Validation of age determination methods and growth studies of the sand sole Pegusa lascaris (Soleidae) from the eastern-central Atlantic

Abstract

ABSTRACT. The age and growth of the sand sole Pegusa lascaris from the Canarian Archipelago were studied from 2107 fish collected between January 2005 and December 2007. To find an appropriate method for age determination, sagittal otoliths were observed by surface-reading and frontal section and the results were compared. The two methods did not differ significantly in estimated age but the surface-reading method is superior in terms of cost and time efficiency. The sand sole has a moderate life span, with ages up to 10 years recorded. Individuals grow quickly in their first two years, attaining approximately 48% of their maximum standard length; after the second year, their growth rate drops rapidly as energy is diverted to reproduction. Males and females show dimorphism in growth, with females reaching a slightly greater length and age than males. Von Bertalanffy, seasonalized von Bertalanfy, Gompertz, and Schnute growth models were fitted to length-at-age data. Akaike weights for the seasonalized von Bertalanffy growth model indicated that the probability of choosing the correct model from the group of models used was >0.999 for males and females. The seasonalized von Bertalanffy growth parameters estimated were: L ∞ = 309 mm standard length, k = 0.166 yr Key words: Pegusa lascaris, age determination, otoliths, growth models. RESUMEN.Se estudió la edad y el crecimiento del lenguado de arena Pegusa lascaris de las Islas Canarias a partir de 2107 ejemplares capturados entre enero de 2005 y diciembre de 2007. Para determinar el método de estimación de la edad, se hicieron lecturas de los otolitos sagita enteros y de la sección frontal y se compararon los dos métodos. Ambos métodos no variaron significativamente en la estimación de la edad, pero el método de la lectura del otolito entero es superior en términos de costo y tiempo. El lenguado de arena presenta un ciclo de vida moderado; se han registrado edades de 10 años. Los individuos crecen rápidamente durante los primeros dos años, cuando alcanzan aproximadamente el 48% de su longitud; después del segundo año, su crecimiento se ralentiza considerablemente debido a que invierten su energía en la reproducción. Se observó dimorfismo en el crecimiento entre machos y hembras: las hembras presentaron longitudes y edades ligeramente superiores a las de los machos. Para describir el crecimiento, los modelos de von Bertalanffy (simple y estacional), el de Gompertz y el de Schnute se ajustaron a los datos de talla y edad. Los pesos de Akaike para el modelo estacional de von Bertalanffy indicaron que la probabilidad de elegir el modelo correcto fue >0.999 para machos y hembras. Los parámetros estimados de la ecuación de crecimiento estacional de von Bertalanffy fueron los siguientes: L ∞ = 309 mm longitud estándar, k = 0.166 año , t 0 = -1.653 año, C = 0.820 y ts = 0.691 para las hembras. Se observó una alta correlación entre la longitud estándar y el radio de los otolitos (R 2 = 0.902), que fue descrita mediante una función potencial (a = 85.11, v = 0.906).Palabras cl...

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“…This demonstrated a proportional growth of the otolith with fish size, although the coefficient of determination indicated that 33.3 % of the variation in size was explained by another factor, independent from otolith size. In studies on fish growth, coefficients of determination for the relationship between otolith size and fish size have been observed to vary from 0.4 to 0.9 (Carmona & Alexandres, 1994;Quiñonez-Velázquez et al, 2002;Puentes-Ganada et al, 2004;Morales & González, 2010;Pajuelo & Lorenzo, 2011;Souza-Conceinao & Schwingel, 2011;Cerna et al, 2014). The proportionality of otolith size with fish size is very important when a retro-calculation of previous sizes has to be done, and the more precision you have, the better it is, especially because in some cases, a reabsorption of scale rings (Lee's phenomenon) can be The count of growth bands allowed to identify five age groups (0-4 years); an age-length key for O. medirastre was shown in Table 1.…”

Biological parameters of grey wrasse Symphodus cinereus (Bonnaterre, 1788) (Pisces: Labridae) along the coasts of Rize in the south-eastern Black Sea

“…Among all studies of S. cinereus published to date in which the von Bertalanffy model was utilized in one of its possible forms, estimated values of t 0 have tended to be non-zero and negative (Table 5). This suggests that the von Bertalanffy model is not capable of providing accurate descriptions of growth for this species in the earliest stages of life (Pajuelo & Lorenzo, 2011). Negative t 0 values are frequently observed for demersal fish species that experience rapid spurts of growth in the first year of life with slower rates of growth in subsequent years (Dwyer et al ., 2003; Amaral & Cabral, 2004; Teixeira et al ., 2010).…”

Growth, mortality and hatch-date distributions of striped sea bream Lithognathus mormyrus inhabiting the Çanakkale Strait, Turkey

“…A study investigating this should be conducted in order to ensure correct age and growth rate estimations. Such a study could be based on rearing larvae from hatching (Vigliola, 1997; Pajuelo & Lorenzo, 2011; Duffy et al , 2012; Ellender et al , 2012; Parkinson et al , 2012; Dodson et al , 2013; Farley et al , 2013).…”