Growth Parameters and Spawning Season Estimation of Four Important Flyingfishes in the Kuroshio Current Off Taiwan and Implications From Comparisons With Global Studies

Growth shapes the life history of fishes. Establishing appropriate aging procedures and selecting representative growth models are important steps in developing stock assessments. Flyingfishes (Exocoetidae) have ecological, economic, and cultural importance to many coastal countries including Taiwan. There are 29 species of flyingfishes found in the Kuroshio Current off Taiwan and adjacent waters, comprising 56% of the flyingfishes taxa recorded worldwide. Among the six dominant species in Taiwan, four are of special importance. This study reviews aging data of these four species, documents major points of the aging methods to address three aging issues identified in the literature, and applies multi-model inference to estimate sex-combined and sex-specific growth parameters for each species. The candidate growth models examined included von Bertalanffy, Gompertz, Logistic, and Richards models, and the resulting optimal model tended to be the von Bertalanffy model for sex-combined data and Gompertz and von Bertalanffy models for sex-specific cases. The study also estimates hatch dates from size data collected from 2008 to 2017; the results suggest that the four flyingfishes have two spawning seasons per year. Length-weight relationships are also estimated for each species. Finally, the study combines the optimal growth estimates from this study with estimates for all flyingfishes published globally, and statistically classifies the estimates into clusters by hierarchical clustering analysis of logged growth parameters. The results demonstrate that aging materials substantially affect growth parameter estimates. This is the first study to estimate growth parameters of flyingfishes with multiple model consideration. This study provides advice for aging flyingfishes based on the three aging issues and the classification analysis, including a recommendation of using the asterisci for aging flyingfishes to avoid complex otolith processing procedures, which could help researchers from coastal countries to obtain accurate growth parameters for many flyingfishes.

Conditional Ulam stability and its application to von Bertalanffy growth model

<abstract><p>The purpose of this paper is to apply conditional Ulam stability, developed by Popa, Rașa, and Viorel in 2018, to the von Bertalanffy growth model $ \frac{dw}{dt} = aw^{\frac{2}{3}}-bw $, where $ w $ denotes mass and $ a &gt; 0 $ and $ b &gt; 0 $ are the coefficients of anabolism and catabolism, respectively. This study finds an Ulam constant and suggests that the constant is biologically meaningful. To explain the results, numerical simulations are performed.</p></abstract>

Mathematical Modelling of the Growth of Bacillus cereus Strain wwcp1on Malachite Green Dye

In this paper, various growth models such as Von Bertalanffy, Huang, Baranyi-Roberts, Modified Gompertz, Buchnam-3-phase, Modified-Richards and Modified-Logistics, were presented in fitting and evaluating the growth of Bacillus cereus wwcp1 on Malachite green dye. The Von Bertalanffy model was found to be the best model with the lowest RMSE and highest R2 values. The Accuracy and Bias factor values were near unity (1.0). The von Bertalanffy parameters such as A (lower asymptote bacterial growth), μ (bacterial growth rate) and k (curve fitting parameter) were found to be 2.757 (95% confidence interval from 2.131 to 3.382 ), 0.287 (95% confidence interval from 0.244 to 0.329) and 4.323 (95% confidence interval from 4.285 to 4.361) respectively.

PREDIKSI BERAT TUBUH SAPI PERAH FRIESIAN-HOLSTEIN MENGGUNAKAN MODEL VON BERTALANFFY

Pada makalah ini dibahas mengenai prediksi berat tubuh sapi perah Friesian-Holstein menggunakan model Von Bertalanffy. Laju metabolisme pada model terdiri dari anabolisme dan katabolisme. Prediksi berat tubuh sapi perah ini penting karena dapat digunakan untuk menentukan usia kawin pertama kali sapi perah FH. Usia kawin pertama yang tidak tepat dapat menyebabkan produksi susu yang rendah dan tidak tercapainya berat tubuh pedet yang ideal. Dari hasil simulasi diperoleh konstanta anabolisme sebesar 0,3854 dan konstanta katabolisme sebesar 0,0438. Dengan konstanta tersebut, diperoleh rata-rata kesalahan absolut sebesar 4,9708% (6,5358 kg). Selanjutnya, diperoleh hasil bahwa sapi dapat dikawinkan pada saat memiliki berat tubuh 273,9152 kg sampai 303,2340 kg dengan umur 59-66 minggu (14-16 bulan).

