scholarly journals Precision of larval herring abundance and body length assessments when sampling with BONGO nets for spawning site mapping

2022 ◽  
Vol 246 ◽  
pp. 106165
Author(s):  
Dariusz P. Fey ◽  
Agnieszka Szkudlarek-Pawełczyk
1985 ◽  
Vol 23 (2) ◽  
pp. 253 ◽  
Author(s):  
Seung Yull Cho ◽  
Im Won Chang ◽  
Hyun Jung Jang

2011 ◽  
Vol 4 (1) ◽  
pp. 31-33
Author(s):  
Merel J. Cox ◽  
David Chiszar ◽  
Hobart M. Smith

Nine neonatal and juvenile snakes, four vipers and five nonvipers, were fed rodent meals varying in size, expressed as percent of snake body weight. The number of mandibular protractions and the time to complete swallowing were recorded, with both measures increasing linearly as a function of meal size. These young snakes routinely swallowed meals that were 50% of body weight, and ranged up to 80%, far higher than meals reported by previous workers studying adult vipers (36.4%) and nonvipers (18.4%). Furthermore, the slopes of regressions relating mandibular protractions to meal size in all of our snakes were lower than comparable slopes for adult vipers or nonvipers. We hypothesized that the relatively long and wide skulls of young snakes (i.e., as proportion of body length) were responsible for these ingestive accomplishments, with negative allometric growth being responsible for performance changes during ontogeny.


2019 ◽  
Author(s):  
Sawyer Reid stippa ◽  
George Petropoulos ◽  
Leonidas Toulios ◽  
Prashant K. Srivastava

Archaeological site mapping is important for both understanding the history as well as protecting them from excavation during the developmental activities. As archaeological sites generally spread over a large area, use of high spatial resolution remote sensing imagery is becoming increasingly applicable in the world. The main objective of this study was to map the land cover of the Itanos area of Crete and of its changes, with specific focus on the detection of the landscape’s archaeological features. Six satellite images were acquired from the Pleiades and WorldView-2 satellites over a period of 3 years. In addition, digital photography of two known archaeological sites was used for validation. An Object Based Image Analysis (OBIA) classification was subsequently developed using the five acquired satellite images. Two rule-sets were created, one using the standard four bands which both satellites have and another for the two WorldView-2 images their four extra bands included. Validation of the thematic maps produced from the classification scenarios confirmed a difference in accuracy amongst the five images. Comparing the results of a 4-band rule-set versus the 8-band showed a slight increase in classification accuracy using extra bands. The resultant classifications showed a good level of accuracy exceeding 70%. Yet, separating the archaeological sites from the open spaces with little or no vegetation proved challenging. This was mainly due to the high spectral similarity between rocks and the archaeological ruins. The satellite data spatial resolution allowed for the accuracy in defining larger archaeological sites, but still was a difficulty in distinguishing smaller areas of interest. The digital photography data provided a very good 3D representation for the archaeological sites, assisting as well in validating the satellite-derived classification maps. All in all, our study provided further evidence that use of high resolution imagery may allow for archaeological sites to be located, but only where they are of a suitable size archaeological features.


2011 ◽  
Vol 33 (11) ◽  
pp. 1245-1250 ◽  
Author(s):  
Tian-Qi ZHANG ◽  
Xiao-Feng ZHANG ◽  
Zhao-Jun TAN ◽  
Zhu CAO ◽  
Xuan-Peng WANG ◽  
...  

2021 ◽  
Author(s):  
Haifeng Li ◽  
Xinyu ZHang ◽  
Yi Wu ◽  
Feng ZHang ◽  
CHunlin Li

Abstract Personality has been observed in a variety of animal taxa with important implications in ecology and evolution. Exploring the influence of environmental temperature during early life on personality could help to understand the ontogeny of this phenotypic trait in animals. In this study, we reared newborn mosquitofish Gambusia affinis at high (30°C) and low (25°C) water temperatures and measured their shyness and exploration upon sexual maturity. We tested the repeatability of each behavioral trait; the correlation between them; and the effects of rearing temperature, sex, and body length on the behaviors. When growing up at low temperatures, female fish exhibited repeatability in shyness and exploration, and males exhibited marginal repeatability in shyness. However, neither of the 2 behaviors were repeatable when the fish were reared at high temperatures. There was a negative correlation between shyness and exploration, indicating that the 2 behaviors comprise a behavioral syndrome in this species. Mosquitofish reared at high temperatures were more explorative than those reared at low temperatures, while there was no difference in shyness between the 2 treatments. Body length and sex had no significant effects on the average values of the 2 behaviors. The results indicate that environmental temperature during early life could shape the personality of mosquitofish and modify the average of the behavioral traits. These findings might provide insights to understand the ontogeny of animal personality and how changes in environmental temperature influence animal dispersal by shaping their personality.


