Acute Toxicity and Neurotoxicity of Chlorpyrifos in Black Tiger Shrimp, Penaeus monodon

Acute toxicity and neurotoxicity of chlorpyrifos were determined in black tiger shrimp, P. monodon. LC50 values after 24 to 96 h of exposure were between 149.55 and 59.16 nmol/L. To determine the neurotoxicity of chlorpyrifos, the inhibition of acetylcholinesterase was monitored in the gill of the shrimps exposed to lethal (0.019, 0.194, and 1.942 µmol/L) and sub-lethal (0.019, 0.194, and 1.942 nmol/L) concentrations of chlorpyrifos. In lethal dose exposure, the AChE activities observed in shrimp exposed to 0.194, and 1.942 µmol/L of chlorpyrifos were significantly lower (1.7 and 3.3 times) than that of control shrimp after 30 min of exposure (p<0.05). In sub-lethal exposure tests, the AChE activity of shrimp was significantly lower (1.9 times) than that of control shrimp after exposure to 1.942 nmol/L of chlorpyrifos for 72 h (p<0.05). The sensitive reduction of AChE activity at the sub-lethal concentration, which was 30 times lower than 96 h LC50 value found in this study, indicates the potential use as a biomarker of chlorpyrifos exposure

Morphometric and gravimetric indices of two populations of rice frog (Fejervarya limnocharis) naturally exposed to different environmental cadmium levels

In this study, morphometric and gravimetric indices were used to determine the impact of cadmium exposure on a sentinel species. Scaling coefficient, condition factor (CF), hepatosomatic index (HSI), renosomatic index (RSI) and gonadosomatic index (GSI) were compared between rice frogs (Fejervarya limnocharis) exposed to different environmental cadmium levels. The result showed that frogs caught from the contaminated site had significantly higher CF (10.296), RSI (0.413) and female GSI (7.594) than frogs from the contaminated site (7.594, 0.380 and 1.594, respectively). For Scaling Coefficient and HSI, albeit being statistically insignificant, these indices showed a similar trend. On the other hand, the male GSI showed a reverse trend where frogs from contaminated site showed higher values than their counterpart from the reference site. However, the differences were not statistically significant. This research concluded that there is a relationship between cadmium contamination with morphometric and gravimetric indices. Therefore, it is suggested that the use of these data could give an idea on the effect of cadmium exposure on the rice frog

FORAGING ECOLOGY OF SYMPATRIC PARIDS: INDIVIDUAL AND POPULATION RESPONSES TO WINTER FOOD SCARCITY (COMPETITION, NICHE, BEHAVIOR, OVERLAP)

This study investigated individual variation in foraging behavior in response to seasonal food shortage in populations of Carolina Chickadees (Parus carolinensis) and Tufted Titmice (Parus bicolor) at the Ross Biological Reserve, Tippecanoe County, Indiana. Each individual was banded, sexed, measured (wing, beak, and tarsus lengths), and observed to quantify foraging behavior in the field (foraging height, foraging distance from trunk, foraging substrate diameter, and foraging technique). The data provided descriptions of associations between intraspecific morphological variation and foraging behavior, individual and interindividual variation in foraging, changes in population total niche width and its components, and seasonal variation in breadth and overlap of the feeding niche between the two parid populations. I measured changes in the degree of generalization in foraging at both the individual and the population levels. The flexibility of individuals and populations in response to food reduction from early to late winter helped to test predictions made by foraging theory and competition theory. Correlations between morphological characters and foraging behavior were not strong and provided only partial support for the expectation that intraspecific morphological variation is related to resource utilization and is an adaptation to avoid niche overlap among individuals in the population. Individuals of both species were generalists. Individual foraging generalization increased to a degree that approached population-level generalization in late winter when food is most scarce. Population-level patterns are not always mirrored on the individual level, as is often assumed. Although most individuals showed similar changes in foraging behavior and became more generalized when food was scarce, some individuals shifted in opposite directions or generalized much more than others. Most results are consistent with the prediction based on foraging theory that food scarcity will favor behavioral generalization and broadening diet. Competition pressure for avoidance of overlap in resource use among individuals and between species seems weak in comparison to individualistic generalization. Competition between and within these populations was not strong enough to force either significant divergence among conspecifics or niche divergence of populations in spite of a declining food supply

