multiple adjacent duct endings terminating in each aperture: rod-shaped (S1) and spherical-shaped (S2) bodies. S1 bodies of both species show nano-banding of similar size and are membrane bound. Ultrastructure of the glands, ducts, duct endings and secreted adhesive is similar for both species, but aperture shape differs. Away from the adhesive areas, tegumental inclusions are found to differ between the two species and another, apparently non-adhesive, secretion is found in N. rhinobatidis.

Embryonic development of the nervous system of the temnocephalid flatworm Craspedella pedum

The nervous system of temnocephalid flatworms consists of the brain and three pairs of longitudinal connectives extending into the trunk and tail. The connectives are crosslinked by an invariant number of regularly spaced commissures. Branches of the connectives innervate the tentacles of the head and the sucker organ in the tail. A set of nerve rings encircling the pharynx and connected to the brain and connectives constitute the pharyngeal nervous system. The nervous system is formed during early embryogenesis when the embryo represents a multilayered mesenchymal mass of cells. Gastrulation and the formation of separate epithelial germ layers that characterize most other animal groups are absent. The brain arises as a bilaterally symmetric condensation of postmitotic cells in the deep layers of the anterior region of the embryonic mesenchyme. The pattern of axon outgrowth, visualized by labeling with anti-acetylated tubulin (acTub) antibody, shows marked differences from the pattern observed in other flatworm taxa. in regard to the number of neurons that express the acTub epitope. Acetylated tubulin is only expressed in neurons that form long axon tracts. In other flatworm species, such as the typhloplanoid Mesostoma and the polyclad Imogine, which were investigated by us with the acTub antibody (Hartenstein and Ehlers [2000] Dev. Genes Evol. 210:399-415; Younossi-Hartenstein and Hartenstein [2000] Dev. Genes Evol. 210:383-398), only a small number of pioneer neurons become acTub positive during the embryonic period. By contrast, in temnocephalids, most, if not all, neurons express acTub and form long, large-diameter axons. Initially, the brain commissure, pharyngeal nerve ring, and the connectives are laid down. Commissural tracts and tentacle nerves branching off the connectives appear later. We speculate that the precocious differentiation of the nervous system may be related to the fact that temnocephalids move by muscle action, and possess a massive and complex muscular system when they hatch. In addition, they have muscular specializations such as the anterior tentacles and the posterior sucker that are used as soon as they hatch. By contrast, juveniles of Mesostoma and larvae of polyclads move predominantly by ciliary action that may not require a complex neural circuitry for coordination. (C) 2001 Wiley-Liss, Inc.

Platyhelminth phylogenetics - a key to understanding parasitism?

The comparative method, the inference of biological processes from phylogenetic patterns, is founded on the reliability of the phylogenetic tree. In attempting to apply the comparative method to the understanding of the evolution of parasitism in the phylum Platyhelminthes, we have highlighted several points we consider to be of value along with many problems. We discuss four of these topics. Firstly, we view the group at a phylum level, in particular discussing the importance of establishing the sister taxon to the obligate parasite group, the Neodermata, for addressing such questions as the monophyly, parasitism or the endo or ectoparasitic nature of the early parasites. The variety of non-congruent phylogenetic trees presented so far, utilising either or both morphological and molecular data, gives rise to the suggestion that any evolutionary scenarios presented at this stage be treated as interesting hypotheses rather than well-supported theories. Our second point of discussion is the conflict between morphological and molecular estimates of monogenean evolution. The Monogenea presents several well-established morphological autapomorphies, such that morphology consistently estimates the group as monophyletic, whereas molecular sequence analyses indicate paraphyly, with different genes giving different topologies. We discuss the problem of reconciling gene and species trees. Thirdly, we use recent phylogenetic results on the tapeworms to interpret the evolution of strobilation, proglottization, segmentation and scolex structure. In relation to the latter, the results presented indicate that the higher cestodes are diphyletic, with one branch difossate and the other tetrafossate. Finally, we use a SSU rDNA phylogenetic tree of the Trematoda as a basis for the discussion of an aspect of the digenean life-cycle, namely the nature of the first intermediate host. Frequent episodes of host-switching, between gastropod and bivalve hosts or even into annelids, are indicated.

