RELATIONSHIP BETWEEN PUPAL COLOUR AND SEX RATIO OF THE COMMON MORMON, Papilio polytes romulus CRAMER, 1775 (INSECTA: LEPIDOPTERA), SRI LANKA

A free ranging female common Mormon (Papilio polytes romulus) butterfly was observed laying eggs on a Citrus aurantiifolia (Family: Rutaceae) plant in a home garden in Battaramulla. 16 eggs were collected and reared in the lab. The duration and measurements of each stage were recorded. After eclosion the sex and wingspan of all adult butterflies were recorded and they were released back to the wild. Pupae were observed in two colours: green and brown. Out of 16 pupae, 12 were green (75%) and four were brown (25%). The four brown pupae gave rise to two males (50%) and two females (50%). The 12 green pupae gave rise to 10 males (83%) and two females (17%). The sex ratios regardless of the pupal colour showed male dominance with 12 males (75%) and four females (25%). All four females were of the romulus form. A strong relationship between pupal colour and substrate texture was observed, but no relationship between pupal colour, sex and sex ratios was seen.

Cellular Automata Analysis of Effects of Substrate Conditions on Microstructure and Texture Evolution during Selected Laser Melting

A Cellular Automata Finite Difference (CAFD) method was applied to analyze the effects of substrate grain size and texture on the microstructure and texture evolution during additive manufacturing. It was found that the grain size within the substrate is only effective at a short distance. Grains developed from the surrounding powders can lead to an almost similar microstructure away from the substrate. Texture evolution during build-up can be explained by the two main components of {001}<100> and {011}<100>. Development of the former and the latter components can be described by the competitive growth mechanism at the regions beneath and on the sides of the melt-pool, respectively. As a result, the former component is more pronounced at the higher ratios of the melt-pool width to the hatch distance. An almost similar fiber texture can develop from a substrate with the fiber texture of {001}||build-direction (BD). However, a substrate having the fiber {011}||BD evolves into the component {011}<100>, implying that other components of this fiber are not favored. In either case, due to the highly elongated melt-pool, the orientation {001}||hatch-direction (HD) is preferred and {011}||HD is not likely to happen.

A Study of the Structural Organization of Water and Aqueous Solutions by Means of Optical Microscopy

The structural organization of water and aqueous solutions under an optical microscope in a layer with a thickness of 8 μm was investigated. It is shown that under room conditions water (including “ultrapure” water) and aqueous solutions are microdispersed systems. The revealed effect does not depend on the properties of the substrate (texture, hydrophilicity/hydrophobicity) and is an inherent property of the liquid. The disperse phase is based on contrasting micron-sized formations located in the center of low-contrast homogeneous spheres observed in a layer with a thickness of the order of the diameter of the observed structures. They form loose millimeter-sized associates in the liquid phase. When the water is boiled, the associates become disordered, but the dispersed phase is preserved. An increase in the ionic strength of the solution is accompanied by coacervation of the dispersed phase. When the liquid part of the water evaporates, the microdispersed phase remains on the substrate. The central particles begin to grow and take on the form of crystals. On the basis of the literature data and their own research, the authors believe that the structures are sodium chloride microcrystals surrounded by a thick layer of hydrated water. Possible ways of salt penetration into the aquatic environment are discussed.

Behavioral Analysis of Substrate Texture Preference in a Leech, Helobdella austinensis

ABSTRACTLeeches in the wild are often found on smooth surfaces, such as vegetation, smooth rocks or human artifacts such as bottles and cans, thus exhibiting what appears to be a “substrate texture preference behavior”. Here, we have reproduced this behavior under controlled circumstances, by allowing leeches to step about freely on a range of silicon carbide sandpaper substrates. To begin to understand the neural mechanisms underlying this texture preference behavior, we have determined relevant parameters of leech behavior both on uniform substrates of varying textures, and in a behavior choice paradigm in which the leech is confronted with a choice between rougher and smoother substrate textures at each step. We tested two non-exclusive mechanisms which could produce substrate texture preference: 1) a Diffusion Trap mechanism, in which a leech is more likely to stop moving on a smooth surface than on a rough one, and; 2) an Anterior Choice mechanism, in which a leech is more likely to attach its front sucker (prerequisite for taking a step) to a smooth surface than to a rough one. We propose that both mechanisms contribute to the texture preference exhibited by leeches.

KARAKTERISTIK SARANG PENYU HIJAU (CHELONIA MYDAS) DI PULAU KASIAK KAWASAN KONSERVASI PENANGKARAN PENYU PARIAMAN, SUMATERA BARAT

The research aimed to understand the nesting area characteristic of C. mydas in the Kasiak Island was conducted from March-April 2017, coincidence with the nesting time of green turtle. Observation of the nesting area of green turtle was conducted in the Northern, Southern, Western and Eastern parts of the island. Parameters studied were the slope of the beach, the distance between the water edge during the high tide and the nest, sand texture, types of vegetations around the nest, number of nests present and the quality of water around the island. Results shown that the coast’s slope ranged from 1.74 to 2.890, the distance between the water edge during the high tide and the nest ranged from 1.17 to 1.70 m, the substrate texture was dominated by sand (> 90%), silt (3.4-7.25%) and clay (2-8%). The nest temperature was 25-320C, nest humidity was 30-40% and the common vegetation was Thespesia populnea. Quality of the water around the Kasiak Island are as follows: temperature was 29-300C, salinity was from 33-34 ‰, current speedwas 0.4-0.5 m / s and pH was 8.