INTERACTIONS OF THE HESSIAN FLY, THE BIRD CHERRY OAT APHID, THE ENGLISH GRAIN APHID, AND SELECTED WHEAT VARIETIES (R. PADI, S. AVENAE, ABE)

There were preferences of the bird cherry oat aphid, Rhopalosiphum padi L. on Hessian fly infested plants of \u27Knox 62\u27, \u27Monon\u27 and \u27Seneca\u27 when compared to the non-infested controls. Among them Monon was always the least preferred as determined by the numbers of aphids found on the plants during a five-day period after introduction. However, varietal differences existed even in control plants, and Monon along with \u27Blueboy\u27 were never the preferred hosts. Feeding on fly infested wheats caused aphids to mature early, but did not enhance the longevity and fecundity of the aphids. The intra- and interspecific relationships of R. padi and the English grain aphid, Sitobion avenae (Fabr.) were dependent on the population density. Five, 10 and 15 aphids were used. The higher the density, the longer the developmental period. The longevity and fecundity changes varied and were not consistent. Competition seemed to be evident when the two species were in the same population. In a mixed population, longevity and fecundity of both aphids greatly declined when there were 10 and 15 aphids of each species in the populations. S. avenae needed a longer time to develop from nymphal to adult stage than R. padi, but had a much longer reproductive period and a longer life at all density levels. The differences in fecundity were notable in mixed populations of 10 + 10 and 15 + 15. Life tables and survivorship curves of both species resembled the hypothetical type I of the general curves. High mortality rates were found when aphids were about eight weeks old. No R. padi survived longer than 10 weeks and no S. avenae longer than 12 weeks. The finite rates of increase ((lamda)) for aphids in all density levels were above 1.1, providing the optimum conditions in the laboratory (20 C and 14:10 hour photoperiod). Both viruliferous (PAV strain of BYDV) and non-viruliferous R. padi and S. avenae caused yield losses to some degree in \u27Abe\u27. For the three infestation levels studied, five aphids per plant was the minimum that caused 1000-grain weight reductions, but the effects on other yield components varied. The grain numbers were high in infested plants, but the grains were generally shrunken. Infestations of S. avenae and mixed population at the heading stage of Abe caused greater losses than other treatments. The preference of S. avenae for feeding on heads once emerged may be a key factors for high losses. The interactions of the mixed population probably rely on S. avenae feeding in this particular circumstance

Histological differences in the livers and kidneys of two populations of rice frog (Fejervarya limnocharis) naturally exposed to different environmental cadmium levels

Histological observation has always been important in the study of sentinels. In this research, histological differences in the liver and kidney of two wild populations of Fejervarya limnocharis exposed to different environmental cadmium levels were observed. Liver and kidney samples from 30 rice frogs caught from reference site (Mae Pa) and contaminated site (Mae Tao) were sectioned and stained with Haemotoxylin and Eosin and then observed under light microscope. It was found that liver sections from frogs caught from Mae Tao had higher hepatic macro-melanophage count (MMC) (0.949 ± 0.267 cells/1000 μm2) as compared to those from Mae Pa (0.672 ± 0.299 cells/1000 μm2). Other observable histological features found in frog’s liver from Mae Tao include possible necrotic areas, cellular swellings and chromatin margination. The kidney sections from frogs caught from Mae Tao showed the presence of tumor-like cell aggregation and hemorrhage. However, the proportion of tumor-like cell aggregation and hemorrhage were not significantly different than were expected from random occurrences. The result of the histological study revealed that F. limnocharis caught from Mae Tao had higher hepatic MMC and higher prevalence of renal tumor-like aggregation and renal hemorrhage than the rice frogs caught from Mae Pa. Cellular swelling, possible necrotic area and possible apoptotic cell could also be observed in the liver of contaminated frogs

Sphaerobelum truncatum Wongthamwanich, n. sp.