Author(s):  
Matías Reolid ◽  
Francisco J. Cardenal ◽  
Jesús Reolid

AbstractThe aim of this work is to obtain diverse morphometric data from digitized 3D models of scientifically accurate palaeoreconstructions of theropods from eight representative families. The analysed polyvinyl chloride (PVC) models belong to the genera Coelophysis, Dilophosaurus, Ceratosaurus, Allosaurus, Baryonyx, Carnotaurus, Giganotosaurus, and Tyrannosaurus. The scanned 3D models were scaled considering different body-size estimations of the literature. The 3D analysis of these genera provides information on the skull length and body length that allows for recognition of major evolutionary trends. The skull length/body length in the studied genera increases according with the size of the body from the smallest Coelophysis with a ratio of 0.093 to ratios of 0.119–0.120 for Tyrannosaurus and Giganotosaurus, the largest study theropods. The study of photogrammetric 3D models also provides morphometric information that cannot be obtained from the study of bones alone, but knowing that all reconstructions begin from the fossil bones, such as the surface/volume ratio (S/V). For the studied theropod genera surface/volume ratio ranges from 35.21 for Coelophysis to 5.55 for Tyrannosaurus. This parameter, closely related to the heat dissipation, help in the characterization of the metabolism of extinct taxa. Accordingly, slender primitive forms of the Early Jurassic (i.e. Coelophysis and Dilophosaurus) had relatively smaller skulls and higher mass-specific metabolic rates than the robust large theropods of the Cretaceous (i.e. Giganotosaurus and Tyrannosaurus). This work presents a technique that, when applied to proper dinosaur models, provides extent and accurate data that may help in diverse study areas within the dinosaur palaeontology and palaeobiology.


2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 307-307
Author(s):  
Matthew McIntosh ◽  
Alfredo Gonzalez ◽  
Andres Cibils ◽  
Rick Estell ◽  
Shelemia Nyamuryekung’e ◽  
...  

Abstract Raramuri Criollo (RC) are one of 33 known biotypes of heritage Criollo cattle that exist throughout the Americas today. They have been raised by the Tarahumara peoples of the Copper Canyon in Chihuahua, Mexico, for over 400 years and exhibit remarkable rusticity and adaptation to harsh grazing environments. To date, no quantitative phenotypic description of this biotype exists. Our objective was to characterize RC cattle via 26 phenotype traits to provide a preliminary biotype standard. Twenty-eight multiparous RC cows, 4 primiparous heifers, and 4 bulls were selected from a purebred herd of approximately 200 animals at the USDA-ARS Jornada Experimental Range. These 36 animals were selected by a Criollo cattle expert based on body conformation correctness. SAS 9.4 was used to determine means, SEs or frequency of measured traits. Multiparous pregnant and cycling cows averaged 366.8 ± 9.8 kg live body weight, 121.8 ± 0.9 cm withers height, horn widths of 60.3 ± 1.6 cm, horn diameters of 5.7 ± 0.1 cm, chest girths of 183.6 ± 12.0 cm, hip widths of 44.5 ± 0.5 cm, flank girths of 52.2 ± 0.9 cm, body length of 90.0 ± 1.7 cm, neck lengths of 52.0 ± 0.9 cm, and tail lengths of 83.3 ± 1.4 cm. Bulls consistently averaged higher values for all traits and weighed 618.2 ± 9.8 kg with scrotal circumferences of 36.8 ± 0.7 cm. RC cattle exhibited mostly convex nose bridges (89%), open-back horns (49%), black muzzles, hooves, and eyes (62, 69, and 81%, respectively), small ears (78%), oblique eyes (70%), high-set tail heads (86%), short hooves (95%), and short hair (78%). Our preliminary characterization of RC phenotypes will be useful in selecting RC individuals for genotypic evaluation to eventually maintain a distinct purebred registry of this Criollo biotype.


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