scholarly journals Relationships between total length and otolith size of bluefish Pomatomus saltatrix (Linnaeus, 1766) in the Marmara Sea of Turkey

2018 ◽  
Vol 3 (1) ◽  
pp. 38-44 ◽  
Author(s):  
Habib Bal ◽  
Telat Yanık ◽  
Dilek Türker
Omni-Akuatika ◽  
2020 ◽  
Vol 16 (3) ◽  
pp. 99
Author(s):  
Fransine B Manginsela ◽  
Gybert E Mamuaya ◽  
Rizald M Rompas ◽  
Lawrence J L Lumingas

This study aimed to examine the difference in the otolith size and otolith shape of redtail scad Decapterus kurrodes between sex in North Sulawesi. The otoliths of D. kurroides were studied for sagitta otolith pair samples of 34 juveniles,   58 females and 75 males from Kema Bay. These pairs sagitta otolith images were interpreted using ImageJ tool to describe the otolith size (length, width, perimeter, and area), then we calculated the shape index (form factor, roundness, circularity, rectangularity, ellipticity and aspect ratio or length-width ratio). No significant difference was found in otolith length between left and right otoliths of juveniles of D. kurroides or called symmetrical but significant differences or asymmetrical were found in all sample, females and males. The regressions of total length against otolith sizes (otolith lengt, otolith width otolith perimeter and otolith area of D. kurroides follow a power function. The growth patterns showed dominant allometric growth in total length–otolith sizes relationships of D. kurroides from Kema Bay, Key Words: size, shape index, otolith, Decapterus kurroides, Kema Bay.


2019 ◽  
Vol 49 (4) ◽  
pp. 299-306
Author(s):  
Rory Romero de Sena OLIVEIRA ◽  
Marcelo Costa ANDRADE ◽  
Fabiola Seabra MACHADO ◽  
Élida Jesana Santana CUNHA ◽  
Flaviane Souto de FREITAS ◽  
...  

ABSTRACT The relationships between fish size and sagitta otolith measurements were calculated for the first time for 15 species belonging to six families from the northern Brazilian coast. A total of 220 fish were sampled from the bycatch landed by the bottom-trawl industrial shrimp-fishing fleet between August and September 2016. All species had strong relationships between otolith measurements and fish total length with the coefficient of determination (r 2) ranging between 0.71 and 0.99. The variable most strongly related to fish total length was found to be the sagittal otolith length (OL) with 98% of the variability. These relationships are a useful tool to estimate length and mass of preyed fish from otoliths found in stomach contents of marine predators.


1995 ◽  
Vol 52 (9) ◽  
pp. 1909-1922 ◽  
Author(s):  
Jonathan A. Hare ◽  
Robert K. Cowen

The otolith size – fish size relationship was examined in field-collected larval and pelagic juvenile bluefish, Pomatomus saltatrix. The purpose was to evaluate the central assumption of proportional back-calculation techniques, namely that otolith and somatic growth are in constant proportion. Age-independent variability was found between otolith size and fish size that differed between ontogenetic stages. Stage-specific growth rate effects were also identified. Finally, the otolith size – fish size relationship changed at certain ontogenetic stage transitions. These effects, as well as others that have been found, are discussed with regard to the assumption of constant proportionality between otolith growth and fish growth. In light of this discussion, the overall validity of constant proportionality becomes suspect when applied to the early life history stages of fishes. Future work should take a longitudinal approach to the analysis of the relationship between otolith growth and somatic growth. In addition, regression and proportional methods should be modified to account for growth rate and ontogenetic effects. Finally, a relative size approach is presented that is appropriate in situations that require only relative measures of fish size. This relative size approach has several benefits and these are discussed in relation to other back-calculation procedures.


2020 ◽  
Vol 37 (3) ◽  
pp. 267-274
Author(s):  
İsmail Burak Daban ◽  
Mukadder Arslan İhsanoglu ◽  
Ali İsmen

The total length-otolith length (TL-OL), total length-otolith width (TL-OWi), total length-otolith weight (TL-OW) and total weight-otolith weight (TW-OW) relationships of seven fishes in the Marmara Sea, Turkey were calculated. Measurements of sagittal otoliths (length, width and weight) and individuals (total length and total weight) from these species (Gaidropsarus biscayensis, Mediterranean bigeye rockling; Arnoglossus kessleri, Scaldback; Solea solea, Common sole; Uranoscopus scaber, Stargazer; Lophius budegassa, Blackbellied angler, Lepidorhombus boscii, The four-spot megrim and Lesueurigobius friesii, Fries's goby) were given. Linear regression analysis (y = bx + a) was used to determine the relationship between each morphometric character and the coefficient of determination (r2) were calculated. Highest determination coefficient were determined for L. budegassa and A. kessleri to TW-OW, for S. solea, and U. scaber to TL-OL, for G. biscayensis and L. boscii to TL-OWi, for L. friesii to TL-OW. The relatively lower determination coefficients were found for G. biscayensis, compared with others. These relationships provide vital information on species identification and size estimation of fish in predator-prey studies, we believe these results will be useful in future studies of stomach contents.