Antifungal alkyl amino alcohols from the tropical marine sponge Haliclona n. sp.

Three new amino alcohols presumably deriving from L-alanine were isolated from the tropical marine sponge Haliclona n. sp. and characterized by 2D NMR, while a fourth amino alcohol was characterized as an acetamide derivative. Relative stereochemistry was deduced from the NMR characteristics of oxazolidinone derivatives and absolute stereochemistry secured by preparation and analysis of an MPA ester. The amino alcohol fraction from Haliclona n. sp, acts as an antifungal agent and inhibits the development of larvae of the ascidian Herdmania curvata.

Chronostratigraphy of the CRP-3 drillhole, Victoria Land Basin, Antarctica

An 823 m thick glaciomarine Cenozoic section sitting unconformably on the Lower Devonian Beacon Supergroup was recovered in CRP –3. This paper reviews the chronostratigraphical constraints for the Cenozoic section. Between 3 and 480.27 mbsf 23 unconformity bounded cycles of sediment were recorded. Each unconformity is thought to represent a hiatus of uncertain duration. Four magnetozones have been recognised from the Cenozoic section. The record is complex with several “tiny wiggles” recorded throughout. Biostratigraphical or Sr ages, which could be used to link these magnetozones to the magnetic polarity time scale are restricted to the upper 190 m of sediment. Two diatom datums (Cavitatus jouseanus at 48.9 mbsf and Rhizosolenica antarctica at 68.60 mbsf), together with five Sr-isotope dates derived from molluscan fragments taken from between 10.88 and 190.29 mbsf indicate an early Oligocene (c. 31 Ma) age for this interval. The appearance of a new species of the bivalve ?Adamussium at about 325 mbsf, suggests that the Oligocene age can be extended down to this level. This confirms that the dominantly reversed magnetozone (R1), recorded down to about 340 mbsf, is Chron C12r. The ages imply high sedimentation rates and only minimal time gaps at the sequence boundaries. Below 340 mbsf there are no independent datums to guide the correlation of the magnetozones to the magnetic polarity time scale. However, the absence of in situ dinocysts attributable to Transantarctic Flora, if not a result of environmental control, limits the age of the base of the hole to between c. 33.5 and 35 Ma.

Molluscan stable isotope temperature estimates of the southwestern Ross Sea during the early oligocene and early miocene, CRP-2/2A and CRP-3, Victoria Land Basin, Antarctica

Stable isotope analyses of marine bivalve growth increment samples have been used to estimate early Oligocene (29.4 - 31.2) Ma and early Miocene (24.0 Ma) seafloor palaeotemperatures from the southwestern continental margin of the Ross Sea. Measured δ18O values average +2.5‰ in the early Miocene and range between +1.26 to +3.24‰ in the early Oligocene. The results show that palaeoceanographic conditions in McMurdo Sound during the mid-Cenozoic were significantly different from those of today. The minimum estimated spring through late summer seasonal temperature range was 3°C during the early Miocene and between 1 and 5°C during the early Oligocene. This compares to the equivalent modern day range of

Experimental susceptibility of some reef fish species to Benedenia lutjani (Monogenea : Capsalidae), a parasite of Lutjanus carponotatus (Pisces : Lutjanidae)