Benefits in the Tilapia Growth, by Vetiver Grass in an Aquaponics System

Tilapia aquaculture has growing vertiginously in the world, reaching 7.02 million tons in 2020. In Mexico, the same year reached 72.6 thousand tons. This production values have increased environmental impact and production costs. In Mexico there is a pre-Hispanic aquaponics system, where people culture corn, bean fishes and other organisms. Taken this system as basis, the aim this work was demonstrate the benefits in tilapia aquaculture, by Vetiver grass. Three mini-ponds make up by tilapia juveniles and Vetiver in aquaponics system, and one mini-pond without Vetiver, were cultured during ten weeks. The ammonia, nitrates, dissolved O2, pH etc., and also tilapia weights were recorded along experiment. Results indicated that, ammonia decreased, nitrate increased and tilapia weight increased significantly in mini-ponds with Vetiver than without Vetiver. A von Bertalanffy simplified model was used to calculate time required for tilapias reached 500 g (commercial size) with Vetiver and without Vetiver; it was 48.6 and 54.4 weeks respectively. An extrapolation to commercial tilapia aquaculture, will decreased production cost, due to lower amount of feed and water in tilapia hatcheries; also, a lower environmental impact by wastes discharged to coastal ecosystems, e.g., the amount of ammonia produced in mini-ponds with Vetiver was 4.56 times less than mini-pond without Vitier at week ten. Moreover, tilapia culture with Vetiver, have an aggregated value, because Vetiver is used in perfumes production, reaching 45.2 billons US dollars in 2020.

Age and growth estimates from three hard parts of the spotted catfish, Arius maculatus (Actinopterygii: Siluriformes: Ariidae), in Songkhla Lake, Thailand’s largest natural lake

The spotted catfish, Arius maculatus (Thunberg, 1792), is a euryhaline fish that is economically important in the Indo-West Pacific. Population dynamics studies and stock assessments of this species have focused on marine stocks, but not those from fresh water. In this study, the age and growth of A. maculatus were, therefore, investigated for the inland stock in Songkhla Lake, Thailand. A total of 213 individuals ranging between 35 and 238 mm TL were used. The length–weight relation indicated positive allometry of this population. Three hard parts (otolith, dorsal- and pectoral-fin spines) were used for aging. The marginal increment ratio confirmed that an annulus was deposited once a year in all three hard parts. All of the samples were aged between 0+ and 6+ years. Verification of age estimates from three readers showed that the otolith was the most suitable part for age estimation. Three growth models (von Bertalanffy, Gompertz, and logistic) were applied in the study. The von Bertalanffy model best described the growth of this fish in Songkhla Lake. The obtained asymptotic length was 290.87 mm TL and the relative growth rate parameter was 0.166 year–1. Our results will be applied as inputs for fish stock assessment models. The obtained growth parameters also can serve as a reference for A. maculatus stocks elsewhere.

Estructura de tallas, crecimiento y tasa de explotación de Potamorhina altamazonica (Characiformes: Curimatidae) en el río Ucayali (Perú)

La llambina (Potamorhina altamazonica) es un recurso importante en la pesquería comercial de la región de Ucayali (Perú). En dicho contexto, el presente estudio se fijó como objetivo determinar su estructura de tallas, parámetros de crecimiento y tasa de explotación en el río Ucayali. Se analizaron las muestras tomadas de las capturas de pesca comercial en Pucallpa, ciudad donde se concentra la mayor flota pesquera de esta región. Los resultados se basan en ejemplares muestreados entre enero del 2008 y diciembre del 2012. Se determinó que la talla media de captura fue menor en la región de Ucayali que en la de Loreto, lo que evidencia una mayor presión de la pesca de este recurso en la primera. Los parámetros de crecimiento estimados para sexos combinados fueron L∞=31,45 cm y K=0,37 año-1. Mediante la función de von Bertalanffy se describió satisfactoriamente el crecimiento determinado a partir del análisis electrónico de la frecuencia de longitudes; se observó que la especie creció rápidamente durante el primer año, lo que le permitiría alcanzar una longevidad de 8,1 años en teoría. La tasa de mortalidad total (Z) estimada fue relativamente alta (1,69 año-1), en tanto que la de explotación, considerando el coeficiente de mortalidad natural (M=0,90 año-1) y de mortalidad por pesca (F=0,79 año-1), fue de 0,47 año-1, lo que indica que el recurso se encontraba próximo al nivel óptimo de explotación (E=0,5).

