Oral exudate as a mediator of behavior in larval eastern and western spruce budworms (Lepidoptera: Tortricidae)

The production of oral exudate by larval eastern and western spruce budworms,Choristoneura fumiferana (Clem.) andChoristoneura occidentalis Free., respectively, was investigated in the laboratory. All larvae except those entering into a molt exhibited aggressive behavior and produced exudate in response to handling or intraspecific encounters. Larvae could be induced to produce exudate up to four times over 2–3 min and produced an average of 1.92±0.04 µl (X ± SE) per induction. Larvae on foliage spent much of their time maintaining their silken feeding tunnel, including spinning and combing silk and removing frass. Exposure to conspecific oral exudate deposited inside the tunnel, or released by agitated larvae inside the tunnel, increased the proportion of larvae that dispersed away from the tunnels and, apparently, increased the larval sensitivity to disturbances. The behavior induced by the oral exudate indicates that it acts as an epideictic (spacing) pheromone.     

Migration of Gasterophilus intestinalis larvae (Diptera: Gasterophilidae) in the equine oral cavity

Cogley T. P., Anderson J. R. and Cooley L. J. 1982. Migration of Gasterophilus intestinalis larvae (Diptera: Gasterophilidae) in the equine oral cavity. International Journal for Parasitology12: 473–480. Larvae of G. intestinalis pursued a specific migratory pathway within the equine oral cavity en route to the stomach. The larval migration included the following sequence: burrowing in the tongue mucosa, invasion of the interdental spaces, transitory attachment at the root of the tongue and movement to the stomach. The molt from first to second instar did not occur in the tongue, as commonly believed, but between the interdental spaces. Ninety five percent of the larvae invading the interdental spaces were associated with gingiva of the upper molars. SEM analysis revealed further details of the oral migration: (1) air holes excavated in the epithelium which connect with deeper burrows; (2) an intimate association between air holes and posterior spiracles of larvae; (3) precise impressions of larvae in tissue immediately surrounding the most recently formed burrows; and (4) initial larval entry into the tongue through the use of natural disruptions or healing lesions. Factors influencing the development of the oral migration are discussed.     

Timing and Regulation of Nuclear and Cortical Events in the Cell Cycle of Tetrahymena pyriformis*

SYNOPSIS. Using continuous flow cultures based on the chemostat principle, we varied the cell generation times of the ciliate Tetrahymena pyriformis strain GL, from 4.9 to 22.2 hr and studied various parameters of the cell cycle at 28 C. These included: the duration of the periods required for oral morphogenesis, macronuclear division, cell division, G₁ S, and G₂. The size of individual cells was also measured. Independent of the growth rate, the period of oral morphogenesis occurred during the last 90 min of the cell cycle. In all cases macronuclear and cell divisions took place during the last part of these 90 min, and the final macronuclear separation occurred just before final cell separation. The S-period increased slightly, while the G₁ and G₂ both increased in roughly the same relative proportion to the increasing generation times. Slowly growing cells (generation time 20.5 hr) were shorter but broader and somewhat larger in volume than quickly growing cells (generation time 4.9 hr).     

Thermal stratification and benthic foraging patterns of white sucker

Abundances of white sucker, 100–500 mm FL, were not significantly different among the epilimnia, metalimnia and portions of the hypolimnia shallower than 20 m in each of two lakes. However, small suckers < 200 mm were captured most frequently in the epilimnion and no white suckers were captured in the deepest region, 20–38 m, of the two lakes. White suckers consumed prey from all three temperature zones in each lake. Prominent food items were Hyalella azteca and the chironomid larvae Heterotrissocladius, Djalmabatista and Procladius. Despite differences in relative densities of benthic invertebrates among thermal zones of the two lakes, suckers in neither lake foraged exclusively on prey of epilimnetic origin. Suckers captured in the metalimnia foraged on invertebrates that were common to all three thermal zones. And, only 0–4% of the suckers captured in the hypolimnia of the two lakes contained prey that were unique to the epilimnia. Suckers caught in the hypolimnia mainly consumed deep water invertebrates; 83% of the suckers foraged in the metalimnion and hypolimnion of Islets Lake and 45% foraged in the hypolimnion in Burnt Island Lake. Consequently there was little evidence of a massive inshore feeding migration followed by a post-feeding return to the hypolimnion. Northern pike and lake trout rarely fed on white suckers in these lakes and thus piscivory was an unlikely factor in the observed distribution of suckers.     

Feeding habits and food resources of filter-feeding Trichoptera in a regulated mountain stream

A year-round study was conducted to examine feeding habits and food resources of the filter-feeding Trichoptera Arctopsyche grandis and Brachycentrus occidentalis along a regulated mountain stream gradient. There was a well defined longitudinal species replacement with A. grandis reaching maximum densities 2.3 kilometers below the impoundment, and concomitant with its decline downstream was an increase in B. occidentalis. At all sampling sites the < 75 µm organic seston fraction usually consisted primarily of diatoms (>70%, by areal estimate on microscope slides), whereas the 75–250 µm and > 250 µm seston fractions were predominantly composed of detritus (> 80 %). B. occidentalis larvae consumed primarily detritus and diatoms (> 70 % of the diet), while A. grandis ingested a variety of materials with animals, detritus and/or filamentous algae often constituting > 80% of the diet. Animal material was over-represented in the diets of both species when compared with amounts in the seston. Feeding habits provided partial explanations for the distinct longitudinal distribution patterns of filter-feeding Trichoptera observed in the regulated river.     