Sphaerobelum truncatum Wongthamwanich, n. sp. Figs. 5 –11 Material examined. Holotype male, CUMZ 2010.11, Thailand, Nan Province, Song Khwae District, Na Rai Luang Sub-district, Pang Hi Village; secondary forest; Latitude: 19.3962, Longitude: 100.6951; coll. N. Wongthamwanich; hand collecting; 22 August 2010. Paratypes: 4 males, CUMZ 2010.12 –15, 4 females, CUMZ 2010.16 – 19, 1 male, FMNH-INS 0 0 0 0 0 72 674, 1 female, FMNH-INS 0 0 0 0 0 72 673, 1 male, ZFMK Myr 0 0 1, 1 female, ZFMK Myr 0 0 2, same data as holotype. Etymology. The specific epithet is a Latin adjective, meaning terminating abruptly, and refers to the truncated state of the lateral end of the third podomere on the anterior telopods (Fig. 11 C). Diagnosis. Sphaerobelum truncatum differs from all other Sphaerobelum species in the unique combination of the following characters of the anterior telopods (Figs. 11 A–C): four podomeres above syncoxite, second podomere posteriorly with a process (Figs. 11 B, C) and one spine on the anterior side of the inner margin (Fig. 11 C), third and fourth podomeres located posteriorly juxtaposed to process of second podomere, third podomere distally truncate, fourth podomere with three sclerotized spines all located on small thin separated sclerotized plates: one spine at apex, the other two on posterior side (Figs. 11 B, C). Anterior telopods without sclerotized teeth. S. truncatum differs from the closely related species S. separatum Attems, 1953 in the presence of a well-rounded fourth podomere on the posterior telopod (Figs. 11 D, E), while the tip of the posterior telopod in the latter species is prolonged into a thin process and curved towards the process of the second podomere. S. truncatum is the only giant pill-millipede species known to have a regularly ‘square-wavy’ margin on the endotergum (Fig. 9 B). COI Sequence (paratype, FMNH-INS 0 0 0 0 0 72 674): Accession # JN 885184. See supplementary material. Description. Measurements: Males: length 18.6 –24.0 mm, width at the seventh tergite 10.2–12.6 mm, width of thoracic shield 9.9–12.2 mm, height of thoracic shield 5.7–6.8 mm. Sizes of volvated male (for epimorphic stadia, Figs. 4 A, B): length (tergite 5 –tergite 11 or 12) 12.1–13.9 mm, width (tergite 7) 10.2–12.6 mm, and height (thoracic shield–tergite 8) 10.7–12.6 mm. Females: length 21.2–30.4 mm, width at the seventh tergite 11.5–15.2 mm, width of thoracic shield 11.0– 14.3 mm, height of thoracic shield 6.2–8.1 mm. Sizes of volvated female: length 13.0– 17.6 mm, width 11.5–15.2 mm, and height 11.5–15.4 mm. Habitus (Fig. 5 C): Overall shape elliptical, tapering slightly from sixth tergite towards head. Coloration (Figs. 5 A–C): head dark brown, collum, thoracic shield, tergite, and anal shield black. Antennae and legs light yellow. Head: trapezoid, anterior part of the head with many long setae, posterior part densely dimpled; anterior margin of labrum with a single tooth. Eye field round, width approximately one mm, consisting of more than 60 densely-packed ocelli. No sclerotized crest/ridge between antenna socket and eye field. Tömösváry organ (Fig. 5 D) between eye field and antenna socket, next to, but separated from eye field. Antennae (Figs. 6 A–C): with six visible antennomeres; basal antennomere with a few thinly scattered sclerotized nodules (Fig. 6 C); distal antennomere enlarged, round and club-shaped, with 81–84 sensory cones in males, 36–42 in females. Antennomere lengths: 6> 1> 2 = 3> 4 = 5. Mandibles (Figs. 7 A, B): with a single external tooth, a three-lobed internal tooth, six rows of pectinate lamellae, number of teeth on pectinate lamellae declining from apical to proximal lamella, molar plate with one visible ridge. Gnathochilarium (Fig. 7 C): with numerous long setae on the