Otolith micro- and macrostructure analysis to improve accuracy of growth parameter estimation for white mullet Mugil curema

Abstract

Age and growth studies on the white mullet Mugil curema present (Valenciennes, 1836) dissimilarities with regard to the parameters estimated. It is therefore necessary to undertake a growth analysis based on micro-and macrostructures of otoliths from the species in order to reveal the cause of such dissimilarities. Microstructures were validated through otolith marking by balneation in alizarine complexone and demonstrated daily periodicity. Daily microstructures were observed in individuals up to 15.7 cm in fork length and exhibited 5 distinct growth zones. Zones I, II and III (62 d) composed the first macrostructure and Zone IV (223 d) composed the second. It was not possible to see microstructures in Zone V and, beginning with this zone, macrostructures were considered annual, based on the analysis of mean monthly marginal increments. Using daily microstructures and annual macrostructures, the von Bertalanffy function provided the following parameters: L ∞ = 34.4 cm, K = 0.365 and t 0 = 0.311 yr. The following factors caused the dissimilarities between curves for white mullet: (1) absence of samples for ages 0 + and 1 yr, which caused a high value of mean lengths for these age classes and a diminished K-value; (2) the tendency toward overestimation at the age of 1 yr when estimated from macrostructures; (3) identification of the first 2 macrostructures as annual; and (4) absence of young-of-the-year specimens, causing t 0 to be significantly different from 0. These factors lead to the underestimation of the parameters, which makes growth estimates imprecise. 7: 199-206, 2009 68.7% of the total catch of the species in certain areas along the northeastern coast (Santana da Silva 2007). KEY WORDS: Mugil curema · Otoliths · Age and growth · White mullet Resale or republication not permitted without written consent of the publisher OPEN PEN ACCESS CCESSAquat BiolAge and growth of white mullet from the western Atlantic has been estimated in the United States, Mexico, Cuba and Venezuela from periodic rings of the spines of dorsal fins, scales and otoliths (Richards & Castagna 1976, Alvarez-Lajonchère 1981, Ibáñez-Aguirre et al. 1995, 1999, Gallardo-Cabello et al. 2005, leading to rather dissimilar growth parameters. According to Santana da Silva (2007), dissimilarities have been attributed to: (1) the different hard structures used; (2) nonvalidated growth marks; or (3) the lack of the use of both micro-and macrostructures of otoliths.Taking into account that coastal fishing resources along the Brazilian coast are now either fully exploited or overexploited (Lessa et al. 2006), caution should be taken when management decisions for the white mullet fishery are undertaken. Thus, as accurate age and growth information is needed as input data for agebased approaches used for stock assessments, the goal of the present study is to provide a validated growth curve based both on micro-and macrostructure analyses, which will allow reliable growth parameters for white mullet in northeastern Brazil for the requi...

Multifractal Properties of a Closed Contour: A Peek beyond the Shape Analysis

“…3B ). Thereby obtained peaks closely correspond to the expected length (23.3 cm) and age (2.8 years old) at first sexual maturity for both sexes, as documented previously by Santana et al [21] using gonads. Note that here we observed no difference between the growth of males and females.…”

“…For instance, the minor size of capture can be established based on , aiming to avoid the over-exploitation of a fish stock. Note that the determination of first sexual maturity of fish has to date been possible only through costly and cumbersome experimental techniques [21] . Different methods have been proposed to estimate [27] , [28] .…”

Seasonal growth of Mugil liza Valenciennes, 1836 in a tropical estuarine system

“…In both subtropical and temperate climate zones, M. liza is clearly a marine migrant species activated by cold temperatures and intense winds. During the reproductive period the adult M. liza showed reduced growth, forming an annual hyaline ring, as also observed in other mugilid species (Ibañez‐Aguirre and Gallardo‐Cabello, ; Espino‐Barr et al., ; González‐Castro et al., ; Santana et al., ). These seasonal growth patterns indicate that tropical M. liza has an unique critical ecological event during the year and appear to be more functionally associated with the estuarine environment than in higher latitude populations.…”

Age and growth of the white croaker Micropogonias furnieri (Perciformes: Sciaenidae) in a coastal area of Southeastern Brazilian Bight

“…The use of otoliths in studies of age and growth is a scientific breakthrough of great importance to fisheries science and has been successfully employed, as the case of important fishery resources widely distributed, such as the Brazilian codling Urophycis brasiliensis (Andrade et al, 2004), mapará Hypophthalmus marginatus (Cutrim, Batista, 2005), white mullet Mugil curema (Santana et al, 2009), snowy grouper Epinephelus niveatus (Costa et al, 2011), lebranche mullet Mugil liza (Garbin et al, 2014), among others. The high reliability of these calcified structures is attributed to its protection within the auditory capsules, not suffering degeneration as the scales, being also more stable structure and composition over time (Panfili et al, 2002), thus providing more accurate information on age and growth studies.…”