Selection of the conodont Idiognathodus simulator (Ellison) as the event marker for the base of the global Gzhelian Stage (Upper Pennsylvanian, Carboniferous)

Studies carried out for more than 10 years by the Task Group to establish GSSPs at the base of the Moscovian–Kasimovian and Kasimovian–Gzhelian boundaries have resulted in the proposal that the level at which the conodont species Idiognathodus simulator (Ellison, 1941) first appears be selected to mark the base of the Gzhelian Stage. This expands this eastern European chronostratigraphic unit to a global scale.I. simulator (sensu Barrick et al., 2008) has been identified so far in Midcontinent and eastern North America, the Moscow and Donets basins and southern Urals of eastern Europe, and in south-central China. Correlation of this level based on this species and other conodont species can be reinforced in some areas by ammonoid and fusulinid data.     

Benthic fish exhibit more plastic crypsis than non-benthic species in a freshwater spring

Cryptic coloration reduces the ability of predators to detect prey, but the plasticity of this defense varies. Some organisms possess static and permanent cryptic coloration, whereas in other species color changes may be induced. Depending upon the species, induced color changes may be reversible or irreversible. In this study, we examined a subtle, rapid, and reversible crypsis in which small fish exhibit muted changes in brightness to match varying substrates in clear spring water. In the laboratory, we visually measured the changes in brightness, using a ten-point brightness scale, of five abundant small species in our study spring. Two species, Lucania goodei and Heterandria formosa, exhibited no change, but the other three species exhibited changes in brightness to match background brightness. Two species, Gambusia holbrooki and Poecilia latipinna, exhibited only slight shifts, whereas Lucania parva exhibited relatively large shifts in brightness and color pattern—from virtually white to tan interspersed with dark-brown bands. In the field, L. parva also exhibited significant shifts in brightness and color pattern, both when swimming freely and when enclosed in an open-bottomed cage. These results suggest that rapid cryptic changes in brightness may augment other forms of defense in small vulnerable fish.     

Pathology of tissue loss (white syndrome) in Acropora sp. corals from the Central Pacific

We performed histological examination of 69 samples of Acropora sp. manifesting different types of tissue loss (Acropora White Syndrome-AWS) from Hawaii, Johnston Atoll and American Samoa between 2002 and 2006. Gross lesions of tissue loss were observed and classified as diffuse acute, diffuse subacute, and focal to multifocal acute to subacute. Corals with acute tissue loss manifested microscopic evidence of necrosis sometimes associated with ciliates, helminths, fungi, algae, sponges, or cyanobacteria whereas those with subacute tissue loss manifested mainly wound repair. Gross lesions of AWS have multiple different changes at the microscopic level some of which involve various microorganisms and metazoa. Elucidating this disease will require, among other things, monitoring lesions over time to determine the pathogenesis of AWS and the potential role of tissue-associated microorganisms in the genesis of tissue loss. Attempts to experimentally induce AWS should include microscopic examination of tissues to ensure that potentially causative microorganisms associated with gross lesion are not overlooked.     

Cryptosporidium sp. Infections in Green Turtles, Chelonia mydas, as a Potential Source of Marine Waterborne Oocysts in the Hawaiian Islands

For the first time, Cryptosporidium sp. oocysts were identified in fecal and intestinal samples from free-ranging marine turtles, Chelonia mydas, from the Hawaiian Islands. The oocysts produced positive reactions with commercial test kits recommended for the detection of human-infectious waterborne oocysts of Cryptosporidium parvum.     

Coccidian-like Nature of Toxoplasma gondii

Specific pathogen-free domestic cats were fed with tissue cysts containing Toxoplasma gondii. In two infected cats large numbers of oocysts were produced in the faeces; no oocysts were observed in the faeces of the uninfected control cat. Five days after the feeding of the toxoplasms profuse schizogonic and gametogonic stages were observed in the epithelial cells of the small intestine of one infected cat. A single schizont was observed in an intestinal epithelial cell of a second cat six days after being fed the tissue cysts. There was no evidence of schizogony or gametogony in the uninfected control cat. The stages observed in the intestinal epithelium are identical with those of the well-known endogenous cycles of coccidian parasites. The appearance of these stages, together with the nature of the oocyst, indicates that T. gondii is a coccidian parasite closely related to the genus Isospora.