Ontogenetic development of the sagittal otolith of the anchovy, <em>Anchoa tricolor</em>, in a subtropical estuary

Abstract

Summary:In order to characterize the ontogeny of Anchoa tricolor, the morphology and morphometry of sagitta otoliths were described. A total of 397 pairs of sagitta otoliths of A. tricolor (20 to 85 mm) were measured and analysed by means of digital images. Morphological description was done in terms of shape and features. The Huxley model was fitted to otolith length against total length (TL) and weight (TW), and residual analyses were done in order to detect the polyphasic growth. Six shape indices were calculated (otolith height/otolith length and otolith length/total length aspect ratios, rectangularity, roundness, relative sulcus surface and rostrum index) and after size effect removal, they were analysed in terms of TL. The results of these analyses allowed three distinct growth phases to be identified: (1) up to 40 mm TL and related to low swimming ability; (2) between 41 and 60-70 mm TL, when fish displacements increase but the first maturation has not yet occurred; and (3) after 71 mm TL, when fish become adults. Landmarks and semi-landmarks were used to analyse relative warps during the otolith development. The MANOVA analysis between the centroid size and class intervals showed significant differences in the interaction of all classes except between 71-80 and 81-90 mm.Keywords: shape index; geometric; morphometry; Engraulidae; Brazil; description.Desarrollo ontogénico del otolito sagitta de la anchoa, Anchoa tricolor, en un estuario subtropical Resumen: Se describen la morfología y morfometría de los otolitos sagitta de Anchoa tricolor con el objetivo de caracterizar su ontogenia. Se midieron un total de 397 pares de otolitos sagitta de A. tricolor (20 a 85 mm) y se analizaron por medio de imágenes digitales. La descripción morfológica se hizo en términos de forma y características. Se ajustó el modelo de Huxley a la relación longitud del otolito, longitud total (TL) y peso (TW), respectivamente, y se realizaron análisis de residuos para detectar el crecimiento polifásico. Se calcularon seis índices de forma (OH/OL y OL/LT radios de aspecto, rectangularidad, redondez, superficie relativa del sulcus e índice de rostrum) y, una vez eliminado el efecto de talla, se analizaron en términos de longitud total. Los resultados de estos análisis permitieron identificar tres fases distintas de crecimiento: (1) una fase inicial, hasta 40 mm TL y relacionada con una habilidad natatoria baja; (2) entre 41 y 60-70 mm TL, cuando los desplazamientos del pez aumentan, pero aún no se ha producido la primera madurez y (3) superior a 71 mm TL, cuando el pez es ya adulto. Se utilizaron puntos homólogos y puntos equidistantes para analizar deformaciones relativas durante el desarrollo del otolito. El análisis MANOVA entre el tamaño del centroide y los intervalos de clases de talla mostraron diferencias significativas en la interacción de todas las clases, excepto entre 71-80 y 81-90 mm.Palabras clave: índice de forma; geometría; morfometría; Engraulidae; Brasil; descripción.

Ontogenetic variation in the sagitta otolith of Centropomus undecimalis (Actinopterygii: Perciformes: Centropomidae) in a tropical estuary

“…In the internal part of the otoliths, the presence of a well-developed heterosulcoid sulcus acusticus was noted, with a notable differentiation between ostium and cauda, agreeing with the studies performed by Lombarte et al (2006), Martínez et al (2007) It is still possible to denote that the analyzed otoliths have the cauda curved towards the posterior ventral region of the otoliths, and this is considered a standard for the genus. It is also worth noting the presence of a heterosulcoid sulcus acusticus in this species, and this characteristic is common to the order Perciformes, however, it is also present in the orders Atheriniformes and Clupeiformes (see Carvalho and Corrêa 2014, Siliprandi et al 2014, Carvalho et al 2015.…”

“…The otolith shape usually has an interspecific pattern among the species Echeverría 1999, Tuset et al 2008), however, some internal (physiological) and external factors can modify the shape of otoliths in populations of the same species throughout the ontogenetic development. Several studies demonstrate how the shape of the otoliths can vary (Carvalho and Corrêa 2014, Maciel et al 2019, Carvalho et al 2020 and the ontogenetic variation influenced by growth has already been described for several species (Capoccioni 2011, Vignon 2012, Carvalho et al 2015, Yan et al 2017, Song et al 2019.…”

“…• polar coordinates (Lombarte and Tuset 2015), • landmarks (Monteiro et al 2005, Carvalho et al 2015, • Fourier harmonics (Libungan et al 2015, Bose et al 2017, and • wavelets (Sadighzadeh et al 2014, Tuset et al 2015.…”

Otolith morphometry and microchemistry as habitat markers for juvenileMugil cephalusLinnaeus 1758 in nursery grounds in the Valencian community, Spain

“…The morphometric variables registered were: otolith length (OL), otolith height (OH), otolith perimeter (OP) and sulcus perimeter (SP) in mm (Figure ); and otolith area (OA) and sulcus area (SA) in mm 2 . Using these measurements the shape indices were then calculated: circularity (OP 2 /OA), rectangularity (OA/[OL × OH]), aspect ratio (OH/OL; %), percentage of the otolith area occupied by the sulcus (SA/OA; %), ellipticity ([OL − OH]/[OL + OH]), and form factor ([4π × OA/OP 2 ]) (Avigliano et al., ; De Carvalho, Vaz‐dos‐Santos, Spach, & Volpedo, ; Tuset, Lombarte, & Assis, ).…”

Sagitta otolith of three demersal species in a tropical environment

“…These structures assist the hearing and perception of the external environment (Ladich & Schulz-Mirbach, 2016). Otoliths are excellent tools for various studies of fish populations such as: habitat use and connectivity between populations using the chemistry of the otolith (Carvalho et al, 2017;Maciel et al, 2020), environmental stress indicated by the deposition of vaterita (Carvalho et al, 2019a;Holmberg et al, 2019), and age and growth (Soeth et al, 2018;Maciel et al, 2018).…”