Age and growth of the porthole shovelnose catfish (Hemisorubim platyrhynchos) in the Pantanal

Abstract

The porthole shovelnose catfish, Hemisorubim platyrhynchos, is the sixth largest pimelodidae of the Pantanal. Its age and growth were studied using pectoral fin-spines from fish collected in the Cuiabá river basin, Pantanal. The fish, which came from commercial and experimental fisheries, were all caught with hook and line. Growth-ring formation time could not be defined through the Kruskal-Wallis test on marginal increment (H = 4.142; p = 0.247). Nevertheless, decrease in the marginal increment index occurring as waters recede suggests this as the probable time when growth rings form. Estimation of the parameters of von Bertalanffy growth curve, adjusted through nonlinear regression to observed fork lengths, with L(infinity) fixed at 64 cm, were: k = 0.222 year(-1); t(o) = -2.149 years. Individual life span was estimated at 11.4 years. The results suggest that fork length is a good predictor of age for individuals of this species.

Sciades herzbergii oxidative stress biomarkers: an in situ study of an estuarine ecosystem (São Marcos' Bay, Maranhão, Brazil)

“…In São Marcos' Bay a significant negative correlation was observed between the GST/CAT activity and the L F parameter in all fishes, but a significant correlation between GSI and the activity of the two enzymes was only observed in organisms from the reference site. Fork length (L F ) in catfish was reported to be a good predictor of age for individuals of this species (Penha et al, 2004). We may, therefore, hypothesize that the elevated GST activity might be related to the age of the animals in São Marcos' Bay (at both the reference and potentially contaminated sites).…”

Influence of the flood regime on the reproduction of fish species with different reproductive strategies in the Cuiabá River, Upper Pantanal, Brazil

“…Individuals with lengths less than that of first maturation were classified as young-of-the-year (UEM/Nupélia-Furnas Centrais Elétricas, 2005), except for LM (Group 1), which reached a larger size and whose size limit was that attained in 1 year, estimated from growth equations provided by Perez-Lizama (1994), Miranda et al (2000), Feitoza et al (2004) and Penha et al (2004).…”

Life-history characteristics of Pseudoplatystoma metaense (Teleostei: Siluriformes: Pimelodidae) from the northwestern Orinoco River Basin

“…The relatively long life span of P. metaense and other pimelodid catfish species have been observed by several authors (Ambrósio et al, 2003;Loubens, Panfili, 2000;Mateus, Petrere Júnior, 2004;Penha et al, 2004aPenha et al, , 2004bReid, 1983;Ruffino, Isaac, 1999) and such longevity may be an evolutionary adaptation that supports iteroparity in these species. Many Neotropical freshwater fish are highly fecund, but egg and larval survivorship are low; therefore, spawning over numerous years may be necessary to maintain stable populations.…”