Age and growth of the endemic Xingu River stingray Potamotrygon leopoldi validated using fluorescent dyes

Abstract

Between 2003 and 2005, vertebrae of 151 Xingu River Potamotrygon leopoldi (Potamotrygonidae) (75 males and 76 females) were analysed to derive a growth curve for this species. The disc width (W ) was significantly different between sexes, with females measuring 149-700 mm W and males 109-500 mm W . The average percentage error for vertebrae readings of the whole sample was 2·7%. The marginal increment ratio (R ) showed an increasing trend with the highest value in November, decreasing from December on. The majority of vertebrae displaying R zero, occurred in September, but the annual periodicity of ring deposition throughout the year was not conclusive. Tetracycline (TCN) injected specimens were held in captivity for 13 months and displayed a fluorescent mark in vertebrae confirming a yearly periodicity of band pair formation with the translucent ring deposited in September-October. The Akaike information criterion (AIC) showed that, among the seven models considered, the best fit was obtained for the von Bertalanffy modified with W (where W = W at birth) for both sexes. Growth parameters for females were: W = 149 mm; W = 763·06 mm; k = 0·12 year , whereas for males: W = 109 mm; W = 536·4 and k = 0·22 year . Maximal ages were 7·2 years in males and 14·3 years in females. The species shows sexual dimorphism expressed in the growth pattern, size at maturity, longevity and asymptotic sizes. Concern for sustainability is raised due to the construction of the Belo Monte Hydroelectric Power Plant (2015 and 2016) in the State of Pará causing changes to the habitat of this species, which is endemic to the Xingu River and two of its tributaries.

Age and growth parameters of the Panamic stingray (Urotrygon aspidura)

“…Dashes indicate that data were not available because variables were not included in a model. (Hale and Lowe, 2008;Cicia et al, 2009;Charvet et al, 2018). This validation does not imply a generalized pattern for batoids, but it does allow inference that yearly periodicity occurs regularly in this group, regardless of the taxonomic classification, habitats, or latitudinal distributions of the species.…”

Age, growth and maturity of the yellow stingray (Urobatis jamaicensis), a biannually reproductive tropical batoid

“…Both methods of model fitting were used to determine best fit as one method may provide additional information over the other when size‐at‐age data is limited, such as with the lack of an asymptote (LS) or for nonlinear data and small sample sizes (ML) (Cotton et al ., 2011). Akaike information criterion (AIC) analysis was used to determine which growth model would yield the best fit for the DW‐at‐age data for least‐squares regressions, while ML estimation used a form of AIC (AICc) with adjustment for small‐sample biases (Charvet et al ., 2018; Cotton et al ., 2011; Gianeti et al ., 2019).…”

Idade E Crescimento De Peixes De Riacho: Métodos E Desafios Para a Obtenção De Estimativas Robustas

“…A principal crítica a esses modelos é a sua escolha a priori, ao invés de uma abordagem multimodelo para decisão sobre o melhor descritor do crescimento (Katsanevakis & Maravelias 2008). Abordagens multi-modelo foram adotadas nos estudos de Colossoma macropomum (Characiformes, Serrasalmidae) (Penna et al 2005) e Potamotrygon leopoldi (Myliobatiformes, Potamotrygonidae) (Charvet et al 2018), sendo que o modelo de von Bertalanffy foi o mais robusto e adequado para descrever o crescimento das espécies analisadas. No caso de P. trucha (Lopez Cazorla & Sidorkewicj 2011), o melhor ajuste foi o modelo de Gompertz.…”