Observations on the mating behavior, spawn mass and larval development of Hydatina physis Linne, 1758 (Cephalaspidea: Hydatinidae) from Karachi

Reproduction of Hydatina physis was studied in a population from Karachi, Pakistan, including mating and egg laying behavior, spawn characteristics and development.Individuals first appear in the field in October and remain until March. The spawning occurs from mid-November till mid-February with a peak in December. During this period the individuals were also observed pairing. In captivity, mating lasts for 30 minutes, second mating occurs two days later. Oviposition occurs in a very interesting and unusual manner. The mother turns "up-side-down" with its food fully expanded and the shell completely hidden underneath, the expanded foot serves as protective cover to the eggs. Eggs are deposited in a complexly folded mass with a short stem and an adhesive disc. Capsules, arranged in a single layer, contain 4-6 eggs each of wich is 70 um in diameter. Development is planktotrophic and veligers hatch after 14 days at a temperature of 26-28 degrees Celsius.

Sinum haliotoideum (Linnaeus, 1758), a gastropod mollusc new to the marine waters of Pakistan (northern Arabian Sea)

Sinum haliotoideum (Linnaeus, 1758) was collected on only two occasions. However, it was given attention when the recently collected specimen netted on 24 August, 1993 was brought live to the laboratory where its movement towards the source of light was noticed, leading to a careful examination and illustration. The specimen survived for 4 days. Illustrations and shell from the earlier collected specimen (August, 1991) were sent to Dr. Alan R. Kabat, division of Mollusck, National Museum of Natural History, Smithsonian Institution, USA, who confirmed that the specimen was Sinum haliotoideum (Linnaeus, 1758). He further informed that this is a moderately common Indo-Pacific species. The material has been deposited in the collections of the Marine Reference Collection and Resource Centre. (MRC) The species being new to the region is briefly described.

Video tracking using dual-treewavelet polar matching and particle filtering

In this paper, we describe a video tracking application using the dual-tree polar matching algorithm. The models are specified in a probabilistic setting, and a particle ilter is used to perform the sequential inference. Computer simulations demonstrate the ability of the algorithm to track a simulated video moving target in an urban environment with complete and partial occlusions. © The Institution of Engineering and Technology.

Growth of the green mussel, Perna viridis (Linn. 1758), from Moheshkhali Channel of the Bay of Bengai, Bangladesh

Growth of Perna viridis L. inhabiting Moheshkhali jetty of the channel was studied for one year from November, 1990 to October, 1991. The mussel attained 88.12mm±14.69 in length within 12 months with a mean growth rate of 7.34mrnlmonth. Employing von Bertalanffy's growth equation it was found that P. viridis can be 88.43mm, 114.69mm and 121.9lmm at the age of 1, 2 and 3 year respectively. The highest growth rate was recorded during November-April, coinciding with the maximum abundance of phytoplankton and the greatest salinity. The maximum growth rate (99.38%) was recorded at an early stage and was followed by a sharp decline to 4.47%. The growth pattern of P. viridis fitted well with the von Bertalanffy's growth equation.

Length-weight relationship and condition factor of Perna viridis (Linnaeus, 1758) and Meretrix meretrix (Linnaeus, 1758) from Mumbai waters

Length weight relationship of the two commercially important molluscs P. viridis and M. meretrix was found to be W=-0.40263L super(2.044719) & W=-0.04359L super(2.2315498) respectively. Condition factor was recorded to be less than 1.0 for most part of the year in P. viridis and for M. meretrix it ranged from 0.39 to 4.61. The present study reveals that there was allometric growth in both the species and the growth was not satisfactory since it showed lower K-value during most part of the year.

Mutation analysis of a large Chinese pedigree with congenital preaxial polydactyly

Mutations in the long-range limb-specific cis-regulator (ZRS) could cause ectopic shh gene expression and are responsible for preaxial polydactyly (PPD). In this study, we analyzed a large Chinese isolated autosomal dominant PPD pedigree. By fine mapping

Association of early growth response-1 gene polymorphisms with total IgE and atopy in asthmatic children

Early growth response-1 (Egr-1) is expressed in human airways and found to modulate tumor necrosis factor, immunoglobulin E (IgE), airway responsiveness, and interleukin-13-induced inflammation in mice. We investigated the effects of Chinese-tagging singl

Polymorphisms of the estrogen receptor alpha (ESR1) gene and the risk of Alzheimer's disease in a southern Chinese community

