The Forest Owlet Heteroglaux blewitti: vocalization, breeding biology and conservation

The little-known, endemic Forest Owlet Heteroglaux blewitti was studied from June 1998 to June 1999 in Maharashtra, India. Vocalizations associated with contact, courtship feeding and food solicitation were recorded and sonagrams are presented for the first time. The nesting period started in October 1998 and continued until May 1999. Four nests were located and three were monitored for intensive studies on the breeding biology. Thirty days were spent on incubation ( n  = 2), mainly performed by the female while the male supplied food to the female and chicks. The observed brood size was two. The chicks fledged at 40 days but were dependent on their parents for food and protection for a further 45 days. The very low population density of the species could be due to degraded and fragmented habitat, scarcity of nest-sites or cronism observed in the species.     

ELECTROPHORETIC AND MORPHOMETRIC CHARACTERS IN POPULATION DIFERENTIATION OF THE PEARL OYSTER, PINCTADA RADIATA (LEACH), FROM AROUND BAHRAIN

Variation at the leucine aminopeptidase (Lap), glucose phosphateisomerase (Gpi) and tetrazolium oxidase (To) loci was investigatedin samples of three populations, Al-Mayana (MAY), Shigita (SH)and Mina Salman (MS), of Pinctada radiata from pearl oysterbeds around Bahrain. The To locus was monomor-phic. SignificantLap and Gpi heterozygote deficiencies were evident and it issuggested that these were generated by selection. The MS population,to the East of Bahrain, differed significantly in Gpi allelefrequencies from both Northern populations (MAY, SH) and Nei'sgenetic identity indicates a close relationship between theNorthern populations. Measurements of shell morphometrics were used both as ratiosof one dimension to another, and as regressions of one dimensionon another to examine relatedness between populations. Boththese mor-phometric approaches gave different results from eachother and also differed from the electrophoretic data. It isconcluded that estimates of relatedness in pearl oysters basedon electrophoretic data will be more reliable than those basedon shell shape. (Received 20 November 1990; accepted 12 April 1991)     

Differentiation of citrus tristeza closterovirus (CTV) isolates by single-strand conformation polymorphism analysis of the coat protein gene

Citrus tristeza closterovirus (CTV) isolates of several geographical origins were compared for variations in their coat protein (CP) gene by analysis of single-strand conformation polymorphism (SSCP). The CP gene of 17 isolates was reverse transcribed, amplified by polymerase chain reaction (PCR), and 22 clones were inserted into a plasmid vector. These clones were sequenced and found to have between 91.7% and 99.8% sequence homology. Clones were amplified and the PCR products denatured and compared by SSCP analysis in 8% polyacrylamide gels. Using two different electrophoretic conditions, the patterns were different for 16 or 17 clones. Four pairs of clones (T36/T66, P1/Q2, 03/8Q, and E1/E2) differing by 10, 2, 1 and 1 nucleotides, respectively, could not be distinguished using either condition. When these clones were compared by SSCP after digestion with Eco91I (BstEII) three of the pairs (T36/T66, P1/Q2, and 03/8Q) could be differentiated, whereas the clones E1 and E2 (differing by 1 nucleotide) remained indistinguishable. Thus, SSCP analysis combining two electrophoretic conditions and restriction of eight clones with Eco91I allowed discrimination between 21 of the 22 CP gene clones selected. SSCP analysis may provide a procedure to identify and differentiate CTV isolates based on comparisons of several genes or gene regions. It is rapid and cheap and may drastically reduce the amount of sequencing necessary for accurate comparisons.