Pentastomids of Wild Snakes in Australia

Pentastomids are endoparasites of the respiratory system of vertebrates, maturing primarily in carnivorous reptiles. Adult and larval pentastomids can cause severe pathology resulting in the death of their intermediate and definitive hosts. The study of pentastomids is a neglected field, impaired by risk of zoonoses, difficulties in species identification, and life cycle complexities. We surveyed wild snakes in the tropics of Australia to clarify which host species possess these parasites, and then sought to identify these pentastomids using a combination of morphological and molecular techniques. We detected pentastomid infections in 59% of the 81 snakes surveyed. The ubiquity of pentastomid infections in snakes of the Australian tropics sampled in this study is alarmingly high considering the often-adverse consequences of infection and the recognized zoonotic potential of these parasites. The pentastomids were of the genera Raillietiella and Waddycephalus and infected a range of host taxa, encompassing seven snake species from three snake families. All seven snake species represent new host records for pentastomids of the genera Raillietiella and/or Waddycephalus. The arboreal colubrid Dendrelaphis punctulatus and the terrestrial elapid Demansia vestigiata had particularly high infection prevalences (79% and 100% infected, respectively). Raillietiella orientalis infected 38% of the snakes surveyed, especially frog-eating species, implying a frog intermediate host for this parasite. Raillietiella orientalis was previously known only from Asian snakes and has invaded Australia via an unknown pathway. Our molecular data indicated that five species of Waddycephalus infect 28% of snakes in the surveyed area. Our morphological data indicate that features of pentastomid anatomy previously utilized to identify species of the genus Waddycephalus are unreliable for distinguishing species, highlighting the need for additional taxonomic work on this genus

Using Combined Morphological, Allometric and Molecular Approaches to Identify Species of the Genus Raillietiella (Pentastomida)

Taxonomic studies of parasites can be severely compromised if the host species affects parasite morphology; an uncritical analysis might recognize multiple taxa simply because of phenotypically plastic responses of parasite morphology to host physiology. Pentastomids of the genus Raillietiella are endoparasitic crustaceans primarily infecting the respiratory system of carnivorous reptiles, but also recorded from bufonid anurans. The delineation of pentastomids at the generic level is clear, but the taxonomic status of many species is not. We collected raillietiellids from lungs of the invasive cane toad (Rhinella marina), the invasive Asian house gecko (Hemidactylus frenatus), and a native tree frog (Litoria caerulea) in tropical Australia, and employed a combination of genetic analyses, and traditional and novel morphological methods to clarify their identity. Conventional analyses of parasite morphology (which focus on raw values of morphological traits) revealed two discrete clusters in terms of pentastome hook size, implying two different species of pentastomes: one from toads and a tree frog (Raillietiella indica) and another from lizards (Raillietiella frenatus). However, these clusters disappeared in allometric analyses that took pentastome body size into account, suggesting that only a single pentastome taxon may be involved. Our molecular data revealed no genetic differences between parasites in toads versus lizards, confirming that there was only one species: R. frenatus. This pentastome (previously known only from lizards) clearly is also capable of maturing in anurans. Our analyses show that the morphological features used in pentastomid taxonomy change as the parasite transitions through developmental stages in the definitive host. To facilitate valid descriptions of new species of pentastomes, future taxonomic work should include both morphological measurements (incorporating quantitative measures of body size and hook bluntness) and molecular data

Kelehear and Shine data

Information on behaviour and morphology of male cane toads in tropical Australi

Description of an extant salamander from the Gulf Coastal Plain of North America: The Reticulated Siren, Siren reticulata.

The salamander family Sirenidae is represented by four extant species that are restricted to North America. Sirens are abundant throughout the southern United States and are among the world's largest amphibians, yet the biology, ecology, and phylogeography of this group is poorly-known. In this study we use morphological and genetic evidence to describe a previously unrecognized species from southern Alabama and the Florida panhandle. We name this species the Reticulated Siren, Siren reticulata. Future studies will enable more precise phylogenetic information about S. reticulata and will almost surely reveal additional undescribed species within the family

Histology of the cane toad urinary bladder walls containing acanthocephalans.

<p>A) Cystacanth larva within the bladder wall, note spines inverted. B) Everted acanthocephalan spines embedded in inflammatory cells. Both images are focus-stacked from three photographs to maximize depth of field.</p

Gross appearance of abnormalities involving fusion of the cane toad urinary bladder with other organs.

<p>A) Urinary bladder fused to liver, note adjacent cysts on liver tissue and dark intrusion inside the lumen of the urinary bladder. B) Urinary bladder fused to mesentery via thin string, note adjacent cysts on mesentery. C) Urinary bladder fused to Spirurid cyst on stomach wall.</p

Wild Cane Toads (<i>Rhinella marina</i>) Expel Foreign Matter from the Coelom via the Urinary Bladder in Response to Internal Injury, Endoparasites and Disease

<div><p>Dissections of >1,200 wild-caught cane toads (<i>Rhinella marina</i>) in tropical Australia confirm a laboratory report that anurans can expel foreign objects from the coelom by incorporating them into the urinary bladder. The foreign objects that we found inside bladders included a diverse array of items (e.g., grass seeds, twigs, insect prey, parasites), many of which may have entered the coelom via rupture of the gut wall. In some cases, the urinary bladder was fused to other organs including liver, fat bodies, ovaries, Bidder’s organs, lungs, mesentery, stomach wall, gall bladder, and the abdominal wall. Acanthocephalan parasites (of a range of developmental stages) were identified from the walls of the urinary bladders of three cane toads. This organ may play a significant role in destroying or excreting metazoan parasites, as well as inanimate objects.</p></div