Classification of guppies’ (Poecilia reticulata) gender by computer vision

Labor costs of guppy growers and breeders are largely those of manual sorting (by strain, quality and gender) and counting fish. In most farms, female and male fish are grown together and sold either separately or together. Sorting fish according to gender is important for marketing as well as for breeding programs, so that a device for sorting and counting fish can potentially reduce production costs and improve quality.

A project aiming to develop sorting and counting technologies for ornamental fish growers included development and testing of image-processing algorithms for sorting guppy fish (Poecilia reticulata) by gender. The algorithms are derived from shape and color differences between female and male guppies. An algorithm for the determination of landmarks on fish contours was developed and found to be accurate in accordance with human judgment, enabling extraction of specific shape and color features of the tail and the body.

The algorithms were applied to three sets of images of guppies of the “Red-Blond” strain. Gender identification accuracy was approximately 90% using shape features, approximately 96% using color features and was slightly improved when both color and shape features were used.

Some of the components used are essential for future development of a computer vision based system for sorting and grading ornamental fish by strain and quality.     

Correction to: Factors affecting reproductive performance in dromedary camel herds in Saudi Arabia

Tropical Animal Health and Production - This article was originally published with incorrect affiliation 1. The correction affiliation is presented below.     

Inner structures of some coronaviruses.

When treated with formaldehyde, Tween 80, sodium oleate and Nonidet P-40, avian infectious bronchitis virus, porcine transmissible gastroenteritis virus, neonatal calf diarrhea coronavirus, porcine hemagglutinating encephalomyelitis virus as well as the human coronavirus show similar inner structures by negative staining. The first one is an inner membranous bag. This structure could be evaginated following treatments used and does not show the characteristic projections of coronaviruses. Subsequently, the inner fold could be separated from the outer membrane at the point of junction between these two membranes. Each virus does not react in the same way to the action of the different products. The transmissible gastroenteritis virus appears more sensitive to treatments than other viruses. On the other hand, the hemagglutinating encephalomyelitis virus is the most resistant. The variable sensitivities of these viruses are not related to the type of host-cells. Also, a second internal structure, which is more dense than the viral particle, encircles partially the aperture of the internal tongue-shaped structure and seems to emerge from the viral particle through the aperture of the inner bag.     

Use of electron microscopy and an enzyme-linked immunosorbent assay for the detection of rotaviruses in neonatal calf diarrhea.

Electron microscopy and an enzyme-linked immunosorbent assay were compared for the diagnosis of rotaviruses associated with neonatal calf diarrhea. One hundred percent correlation was observed when 125 samples were tested by both techniques. Both techniques were equally efficient in detecting rotaviruses. The enzyme-linked immunosorbent assay was more sensitive but being specific could not detect other viruses.     

Reducing preharvest drop of ‘Temple’ orange fruits by 2,4-D — Role of cellulase in the calyx abscission zone

One or two treatments of 2,4-D (18 p.p.m.) applied to ‘Temple’ orange trees during the last 6 weeks before the regular picking-period in late January, successfully reduced natural preharvest fruit abscission, allowing picking to be delayed by at least one month, and thus producing better external and internal fruit quality. It has been demonstrated for the first time that the delaying effect of auxin treatment on preharvest abscission was directly related to the decrease in the activity of endo- and exo-cellular cellulase. Most of the increase in cellulase activity during the abscission process was, however, due mainly to the activity of exo-cellular cellulase. When frost occurred a few days after application of 2,4-D, the auxin treatment significantly decreased total cellulase activity, thus reducing fruit abscission.The data proved that, except for the difference in the length of time between application and the onset of the hormone effect, the control mechanism of 2,4-D on abscission and on cellulase activity in intact fruit is similar to that previously reported for fruit explants.     

Influence d''infections préalables sur l''evolution de la pleuro-pneumonie porcine expérimentale chez des porcs exempts d''organismes pathogènes spécifiques.

This study was designed to determine in six-week old specific pathogen free pigs, the effect of previous experimental exposure to Mycoplasma hyopneumoniae and transmissible gastroenteritis virus on a challenge infection with Actinobacillus pleuropneumoniae. Pigs exposed simultaneously to M. hyopneumoniae and transmissible gastroenteritis virus appeared more resistant to challenge (one week later) with A. pleuropneumoniae. Four pigs out of a group of ten died following the challenge infection, compared to all ten pigs in the control group not submitted to previous infections. Clinical signs and lesions were also less severe in the previously infected group than in the control group. Pigs submitted to a single previous infection with M. hyopneumoniae only appeared to be less resistant to the challenge infection than pigs submitted to the dual previous infection with M. hyopneumoniae and the transmissible gastroenteritis virus. A correlation was found between the resistance of pigs to the challenge infection and their serum gammaglobulin levels.     

Serology of bovine parainfluenza virus type 3: comparison of the enzyme linked immunosorbent assay and hemagglutination inhibition.

An enzyme linked immunosorbent assay (ELISA) for the detection of antibody to bovine parainfluenza virus type 3 has been compared with the hemagglutination inhibition test on 130 field sera, and seven other paired sera showing a significant raise of titers. The ELISA was found to be four to 64 times more sensitive than the hemagglutination inhibition test and the two tests demonstrated a good correlation.     

Detection of bovine coronavirus and type A rotavirus in neonatal calf diarrhea and winter dysentery of cattle in Quebec: evaluation of three diagnostic methods.

The use of direct electron microscopy, enzyme-linked immunosorbent assay, and protein A-gold immunoelectron microscopy for the identification of bovine coronavirus and type A rotavirus were examined. Two hundred and forty-nine samples from diarrheic calves and winter dysenteric cattle from seven geographic areas in Quebec were examined for the presence of viruses by direct electron microscopy of negatively stained preparations. In addition, all the samples were analyzed by enzyme-linked immunosorbent assay, and a random selection of 47 samples were also analyzed by protein A-gold immunoelectron microscopy. Thirty-nine percent of samples examined by direct electron microscopy contained viral particles; bovine coronavirus and type A rotavirus were the most common viruses involved. Overall agreement between any two of the methods used compared favorably with results obtained by others using similar methods. The presence of coronavirus and rotavirus in fecal samples obtained from neonatal calves and the presence of coronavirus in samples from winter dysenteric adult cattle suggested their etiological roles in the respective diseases. Furthermore, results from protein A-gold immunoelectron microscopy of coronavirus-like particles implied that a different coronavirus or some other viruses might be involved in these diseases. Finally, the efficiency of direct electron microscopy, enzyme-linked immunosorbent assay and protein A-gold immunoelectron microscopy as diagnostic tools is discussed.     

Endonucléases de restriction: isolement et identification d'une souche d'adénovirus canin de type 1

For the first time in Quebec, a type 1 canine adenovirus was isolated in cell culture and typed by restriction endonuclease analysis. This virus originated from the internal organs of a young dog killed by a severe respiratory disease without showing any sign of hepatitis.     

Atmospheric bismuth-212: measurement and some geophysical applications

The concentrations of lead-212 and its short-lived daughter bismuth-212 in air near the ground were determined simultaneously by adaptation of the immersed-filter, delayed-coincidence technique of Assaf and Gat to measurement of the 3 x 10-(7)-second bismuth-212 and polonium-212 pair. The radioactive disequilibrium between lead-212 and bismuth-212 depends strongly on the efficiency of the ground in acting as a sink for these nuclides. This efficiency is low under dry conditions.