2020 ◽  
Vol 5 (2) ◽  
pp. 504
Author(s):  
Matthias Omotayo Oladele ◽  
Temilola Morufat Adepoju ◽  
Olaide ` Abiodun Olatoke ◽  
Oluwaseun Adewale Ojo

Yorùbá language is one of the three main languages that is been spoken in Nigeria. It is a tonal language that carries an accent on the vowel alphabets. There are twenty-five (25) alphabets in Yorùbá language with one of the alphabets a digraph (GB). Due to the difficulty in typing handwritten Yorùbá documents, there is a need to develop a handwritten recognition system that can convert the handwritten texts to digital format. This study discusses the offline Yorùbá handwritten word recognition system (OYHWR) that recognizes Yorùbá uppercase alphabets. Handwritten characters and words were obtained from different writers using the paint application and M708 graphics tablets. The characters were used for training and the words were used for testing. Pre-processing was done on the images and the geometric features of the images were extracted using zoning and gradient-based feature extraction. Geometric features are the different line types that form a particular character such as the vertical, horizontal, and diagonal lines. The geometric features used are the number of horizontal lines, number of vertical lines, number of right diagonal lines, number of left diagonal lines, total length of all horizontal lines, total length of all vertical lines, total length of all right slanting lines, total length of all left-slanting lines and the area of the skeleton. The characters are divided into 9 zones and gradient feature extraction was used to extract the horizontal and vertical components and geometric features in each zone. The words were fed into the support vector machine classifier and the performance was evaluated based on recognition accuracy. Support vector machine is a two-class classifier, hence a multiclass SVM classifier least square support vector machine (LSSVM) was used for word recognition. The one vs one strategy and RBF kernel were used and the recognition accuracy obtained from the tested words ranges between 66.7%, 83.3%, 85.7%, 87.5%, and 100%. The low recognition rate for some of the words could be as a result of the similarity in the extracted features.


Author(s):  
V. Turlyun

The analysis of some herds of imported cattle under the conditions of Russian farms had been shown that the genetic potential of imported cattle in many farms has being realized only by 57 %, with the output of up to 50 % of the cattle during the first 2 years. The reason for this is the discrepancy between the conditions of the biological needs of animals. In this regard, the study of factors that affect the provision of comfortable conditions for animals plays an important role. This is especially true for Holstein animals, which are more susceptible to various diseases. In accordance with the technological solutions used in modern large complexes, the loose housing method of maintenance is mainly used. This method allows the animal to move freely, providing access to the consumption of water and feed, as well as timely rest. This determines the importance of the requirements for the size of the boxes for the rest of animals, which should ensure dryness and cleanliness in the process of resting cows, prevent damage to animals, as well as the ability of other animals to displace each other. The crossbars should not interfere with the free movement of the cow in the process of lowering to the floor and getting up due to their flexibility. The dimensions of the boxes should be made taking into account the measurements of the animals’ torso, as well as the amplitude of movement in the process of lowering and rising. The purpose of the research was to study the size of boxes and their compliance with the biological needs of highly productive imported cattle. An analysis of the compliance of conditions for housing highly productive cattle of Canadian and Australian origin with their biological needs under the conditions of a mega farm has been presented in the paper. Calculation on the basis of measurements of animals has been shown that animals of the Canadian selection require boxes with a total length of at least 279 cm, Australian – 271 cm. The difference with the required width of the box has been also established. For the group of cows of Canadian selection it should be at least 120 cm, for the Australian – 114 cm. Research results have been shown that the discrepancy in the design of boxes for comfortable rest of animals is a deterrent to the realization of their genetic productive potential.


1995 ◽  
Vol 32 (7) ◽  
pp. 63-70
Author(s):  
I. Ethem Gönenç ◽  
Oguz Müftüoglu ◽  
Bilsen Beler Baykal ◽  
Ertugrul Dogan ◽  
Hüseyin Yüce ◽  
...  

Unlike other seas of the world, the Black Sea shows unique quality and trophic properties. Fortunately, only the upper layer water of the Black Sea is introduced into the Bosphorus and has a significant effect on the quality and trophic conditions of the Marmara Sea. These effects are discussed in the light of data obtained from collaborative efforts of Turkish and Romanian research institutions and processed satellite images. In conjunction with these discussions, recommendations for a suitable effluent disposal strategy for Istanbul's wastewater have been given.


1995 ◽  
Vol 32 (2) ◽  
pp. 141-148 ◽  
Author(s):  
I. S. Hansen ◽  
H. J. Vested ◽  
M. A. Latif

A modelling study of the hydrodynamics and spreading of wastewater from existing and future outfalls in the Bosphorus region has been conducted applying a 3-Dimensional model. The modelling is based on SYSTEM 3, which is a general modelling system for baroclinic flow simulating unsteady currents, waterlevels, salinity and temperature within the model area. The model set-up covers the Black Sea-Bosphorus-Marmara Sea junction area. The set-up is calibrated by data from a dedicated field program and previous field experience. The model is designed to describe the characteristic features of the flow in the junction area such as the effects of variations in waterlevel differences between the Sea of Marmara and the Black Sea on the important two-layer structure in the strait and the flow fields generated by the upper layer jet in the Bosphorus-Marmara junction. This model has been applied for evaluation of disposal of wastewater and for the subsequent water quality studies. The general use of a baroclinic 3-D hydrodynamic model to simulate disposal of wastewater is discussed. Examples of the application of the model of the junction area to evaluate the different strategies for disposal of wastewater are presented.


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