Background: Alzheimer's disease (AD) is a neurodegenerative disease with a higher prevalence in women. Expression of estrogen receptor 1 (ESR1) gene has been identified throughout the brain. Owing to the putative neuroprotective effects of estrogen, estro

Evidence for Positive Selection on the Osteogenin (BMP3) Gene in Human Populations

Background: Human skeletal system has evolved rapidly since the dispersal of modern humans from Africa, potentially driven by selection and adaptation. Osteogenin (BMP3) plays an important role in skeletal development and bone osteogenesis as an antagonist of the osteogenic bone morphogenetic proteins, and negatively regulates bone mineral density. Methodology/Principal Findings: Here, we resequenced the BMP3 gene from individuals in four geographically separated modern human populations. Features supportive of positive selection in the BMP3 gene were found including the presence of an excess of nonsynonymous mutations in modern humans, and a significantly lower genetic diversity that deviates from neutrality. The prevalent haplotypes of the first exon region in Europeans demonstrated features of long-range haplotype homogeneity. In contrast with findings in European, the derived allele SNP Arg192Gln shows higher extended haplotype homozygosity in East Asian. The worldwide allele frequency distribution of SNP shows not only a high-derived allele frequency in Asians, but also in Americans, which is suggestive of functional adaptation. Conclusions/Significance: In conclusion, we provide evidence for recent positive selection operating upon a crucial gene in skeletal development, which may provide new insight into the evolution of the skeletal system and bone development.

Adaptive Evolution of Digestive RNASE1 Genes in Leaf-Eating Monkeys Revisited: New Insights from Ten Additional Colobines

Pancreatic RNase genes implicated in the adaptation of the colobine monkeys to leaf eating have long intrigued evolutionary biologists since the identification of a duplicated RNASE1 gene with enhanced digestive efficiencies in Pygathrix nemaeus. The recent emergence of two contrasting hypotheses, that is, independent duplication and one-duplication event hypotheses, make it into focus again. Current understanding of Colobine RNASE1 gene evolution of colobine monkeys largely depends on the analyses of few colobine species. The present study with more intensive taxonomic and character sampling not only provides a clearer picture of Colobine RNASE1 gene evolution but also allows to have a more thorough understanding about the molecular basis underlying the adaptation of Colobinae to the unique leaf-feeding lifestyle. The present broader and detailed phylogenetic analyses yielded two important findings: 1) All trees based on the analyses of coding, noncoding, and both regions provided consistent evidence, indicating RNASE1 duplication occurred after Asian and African colobines speciation, that is, independent duplication hypothesis; 2) No obvious evidence of gene conversion in RNASE1 gene was found, favoring independent evolution of Colobine RNASE1 gene duplicates. The conclusion drawn from previous studies that gene conversion has played a significant role in the evolution of Colobine RNASE1 was not supported. Our selective constraint analyses also provided interesting insights, with significant evidence of positive selection detected on ancestor lineages leading to duplicated gene copies. The identification of a handful of new adaptive sites and amino acid changes that have not been characterized previously also provide a necessary foundation for further experimental investigations of RNASE1 functional evolution in Colobinae.

Changes in length and weight of milkfish fry preserved in formalin

Fry shrank immediately after they were preserved in formalin, but from the second week onwards shrinkage was almost nil. Fry in freshwater formalin solutions shrunk less than those in seawater formalin solutions. It is recommended that milkfish Chanos) fry be preserved in formalin solutions for 1 wk prior to length measurement and at least for 3 wks before determining body weight.

Developmental and ecological stages in the life history of milkfish Chanos chanos Forsskal

Seven stages in the life history of the milkfish C. chanos , are recognized and suggested: A, embryonic; B, yolksac larval; C, larval; D, postlarval; E, juvenile; F, subadult; G. adult. An outline is presented of the life history. It is concluded that the milkfish, throughout the known stages of their life history are well adapted and equipped for optimal survival. High swimming performance, broad flexibility in feeding habits, high adaptability to a wide range of physicochemical conditions of the environment are but a few of the adaptations. The main driving force in all developmental stages is the evolutionary response to food distribution and availability followed by predation pressure.

Occurrence of milkfish, Chanos chanos (Forsskal) eggs around Panay Island, Philippines

The study documents the occurrence of milkfish, Chanos chanos (Forsskal) eggs around Panay Island, Philippines: in Cuyo East Pass, Panay Gulf, Visayan Sea, Sibuyan Sea and Cagayan Islands. Most of the eggs, 545 out of 551, were obtained from Cuyo East Pass compared to Cagayan Islands and Sibuyan Sea while no milkfish egg was recovered from either Panay Gulf or Visayan Sea.