The effect of five organophosphorus insecticides on survival and temperature tolerance in the copepod, Macrocyclops albidus (Copepoda: Cyclopidae)

Macrocyclops albidus were exposed for 24 hours to ABATE®, fenthion, malathion, methyl parathion, and chlorpyrifos at concentrations of 1, 5, 10, 25, and 50 parts per billion (ppb). Exposure to chlorpyrifos resulted in the greatest mortality to M. albidus; concentrations of 25 and 50 ppb caused 100% mortality. The thermal tolerance was lowered significantly by all chemicals at concentrations from 1 to 50 ppb.     

The effects of sublethal concentrations of five organophosphorus insecticides on temperature tolerance, reflexes, and orientation in Gambusia affinis affinis (Pisces: Poeciliidae)

Gambusia affinis were exposed to the insecticides ABATE®, fenthion, chlorpyrifos, methyl parathion, and malathion for 24 h at concentrations of 1, 5, and 10 ppb and for 48 h at 5 ppb. The thermal tolerance was lowered significantly for male and female G. affinis by the toxicants methyl parathion and chlorpyrifos at 5 and 10 ppb with 24 h exposure. Activity was restricted with fish exposed to methyl parathion and chlorpyrifos at concentrations of 10 ppb for 24 h and at 5 ppb for 48 h.     

Thermoregulation in four Australian lizards of the genus Egernia (Sauria: Scincidae)

Mean thermal preferenda for the head and body were found to be similar in Egernia whitei, E. cunninghami, and E. bungana (range in T_H= 33.6^o -33.8^o C; range in T_B= 34.0^o-35.3^oC). However, those for E. majors were significantly lower (T_H= 31.1^o C, T_B=32.9^oC). Significant differences were found between mean head and body preferred temperatures in E. cunninghami and E. major. Higher temperatures were tolerated by the body than the head in all four species. Gaping was not observed to occur prior to cessation of respiration in any of the four species during radiant or solar heating. Based upon thermal preferenda and critical thermal maxima data, thermal safety margins for body temperature were calculated for E. whitei and E. cunninghami Postural orientation to the sun's rays increased and decreased heat gain. The seeking of shade was the most effective method employed by all four species for reducing head and body temperature.     

A New Coccidium, Eimeria bandipurensis n. sp., from the Indian Palm Squirrel, Funumbulus palmarum

SYNOPSIS. Eimeria bandipurensis n. sp., is described from the gut of an Indian palm squirrel, Funumbulus palmarum , obtained from a village, Bandipur, in West Bengal. Spherical and egg-shaped oocysts were encountered, the former averaging 17 μ in diameter and the latter 18 by 16 μ. Oocystic residuum was absent while the sporocystic residuum was represented by refractile globules. A Stieda body was present in the sporocyst. Sporozoites were banana-shaped with one end broader and the other pointed with a clear globule at each end.     

Thermoregulation in the Red-beillied Blacksnake, Pseudechis porphyriacus (Elapidae)

Cold Pseudechis porphyriacus aid heating by basking, flattening and tilting. When body temperatures are higher, thermoregulation is achieved by shuttling between sun and shade. A warm snake in a cooling environment frequently coils.
The major factors associated with rate of temperature change in the body core were (1) horizontal gradient between body and neck, (2) posture and (3) vertical gradients from body core to body surface.
The role of behavioral, physiological and physical factors in thermoregulation are discussed.     

A New Coccidium Sivatoshella lonchurae n. gen., n. sp., from Lonchura malabarica and L. punctulata

SYNOPSIS. A new coccidium Sivatoshella lonchurae n. gen., n. sp. (Coccidia, Eimerüdae) is described from the gut of the passeriform birds Lonchura malabarica (Linn.) and L. punctulata (Linn.). Endogenous stages of the parasite conform to those of the family Eimerüdae. Oocysts are spherical, 36–38 μ (avg. 37.5 μ) in diameter. Wall 3.6 ä thick, 4-layered; outermost layer thin transparent and colorless; next, slightly broader and light green; 3rd, thinner and light yellow; innermost dark black. Oocyst residuum absent. Micropyle absent. Sporocysts 28–29 μ long and 18 μ wide. They are 2 broad pear-shaped bodies with Steida body and a prominent substeidal body at the narrow pole. Sporocyst residuum present as minute refractile globules embedded in a dark matrix. Sporozoites broad, comma-shaped, with one large vacuole at the broad pole and nucleus at the center of the body. Sixteen sporozoites in each sporocyst, arranged at the periphery of the residual mass. Sporulation time : 24–48 hours at 31 C. Habitat: duodenum and small intestine of Lonchura malabarica (Linn.) and L. punctulata (Linn.). Locality: Calcutta, W. Bengal, India.     