lingual lamella. Inner palpi with numerous elongate and sharp sensory cones (Figs. 7 D, E), reduced lateral palpi with a field of 6 sensory cones (Figs. 7 D, F). Collum: anterior and posterior margin with a few setae, center part sparsely setae, densely covered by dimplelike impressions. Thoracic shield: ridge on lateral lobe absent, accompanied by a few long setae; center part of anterior margin covered sparsely with long setae. Tergites 3–12 (Fig. 8): Anterior margins dominated by small conical spines (Fig. 8 C). Two submarginal rows of round sclerotized nodules: nodules of anterior-most row large and isolated, those of second row small and close together (Fig. 8 B). Anterior fifth of tergite with smooth zone, followed by a zone of 3–5 irregular rows of long setae, and then by an area of short setae (Fig. 8 B). Central four fifths of tergite dominated by short setae, nodules and slightly curved long setae inserted in large dimples (Figs. 8 A, D). Posterior margins with a few thick setae (Fig. 8 A). Endotergum (Fig. 9): with a regularly ‘square-wavy’ margin (Fig. 9 B), outer zone with three rows of irregular marginal setae not reaching posterior margin. A single row of small elliptical cuticular impression present next to marginal ridge. Intersegmental membrane smooth, without cones or setae (Fig. 9 A). Anal shield: densely covered with long setae; round in both sexes. Inner side with three or four striae. Ventral side with one long black locking carina (Fig. 5 C, Lc). Legs: first pair of legs without coxal lobe (Fig. 5 F), first tarsi with two ventral spines and without apical spine; second pair of legs with small coxal lobes in male (Fig. 5 H), second tarsi with four ventral spines and without apical spine; third leg pair with acute coxal lobes, third tarsi with five or six ventral spines and one apical spine; ninth pair of legs with seven ventral spines and one apical spine on tarsus, femur with one long ridge (Fig. 11 G). Femur of ninth pair of leg 2.0 times longer than wide, tarsus 4.8 times longer than wide (Fig. 11 G). Stigmatic plate of first leg (Fig. 5 F): rounded, short and weakly curved, but forming a steep angle towards the coxa. Female vulva (Figs. 5 G, 11 H): consisting of two basal plates which are fused proximally and divided distally. Operculum pointed, basal part of operculum surrounding apical part of basal plates, distally protruding above coxa to basal half of prefemur. Vulva covers half (1 / 2) of coxa width, vulva is one-third (1 / 3) longer than coxa. Subanal plate (Fig. 10 A): brown, semicircular with a central shallow notch, laterally with four rib-like structures. Male gonopore (Fig. 10 B): covered by undivided sclerotized plate. Anterior telopods (Figs. 11 A–C): syncoxite with small spines, telopodite consisting of four podomeres, all podomeres covered by long setae. First podomere width equals height. Second podomere with posterior lobe-like, curved process with rounded edges; process protruding up to end of third podomere; anterior side of process with a single spine at inner margin. Third podomere distally truncate. Fourth podomere as long as third podomere, with three sclerotized spines located on small thin sclerotized fields, one spine at apex and the other two located on posterior side. Sclerotized teeth absent. Posterior telopods (Figs. 11 D, E): inner horns with sharp-edged tips, slightly curved backwards. Telopodite consisting of four podomeres. First podomere parallelogram-shaped. Second and third podomere dominated by short setae, margins with long setae. Process of second podomere weakly curved, distally glabrous, posteriorly apically enlarged and swollen (Fig. 11 D), anteriorly apically concave, spatulate, with a single sclerotized spine (Fig. 11 E). Moveable