A NEW SPECIES OF BEAKED WHALE MESOPLODON PERUVIANUS SP. N. (CETACEA: ZIPHIIDAE) FROM PERU

Mesoplodon peruvianus , a new species of beaked whale, is described on the basis of ten specimens which have either stranded or been captured between 11°12'S and 15°19'S latitude along the coasts of the provinces of Lima and Ica, south central Peru. This is the thirteenth living species of Mesoplodon recognized in the world's oceans. The animals that were examined were uniformly gray above, shading to lighter gray below. This whale is the smallest species of Mesoplodon (maximum body length 3.72 m) and is characterized by its teeth, which are small (31 to 65 mm long), ovate in cross section, and positioned 2.5% to 8.4% of the mandibular length from the anterior extremity, and posterior to the mandibular symphysis.     

A review of the bioavailability of petroleum constituents

Exposure to petroleum constituents at contaminated sites may occur through a variety of pathways, including inhalation of vapors and particulates, ingestion of water and soils, and dermal contact with water and soils. Accurately assessing the human health risks from such exposures requires information on the medium‐ and route‐specific bioavailability of petroleum constituents (e.g., how well these chemicals enter the body via the gastrointestinal tract and skin). For example, when the medium or exposure route in an animal toxicity assay (e.g., ingestion of water) differs from the actual route of human exposure at the petroleum contaminated site (e.g., dermal contact with soil), adjustments should be made that reflect the relative bioavailability of the chemical in the different media. The focus of this article is on (1) the availability of oral and dermal absorption data for one PAH (benzo[a]pyrene, (B[a]P) and three VOCs in soil (benzene, toluene, and xylene); (2) factors affecting the uptake of these PAHs and VOCs from soil; and (3) ways to incorporate bioavailability data into human health risk assessments. Based on our review, we recommend the following default values for the oral and dermal absorption of B[a]P, benzene, toluene, and xylene from soil:

A review of the bioavailability of petroleum constituents

All authors

Jennifer Bramard & Barbara D. Beck

https://doi.org/10.1080/15320389209383417

Published online:

02 December 2008

Display Table

Site‐specific information such as chemical concentrations in soil, soil characteristics, soil loadings on the skin, contact site, and contact time could result in modifications of these numbers. As shown, our default absorption values are generally less than those recommended by the U.S. EPA (1991a,b,c). The implications of these estimates of bioavailability for risk assessment and for the selection of soil cleanup levels at petroleum‐contaminated sites are discussed.     

Observations on the life history of the belted sandfish,Serranus subligarius (Serranidae)

Synopsis The biology of Serranus subligarius, a typical inhabitant of low limestone reef outcroppings and artificial reefs from North Carolina to Florida and in the northern Gulf of Mexico, was studied on inshore jetties in the northeastern Gulf of Mexico from February 1974 to April 1975. The length-weight relationship was expressed by the equation W = 0.000006L^3.431. Growth was greatest in the first year (43.5 mm SL) and declined in the remaining three years of life (17.3, 10.5, and 7.1, respectively). In individuals larger than 40 mm SL, gammaridean and caprellid amphipods were the most numerous food items but crabs, shrimp, and fishes were the most important food items by weight. In individuals less than 40 mm SL, copepods were the most numerous food item, but gammaridean amphipods and shrimp were the most important items by weight. Two incidents of cannibalism were recorded. The ovotestis of the belted sandfish is composed of two lobes which are broadly united posteriorly, with the testicular tissue restricted to a broad band encircling the posterior region of the gonad. Age-group 1 fish are functional synchronous hermaphrodites. Testicular tissue matures in the fall or winter of a fish's first year (all specimens examined histologically, including those from the nonspawning season, contained flagellated spermatozoa) while ovarian tissue matures in the following spring. Spawning season in 1974 extended from late April or early May to September. Crossfertilization is the usual reproductive mode, although individuals are capable of selffertilization.     

Evolution des activités protéolytiques digestives chez les Jeunes Mulgilidae

Proteolytic activity in the stomach, pyloric caeca and intestine decreases with increasing size in the three fish species Mugil auratus, M. capito and M. saliens. Differences between these species are found mainly in the gastric proteolytic activity which appears to be related to diet. This activity is pronounced in M. saliens whose diet is mainly carnivorous. Comparison of regression lines relating gastric proteolytic activity to size reveals differences which distinguish M. auratus from both of the other species. Total proteolytic activity exhibits high variability depending on the types of diet.