Studies on the Physiology of Rice: XV. CHANGES IN THE NITROGEN METABOLISM OF SEEDS DURING GERMINATION AND THEIR RELATION TO THE APPLICATION OF GROWTH REGULATORS

Seeds of rice variety ‘Chinsurah Boro’ were treatedwith two concentrations of indoleacetic acid (IAA) and maleichydrazide (MH), 0.1 mg. per litre and 0.01 mg. per litre, duringthe first 7 days of germination, and the resulting changes innitrogen metabolism of both endosperm and embryo were determined.The seedling growth at different times during the treatmentwas recorded. Uptake of water by the embryo increased up to 72 hours, butthereafter the percentage water content fell, owing to large-scaletranslocation of dry matter to it. The endosperm showed increasingwater content for 5 days. There are two marked stages of nitrogen metabolism of the seedduring germination. During the first 72 hours hydrolysis ofprotein in the endosperm and translocation of soluble nitrogento the embryo are the predominant features. Thereafter the embryoactively synthesizes protein from the products of translocation. IAA and MH affected the seedling growth similarly. Initiallythere was a small retardation of leaf growth, but at later periodsrecovery took place. Root growth was more adversely affectedthan shoot growth, the effect also persisting longer. Thesechanges in growth were reflected in the nitrogen metabolismof the seedlings. For the first few days IAA and MH retardedthe supply of soluble nitrogen from the endosperm to the embryo,consequently there was less soluble nitrogen in the embryo thoughprotein synthesis there was affected only slightly. The differencein soluble nitrogen between the treated and untreated embryospersisted throughout the seven days. An attempt is made to explainthis on the basis that primarily IAA and MH retard the enzymaticactivity responsible for the hydrolysis of protein in the endosperm.     

SHOREBIRD HABITAT USE AND NEST-SITE SELECTION IN THE PLAYA LAKES REGION

Abstract: Wetlands in the Playa Lakes Region (PLR) provide important habitats for wintering waterfowl, cranes, and both migrant and breeding shorebirds. Playa Lakes Region wetlands experience naturally fluctuating hydroperiods but are exposed to anthropogenic stresses, which are exacerbated during summer and may influence PLR wetland occupancy and selection by breeding shorebirds. We examined wetland-scale habitat use and nest-site selection of the 4 dominant shorebirds (American avocets [Recurvirostra americana], black-necked stilts [Himantopus mexicanus], killdeer [Charadrius vociferus], snowy plovers [C. alexandrinus]) nesting in playas, saline lakes, and in both created and riparian wetlands in the PLR of Texas, USA. All 4 species nested in saline lakes. Only avocets and killdeer nested in playas, and snowy plovers nested in riparian wetlands. No nests were found in created wetlands. Wetland habitat changed (P < 0.001) during the breeding season, while water habitats generally decreased. Used (i.e., shorebirds found nesting) wetlands had more (P < 0.05) mudflats than non-used (i.e., shorebirds not found nesting) wetlands, which had more (P < 0.05) dry habitats. Used and non-used wetlands had similar (P > 0.05) amounts of water habitats. Nests were located close to vegetation on bare dry ground and dry ground with vegetation. Because water is ephemeral in PLR wetlands, shorebirds must select—in a somewhat predictive manner upon arrival—wetlands with suitable nest-site and brood-rearing habitat. Although surface water is necessary for nesting, its presence is not adequate for delineating suitable PLR wetland habitat for breeding shorebirds. Our findings that created wetlands cannot compensate for regional wetland losses in habitat or function highlights the need for conservation of natural PLR wetlands