The susceptibility of species of lutjanid, lethrinid and serranid fish to infection by either larval or post-larval (juvenile and adult) specimens of the capsalid monogenean Benedenia lutjani Whittington and Kearn (1993) was examined experimentally. Four species of lutjanids became infected when exposed to larvae of B. lutjani, but three species of lethrinids and four species of serranids were not susceptible to larvae under the same conditions. Variability in the intensity of infection by larvae occurred within and between lutjanid species. Few post-larval specimens of B. lutjani transferred between individuals of the specific host Lutjanus carponotatus (Richardson 1842) in 60-l aquaria and none transferred between specimens of L. carponotatus in a 7,500-l concrete tank. These results indicate that transfer of post-larval B. lutjani between individuals of the specific host is unlikely to occur in the wild. Other lutjanid species did not become infected when exposed to specimens of L. carponotatus infected heavily by post-larval B. lutjani, but two lethrinid species were susceptible to infection under the same conditions. These data indicate that different factors may mediate host-specificity for larval and post-larval B. lutjani.

Spermatozoal ultrastructure of spiny oysters (Spondylidae, Bivalvia) including a comparison with other bivalves

Sperm ultrastructure in three representative species of the marine bivalve family Spondylidae (spiny or thorny oysters) is examined and compared with available data on other bivalves, especially other families of the subclass Pteriomorphia. Spondylid spermatozoa are of the externally fertilizing aquasperm. type (ect-aquasperm). The acrosomal vesicle is conical with a deep basal invagination extending almost the full length of the vesicle. Vesicle contents are divisible into an inner, highly electron-dense anterior layer and a less dense posterior layer. The anterior layer is folded back on itself posteriorly and exhibits radiating plates (best developed peripherally). The vesicle rests on, and is partially embedded in, an extensive granular deposit of subacrosomal. material at the nuclear apex. This deposit extends partly into acrosomal vesicle invagination and also fills a broad depression in the anterior of the nucleus. No pre-formed axial rod (perforatorium) is present. The nucleus is round-pyriform and its contents coarsely fibrogranular. At the base of the nucleus, four broad depressions partially accommodate the midpiece mitochondria. The midpiece consists the four spherical mitochondria and the proximal and distal centrioles. The centrioles are arranged at approximately 90degrees to each other, and each consists of nine, angularly-oriented, microtubular triplets embedded in a granular matrix. A short, periodically banded rootlet connects the proximal centriole to the nuclear fossa, whereas the distal centriole, which forms the basal body to the flagellar axoneme, is anchored to the plasma membrane by nine terminally forked satellite fibres. Extensive deposits of putative glycogen rosettes surround the centrioles and mitochondria. The flagellum consists of a 9+2 axoneme sheathed by the plasma membrane. Spondylid spermatozoa strongly resemble those of the Pectinidae, further confirming the traditional view (based on comparative anatomy and shell morphology) of a close relationship between the Spondylidae and the Pectinidae. Differences in acrosomal shape and dimensions were noted between the three species examined, indicating potential taxonomic utility for comparative sperm ultrastructure within the Spondylidae.

Biosynthesis and insecticidal properties of plant cyclotides: The cyclic knotted proteins from Oldenlandia affinis

Several members of the Rubiaceae and Violaceae families produce a series of cycloticles or macrocyclic peptides of 29-31 amino acids with an embedded cystine knot. We aim to understand the mechanism of synthesis of cyclic peptides in plants and have isolated a cDNA clone that encodes the cyclotide kalata Ell as well as three other clones for related cycloticles from the African plant Olden-landia affinis. The cDNA clones encode prepropeptides with a 20-aa signal sequence, an N-terminal prosequence of 46-68 amino acids and one, two, or three cyclotide domains separated by regions of about 25 aa. The corresponding cycloticles have been isolated from plant material, indicating that the cyclotide domains are excised and cyclized from all four predicted precursor proteins. The exact processing site is likely to lie on the N-terminal side of the strongly conserved GlyLeuPro or SerLeuPro sequence that flanks both sides of the cyclotide domain. Cyclotides have previously been assigned an antimicrobial function; here we describe a potent inhibitory effect on the growth and development of larvae from the Lepidopteran species Helicoverpa punctigera.