Substrate texture affects female cricket walking response to male calling song

Field crickets are extensively used as a model organism to study female phonotactic walking behaviour, i.e. their attraction to the male calling song. Laboratory-based phonotaxis experiments generally rely on arena or trackball-based settings; however, no attention has been paid to the effect of substrate texture on the response. Here, we tested phonotaxis in female Gryllus bimaculatus , walking on trackballs machined from methyl-methacrylate foam with different cell sizes. Surface height variations of the trackballs, due to the cellular composition of the material, were measured with profilometry and characterized as smooth, medium or rough, with roughness amplitudes of 7.3, 16 and 180 µm. Female phonotaxis was best on a rough and medium trackball surface, a smooth surface resulted in a significant lower phonotactic response. Claws of the cricket foot were crucial for effective walking. Females insert their claws into the surface pores to allow mechanical interlocking with the substrate texture and a high degree of attachment, which cannot be established on smooth surfaces. These findings provide insight to the biomechanical basis of insect walking and may inform behavioural studies that the surface texture on which walking insects are tested is crucial for the resulting behavioural response.

Kelimpahan dan pola pertumbuhan kepiting bakau (Scylla serrata) di hutan mangrove Kelurahan Belawan Sicanang, Kecamatan Medan Belawan, Provinsi Sumatera Utara

Kepiting bakau (Scylla serrata) merupakan salah satu spesies kunci dalam ekosistem mangrove yang memegang peranan yang sangat penting. Hutan mangrove yang ada di Kelurahan Belawan Sicanang sudah banyak mengalami konversi lahan seperti tambak dan pemukiman. Kondisi ini menyebabkan terjadinya penurunan kualitas habitat dan penurunan populasi untuk sumberdaya kepiting bakau akibat terjadinya kerusakan daerah asuhan dan mencari makan biota ini. Penelitian ini bertujuan untuk mengetahui kondisi ekologi mangrove, untuk mengetahui kelimpahan kepiting bakau (Scylla serrata), untuk mengetahui pertumbuhan kepiting bakau (Scylla serrata) di Hutan Mangrove Kelurahan Belawan Sicanang Kecamatan Medan Belawan Provinsi Sumatera Utara. Penelitian berlangsung pada Mei - Juni 2016. Metode yang digunakan dalam penentuan lokasi adalah purposive sampling dan dibagi menjadi 3 stasiun berdasarkan aktivitas yang berbeda. Struktur populasi kepiting bakau (Scylla serrata) ditinjau dari kelimpahan kepiting bakau (Scylla serrata), hubungan lebar karapas dengan bobot tubuh, pola pertumbuhan, dan faktor kondisi. Kualitas habitat kepiting bakau (Scylla serrata) dilihat dari kualitas air, tekstur substrat, C-organik, dan pasang surut. Hasil menunjukkan bahwa kelimpahan kepiting bakau (Scylla serrata) 16300 - 17000 ind/ha, dengan pola pertumbuhan allometrik negatif (b<3), faktor kondisi berkisar antara 0 - 1 yang tergolong ke dalam pipih atau tidak gemuk. Kualitas air dan substrat yang dikaji termasuk ke dalam kualitas air yang menunjang kehidupan kepiting bakau (Scylla serrata), tekstur substrat yaitu lempung berpasir dan lempung liat berpasir, serta C-organik < 1% tergolong sangat rendah, dimana tipe pasang surutnya adalah mixed prevailing semidiurnal.Mangrove crab (Scylla serrata) is one of the keystone species in the mangrove ecosystem, which had a very important role. Mangrove forests existed in Village Belawan Sicanang have been many experienced land conversion as embankment and settlements. These conditions led to degradation in habitat quality and population decline for mangrove crab due to the occurrence of the damage to the nursery ground and the feeding ground. The research aimed to determine abundance mangrove crabs and to determine the growth of mangrove crab. The research took place in May - June 2016. The method used in the determination of the location is purposive sampling and divided into 3 stations based on different activities. The mangrove crab population structure in terms of the abundance of mangrove crab, carapace width relation with body weight, growth pattern, and factor condition. The quality habitat mangrove crab viewed the water quality, the substrate texture, C-organic, and tides. The results showed that the growth pattern was negative allometric (b < 3), factor condition ranges between 0 - 1 which classified into flat or not fat. The water quality and substrate were assessed included in the water quality that supported life mangrove crab, the substrate texture was sandy loam and sandy clay loam, C-organic classified < 1% was very low, the type of tides was mixed semidiurnal prevailing.