finger consisting of third podomere and small fourth podomere, slightly curved. Third podomere at inner margin with one small light colored spine, without any crenulated teeth. Fourth podomere at inner margin with two small sclerotized spines located in single brown sclerotized field. Intraspecific variation. Only seven males and six females of S. truncatum were available for analysis. However, some characters presented a clear difference between the sexes, such as the body length of females that tended to be longer than that of the males, while males have more sensory cones on the distal antennae than females. Life history. Adult specimens were collected in late August 2010 during the rainy season. Numerous eggs were found in an adult female, with most of them aggregated into many small clusters located between the intestine and the body wall, from the second leg pairs to posterior end of the body. The eggs as preserved in 70 % ethanol were orange in color. Mature eggs were round in shape with a diameter of about 2–2.5 mm. Distribution and ecology. The new species is only known from the type locality at 440–450 m altitude. There is a small stream running along the secondary dry evergreen forest and the forest floor is covered by laterite soil with saplings and seedlings, including a leaf litter of up to 3 cm depth. At the time of collection, the weather was a light precipitation, 92 % relative humidity, 25.5–26 °C and 27 °C soil and air temperature respectively. Most specimens were found on a 60 degree slope and only a few specimens were found on a flat plain area. Animals were found rolled up above the forest ground close to tree bases, in shallow soil pockets and under leaf litter. FIGURE 11. Sphaerobelum truncatum n. sp., A-G holotype, H female paratype, drawing, A: right anterior telopod, anterior view; B: last three podomeres of right anterior telopod, posterior view; C: last three podomeres of right anterior telopod, lateral view; D: last three podomeres of right posterior telopod, posterior view; E: last three podomeres of right posterior telopod, anterior view; F: stigmatic plate of 9 th left leg; G: 9 th left leg, posterior view; H: second right coxa with vulva, posterior view. Arrows point to the second podomere process. Abbreviations: Cx = coxa; ST = stigmatic plate; O = operculum; EP = external plate of vulva; IP = mesal plate of vulva. Roman numbers refer to number of podomere. Scale bars = 1 mm. Behavior. Sphaerobelum truncatum seems to be more active than Zephronia sp. They unroll their body in less than 5 minutes after capturing in the hand, which has never been observed for Zephronia sp. Sphaerobelum truncatum is well camouflaged, having similar color patterns to various objects in the environment, such as dried leaves and fruit seeds. The animals can also hide during the day by digging into the soil.Published as part of Wongthamwanich, Nattarin, Panha, Somsak, Sierwald, Petra, Wesener, Thomas & Thirakhupt, Kumthorn, 2012, A new species of the giant pill-millipede genus Sphaerobelum Verhoeff, 1924 from northern Thailand, with an extensive description and molecular characters (Diplopoda: Sphaerotheriida: Zephroniidae), pp. 29-43 in Zootaxa 3220 on pages 34-42, DOI: 10.5281/zenodo.21275

First occurrences of Atoposaurid Crocodyliforms in the Late Jurassic and Early Cretaceous of the Khorat Plateau, northeastern Thailand

Lauprasert Komsorn, Cuny Gilles, Buffetaut Éric, Suteethorn Varavudh, Thirakhupt Kumthorn. First occurrences of Atoposaurid Crocodyliforms in the Late Jurassic and Early Cretaceous of the Khorat Plateau, northeastern Thailand. In: Documents des Laboratoires de Géologie, Lyon, n°164, 2008. Mid-Mesozoic life and environments. Cognac (France), June 24th-28th 2008. pp. 59-61