Ajuste de modelos não lineares às notificações de Covid-19 no município de Palmas - Tocantins

Compreender como a transmissibilidade de uma doença ocorre é importante para estabelecer medidas necessárias para combatê-la. Desta forma, o objetivo é identificar qual modelo não linear, entre os modelos de Gompertz, Von Bertallanfy e Logístico, se ajustaria melhor a curva de prevalência de casos de Covid-19 da cidade de Palmas-TO. Bem como analisar dados de notificações de casos e óbitos, em variáveis como gênero e faixa etária. Serão utilizados dados até setembro de 2021, encontrados no site da SESAU-TO, as notificações são confirmadas através do teste RT-PCR. As fórmulas dos modelos serão compiladas e representadas em gráficos. Para definir o melhor modelo será desenvolvido um IA, cujo menor valor indica o melhor ajuste. Podemos observar que apesar da maior taxa de acometimento ser em adultos, a maior letalidade foi em idosos. Em relação a variável gênero, a maior taxa de acometimentos foi no sexo feminino e de letalidade no sexo masculino. Podemos concluir que o modelo que apresentou melhor ajuste às notificações foi o de Gompertz, apresentando um menor valor de IA. Ademais, o valor estimado encontrado ao final do período observado no modelo Gompertz foi o mais semelhante ao número de notificações em Palmas dentre os modelos analisados. Foi também observado que o modelo de Von Bertalanffy apresentou um IA baixo, sendo também uma curva adequada para Palmas. Contudo, quanto a curva do método Logístico, foi o mais ajustado no início do período, porém com o avançar das mutações, acabou não se tornando efetiva para o município.

O MODELO MATEMÁTICO DE VON BERTALANFFY COM O MÉTODO DE GAUSS-NEWTON NA ESTIMAÇÃO DE PARÂMETROS

A aplicação de modelos matemáticos em fenômenos biológicos tem sido cada vez mais útil e vem impulsionando o ramo da Biologia conhecido como Biomatemática. Na aquicultura, a modelagem matemática é uma importante ferramenta para otimizar e aumentar a produção de pescados e destaca-se, entre outros modelos, o modelo matemático de Von Bertalanffy. A função desse modelo nos permite descrever com precisão o crescimento de diferentes espécies de peixes e fazer bons prognósticos de peso e comprimento. O propósito deste trabalho consiste em aplicar o Método de Gauss-Newton para estimar os parâmetros do modelo de Von Bertalanffy, caracterizado por uma função não linear. Com base em um conjunto de valores de peso em função do tempo de uma espécie de peixes, o objetivo é analisar a eficiência do modelo de Von Bertalanffy para descrever o crescimento dessa espécie, assim como a do Método de Gauss-Newton na estimação dos parâmetros, comparando a curva da função obtida a partir dos mesmos, com a curva dos valores experimentais observados em pesquisas da área de aquicultura da Universidade Federal da Grande Dourados (UFGD).

Age, growth and mortality of the European Seabass, (Dicentrarchus Labrax) in Bardawil lagoon, North Sinai, Egypt

Age, growth, and mortality of European Seabass (Dicentrarchus labrax) were studied from a small-scaled fishery of Bardawil lagoon, (North Sinai, Egypt). 181 specimens (16.6 to 35 cm total Length and 39.8 to 367.2 g total weight). The relationship between length and weight was W = 0.0054L3.1428. Age was determined by otoliths and age groups I to IV years were observed. Growths in length and weight at the end of each year were calculated. The growth parameters of von Bertalanffy equation were calculated as (L∞ = 48.69 cm, K = 0.1677 yr -1 and t0 = -0.447 yr -1). Growth performance index was calculated (φ = 2.60 for length and 1.25 for weight). Mortality rates were 0.867 yr-1, 0.25 yr1and 0.617 yr-1 for total, natural and fishing mortality, respectively. The currently exploitation rate E = 0.712 yr-1 indicating that, the population of this species is being heavily exploited.